CHAPTER – I

HISTORY OF RAILWAYS AND EVOLUTION OF SIGNALLING SYSTEM

1 Evolution of Indian Railways: 1.1 The fundamentals of Railway transportation are to move vast traffic carrying goods and people speedily and with safety on a prepared track that supports and guides the vehicles which roll along its surface. A railway train must go where the rails lead it to.

The process might have begun accidentally when Babylonians and perhaps their Sumerian ancestors observed that their two wheeled, animal drawn, carriage gauged out parallel ruts in the ground path, which they most commonly followed. Greeks made the smooth stone ways for transporting their heavy material for building monuments. Thus the railway existed even earlier to evolution of steam engines as long back as 2245 BC i.e. some 4250 years back. 1.2 Horse traction began after introduction of iron rails and lasted beyond 19th century. The revolution to transport industry came with the evolution of steam engines. Although steam loco was invented in 1803 but it took innumerable refinements before it could be adopted for reliable and safe substitute for horse. The story of railways as we perceive to is 180 years old only. A pair of bullocks hauled traffic on first indigenously financed railways named as Gailwar’s Baroda State railway (GBSR), which was opened in 1863. 1.3 Idea to connect the then Bombay with Thana with a railway track was conceived by Chief Engineer, Bombay Government in 1843. Great India Peninsula Railway (GIPR) Company was incorporated in England by an act of Parliament on 1st August, 1849. The Railway Company entered into a contract with East India Company on17th August, 1849, accordingly the Railway Company was to raise capital of ₤ 500,000. The construction of the line from Bombay to Kalyan started on 31st October, 1850. The first railway line in India covering 34 kilometres between Boribunder, the then Bombay and Thana was opened on 16th April 1853, barely 28 years after the World’s first train made its initial success run between Stockton and Darlington in England in 1825. Within one year the line was extended to Kalyan on 1st May, 1854. This was first railway system in Asia. 1.4 In Eastern sector, first passenger train moved out of Howrah station for Hogly on 15th August, 1854 covering a distance of 39 kilometres. The railway line was extended by 61 kilometres upto Pundooah on 1st Septmber, 1854 and then further extended upto Raniganj on 3rd February, 1855. First by 101 kilometres railway line was opened between Veyasarpaudy and Walajah Road on 1st July 1856 in South. In North first Railway line was laid between Allahabad and Kanpur, a distance of 192 kilometres on 3rd March, 1859 and then in Amritsar-Atari section was opened after three years. Hathras Road to Mathura Cantt. section was opened on 19th October, 1875. Dibrugarh Town to Dinjan section in East was opened on 15th August, 1882. 1.5 During 1854 and 1860, the contract to private companies to built and operate the railways was made by East India Company or after 1858 by the secretary of State for India, with the East Indian Railway company, the GIPRS company, the Madras railway company, the Bombay Baroda and Central India Railway company, the Eastern Bengal railway company, the

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Great southern of India Railway Company and Calcutta and South Eastern railway company. Under these contracts the Railway Companies undertook and managed specified lines to which East India company and later Secretary to State for India agreed to provide land free of cost and also guaranteed return on capital varying as 5%, 4 ¾%, 4 ½% in different cases according to market rates prevalent at the time of execution of the contract. The rate of exchange for remittance of interest was also fixed. Half of any surplus of profits earned was to be used towards repaying the Government any sums by which it had been called upon to supplement at the net earning in any previous period to make good the guaranteed rate of interest, and the remainder was to belong to the share holders. The terms on which the contracts were given were considered in India as well as in England as unduly generous for the British Investors. 1.6 Government ownership of Railways – For several years after 1869, the capital expenditure on Railways was mainly incurred direct by the Government and no fresh contracts were made with guaranteed companies except for small extensions. However, consequent on severe famine in 1878, the necessity of rapid extension of the railway system was felt by Government and it was decided to use private enterprise to the extent possible with such guarantees as would secure investment of capital without involving Government in financial or other liabilities of an objectionable nature. On this basis, a number of companies were formed between 1881 and 1892, and the guarantees which were given to some of these companies were much more favourable to Government than in the case of companies formed prior to 1869. In dealing with the guaranteed companies formed before 1869 and with those formed in 1881 and subsequently, Government’s endeavour was to secure, at the earliest possible date, wherever it had the right to terminate the original contract after a specific period, either more favourable terms under fresh contracts or ownership by purchasing the company under the terms of the contract. Thus under the terms negotiated with the various guaranteed Railway Companies, the dates of termination of contracts fell between 1879 and 1907 1.7 Company management of Government Railways –The Eastern Bengal, the Oudh and Rohilkhand, the Sind-Punjab and Delhi, and the Southern Punjab Railways, the last two forming part of the North Western Railway, Company Railways were transferred to Government management after purchase. The management of some of the other purchased lines was, however, entrusted to working companies constituted under contracts which determined the relationship between the Government and the Working Companies generally. The contracts with the working companies were terminated in due course and the management of the companies was taken over directly by the Government on the dates given below: Name of the Railway Date of taking over by Government 1) The East Indian Railway 1st January, 1925 2) The Great Indian Peninsula Railway 1st July, 1925 3) The Bombay Baroda and Central Indian Railway 1st January, 1942 4) The Assam Bengal Railway 1st January, 1942 5) Oudh and Tirhut Railway 1st January, 1943 6) The Madras and Southern Mahratta Railway 1st April, 1944 7) The South Indian Railway 1st April, 1944 8) The Bengal Nagpur Railway 1st October, 1944

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1.8 Partition of country affecting railways– With the attainment of independence and partition of the country on the 15th August, 1947, two of the exiting Railway systems (viz., North Western Railway in the west and the Bengal Assam Railway in the East), Which fell into both the territories, had to be divided. The portions of these systems falling in India were either partly added to the other existing lines or partly formed into separates units, thus the Eastern Punjab Railway and the Assam Railway Administration came into being as separate units although they were not considered economical, efficient and self- sufficient systems. An administrative re-organisation with a view to securing both efficiency in operation and economy in management, therefore, became a compelling necessity. 1.9 Taking over of the ex-States Railways – As a result of integration of the Indian State into a small number of sizeable units after their incorporation in the Union, and the further integration with the Union of their federal functions, the railways owned and managed by those States came under the control of the Central Government in addition to those which were already being worked by the Indian Railways and were later merged into the contiguous Indian Railway System. These were Gaekwar’s Baroda State Railway, 736 miles, taken over on 1st August, 1949 was merged with the Bombay and Baroda and Central Indian Railway System from the date taking over; Bikaner State Railway, 883 miles; Cutch State Railway, 72 miles; Dholpur State Railway, 56 miles; Jaipur State Railway,253 miles; Jodhpur State Railway, 807 miles; Mysore State Railway, 2 miles; Nizam’s State Railway, 1,396 miles; Rajasthan Railway,179 miles; Saurashtra Railway, 1,274 miles; Scindian State Railway, 294 miles, were taken over on 1st April, 1950. 1.10 Re-organisation of Railways in 1951 - 1952– The revision of financial convention, with effect from 1st April, 1950 regulating relationship between general and the Railway finances, along with the integration of all the railways, compelled reorganisation of the entire Railway system resulting in creation of six Zonal Administrative units viz. 1.) Southern Railway with 9867 route kilometres formed on 14th April 1951 merging Madras and Southern Railway 4732 kilometres, South Indian Railways, 3782 kilometres and Mysore State Railways, 1173 kilometres; 2) Central Railway with 8739 route kilometres, formed on 5th November, 1951 merging Great Indian Penisula Railway, 5823 kilometres, Nizam’s State Railway, 2353 kilometres, Dholpur State Railway, 90 kilometres and Scindia State Railway, 473 kilometres; 3) Western railway with ,8793 route kilometres merging Bombay Baroda and Central India Railway except Delhi – Rewari- Fazilka and Kanpur – Achnera sections, 5670 kilometres, Surashtra Railway, 2195 kilometres, Jaipur State Railway, 469 kilometres, Rajsthan railway 317 kilometres, Cutch State Railway, 116 kilometres and Marwar- Phulad section of Jodhpur Railway,26 kilometres ; 4) Eastern Railway with 9123 route kilometres formed on 14th April, 1952 merging Bengal Ngpur Railway 5455 kilometres and East Indian railway except some portion merged in Northern railway, 3668 kilometres; 5) Northern Railway with 9672 kilometres formed on 14th April, 1952 merging East Punjab Railway, 3083 kilometres, Bikaner State Railway, 1422 kilometres, Jodhpur Railway except Marwar- Phulad section, 1280 kilometres, Moradabad, Lucknow and Allahabad Divisions of East Indian Railway, 3383 kilometres and Delhi – Rewari – Fazilka section of Bombay, Baroda and Central India Railway; and 6) North Eastern railway with 7675 kilometres formed on 14th April, 1952 merging Oudh Tirhut Railway, 4413 kilometres, Assam Railway, 2857 kilometres and Kanpur – Achnera section of Bombay, Baroda and Central India railway 405 kilometres.

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1.11 Re-organisation of Railways in 1955 – 1966: These Railways were reorganised need based again in 1955-1966. Eastern Railway was split to form Eastern Railway and South Eastern Railway on 1st August, 1955; North Eastern Railway was bifurcated to form North Frontier railway and North Eastern railway on 15th January, 1958; A portion of Southern Railway and Central Railway was taken out to form South Central Railway on 2nd October, 1966. With this six zones were reorganised into nine zones by 1966. 1.12 Re-organisation of Railways in 2001 and 2003: Two new zones viz. North Western Railway with its headquarters as Jaipur and East Central Railway with its headquarter as Hajipur, were created on 01.10.2001 and further five more Zonal railways viz. North Central Railway with its headquarter as Allahabad, South East Central Railway with its headquarter as Bilaspur, East Coast Railway with its headquarter as Bhubaneshwar, South Western Railway with its headquarter as Hubly and West Central Railway with its headquarter as Jabalpur were created on 01.4.2003, by carving out of existing railways. With this sixteen Zonal railways exist as on date. In addition RDSO was given independent status retaining its headquarter as Lucknow. 1.13 Indian Railway act 1890: In order to regulate working and to provide suitable machinery for working of railway system, The Indian Railway Act, 1890 was enacted on 21st March, 1890 to take effect from 1st May, 1890. The act lays down the statute regarding construction and maintenance of work, opening of railways, responsibilities of Railway administration as carriers, railway accidents and a number of allied to railway working. With the constitution of Railway Board for controlling the administration of railways in India, Railway Board Act, 1905 was passed on 22nd March, 1905, to invest certain powers and functions with the Railway Board, under Indian Railway Act, 1890. 2 Evolution of Railway Signalling system: 2.1 The present shape of railway signalling has

evolved after covering long passage from train lead by a horseman with a red flag in his hand and a lighted candle placed on the table of Station Master, first signal ever used at Hartlepool in England. The policeman at the back of horse called as Bobies used to maintain a time interval between the trains.

2.2 During 1829, in USA hand signals were used in

the day and lighted lantern in the night in Balti- more Ohio Rail Road. Thereafter bell shaped peacock signals and ball signals were devised followed by Kite signals. Marine telescopes were used by flagmen to observe signals and to repeat them to adjoining station. Block signalling was a crucial development for railway signal and interlocking. Willium F. Cooke and Charles Wheat Stone, people who developed Railway telegraph, developed Cooke & Wheat stone needle graph in 1837. In 1838, Disk and crossbar signal was used on Great Western Railway as suggested by Brunel, a Permanent Way Engineer of British Rail Road.

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2.3 In 1840 red metal disk, four feet diameter with word danger painted on it was used on British Railway. Coming to present day signalling system first were semaphore signals. Charles Hutton erected first semaphore signal at Newcross England, in 1841.The ‘V’ notch in the tail of signal was introduced by John Sexy in 1872, to indicate signal to be permissive. Somersault Semaphore was introduced by Edward French in 1877. During the intervening period continuous development in the shape of spectacles and fixing of lenses was done by British Rail Road Engineers James Deakin in 1843, James Stevens in 1847, Boakes & Reilly in 1853, John Saxby in 1854 and by Rowe in 1865.

2.4 The first mechanical interlocking was installed at Bricklayers arms Junction in England

by C.H. Georgy with levers for points and stirrups for signals, in 1843, which was improvised by Stevens in 1847. Further developments were done by Douglas Galton, Col Yolland, John Saxby & Austin Chambers Signal Engineers in U.K. and Ashbel Welch signal engineer in U.S. Operation of trains using signals only without train order was first demonstrated by Eastern Rail Road Company in 1843, through Salem– Massachutssets Tunnel. This system went through further developments and became train traffic control.

2.5 George Boole developed his algebra of logics named after him as Boolien’s algebra, in

1847, which was widely used to design electrical interlocking circuits. Single stroke bell system was developed by Charles Vincent Walker in 1851. In 1858, Block System based on space interval was developed in England. Tyer developed a train indicator in 1861. In 1863 a banner signal was used in Philadelphia Railway. A rotating disk painted half red and half white was also used during this period. In United States Ashbel Walch introduced manual block system with space interval, for the first time in 1863. Charles Ernest Spangnoletti developed disk block instrument in 1864. Strowley in1866 patented in England the wedge system for facing point tongues. Lock bar to prevent operation of points under wheel was introduced by Liversey, Edwards & Jeffereys in 1868. Saxby in collaboration with Liversey and his partners introduced Facing point plunger lock in 1870. Schrender, Spiear, Cohman, Hanton, and others in U.S. and Schnable & Hunning of Germany used hydraulic pressure for operating signals, in 1871. Harve Talden & Guerben developed it for operation of points and signals, in 1881. Electromagnetic control came in1882 at Board Brock in New Jersey, U.S.A.

2.6 Siding control was introduced by James Annet in 1876. First power interlocking was

installed in U.S. in 1876 under patent of Pratt & Burr, Tylor’s electric interlocking in1889, and Ramsey & Weir’s in 1888. In 1876, Sykes introduced lock and block system at St. Pauls station in London. In 1878 Edward Tyer introduced tablet apparatus. The Tyer’s system was modified by Webb & Thompson in1888. Track locking was devised by Lackson in 1880. First electromechanical signal- interlocking was installed by Sykes in 1883 at Victoria Terminal in England. Absolute Block System was made compulsory in Britain for all passenger trains in 1889 by an act of Parliament. Direct current motor operation of signals was developed by Ramsay, Weir Latting and others in 1890. Sykes & Wyles after the Aburmuile head on collision introduced electrical interlocking between Starter signal and the corresponding Block Instrument for the first time in Farnham London and South Western Railway in 1893. Telephone was used for

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the first time for train order in 1897 in the Smith Fork branch of Pennsylvania Rail Road.

2.7 Colour light signals were first used in United States in 1904. The visibility of this signal

was 150 Mts only. These signals were initially meant for tunnels first having been installed in East Boston tunnel of Boston Elevated Railway. The visibility of these signals was improved to 450 Mts. In 1912 and to 1050 Mts. range in 1914. Position light signals were developed in 1915. First colour light signal were used in Britain at Liverpool cross Road Railway in 1920 while first search light signals of 1350 Mts. visibility range were developed in the same year. Double wire signalling was developed around 1920 in Germany. Colour light signals with two coloured lamps were introduced in 1921.A.F. Bound introduced speed signalling at Mir field in England. Automatic signalling with semaphore signals was developed by A.H. Johnson in England in 1926. LMG Ferreia & R.J. Insell of Great Western Railway introduced route working with miniature levers.

2.8 The basics thus installed have continued to march forward thereafter changing shape in

the form of Relay interlocking, Route relay interlocking, Block Proving by Axle counters, change of analogue axle counters to Digital Axle counters, DC track circuits to multi section digital axle counters, Audio Frequency track circuits, Jeomont Track circuits etcetera.

2.9 The conventional signals erected by the side of track have gone into the cab of Electric

locomotives. With the fast pace of advancement, it was no more possible to run the trains followed by a man riding horseback or guided by a lighted candle on the Station Masters table. The signalling has passed through phase from semaphore via colour light to cab signalling. The points in the yard operated by solid rod switching over to operation by electric point machines.

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CHAPTER-II

INTRODUCTION TO INDIAN RAILWAY SIGNAL ENGINEERING

1 The Railway Signalling System: Had there been all trains standing, they were the safest. Had there been only one train on one track, it was still safer, but Indian Railways is spread over about 63,332 route kilometres of track, about 7000 stations, running about 14300 trains daily carrying about 13 million passengers and 2 million tonnes of freight every day, necessitating deployment of 1.57 million people, as during financial year 2006-2007. Such a huge network cannot be managed without sharing responsibility with mechanisation. This necessitated the need of signalling system and the need of signals as a means of communication between men on ground and with the driver of the train now designated as Loco Pilot running on fixed path. Before proceeding ahead it is important to understand the basics of Railway structure, associated terms and rules which govern the design of railway signalling system: The working of trains is governed by General Rules (GR) of Indian Railways. The signalling system is designed to comply these rules technically, in consideration of technical feasibility and financial aspects vis-à-vis manageability of compliance of these General Rules manually versus mechanisation, depending upon density of traffic and speed of the trains permitted in the section. The guidelines for technical measures for compliance of these General Rules are given in Signal Engineering Manual and Railway Opening of Public carriage Rules. The latest General Rules taken into consideration are as issued in the year 2007 and Signal Engineering Manual Volume-I, I988 and Volume –II of 2001. 2 Generally used terms, Stations and signals: 2.1 Generally used terms: i) Approved special instructions: means special instructions approved of or prescribed

by the Commissioner of Railway Safety.[GR 1.02 (4)] ii) Special Instructions: Instructions issued from time to time by the authorised officer in

respect to particular cases or special circumstances.[GR 1.02 (53)]. iii) Running Line: the line governed by one or more signals and includes connections, if

any, used by a train when entering or leaving a station or when passing through a station or between stations. [GR 1.02 (47)].

iv) Running train: a train which has started under an authority to proceed and has not completed its journey. [GR 1.02 (48)].

v) Shunting: The movements of a vehicle or vehicles with or without an engine or of any engine or any other self propelled vehicle, for the purpose of attaching, detaching or transfer or for any other purpose.[ GR 1.02 (49)].

2.2 Station: Station is that part of track where train traffic is dealt with to stop, despatch, make trains run-through, perform shunting, loading unloading of goods, watering of coaches,

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maintenance and many other activities for a goods or passenger train. As per General Rule 1.02. (51), issued by Indian Railways, the station is defined as “any place on a line of railway at which traffic is dealt with, or at which an authority to proceed is given under the system of working”. The station is sectionalised in two parts i.e. Station section and Station limits. 3 Classification of Stations: In the present context, stations are classified with reference to operational facilities and standard of interlocking. The speed of the trains in a particular section is broadly guided by the standard of track, the standard of rolling stock, and the ruling gradient. The operational facilities at the stations as well as type of interlocking and the system of signalling at the stations also affects average speed of the section. The electrical/solid state interlocking operated through central panel reduces operational time by way of eliminating inter cabin coordination as well as faster operation as compared to interlocking in mechanical lever frames, or panels in end cabins. The system of colour light signalling also similarly reduces operation time as compared to semaphore signalling system. It is pertinent to note that the standard of interlocking at the station does not function as ruling factor for deciding speed of the section. 3.1 Classification of stations based on operational requirements: [GR 1.03] Stations are classified as ‘Block Stations’ and ‘Non-Block Stations’. 3.1.1 Block Stations are those stations at which the Loco Pilot must obtain an authority to proceed under the system of working to enter the block section with his train. The Block station, under the Absolute Block system consists of three classes viz. class `A’, class `B’ and class `C’. However when any station which cannot be worked under `A’, `B’, or `C’ class is termed as `Special’ class station [GR 1.03]. These stations are characterised by the conditions for granting line clear under GR 8.02, 8.03 and 8.04 as follows: i) Class `A’ stations: Stations where Line Clear may not be given for a train, unless the

line on which it is intended to receive the train, is clear for at least 400 metres beyond the Home Signal, or up to the Starter signal;

ii) Class `B’ stations: Stations where Line Clear may be given for a train before the line has been cleared for the reception of the train within station section; and

iii) Class `C’ stations: The capacity of a section to accommodate trains, if gets saturated i.e. trains running in a specific section are more than the section can accommodate, the longer block section is bifurcated by creating a Block Hut or, on a double line section, an Intermediate Block post, in between. In this way two trains can be run in the section where only one train was running. This is a small step as an alternative of Automatic Block Signalling, where more than two trains ca be run by splitting the Block section into smaller Automatic Block sections.

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a) Block Hut, is a ‘C’ class station for the purpose of splitting the block working only, where Line Clear may not be given for a train, unless the whole of the last preceding train has passed complete at least 400 metres beyond the Home signal, and is continuing its journey. This also includes Intermediate Block Post.

b) Intermediate Block Post means a class “C” station on a double line remotely controlled from the block station in rear.

The Signalling arrangement on an Intermediate Block post is to split a long block section into two portions each constituting a separate block section providing an intermediate Block Post.

iv) Non-Block stations or class `D’ stations: are scheduled stopping stations for specified trains. These stations are situated between two consecutive block stations, and do not forms the boundary of any block section. The stations at which there is outlaying siding are also called as DK station and those where there is no siding, are also called as flag station.

3.2 Classification of stations based on Standard of Interlocking and; 3.2.1 The Standards of Interlocking: On Indian railways three standards of interlocking were prescribed prior to introduction of Signal Engineering Manual volume-I 1988. On introduction of Signal Engineering Manual Volume-I, 1988, these standards were enhanced to five standards and then subsequently modified to four, restricting maximum speed from unrestricted as permitted through Signal Engineering Manual in force prior to the introduction of Signal engineering Manual 1988, to a maximum of 160 Kilometres per hour through Correction slip No. 6 to SEM 1988 clause 7.131. i) The standards of interlocking decide maximum permissible speed of the train across the

station. For example maximum permissible speed of the train on which the train can run-through across a station provided with standard-I interlocking, is 50 Kilometres per hour. This in turn decides the minimum equipment of signals, point fittings, isolation, type of signalling system, type of operating system and type of interlocking. These are chosen in such a way that it is possible to achieve desired level of speed of the train at and across the station with maximum safety, minimum operation time, minimum level of human involvement and minimum financial implications, corresponding to the given speed.

ii) The minimum equipment of signals as provided for any of the standards of interlocking may by be increased depending upon operational requirements but not to the extent that it changes the given standard of interlocking.

iii) The classification of standards of interlocking on all Indian railways with reference to the maximum allowable speed of the trains, minimum equipment required at such stations as well as other features as prevalent before the introduction of Signal Engineering Manual 1988, are tabulated below in table number 3.2.1.a:

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1 Standard : I 1.1 Allowable speed: 50 kilometre per hour 1.2 Isolation: It is recommended that main line be isolated but it is not compulsory if, in every case, in which trains are permitted to run through on non isolated line, all shunting is stopped and no vehicle which is not attached to an engine or not properly secured by the Station Master in accordance with approved special instructions, is kept standing on a connected line which is not isolated from the through line (clause 4.11 & 5.23 of General rule book 2007). 1.3 Signals: 1.3.1 In semaphore signalling system: 1.3.1.1 Outer and Warner to be provided. Provision of starter signal is optional; 1.3.1.2 Warner signal shall be provided for Metre Gauge stations where trains run through, if

considered necessary; 1.3.1.3 All signals shall be operated from an interlocked frame under control of Station

Master. 1.3.1.4 On the section with light traffic the outer signal may be operated from the location

near the facing point ensuring that Outer signal shall not be possible to be taken ‘Off’ unless home signal has been taken ‘Off’.

1.3.1.5 In exceptional cases, under approved special instructions, Warner where provided, may be operated from the same location as that of outer such that Warner can not be taken ‘Off’ unless other relevant signals for main line have been taken ‘Off’ and line clear has been taken in advance

1.3.1.6 In exceptional cases, under approved special instructions two home signals may be placed on the same post in lieu of bracketed home signal. The top arm shall apply to main line and the lower one to shall apply to other lines;

1.3.2 In Multiple Aspect Signalling system: A Distant and a Home signal in each direction. 1.4 Points: Facing points shall be equipped with: 1.4.1 A key lock of approved type; 1.4.2 A means for locking each switch independently; 1.4.3 A means for preventing the points from being unlocked during the passage of train;

unless the arrangement is such that a key is used to release the signals and can not be brought back to the points until such signals have been put back to ‘On’ position;

1.4.4 A means for detecting each switch independently by respective signals; 1.4.5 A gauge ties plate where steel sleepers are not provided. 1.5 Interlocking: 1.5.1 Interlocking between points and signals may be carried out by means of key locks

and shall be so arranged that the Station Master can not lower a fixed signal for the movement of a train unless all facing points falling in the route of the train are properly set and locked.

1.5.2 If Warner signals are provided the interlocking between the Warner signal and the points must extend to the trailing points.

1.5.3 Where the interlocking between points and signals is electrically transmitted the insulation of the line wires used in connections therewith shall be of the same

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standard as laid down as laid down for installation of block instruments; 1.5.4 Interlocking between points and signals must ensure that no signal can be taken ‘Off’

to admit a train on line that has been fitted with a tarp switch, unless the trap switch has been closed.

2 Standard : II 2.1 Allowable speed: 75 KMPH 2.2 Isolation: Required, with the condition that the line on which the train is to run has been

isolated from all other lines by the setting of points or other approved means and interlocking is such as to maintain this condition during the passage of the train. (Clause 4.11 of General rule book 2007).

2.3 Signals: 2.3.1 In semaphore signalling system: 2.3.1.1 Outer, Warner and bracketed home signals must be provided. Provision of starter is

optional; 2.3.1.2 Taking ‘Off’ of Warner signal shall be dependent upon the receipt of line clear on the

block instrument; 2.3.2 In Multiple Aspect Signalling system: A Distant, a Home and a starter signal in each direction 2.4 Points: Facing points shall be equipped with: 2.4.1 A plunger type facing point lock. If the plunger is hand operated or economical lock

type, its full travel should be detected by relevant signal. 2.4.2 A means for locking each switch independently; 2.4.3 A means for preventing the points from being unlocked during the passage of train;

unless the arrangement is such that a key is used to release the signals and can not be brought back to the points until such signals have been put back to ‘On’ position;

2.4.4 A means for detecting each switch independently by respective signals; 2.4.5 A gauge tie plate where steel sleepers are not provided. 2.5 Interlocking: 2.5.1 The interlocking between points and signals may be direct or indirect. Where indirect

interlocking is used signals shall be operated from a position under the control of the Station Master, and a key must be provided to enable the Station Master to lock up the signal frame. The interlocking between points and signals must be carried out under the same conditions as prescribed for standard – I and must ensure that all trailing points are correctly set and held in position by the lowering of signal for movement over them. When points and signals are operated from locations at either end of the station the interlocking between points and signals must be direct and must ensure the same conditions as laid down for direct interlocking. The Station Master must be provided with a control over the Home and Last stop signal.

3 Standard: III 3.1 Allowable speed: Unrestricted 3.2 Isolation: Required, with the condition that the line on which the train is to run has been

isolated from all other lines by the setting of points or other approved means and

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interlocking is such as to maintain this condition during the passage of the train. (Clause 4.11 of General rule book 2007).

3.3 Signals: 3.3.1 In semaphore signalling system: Outer, Warner, Bracketed home signals and Starter signals must be provided while

Advanced starter signals may be provided as and where necessary; 3.3.2 In Multiple Aspect Signalling system: A Distant, a Home and a starter signal in each direction. 3.3 Points: 3.3.1 A plunger type facing point lock; 3.3.2 A means for detecting the full travel of the lock plunger by related signals when the

lock and switches are operated by the same lever. (Operation of lock and switches by the same lever has since been stopped );

3.3.3 It is desirable that plunger detection may also be provided for independent ly operated facing point locks.

3.3.4 A means for detecting each switch independently by respective signals; 3.3.5 A means for detecting each switch independently; 3.3.6 A gauge tie plate where steel sleepers are not provided. 3.4 Interlocking: 3.4.1 The interlocking between points and signals must be direct. For this the operation

system of all signalling functions shall be essentially centralised at one place in one frame or cabinet.

Table 3.2.1.a Table showing Standards of Interlocking and associated minimum equipment of Signals and

Points before introduction of SEM 1988.

All works after the introduction of Signal engineering Manual 1988 (Volume-I only) have to be introduced in conformity to Signal Engineering Manual1988 only. The stations are classified as Standard -I, Standard- II, Standard- III and Standard- IV, with reference to standards of interlocking paragraph 7.131 of Signal Engineering Manual 1988 read with correction slip No.6. The maximum speed of the trains and minimum equipment as well as other features at stations with reference to corresponding standard of interlocking, are tabulated below, as may be seen in table No. 3.2.1.b: SN Features Standard I Standard II Standard III Standard IV Allowable

speed Upto 50 KMPH

Upto 110 KMPH Upto 140 KMPH

Upto 160 KMPH

1 Isolation Required * Required Required Required 2 Signalling 2 Aspect/ Multi

Aspect 2 Aspect/ Multi Aspect

Multi Aspect Multi Aspect

3 Double Distant

Not required Required Required Required

4 Point Operation

Mechanical Mechanical/ Electrical

Mechanical/ Electrical

Electrical

5 Point locking Key/Facing Point Lock

Facing Point Lock / Point

Facing Point Lock / Point

Point machine (Clamp type is

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/Hand Plunger Lock

machine machine desirable)

6 Point detection

Mechanical/ Electrical

Mechanical/ Electrical

Mechanical/ Electrical

Electrical

7 Lock detection

Not Required Required Required Required

8 Interlocking Key/ Mechanical

Mechanical/ Electrical/ Electronics

Mechanical/ Electrical/ Electronics

Electronics

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Track circuiting to be done of:

Not required 1. Mechanical Interlocking – Main run through lines 2. Electrical/ Electronic interlocking – All running lines

All running lines

All running lines

10 Block working (min)

Token Token/SGE SGE/Track circuit #

SGE/Track circuit #

11 Preventing signal passing at danger

Not required Not required Not required Desirable

* but not compulsory subject to in every case in which trains are permitted to run through on non isolated line, all shunting shall be stopped and no vehicle which is not attached to an engine or not properly secured by the Station Master in accordance with approved special instructions, may be kept standing on a connected line which is not isolated from the through line (Clause 4.11 & 5.23 of General rule book 2007). Abbreviations used in the table- SGE - The type of double line block instrument; # At stations where central panel is provided or at high density routes, means for verifying complete arrival of trains by suitable means shall be required.

Table 3.2.1.b

Table showing Standards of Interlocking and associated minimum equipment of Signals and Points with the introduction of SEM 1988.

4 Station Limits: This is complete area of station yard under the control of Station Master and is covered by outermost signals of the station except where otherwise specified by railway authorities under special instructions. As per General Rule book 2007, clause 1.01(52) issued by Indian Railways, Station limit is defined as “the portion of railway which is under the control of a Station Master and is situated between the outermost signals of the station or as may be

13

specified by special instructions”. The Station Master is responsible for all happenings in the Station Limits. (Fig 4).

HOMEDISTANT

STATION LIMIT

BLOCK SECTION

ADVANCED STARTER

ADVANCED STARTER DISTANTHOME

STARTER

BLOCK SECTION STATION SECTION

STARTER

Fig. 4

Station section, Block section and Station Limit 5 Station Section and Block Section: The entire area of track over which a train traverses is sectionalized into two main segments viz. (i) Station section and (ii) Block section. (Fig.5.2.a; 5.2.b; 5.2.c, 5.2.d, 5.2.e, & 5.2.f; for semaphore & MACLS signalling area on single & double line.) 5.1 Station Section: Station section is that part of Station Limits which is not covered by Block Section. The area of station section varies with the class of station, situated on a double line or single line section. Based upon General Rules 1.01(54), Station section means: 5.1.1 That section of the station limits at a class `B’ station provided with two aspect signals, which is included: i) on a double line, between Home signal and the Last Stop signal of the station in either

direction; or ii) on a single line:

a) between the Shunting Limit Boards or Advanced Starters (if any), or b) between the home signals if there are no shunting Limit Boards or Advanced Starters, or c) between the outermost facing points, if there are no Home signals or Shunting Limit Boards or Advanced Starters;

5.1.2 At a class `B’ station, provided with manually operated multiple aspect or modified lower quadrant signals, which is included: i) On double line: a) Between the outermost facing points and the Last Stop signal of the station on either direction; or b) Between the Block Section Limit Board, where provided, and the Last Stop signal of the station in either direction; or ii) On single line: Between the Shunting Limit Board or Advanced starters (if any) or

between the outermost facing points, if there are no Shunting Limit Boards or Advanced Starters.

14

STATION SECTION

400 mts

ADVANCED STARTER OR SHUNTING LIMIT BOARD

OR

OUTERWARNER

HOME

STARTER

400 mts

ADVANCED STARTER OR SHUNTING LIMIT BOARD

OR

OUTERWARNER

STATION SECTIONBLOCK SECTION

HOME

STARTER

Fig 5.2.a

Block section & station section on `B’ class stations on single line section in two aspect signalling territory

STATION 'A' STATION 'B'

STATION SECTION

STATION SECTION

STATION SECTION

STATION SECTION

BLOCK SECTION

BLOCK SECTION

HOME STARTER

ADVANCEDSTARTER

OUTERWARNER

ADVANCEDSTARTER

STARTERHOME

OUTERWARNER

Fig 5.2.b

Block section & station section on `B’ class station on a double line section in two aspect signalling territory

5.1.3 The Station Section and Block Section of class `A’ & `C’ stations overlap each other while station section of class `Special’ station is defined based upon the layout of the station. 5.1.4 Here it is very important to understand the difference between Station Section and Station Limits. 5.2 Block Section: As per General Rules book, clause 1.01(10), Block section is that portion of running line between two block stations on to which no running train may enter until Line Clear has been received from the Block station at the other end of the block section. (Fig.5.2.a; 5.2.b; 5.2.c, 5.2.d, 5.2.e, & 5.2.f; for semaphore & MACLS signalling area on single & double line.) The Block Station is the station on either ends of a Block Section.

15

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16

6 Fixed Signal: Signal of fixed location called as fixed signal is the means through which the status of the track on which the train is to move, is communicated to the driver of the train, now designated as Loco Pilot, by the Station Master at the station or by a train running in the Automatic Block Signalling section ahead of other train. As per General Rule book clause 1.02.(21), issued by Indian Railways, the fixed signal is defined as “signal of fixed location indicating a condition affecting the movement of a train and includes a semaphore arm or disk or fixed light for use by day and fixed light by night”. This signal can be a semaphore arm or a colour light, housed on a signal post. Signals are classified by their: i) Structural design, ii) Usage, and iii) Placement Signals are also used depending upon geographical terrain, traffic requirement, economical considerations, traction in the section, and modernization in signalling system. 6.1 Classification of fixed signals based on structural design: These signals, depending upon their structural design are `Semaphore Lower quadrant, Semaphore Upper quadrant, Modified Lower quadrant and Colour light signals. Details of signal posts, arms of semaphore signals and signal units of colour light signals shall be discussed in ensuing volume of this book. 6.1.1 Mechanical semaphore signal: (i) Two aspect lower quadrant signalling system (Fig.6.1.1.a): The word `semaphore'

was used first by a Greek historian: `Sema' stands for sign and `Phor' means to bear. A semaphore signal consists of a spectacle, as it looks like a human spectacle, and an arm fixed to it. The Fig 6.1.1.a shows Stop and Warner signals on the same post. The arm

of stop signal is square ended, painted red with a white strip at the tail end of the signal arm while the Warner signal is fish tailed painted red with a white strip in the same profile as the fish tail of the arm, at the tail end of the signal arm. The spectacle bears coloured glasses, which are red yellow or green depending upon the aspect to be displayed. A lamp with the lens to send a focussed beam of light through the coloured glasses, is

pivoted on a base plate with a pin fixed to a signal post.

Fig 6.1.1.a

Two aspect semaphore signal showing Warner below outer on the same post

17

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Fig

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18

(ii) Modified lower quadrant signalling system (Fig.6.1.1.b): Looking at the constraint that a lower quadrant semaphore signal could display only two aspects i.e. arm at horizontal position showing stop in the day and showing red light also in the night, which was grossly inadequate with the traffic moving at faster speed the two aspect semaphore signals were modified by placing Warner signal below the main line home signal on the same doll on which the home signal was placed. The home signal is preceded by a Distant signal. With this the approaching Loco Pilot did not have to face first signal of the station as a stop signal while coming from the block section. A pre-warning serves the same purpose as multiple aspects signalling system.

(iii) Multiple aspect Upper quadrant signalling system (Fig 6.1.1.c): Lower quadrant two aspect signalling system has limitation of communication, which is slightly improved by modified lower quadrant signalling system. In the upper quadrant multiple aspect Signalling system the arm and light arrangement is similar to two aspect semaphore signals. The ‘ON’ aspect is displayed by horizontal position of arm while caution aspect is displayed by arm raised to 450 above horizontal & proceed aspect by arm raised to 900 above horizontal. It has an advantage of communication being of multi aspects added by improved visibility in hilly terrain, while in case of lower quadrant signalling the third aspect could not be achieved as the signal arm if lowered by another 450 got merged with the signal post while in upper quadrant this aspect is visible, giving advantage of one more aspect.

ADVANCEDSTARTER

DISTANT

STARTER

BSLB

WARNER HOME

Fig 6.1.1.b

Modified lower quadrant signalling system

Fig 6.1.1.c

Multi aspect upper quadrant signals showing three aspects

19

6.1.2 Multiple aspect colour light signalling system (Fig 6.1.2): The colour light signals, simple in structure have all the advantages of communication and visibility both in day and night. Rightly so, the colour light signalling system operated by central panel has been scheduled for operation in all new installations or replacements. The signal unit houses signal lamp, a transformer to convert 110V AC to 12V AC, and a Lamp checking relay, meant to monitor the status of the lamp. The lamp could be two pole double filament, one filament being main and other being auxiliary or it could be three pole double filament lamp. In case of two pole double filament lamp fusing of any of the filament shall be detected by dropping of the lamp checking relay, which shall be treated by the preceding signal as lamp fused & accordingly less restrictive aspect, shall be displayed by it. The lamp therefore is required immediate replacement. In case of three pole double filament lamp the fusing one filament shall result in switching over to the other filament, while simultaneously giving indication to the Assistant Station Master that one filament has fused. However in this case the preceding signal shall not detect this situation as lamp fused continue displaying the aspect as in normal case. The lamp replacement may be done as early as possible. This arrangement as such is an added advantage over the two pole lamps. In both cases the signal is not blanked off. The signal unit is provided with a couplet of stepped lenses, outer one being clear while inner one is coloured red or yellow or green. The electric signal lamp is placed at the focal point of the lenses couplet such that the desired colour focussed parallel beam of light is emitted. The unit is available in two, three and four aspect configurations.

Now with the advent of High power Light Emitting Diodes (LEDs), the cluster of LEDs as sealed and focussed signals in the form of a unit, is being used, housed in the same signal units in place of 12 Volt signal lamps and lenses. The LED signal unit is lighted by 110V AC or 110V DC eliminating use of 110V/12V transformer. With the use of LEDs the frequent signal going blank due to fusing of incandescent signal lamps has been literally reduced to zero. Junction type route indicators are used with multiple aspect signals. The signal unit is provided on an offset bracket mounted on the signal post & route indicator on the top of the signal. This route indicator is capable of providing six route arms, being fixed with each hexagonal face while for main or straight line no arm in the route indicator is provided. With this the limit of arm type route indicator is indication for seven routes only. The arm type unit is in two parts, the central part is with hexagonal shape each face to accommodate one arm of four lamps. The central body accommodates one lamp called as pilot lamp and is common to all six arms, all the five lamps placed in route indicator unit form a row. The unit is provided with clear lens, each lamp displaying focussed white lunar light. The route indicator is provided on the top of signal post in such a way that top of the signal unit is just below route indicator. For more than seven routes, `Theatre’ type route indicators are used which display the number of the line on which the train is being received, through an array of lamps lighted to form the numbers. The figure 6.1.2 shows multiple aspect colour light signal and a route indicator with one arm with a four aspect colour light signal unit.

20

Fig 6.1.2

Multiple aspect Colour Light Signal and route indicator 6.1.3 Visibility of signals: The Loco Pilot of the train is very much dependent of visibility of the signals. Some time is taken by any human being between seeing or hearing some thing and reacting to the same. This time between seeing or hearing and reacting to the same, is known as reaction time. So is the case with the Loco Pilot. This time is taken to be seven seconds. A train moving at a speed of 100 kilometres per hour shall traverse 194 metres in seven seconds. The second major factor to decide minimum visibility of the signal is the braking distance, which in turn depends on the braking power, total mass of the train, gradient and the speed of the train. Taking into consideration all of these factors the minimum visibility of the signals has been prescribed to be as follows: [GR & SR (NCR) 3.26/3] Type of signalling system Visibility (A) Two aspect lower quadrant signalling system:

With 100 KMPH Section speed, 1200 Metres i) Outer signal With less than 100 KMPH Section speed, 800 Metres

ii) Warner signal on a post by itself

400 Metres

iii) Home, main line starter and Advanced starter signals

Each signal should be visible from its previous stop signal

iv) Loop line starter signal 200 Metres v) Warning Boards: Boards of different design for passenger and goods trains at a distance of

1000 Metres, and 1400 metres are provided in rear of first stop signal for passenger and goods trains respectively to warn the Loco Pilot of approaching train that he is approaching first stop signal.(fig 6.1.3)

(B) Multiple Aspect signalling system: i) Distant signal 400 Metres and if Inner Distant is also provided the

visibility for Inner Distant shall also be 400 metres ii) All other signals at station Aspect of each signal shall be visible from its previous

signal in the direction of the train (C) Where adequate visibility of stop signal cannot be maintained, repeater or Co-acting signal

21

shall be provided or speed restriction shall be imposed if the desired level of visibility is not available.

(D) If no signal indication is available to the Loco Pilot, he shall control the train considering that the next signal is red.

(E) Warning Boards: Warning Board on its face, facing the approaching train is provided at a distance of 1000 metres with zebra design and 1400 metres with a circle in between two horizontal bands, painted in yellow on black background, in rear of first stop signal for passenger trains and goods trains respectively in case of two aspect signalling territory to warn the Loco Pilot that he is approaching first stop signal. If no signal indication is visible from the sighting board, the Loco Pilot shall control his train assuming that the stop signal ahead is On. (Fig 6.1.3). [GR & SR (NCR) 3.26/4] 6.2 Classification of fixed signal based on usage: The fixed signal is used as a Stop signal, Warner or Distant signal, Shunt signal, Calling-on signal, Gate signal, Repeater signal, Co-acting signal, Goods signal, Automatic Block signal and a signal with `A’ marker. For the purpose of identification meant for specific use the signals are provided with markers on the signals posts. These markers are alphabets or symbols clamped with the signal arm or post in case of semaphore signals and written on circular plate clamped on signal post below the signal unit in case of colour light signals. 6.2.1 Stop Signal: This signal essentially has a Stop aspect, which is its normal aspect also, be it a two aspect lower quadrant, Modified Lower Quadrant (MLQ), Multiple Aspect Upper Quadrant (MAUQ) semaphore signal or a Multiple Aspect Colour Light Signal (MACLS). Other aspect is ‘Off’ aspect. The Loco Pilot shall not pass this signal when the signal is ‘On’ except when authorised by the Station Master under a written authority to pass the signal at danger. 6.2.2 Warner or Distant signal: The signal is called Warner signal in case of two aspect signalling system whether it is a semaphore signalling system or colour light signalling system and Distant signal in case of Multi Aspect Signalling system. The signal is provided with a `P’ marker, which is the letter `P, painted in black on a white circular disk clamped on the signal post. The normal aspect of Warner or Distant signal is ‘Caution’ in case of lower quadrant two aspect signalling system, Upper Quadrant Multiple Aspect Signalling system and Multiple Aspect Colour Light signalling system. This signal does not have Stop aspect. In case of Multiple Aspect Colour Light signalling System ‘Attention’ aspect is also given in addition to caution aspect. There being no Stop aspect on this signal the Loco Pilot is never required to stop on this signal except when the signal light is extinguished. On a Warner or Distant signal provided with `P’ marker if the signal light is extinguished during night and also during day time in case of

Fig 6.1.3

Goods & passenger warning boards

22

Multiple aspect colour light signal the Loco Pilot shall stop at this signal, the Loco Pilot shall move with cautious speed prepared to stop at the next signal only after satisfying himself that the signal is provide with a `P’ marker. In case `P’ marker is not there it shall not be possible for the Loco Pilot to distinguish between a Stop signal and a Warner or Distant signal (in case the arm of semaphore signal is also not visible), which in turn can result in passing a signal at danger or waiting on a Warner / Distant signal for which Station Master shall not be issuing a written authority to proceed, there by detaining the train unduly. This makes `P’ marker very important. 6.2.3 Shunt signal: Shunting is a process of attachment, detachment, placement of any vehicle to or from a train which is attached or not to an engine, with or without the help of an engine. Shunt signals are meant for signalled shunting in the interlocked station section performed with a loco motive engine. The shunt signal leads moment from one shunt signal to the next shunt or stop signal whichever falls first in the route. In Semaphore signalling system, shunt signals are of two type i.e. (i) miniaturised spectacle with a miniaturised arm and (ii) of `disk’ type which is a circular disk painted white with a red horizontal strip on its face. When taken off, in case of miniaturised arm type shunt signal the arm is painted red. During night time it displays red light when `On’ and a yellow light when taken `Off’. In case of disk type it displays the red strip in horizontal position when `On’ and inclined to 450 to horizontal. During night time the aspects displayed are red and yellow respectively. These signals may be mounted on a post by itself or on the same post as that of running signal depending upon operational requirements. (Fig 6.2.3.a).

Fig 6.2.3.a Semaphore shunt signals from left to right Disk type in two aspect territory, in multiple aspect territory and arm type, mounted on post by itself, showing ‘On’ & ‘Off’ aspects

In Colour light signalling system, shunt signal is mounted on a post by itself or on the same post as that of a running signal based upon operational requirement. When mounted on a post by itself it displays two lunar white lights placed to form a horizontal line meaning thereby its ‘On’ aspect akin to ‘On’ aspect of a semaphore signal which means dead stop and two lunar white lights placed to form a line inclined at an angle 450 to horizontal, meaning thereby its ‘Off’-

23

aspect akin to `Off’ aspect of a semaphore signal which means proceed. One of the lamps is common in formation of line horizontal and inclined and is known as pilot lamp. When mounted on the same post as that of a running signal it displays no light as `On’ aspect and two lunar white lights placed to form a line inclined at an angle 450 to horizontal meaning thereby its `Off’ aspect. The signal can not be used for direct reception or despatch of a train from or to the Block section or Automatic Block section. The signal may be mounted on a post by itself and when it is mounted on the

post of a running signal it is mounted on an elbow (an offset bracket) below the running signal. (Fig 6.2.3.b). When a shunt signal is mounted on the same post as that of a running signal, both main or shunt signal can not be taken ‘Off’ at the same time. Either the main signal shall be taken `Off’ or the shunt signal at any one time.

6.2.4 Calling-on signal: In bigger yards where reception signal is placed at such a distance and on a route with high density traffic where loss of time to the train is with serious consequences resulting in queuing up of following trains, the Calling-on signal is provided on the same post as that of reception signal below the main signal arm or unit to receive the train when the main running signal has failed or the train has to be received on an occupied line. The Calling-on signal and the main signal on the post of which the Calling-on signal has been provided, can not be taken `Off’ simultaneously. The Calling on signal may also be provided on the post of signals other than reception signals, under special approved instructions except on the post of last stop signal. i) Calling-on Signal in Semaphore Signalling system, [GR 3.13] be it lower quadrant or

upper quadrant it has miniaturised spectacle fitted with a miniaturised arm painted white in colour with a red strip near the end of the arm. The signal displays arm in horizontal position to show ‘On’ aspect during day time. In case of lower quadrant signalling system the arm is inclined to 450 below horizontal and in case of upper quadrant system the arm is inclines to 450 above horizontal to display ‘Off’ aspect during day time and also shows yellow light during night time. (Fig 6.2.4.a & b).

'On' Position 'Off' Position

Fig 6.2.3.b

Colour light shunt signal mounted on post by itself showing ‘On’ & ‘Off’ aspects

Fig 6.2.4.a Miniature arm lower quadrant calling on

signal fixed below main stop signal

24

C C

Fig 6.2.4.b Miniature arm upper quadrant calling on

signal fixed below main stop signal

Fig 6.2.4 c Miniature colour light calling on signal fixed

below main stop signal ii) In Colour light signalling system it is miniaturised unit provided on the same post as

that of the corresponding main signal on an elbow (Offset bracket), below the running signal unit. It displays no light in `On’ aspect and miniaturised yellow light as `Off’ aspect during day as well as night time. (Fig 6.2.4.c).

It must be ensured that the train approaching the concerned reception signal has come to a stop before the Calling-on signal acquires `Off’ aspect.

6.2.5 Gate signal (Fig 6.2.5): Level crossing gate falling in the Block section, when interlocked, is provided with the Gate signals on either side of the gate to protect the road traffic across the gate. It is provided at a distance of 180 metres in case of multiple aspects signalling system and at a distance of 400 metres in case of two aspect signalling system, from the edge of the road on either side. The signal is preceded by a Warner or Distant signal depending upon the system of signalling of the section. A gate signal is essentially same in structure and design as an stop signal in semaphore signalling system as well as in Colour light signalling system provided with a ‘G’ marker on its post in addition. The ‘G’ marker is letter ‘G’ painted in black on a circular disk painted yellow. The disk is clamped with the signal post. The gateman posted on duty at the level crossing gate is not competent to issue authority to pass the gate signal on red. The provision of the `G’ marker on the signal distinguishes the signal for following rules of the gate signal. (i) On a gate signal in Block Section, the Loco Pilot shall stop at the signal & whistle in

prescribed code, wait for one minute during day and for two minutes during night and if the signal is not taken ‘Off’ during this time the Loco Pilot shall move his train ahead cautiously up to level crossing and if the gate man is available and exhibiting all right signal he shall pass the gate cautiously but in case the gateman is not available or is available but not exhibiting alright signal, it shall be ensured that the gate is closed and

25

then pass the gate cautiously following the hand signal by the gate man or in his absence by one of the engine crew members of the train.

(ii) The gate signal provided in the Automatic Block Signalling section is provided with ‘A’ marker and a ‘G’ marker. The ‘A’ marker is the letter ‘A’ stencil cut on black painted glass sheet on the face of ‘A’ marker signal unit or, which is provided on an offset bracket on the same signal post to which is qualifies. In case of LED signals where used the letter `A’ is displayed in the face of the LED signal unit. The ‘G’ marker is the letter ‘G’ painted in black on a circular disk painted yellow and clamped on the signal post. The ‘A’ marker is lighted to show that the Gate is closed and locked against road traffic. When the ‘A’ marker is not lit the signal is treated as manual signal and provisions of Gate signal provided on an interlocked gate in Block section in Absolute block signalling section shall be followed as described above in paragraph (i) above. See fig.6.2.5

A

G

fig 6.2.5

LED `A’ marker, fixed on gate signal in Automatic Block section area with a `G’ marker

(iii) The gate provided in the station sections are protected by main running signals of the station and are accordingly interlocked to these signals.

6.2.6 ‘A’ Marker on signals in station section: The signals provided with `A’ marker in the station section wherein adjoining section is worked as Automatic Block signalling section when lit means that the signal is working as automatic signal and when the `A’ marker is not lit it means that the signal is working as manual stop signal and the Loco Pilot shall follow rules of manually operated signals. 6.2.7 Repeater signal: In cases when a signal is not visible to the Loco Pilot from adequate distance due to curvature or any other reasons or in cases where signal is not visible to the guard of the train at the rear end of a platform, a repeater signal is provided at a suitable convenient position in rear of main signal. A repeater signal is provided with an 'R' marker and is of the following type. (i) A square ended semaphore arm painted yellow with a black band near the tail end of the

arm. (ii) A Colour light repeating signal. (iii) A rotary or disc banner type signal. These three types of repeating signals in their `Off' position are shown in fig.6.2.7. It is pertinent to note that a repeater signal essentially does not have a red aspect. The post of semaphore repeater signal is provided with a white circular disk painted with letter `R’ in black while the post of colour light signal is provided with a black circular disk panted with letter `R’ in white.

26

R

R

R

Fig 6.2.7.

Off aspects of repeater signals semaphore , banner type and colour light from left to right

The ‘On’ aspect in case of semaphore repeater signal during day is a horizontal arm painted yellow with a black band at the square end of the arm, and during night it displays yellow colour light. This signal displays green light during night time when taken `Off’, its arm inclined to 450 below horizontal. The Banner type repeater signal disk is painted with black strip across its diameter

with a yellow strip in the middle of it, which is horizontal when the signal is `On’ and inclined to 450 when `Off’ The colour light repeater signal displays green colour to repeat the `Off’ aspect of the main signal and yellow colour when `On’.

6.2.8 Co-acting signal (fig.6.2.8): The signal to which the train is approaching should be continuously visible to the Loco Pilot. Whenever a signal is not visible to the Loco Pilot continuously obstructed by over bridge, flyover, or any other structure, another signal is placed on the same post, as that of main signal, at a suitable height to enable continuous visibility of the signal to the Loco Pilot. This signal known as co-acting signal is an exact replica and moves in unison together with its main signal semaphore signal as well as colour light signal.

Fig.6.2.8 Off aspect of Co-acting signals

6.2.9 Goods signal (fig 6.2.9): A semaphore reception signal provided with stencil cut letter ‘O’ on the signal arm encircling the white strip of red painted arm provided on a post by itself or on a doll along with other running signals leads the train to goods running lines only.

fig 6.2.10

On aspect of Dock signal

fig 6.2.9

On aspect of Goods signal

6.2.10 Dock signal (fig 6.2.10): A semaphore reception signal provided with stencil cut letter ‘D’ on the signal arm encircling the white strip of red painted arm provided on a post by itself or on a

27

doll along with other running signals leads the train to dock platform. 6.2.11 Signals at class `D’ station: At a `D’ class station, a train may be stopped under manner authorised by special instructions. To indicate to the Loco Pilot that he was approaching a `D’ class station an indicator board shall be provided by the Engineering department with letter `H’ of 300 mm height, painted black on a sheet. Painted yellow at a distance of 600 metres from the centre line of the station. The board shall be 600mm X 600mm.on a 2 Metres post painted white and black alternate strips of 300 mm height each. 6.2.12 Automatic Block signal: The Automatic Block signals are either three aspect or four aspect Colour Light signals. In three aspect signalling scheme each signal has essentially Red, Yellow and green aspects It shall have double yellow aspect also if the signal is a in four aspect signalling scheme. The normal aspect of this signal is always green. The aspects of these signals are controlled by passage of the train. As soon as a train passes over the track circuit ahead of the Automatic Block signal, the aspect of the signal becomes red. As the train moves on and not only clears the next signal but also signal over lap beyond the same, the aspect of the signals turns to yellow and this keeps on changing to double yellow and green as the train moves ahead of next to next signal along with overlap and then next to next to next along with overlap. The following train shall be guided by the aspects as being displayed to it as per extent rules. The aspect sequence, with reference to train movement may be seen in fig. 6.2.12.a in three aspect signalling areas and 6.2.12.b in four aspect signalling section.

fig.6.2.12.a

Aspect sequence of three aspect Automatic Block signal

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TRAIN

TRAIN

TRAIN

TRAIN

TRAIN

fig.6.2.12.b

Aspect sequence of four aspect Automatic Block signal 6.2.13 The ‘Position’, ‘Aspect’ and ‘Indication’ of signals: The signal is only means of communication between the persons at the ground and the Loco Pilot or any other person on the Loco. For communication, there is always a language. The language used for this communication is a combination of `Position’ `Aspect’ and `Indication’ of the signal as discussed below: i) Position of the signal: Any signal shall have two `Positions’ which is `On’ or `Off’.

The arm of a semaphore signal shall be painted with the same colour as the light it displays during night in its horizontal position, this position of Semaphore signal is called `On position’ The arm is painted red in case of sop signal and yellow in case of a Warner signal. Both signals, when their arm is horizontal, shall be said to be in their `On position’. Since the colour light signal displays same light during day as it displays during night, it is called to be in `On position’ when it is normal, it may be a Stop signal or a Distant signal. Any other position of the arm of semaphore or colour light signal is called ‘Off position’ except in case of a signal in Automatic Block signalling territory. In Automatic Block Signalling area only colour light signals are to be provided. The signals remain in `Off’ position normally.

ii) Aspects of the signal: A Stop signals, in its ‘On position’ conveys ‘Stop Aspect’ while a Warner or Distant signal in its ‘On position’ conveys ‘Caution aspect’.

A two aspect semaphore stop signal in its `Off position’, arm inclined to 450 below horizontal and a green light by night, conveys `Proceed Aspect’ while; A Multiple Aspect Upper Quadrant semaphore signal inclined to 450 above horizontal with a yellow light by night or a Colour Light Signal displaying yellow colour light, in its `Off position’ conveys `Caution Aspect’.

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A Multiple Aspect Upper Quadrant semaphore signal raised to 900 above horizontal with green light by night or a colour light signal displaying green colour light, in its `Off position’ conveys `Proceed Aspect’. A Multiple Aspect Colour Light Signal displaying double yellow colour lights, in its `Off position’ conveys `Attention Aspect’.

iii) Indication conveyed by the Aspect of the signal: The detailed meaning of the Aspect of signals is of the certain meaning to the Loco Pilot or any observer. a) Stop aspect indicates stop dead; b) Proceed aspect indicates proceed. Here Proceed means proceed with the maximum

permissible speed in the area; c) Caution aspect indicates proceed and be prepared to stop at next stop signal; d) Attention aspect indicates proceed and be prepared to pass next signal at such

restricted speed as may be prescribed by special instructions. In this situation if the train is indicated to move on straight line, the next signal shall be passed on Caution aspect prepared to stop at next signal with Stop aspect, but if the train is indicated to traverse a 1 in 8 ½ turnout, the Loco Pilot shall have to restrict the speed at 15 kilometres per hour or if the turnout happens to be I in 12, the speed shall be restricted to 15 kilometre per hour and so on. The speed on 1 in 12 turnouts has been increased on certain sections to 30 KMPH.

The Aspects and corresponding indications are tabulated below in Table 6.2.13: Position Aspect Indication Two aspect Semaphore stop signal: ‘On’ Stop Stop Dead ‘Off’ Proceed Proceed Outer & Warner on the same post: Outer ‘On’ & Warner ‘On’ Stop Stop dead Outer ‘Off’ & Warner ‘On’ Proceed Proceed with caution Outer ‘Off’ & Warner ‘Off’ Proceed Proceed Multiple Aspect Signal: ‘On’ Stop Stop Dead ‘Off ’ Caution Proceed & be prepared to stop at next

signal. ‘Off ’ Attention Proceed & be prepared to pass the next

signal at such restricted speed as may be prescribed bys special instructions

‘Off ’ Proceed Proceed Modified Lower quadrant: Main line Home and Warner on the same doll: Home ‘On’ & Warner ‘On’ Stop Stop dead Home ‘Off’ & Warner ‘On’ caution Proceed & be prepared to stop at next signal Home ‘Off’ & Warner ‘Off’ Proceed Proceed Shunt signal semaphore & colour light:

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‘On’ Stop Stop dead ‘Off’ Proceed slow Proceed with caution for shunting Calling on signals: ‘On’ - - Loco Pilot should follow the aspect of main

signal. ‘Off’ Proceed slow Stop and then draw ahead with caution and

be prepared to stop short of any obstruction Automatic Block Signal on single or double line: ‘On’ Stop Stop for one minute in the day and two

minutes during night and then follow the procedure described in Chapter-III & paragraph 3.8 & 3.2 respectively, of this book.

‘Off’ Proceed Proceed ‘A’ marker on semi-automatic Stop signal: White illuminated letter ‘A’ against black background.

- - The stop signal is working as Automatic signal. Follow rules of Automatic signal.

Letter ‘A’ extinguished - - The stop signal is working as Manual stop signal. Follow rules of stop signal.

Intermediate Block stop signal: Same as home signal provided at intermediate block post

Co acting signals: Same as main signal

Repeating signals: - - ‘On’ - - Signal to which it repeats is ‘On’, proceed

to stop at the signal to which it repeats. ‘Off’ - - Signal which it repeats is ‘Off’, proceed to

the signal to which it repeats and act according to the aspect after reaching there.

Goods signal: ‘On’ Stop Stop dead ‘Off’ Proceed Proceed, signal is for goods running line

only Dock signal: Stop Stop dead Proceed Proceed, for Dock Platform only

Here proceed means proceed at maximum permissible speed permitted for the section. Table 6.2.13

The aspects, indications and their meaning

6.3 Classification of signals based on placement: On a station, a fixed signal can be placed as reception or a departure signal.

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6.3.1 Reception signals: In two aspect semaphore signalling system reception signals are Outer, Warner and Home. In Multiple aspect signalling system reception signals are Distant and Home. (i) Warner /Distant signal: In two aspect signalling area the first signal faced by the Loco

Pilot is Warner. This signal is placed on a post by itself or two metres below the Outer signal on the same post as Outer. The arm of the signal is fish tailed with its face painted red with a white band parallel to the fish tail, (fig.5.2.a & 5.2.e).

When placed on a post by itself a fixed green light is provided 1.5 to 2 meters above the arm. The signal shows by night, a red light when in `On’ position and a green light when in `Off’ position along with the fixed green light above it. The fixed green light is replaced by the Outer signal when the Warner is placed on the same post as Outer signal. Two aspect colour light Warner signal also displays same aspects by day and night both as semaphore signals display by night in both situations as when placed on a post by itself or on the same post as outer signal. Distant signal in Modified, two aspect semaphore signalling territory: The arm of the distant signal is fish tailed, its face painted yellow with a black band parallel to the fish tail. The signal shows yellow colour light by night when `On’ and one green when taken `Off’. The Distant signal in Upper Quadrant arrangement is such that a hole provided in the disk moving with the arm obstructs the yellow light of the lamp placed 1.5 metres below the arm, such that the view of the fixed lamp is obstructed in other two positions of the arm of the signal except when it is inclined to 450 to the horizontal. Distant signal in Semaphore Multiple Aspect Upper Quadrant (MAUQ) signalling territory has fish tailed arm with its face painted yellow with a black band painted parallel to the fish tail. This shows yellow light by night when `On’, one yellow light with another yellow light when inclined to 450 above horizontal and green light when `Off’ at 900 above horizontal. Distant signal in Multiple Aspect Colour Light signalling territory, also displays the same colours as MAUQ signals by day as well as by night. In sections with Rajdhani trains route or where heavy Haul goods trains are run, two distant signals are provided preceding Home signal. The first Distance signal encountered by the Loco Pilot is called distant signal. Its signal post is painted with black and yellow strips of 12” each. The next distant signal post is painted with aluminium paint. Both the signals are provided with a `P’ marker plate on their post and other wise are identical.

(ii) Outer signal: An Outer signal is first stop and reception signal in two aspect lower quadrant signalling section only. The placement of Outer signal varies depending upon the section being single line or double line. In case of two aspect signalling the adequate distance beyond the first stop signal of the station is 400 metres as such in case of double line section the outer is placed at a distance of 400 metres from the next

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reception signal i.e. Home signal. If the section is single line, the outer signal has to be place at a distance of 400 metres from the last stop signal which is Advanced starter signal. The advanced starter signal is placed at a distance of 120 metres from the last trailing point in single line section. The block section extends not only upto first stop signal but also an adequate distance beyond the first stop signal which is 400 metres in this case as such with the entry of the train inside outer signal and clearing the adequate distance of 400 metres the train enters into Station Section having cleared the Block section.

(iii) Home signal, Routing Home signal & Route indicators: After the outer signal, the next reception signal towards the station is Home signal. The purpose of this signal is to inform Loco Pilot of the line to which the train is being received. In two aspect lower quadrant or colour light signalling section Home signal is provided right at the entrance, short of points meant for diversion of the train to the nominated line because the block overlap is provided just beyond outer signal. There are different signals on small posts called `Dolls’ mounted on a `gantry’ provided on single signal post, for different lines in case there are more than on lines for the train to be received. The doll bearing main line signal is kept higher than all other dolls on the same gantry while the signals have to be placed in sequence such that the outermost signal pertains to the outermost line and the inner most to innermost line. This arrangement works as route indicator to the Loco Pilot (Fig. 6.3.1.a). In some cases when under approved special instructions two or more signals are to be provided on the same post, the top most signal shall apply to the extreme left line, next signal to next line and so on so forth. Under exceptional circumstances two home signals are to be provided on the same post the main line signal shall be placed higher then the other signal. In Multiple Aspect Colour Light signalling section, the Home signal post and unit is one for all reception lines. When there are more than one reception lines, route indicator is provided on the top of the signal post which indicates the route on which train is intended to be received. When Junction Type i.e. five lamps lit in a row formation, route indicator is used, the maximum routes that can be covered by one such route indicator are seven. In such a situation another Home signal is provided just before second set of reception lines. When it is not considered to provided another intermediate signal for another bunch of routes, theatre type route indicator is used which displays routes in numerals formed by array of lamps, when the number of routes to be indicated by the signal is more than 7. However theatre type of route indicator shall be used to display maximum number of ten routes.

Fig.6.3.1 a

Semaphore Home and routing home signals on a gantry

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One of the purposes of indicating line to the Loco Pilot, on which the signal is leading to is, to enable Loco Pilot observe speed restriction of 15 Kmph and 30 Kmph while negotiating 1 in 8 ½ and 1 in 12 turnouts respectively, while entering into a loop line. Where the reception lines are situated scattered in the form of bunches, the branching off is required to be done at different stages requiring inturn more number of signals in between the first reception signal and the last berthing track of the yard. In such a situation intermediate home signals are provided. (Fig. 6.3.1.b)

DISTANT HOME

ROUTING HOME

Fig.6.3.1.b

Colour light Home and routing home signals 6.3.2 Departure signals: Starter and Advanced starter signals are departure signals. A signal at a block station which is controlled by the block instrument and after passage of this signal the train enters into the block section is also known as Last Stop signal (LSS). (i) Starter signal: This is the first signal permitting despatch of a train from the station.

The signal is provided at the departure end of each line. In case there is no Advanced Starter at the station this signal is interlocked with the block instrument and permits entry of the train into the block section only when the line clear has been obtained from the station in advance. The starter signal is provided with a route indicator if more than one line is taking ‘Off’ from the station. However when Advanced starter is provided at the station the starter signal permits movement of the train up to advanced starter signal only and is not interlocked with the Block instrument. The starter signal is not used for shunting.

(ii) Advanced Starter signal: This signal is the last stop signal of the station and is interlocked with the Block instrument in such a way that it is not possible to take this signal ‘Off’ unless line clear has been obtained from the station in advance.

An independent Advanced starter signal is provided for each main or branch line taking ‘Off’ from the station provided after all points at the station. (Fig. 6.3.2)

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ADVANCED STARTER

ADVANCED STARTER

Fig. 6.3.2

Independent Advanced starter signal for each departure line out side all points of the station

7. Interlocking in the station section: In a complex network where the traffic is heavy, it is important that the signal is taken ‘Off’ only after ensuring that the track is clear, points are set and secured for the scheduled route on which train is to traverse, interlocked level crossing gates falling in the route of train including overlap are closed and locked for road traffic. This eventually means that a desired sequence of operation of points and signals is required to be ensured before the signal can be taken ‘Off’. This desired sequence of operation is achieved through interlocking of these equipment with each other through mechanical, electrical or electronics means. As per General Rule book 2007, clause 30, chapter- I, issued by Indian Railways , the interlocking is defined as “an arrangement of signals, points and other appliances , operated from a panel or lever frame, so interconnected by mechanical locking or electrical locking or both that their operation must take place in proper sequence to ensure safety”. The interlocking is defined in Railway Signalling published by B.S.I as number 719/1936 as “an electrical or mechanical means of making the operation of one piece of apparatus is dependent upon the operation of certain predetermined conditions being fulfilled by other apparatus”. With the advent of Solid State interlocking this stands modified to add ‘electronic’ to `electrical or mechanical’ in the above definition. The interlocking can therefore be understood as ‘an arrangement through which operation of points and signals in a pre determined sequence is ensured’. 7.1 The basic rules to be observed while designing interlocking which is predetermining sequence of operation of points, locks, closing of level crossings etc., have been given as essentials of interlocking in signal Engineering Manual 1988 part-I paragraph 7.82, as reproduced in following paragraph: 7.1.1 Essentials of interlocking: Lever frames and other apparatus provided for the operation and control of signals, points, etc., shall be so arranged as to comply with the following essentials (SEM part-1, 1988 clause 7.82) : i) It shall not be possible to take “ OFF’ a running signal, unless all points including

isolation are correctly set, all facing points are locked and all interlocked level crossings closed and locked against public road for the line on which the train will travel, including the overlap.

ii) After the signal has been taken ‘OFF’ it shall not be possible to move any points or lock on the route, including overlap and isolation, nor to release any interlocked gates until

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the signal is replaced to the ‘ON’ position. iii) It shall not be possible to take ‘OFF’ at the same time, any two fixed signals

which can lead to any conflicting movements. iv) Where feasible, points shall be so interlocked as to avoid any conflicting

movement.” It is very important to understand that it is the signal, which is taken ‘Off’ last, after ensuring essentials of interlocking, be it operated by a lever or taken ‘Off’ electrically/electronically, only when all points en-route have been set for the route on which train is intended to move, this should include overlap, all points falling in facing direction of the train are locked including points falling in overlap as if the train was to pass over these points as well, all level crossing gates which are interlocked with the signals and fall not only within the route but also in the overlap, have been closed to road traffic and locked, while at the same time no two signals should come ‘OFF’ simultaneously which may conflict route of the train. The signal being the last, it should always be possible to put it back to ‘On’ in case of emergency, without any hindrance, by lever in lever frame or by push button on panel. 7.2 Correspondence between operating and operated units: 7.2.1 All signals, points, Locks on points, Level crossing gates, inter-cabin slots, Block working system and any other equipment involved with the train movement are operated by levers in case of mechanical system, switches or buttons if it is electro mechanical or electrical system and buttons or a visual display unit (VDU) with a key board similar to computer system, if it is electronic system of operation and interlocking. These devices may be called operating devices. 7.2.2 On station interlocked to standard – III and above, the operating units are required to be grouped together in one place and interlocked. These operating devises transfer command to operate the signals, points, Locks on points, Level crossing gates, inter-cabin slots, Block working system and any other equipment involved with the train movement. These equipment may be called as operated units. A medium to carry command to these operated units is wire run for signals and rod, in case of points in mechanical system and a cable in case of electrical or electronic system of operation and interlocking. 7.2.3 Although all measures are taken to ensure that there is no failure of correspondence between a command given through operating unit and the operation of the equipment but in case of such a failure the outcome could be disastrous, as interlocking shall permit taking ‘Off’ of the concerned signal while at site the conditions shall not be conducive for passage of train. As such a process of correspondence check is inculcated in the system without which any amount of interlocking shall be of no avail. The devices for checking correspondence are Circuit Breakers (CB) attached to signal arms to check that the signal is ‘Off’ or ‘On’ in correspondence with the signal lever, a point detector is used to check if the point is set to normal or reverse and the lock plunger on the point has moved its full travel in correspondence to the lever operating it, in mechanical arrangement. In electrically operated equipment the signal aspect is checked for signal being lighted ‘On’ or ‘Off’ through lamp checking devices/relays similarly the setting of point operated by electric point machines to be normal or reverse and locked properly, is

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checked by electric detector inbuilt in the point machines, or in older version, associated with point machines. The method of achieving the system of correspondence check is dealt with in ensuing volumes-III & IV of the book. 7.3 Other ingredients of interlocking: 7.3.1 Route holding: In terms of second essentials of interlocking, as mentioned in preceding paragraph, after the signal has been taken ‘Off’ it shall not be possible to move any point or lock on the route, including overlap and isolation until the signal is replaced to the ‘On’ position. Route as mentioned here covers all points, locks and Level crossing gates on track, in between signal and the destination as well as the overlap that is the specified distance of 180 metres in case of two aspect signalling and 120 metres in case of multi aspect signalling, beyond the signal next to the signal for which route holding is considered here. This can be achieved either mechanically or electrically or a combination of both. When a train is approaching the station from a Block section and the Loco Pilot sees the signal approaching as ‘Off’, the route to which the signal leads should get locked and it shall not be possible to be disturbed. It is possible only when there is a track circuit available between the Sighting Board and the signal which when occupied shall detect arrival of the train within normal baking distance. It shall also not be possible to disturb the route even when the train has passed the signal and even it is replaced to ‘On’, till the train has reached its destination. 7.3.2 Approach Locking: Holding the route beyond the signal, to which it leads, while the train is approaching, is called ‘Approach Locking’. When the train is approaching a signal and the Loco Pilot has seen the signal ‘Off’, which means accepted the signal as ‘Off’, he shall get busy in taking action with reference to the aspect of signal. In case the aspect was green he shall further get relaxed and continue to move at optimum speed, but if the signal is ‘Off’ with Caution or attention aspect the Loco Pilot shall be further busy in controlling the speed of the train depending upon the aspect of the signal. By the time he gets relaxed he must have traversed considerable distance. During the intervening period at a speed of 60 KMPH he shall have traversed one KM in one minute which means if the Distant signal is at one KM from home he shall be almost crossing the home signal. Putting back the signal lever in order to change the route at the last moment when the Loco Pilot has accepted the ‘Off’ aspect, shall be extremely dangerous if the train encounters an unlocked or moving point under the wheels. The approach locking can be provided only when the track between the signal, being approached, and the sighting board, when the train is approaching the station from block section, is track circuited. Generally this is available only when Automatic Block signalling is provided in the adjoining block section where track circuits are available by default. However at stations provided with panel interlocking, entire yard is track circuited as such approach locking for all other signals in the yard is available except for Home signal and for Shunt signals provided on siding which are not track circuited to entire length of the siding.

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When a track circuit has been provided between the Sighting Board and the signal to which the Loco Pilot is approaching from the Block section, the route gets approach locked as soon as the track circuit is occupied by the approaching train. The route shall not be Approach locked till the train occupies the track circuit and in such situation it shall be possible to change the route. In such a situation the route shall be released immediately upon putting back the signal. After the Loco Pilot has accepted the signal, the route shall be released when the train reaches its destination, in normal course. See figure 7.3.3 in which the route has been shown as set for reception of train on loop line with destination as its berthing portion between the two opposite signals on the same line. 7.3.3 Dead Approach Locking: Approach locking is known as ‘Dead Approach locking’ when the signal, once taken ‘Off’, locks the route dead and the route can not be released upon putting the signal back to ‘On’ except after a lapse of 120 seconds after the signal is put back to ‘On’, since there is no means to hold the route such as a track circuit at a place where the Loco Pilot accepts the signal. As discussed in preceding paragraph, the Dead Approach Locking is required to be provided for routes of signals leading from non track circuited approach track, which usually are Home signals and Shunt signals.

DESTINATION

BOARDSIGHTING

ADVANCED STARTER STARTER

ROUTE

TRAIN

Overlap 120mts.

DISTANT HOME

STARTER

fig. 7.3.3

(Dead) Approach Locking 7.3.4 Ways and means to achieve Approach locking and Dead approach locking: (A) Through Mechanical means: The Approach or Dead Approach locking is achieved

manually, in case of operation of points & locks by levers in the lever frame, by keeping the lever of the Stop signal to which the Loco Pilot is approaching, in pulled position. The entire route ahead of the signal i.e. facing point locks, points and level crossing gates, falling in the route of signal remains locked by the signal lever in the interlocking frame, only up till the signal lever is kept in pulled position. As soon as the signal lever is put back to normal the entire interlocking ahead of signal gets free, but is kept locked by Back locking.

(B) Through track circuits: The Approach locking is achieved by providing the track

circuit between the sighting board and the concerned signal when the train is approaching from the Block section and for other signals which are preceded by track circuits in the yard. The maintenance of such a track circuit out side station section, is quite difficult and is more prone to interference from outsiders, as such is not very much used. However when the adjoining Block section is provided with Automatic Block signalling, the track circuit is available between the Home signal of the station and

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preceding Auto Block signal and as such is used for the purpose of Approach locking also. The route is kept held through selection circuits. However the route can be released even after the Loco Pilot has accepted the signal, by putting back the signal and ensuring that the train has come to a stop, after 120 second of action taken to release the route.

7.3.5 Back Locking: After the train has passed the signal, it is important to put back the signal to ‘On’ which in turn shall release entire route ahead, which was kept locked by the signal lever or approach locking circuits so far. When a track circuit is provided ahead of the signal, the signal is replaced back by occupation of the track circuit. In case of mechanical signal the reverser provided with the signal is released putting back the signal to `On’ and in case of colour light signal the signal is put back to ‘On’ by occupation of track circuit through selection circuits. Occupation of this track circuit also simultaneously initiates back locking circuits. (A) Back locking Mechanically: All facing points, trailing points and facing point locks

enroute get locked by the signal lever in interlocking trough provided with the lever frame and are kept locked till the signal lever is put back to normal. In cases where the signal is put back to `On’ by occupation of signal replacement track circuit, by the train, provided just ahead of the signal, the operator is at liberty to put back the signal lever, unlock the point and operate it while the train is still traversing the route, be it reverser controlled semaphore signal or multiple aspect colour light signal. As such under such a situation (i) the signal should be placed as close to the corresponding first facing point as possible, (ii) In case the signal is more than 180 metres from the corresponding facing point, a holding bar shall be provided in such a way that the distance between the signal and holding bar and between point and holding bar does not exceed 180 metres. It must further be ensured that the if next facing point lock bars on the route of the train are not within 180 metres from the centre of the immediately preceding lock bars, a holding bar is inserted in between the two such points such that the distance of the holding bar is not more than 180 metres from the adjoining facing point lock bar on either side under any circumstances. These lock bars and holding bars are interlocked in such a way that first lock bar or holding bar which ever the train shall encounter first after passing the signal shall keep all the lock bars and holding bars in the route of train held till the last lock bar is released by train thereby holding all points enroute.

At stations where trains are allowed to run through at an speed of more than 50 KMPH, the trailing points should also be held by providing fouling bars along with chain of holding bars if the distance between such a trailing point and signal controlling the same is more than 180 Metres, as described above, such that the distance between successive holding bars does never exceed 180 metres. The provision of Lock bar, holding bar or fouling bar can be substituted by track circuits as the situation may warrant which some times occurs due to non-availability of adequate space to accommodate a full length lock/ holding bar, between points.

(B) Back Locking by Electrical Means: (Fig 7.3.5) In the same analogy as mechanical interlocking where levers controlling points and lock bars are held by signal lever through interlocking in the lever frame and by lock bars and holding bars at site, ‘Back

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Locking’ is achieved through selection circuits electrically. It is easy as well as more effective to hold the route by track circuiting in the entire yard, as the points in the route

STARTERSTARTER

Overlap 120mts.

DESTINATION

ROUTESIGHTING

ADVANCED STARTER

TRAIN

HOMEDISTANTBOARD

fig. 7.3.5

Back Locking ahead of train, are kept locked continuously till the train keeps the track circuits occupied. Providing the entire yard with track circuits is not always economically viable unless the station is provided with panel/ relay interlocking, where track circuiting the entire yard it is an essential requirement.

Method of achieving route holding electrically shall be discussed in details while dealing with selection circuits in ensuing volume IV of the book.

7.3.6 Track Locking: It is holding the points locked while it is under the wheels of a train. Mechanically it is done by attaching a lock bar to the facing point lock. The length of the lock bar is kept as such to cover the maximum distance between the two successive wheel bases of any vehicle. The length of lock bar is accordingly kept to be 42 feet. The lock bar attached with the facing point lock plunger moves to-and-fro along with the plunger through a radial guide, due to which the lock bar has to lift upto rail top level. The unlocking movement of the plunger is not possible if a wheel is over the lock bar as the flange of the wheel shall not allow the lock bar to be lifted to the level of rail top. Electrically, the track locking is also provided through track circuits in the entire point zone. The occupation of the track circuit detects presence of a train over the point zone, which keeps the point locked through selection circuits. 7.3.7 Check Locking and Indication Locking: When points are operated by lever in cabin and electric point machine at site, a lever lock is provided on the point operating lever for the purpose of track locking. The lever can be moved if i) it is not locked in the lever frame, interlocked by any other lever, ii) if it is free, it shall be possible to move the lever to the extent, upto which it does not actuate point operating circuit which is point beyond which it shall not move if the point zone track is occupied and the lever lock, locks the further movement of the lever, iii) the lever shall move further if lever lock is free, it shall then initiate point operating circuit from normal to reverse if the lever is moving normal to reverse or vice-versa, iv) it shall not be possible to set the lever to final normal or reverse position unless the point has physically moved to the position corresponding to the lever position in the lever frame. Holding the lever in its initial stage when the point is track locked is ‘check Locking’ and holding the lever while the point is being set, till it is set is ‘Indication Locking’. This is another

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example of checking correspondence between operating and operated equipment. 7.3.8 Sectional route release: In yards where more than one cabins have to be provided, the train movement takes place with close coordination between cabins associated with the given train movement. This coordination is implemented through inter-cabin slotting. In railway signalling language a ‘Slot’ is the permission given by any of the agency controlling train movement to another agency distantly placed associated with the other one. If there are two cabins one cabin has to ascertain fulfilment of all conditions for the movement of the train in the area under his control and the other cabin has to do the same for his area. The movement of the train can take place only when the entire relevant area of the station fulfils all conditions. To ensure this the leading cabin has to communicate to the other cabin, through electrical or mechanical means about fulfilment of all conditions. This communication is giving `Slot’. In this case as soon the train passes through the cabin at the receiving end, another train movement not affecting the area of the other cabin such as shunting, or departure of train etc can be done, thereby saving time. On bigger stations where more than two cabins are required the inter cabin slotting at one hand delays the train movement while at the other hand is useful in releasing the area of one cabin as soon as the train clears the area of the cabin concerned, thereby allowing other movements to take place thereby saving time. This release of route of the area of the cabin freeing it for use for another movement is ‘Sectional Route Release’. This arrangement is better utilised in bigger yards provided with Central panel, end cabin panel and Route Relay Interlocking. This concept of sectional rout release is used best in case of Centrally Operated Panel or Route Relay Interlocked stations eliminating totally the disadvantages of loss of time due to multi cabin Slotting. 7.3.9 Locking of last trailing point by the Last Stop Signal: In situation when a small train such as a light engine or tower wagon stops at the foot of Last Stop Signal, it shall not be possible to change the route and move a train from another line upon the same line clear. To avoid such a situation the last stop signal keeps the last trailing point or more trailing points locked, which can cause the route to be changed for movement from other line. This can create highly unsafe situation if the track between Starter and Advanced starter signal is not track circuited. 7.3.10 Monitoring devices: Monitoring devices are used for two basic purposes one being to monitor correspondence between operating devices and the operated equipment and secondly to monitor status of the yard such as clearance or occupation of tracks, status of level crossing gates, closed or open, under the control of the Satiation Master, flank protection (fouling of adjoining track by a train standing within fouling mark) and alertness of Loco Pilot checked through Automatic Warning system. (A) Devices to monitor correspondence between operating devices and operated

equipment: Any amount of Interlocking shall be infructuous if the correspondence

41

between the operating units which are levers, switches, buttons or the key board of operating system of Solid State Interlocking and the operated equipment which are points, point locks and signals is not established.

i) Point and lock detectors are used to monitor setting of points for its correct housing

with the stock rail, setting for normal or reverse as the case may be and locking of the point with full travel of the lock plunger.

ii) To monitor the status of signals, the status of signal arm is checked by a circuit breaker attached to the arm in case of semaphore signals and by lamp checking relays in case of colour light signals.

(B) Devices to monitor status of the yard & systems: The interlocking between the

signals and points is established once correspondence between the operating devices such as levers and buttons and operated equipment such as points and signals is also established. However safe movement of the train can take place only when the line on which the train is to be received is also checked for clearance and not fouling with any other train standing on adjoining line, level crossing gates falling in the route of the train which are interlocked are closed and locked against road traffic etc. It is also important to monitor the integrity of the cable which is the media for transfer of commands from the operating levers or panels and transferring status of the field such as correct setting of points, aspect correspondence of signals, closure of level crossing gates etc.

i) Monitoring clearance of the track: The devices used for checking clearance of

track are A) Track Circuits. Different type of track circuits are used out of which most

commonly used are a) Direct Current (DC) Track circuit, b) Alternating Current (AC) track circuits, c) Uneven Impulse (Jeomont) track circuit, d) Audi Frequency Track Circuit (AFTC)

B) Axle counters (A/C): These devices are used depending upon specific requirement. Track circuits shall be discussed in ensuing volume-IV of the book.

ii) Flank Protection: The other area of safety which is required to be monitored by the

system is protection against side collisions. Two railway lines running parallel to each other are kept at a specified minimum distance between them. If the given distance between the two tracks is reduced, the trains running on such tracks shall infringe with each other and shall result in side collision. Whenever two tracks join each other through a turnout or crossover, the two tracks infringe each other till the distance between the two is arrived at safe range. The spot at which the two tracks become unsafe is known as fouling mark. The protection for trains on account of the infringement of tracks is called flank protection. When the flank protection is achieved through track circuits, the track circuits are so designed that unless the train stands clear of the track circuit, it shall not be possible to permit the train movement on such track (Fig 7.3.10(B-I). In yard where point zone is not track circuited the flank protection is achieved by using fouling or clearance bars. A, 42 feet uneven angled MS bar known as fouling bar or clearance bar depending its

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place of usage, is coupled with point in such a way that it shall not be possible to operate the point till the Fouling or the Clearance bar is kept pressed under the wheel. The point for the adjoining line can be set only when the fouling or clearance bar is cleared by the train entering the berthing part of the track. Fig 7.3.10(B-II).

The fouling bar is linked with the trailing point in such a way that the point can not be operated from its last operated position unless the last train received on main line clears it. Similarly the clearance bar is attached to the trailing point in such a way that it shall not be possible to operate the point unless the last rain received on loop line clears the bar.

circuited areaFouling Mark

Track

Fouling Mark

{

Fouling bar

Clearance bar

Fig 7.3.10 (B-I) Flank protection by track circuit

Fig 7.3.10 (B-II) Flank protection by clearance and fouling bars

iii) Level crossing gates:

A) Level crossing gate operated from the same cabin where the lever frame is situated: The closure of level crossing gate is monitored by directly transferring the key provided on the winch of the gate to the lock provided on Gate locking lever in the lever frame.

B) Level crossing gate operated from the Gate Lodge provided near the

gate: A ground lever frame is provided near the gate lodge for locking the Boom of the gate. After the gate is closed and the boom is locked by pulling the lever in the ground lever frame, the key is extracted from the `E’ type lock provided on lock lever, thereby holding the gate & boom by the lock lever in reverse position, and inserted into a rotary key transmitter. The key is released from the corresponding rotary key transmitter at the cabin where the lever frame is placed or the panel room and applied to the gate lock lever in lever frame or into the 2.5” stroke ‘Lever Lock’ in the Panel Room which when operated shall make contact to prove through selection circuits that the key has been received back after locking of the gate at site In case of swing gates the key released from the gate leaves after locking of the gate is interlocked with the lever frame or panel in the same way as in case of lifting barrier gates. The Lever Lock: mentioned here is a device equipped with ‘E’ type lock, when key is applied & rotated in the ‘E’ type lock, its plunger makes 2.5” movement, which is turn operates a circuit Breaker making or breaking

43

contacts to detect presence or absence of key in the ‘E’ type lock, while at the same time the key gets locked with the ‘E’ type lock.

iv) Status of cables: Under electrical system of signalling, the operation of points, colour light signals, detection of points, status of track circuits, proving of closing and locking of gates or any other function, is based on the integrity of the cables laid between the controlling cabin or Station Master’s room to the functions such as points, signals etc. In case of the cable cut, the entire communication between signals pints gates etc is lost and nothing much can be done to avoid such a situation, while damage to the cable which usually results in seepage of water inside cable jacket or damage to cable core insulation shall result in shorting/earthing of cable conductors, which in turn may lead to extending false feed to the relay or signal lighting, creating unsafe situation. The Earth Leak Detector (ELD) is therefore used for continuous monitoring health of the cable. Usually spare conductors of the cable are connected to ELD which in turn detects loss of insulation of the conductors with respect to earth.

7.4 Isolation: When trains move on the track the Loco Pilot has no liberty to steer away his train to protect it from a train which may be fouling its path. To ensure that the moving train does not make a side collision, the junction of crossovers/ turnouts are marked at the position where two tracks come so close so as to foul the adjoining track and may result in side collision. These marks are known as fouling marks. The trains are supposed to stand having cleared these fouling marks after negotiating the crossover or turnout, before a movement to other train is permitted on the same track for a different route so that the other train does not make a side collision. To avoid this to happen the conflicting junctions are required to be Isolated. This is called as isolation. With reference to Indian Railways, Isolation means an arrangement, secured

Trap Point

Fouling Mark

Fig. 7.4 Isolation by trap point

by setting of points or other approved means to protect the line so isolated from the danger of obstruction from other concerned line or lines. [GR1.01 (32)]. On interlocked stations the isolation is ensured through various means as provided in Signal Engineering manual detailed as follows:

7.4.1 Isolation where to be provided: i) At Block station where trains are permitted to run at speeds in excess of 50 Kilometre

per hour, the line on which the speed is permitted shall be isolated from all connected lines during the passage of the train.

ii) The isolation shall not be required to be provided on block stations on which speed permitted is 50 Kilometre per hour or less provided all shunting has been stopped and no vehicle which is not attached to an engine or not properly secured by the Station Master in accordance with approved special instructions, has been kept standing on a connected line which is not isolated from the through line.

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7.4.2 Means of Isolation: The isolation is achieved through one of the following means: [SEM 1988 Para: 7.72 ]

i) Sand hump, trap points or any other approved means of isolation shall be provided on all goods lines and sidings at their junctions with passenger lines, the normal setting being such as to prevent the passenger lines from being fouled.

ii) On interlocked stations the means of isolation shall be interlocked. iii) In order to maintain safety the trap points shall not be inserted on main or run through

lines. iv) However an exception be allowed under approved special instructions in case where

owing to grades in or near stations it is necessary to prevent i) trains being brought to stand at a Stop Signal on a rising grade or ii) vehicles running away from the station.

v) Also an exception may be allowed under approved special instructions, where it is considered necessary in the interest of working to receive trains from opposite direction simultaneously.

vi) At stations where trap sidings are inserted on main lines, through running of the trains shall be permitted only under approved special instructions.

7.5 Overlap: On Indian railways system of working, a pre determined distance beyond the next stop signal is required to be kept clear before taking ‘Off’ any signal, to maintain safety in case the train gets out of control and overshoots beyond the next signal to which the train is approaching. This adequate distance is called overlap. In case of signal to be taken ‘Off’ is within station section the overlap to be kept clear ahead on next signal on the same station is called signal overlap and if the train is leaving the last stop signal of station to approach the first stop signal of the station in advance, the overlap to be kept clear beyond first stop signal at the next station is called Block overlap. The adequate distance for Signal overlap and the Block overlap are different in case of two aspect signalling section and multiple aspect signalling section as follows: 7.5.1 Signal overlap: In case of two aspect signalling territory, Signal Overlap shall be 180 metres, while in case of Multiple Aspect signalling territory it shall be 120 metres. 7.5.2 Block overlap: In case of two aspect signalling territory Block Overlap shall be 400 metres, while in case of Multiple Aspect signalling territory it shall be 180 metres. 8. Block Working: The definition of the station as given in the General rules [GR 1.02(51)] reads that: ‘any place on a line of railway at which traffic is dealt with or at which an authority to proceed is given under the system of working’. Under the chapter of systems of working it is prescribed that The Absolute Block and Automatic Block system alone shall be used on every railway, except on any railway or portion of railway on which the use of any other system of working, as mentioned in the GR, may be sanctioned under special instructions. On sections where Absolute Block system of working is in use, an authority to proceed is required to be given to the Loco Pilot for leaving the station. The stations on either end of the block section are called Block Stations. In this system of working only one train is allowed to be in the block section at one time. The second train is allowed to leave the station only when the

45

first train has reached the next station and all conditions to grant line clear to the following train have been fulfilled. The authority to leave the Block Station can only be given by stopping every train at the station which is an impractical proposition. Uninterrupted running of trains between two Block stations is mechanised and regulated by any one or combination of the following means: 8.1 Electrical Block Instruments of Token or Token-less type: On double line section, only token-less type of block instruments are used. On single line section Token less or Token block instruments are used. Complete arrival of the train i.e. Last vehicle check is required t o be done manually with the use of these Block Instruments. 8.2 Track circuits: Continuous track circuits covering the entire Block section is one of the best methods of Block working as it automatically covers the complete arrival of train. There being a restriction of 350 metres length of Direct Current (DC) track circuits on PRC sleepers, the maintenance of huge number of track circuits on lengthy Block sections, is quite difficult. As such this method of Block Working is used on smaller block sections ranging between 1to2 km. only. However with the introduction of lengthier Audio Frequency Track Circuits (AFTC), with an added advantage of joint less track circuiting, are being used on important routes with longer block sections also. 8.3 Axle counters: Axle counters are one of the electronics alternatives to DC track circuit or AFTC. The use of Axle counters also covers the complete arrival of trains. This system is known as Block Proving by Axle Counters. 8.4 Electrical Communication Instruments: In case of failure of Block instruments, the Line clear can also be obtained through telephones attached with the Block instruments, station to station fixed telephones and other fixed telephones such as Railway Auto phones & BSNL phones, control phones or VHF sets. However the last stop signal, which is interlocked with the line clear, shall not be possible to be taken ‘Off”, the train shall have to be brought to stop for issue of ‘Authority to Proceed’ before permitting it to leave the station. 9. Sidings: To cater for situations where an axle of any wagon or coach of the train becomes hot or for any other reason it is not possible to carryon the train with the vehicle and the vehicle is required to be detached from the train and kept at the intermediate station, short sidings are provided with a trap in the form of a derailing Switch at such stations. Sidings are also provided on stations to facilitate shunting or private sidings taking ‘Off’ from the station to the premises of factory, oil depot etc or to meet with other safety requirements. These sidings are broadly classified in two groups: 9.1 Trap siding: For stabling of vehicles or leading to private sidings provided with trap to safeguard against unauthorised or unwanted escaping of vehicle so as not foul the running line. Such sidings are termed as trap sidings. 9.2 Catch siding and Slip siding: On hilly area where railway track is having steep gradients, the failure of brake of the train or detachment of a vehicle from the running train can lead to rolling of the train or detached vehicle to the adjoining station placed on lower level and

46

hit a train /vehicle standing there. To safe guard against such a situation, at a station where there is a gradient of 1 in 80 falling towards the station or 1 in 100 falling away from the station within 45 metres beyond the outermost points at either end, a catch siding in case of 1 in 80 falling towards the station and a slip siding in case of 1 in 100 away from the station should be provided. As the names suggest a Slip siding is meant to take care of a vehicle slipping away from the station preventing its entry into the block section and a catch siding is meant to take care of a vehicle rolling from the block section to enter into the catch siding instead of entering into the station section. Normally the spring loaded points are kept set for Catch or Slip siding and are set and locked for reception or despatch of a train whenever a train movement is to take place The track for these sidings is laid gradually increasing to a gradient upper than the station, of sufficient length so as to stop the lose vehicle or train of itself due to gravitational forces, without damage. 10. Level Crossing Gates: A road crossing the railway track at the same level as the track has to be protected by a gate. These gates are known as Level Crossing Gates. The level crossing gates may be manned or unmanned. Here only manned level crossing gates are discussed. The level crossing gates may fall within the Station Section, station limits or Block section. 10.1 Classification based on TVUs: The gates are classified as `Special‘class, `A’ class, `B’ class and `C’ class. The classification of the gates is done in consultation with road authorities, on the basis of class of the road, visibility conditions, volume of road traffic across the gate and number of trains passing over the level crossing. These details are prepared based on census done for one week. The census is done at least once in five years and the classification of the gate is revised based on such census, if required. All such criteria are converted into `Train Vehicle Unit’ (TVU) taking train, motor vehicles, bullock carts and tongas as one unit and cycle rikshaw/auto rikshaw as ½ unit. Number of these units for the gates decides the classification of the gate as tabulated below: [IR P Way Manual Para 919] SN Class of the level crossing Criteria 1. `Special’ class TVUs > 50,000 2. `A’ class TVUs between 30,000 and 50,000. 3. `B’ class TVUs > 20,000 4. `C’ class All other level crossings not covered above

10.2 Classification based on management of the level crossing gates: All level crossing gates falling within station limits are managed by the Operating department and are called as Operating gates. The gates falling in the block section are managed by Engineering department and are called as Engineering gates. The management of the gate includes provision of staff, equipment and Accessories. The gates which are interlocked and provided with Lifting Barriers are maintained by S&T department, while all types of the gates which are non-interlocked and

47

interlocked gates provided with swing leaves are maintained by Engineering department. The interlocking part of swing gates is managed by S&T department. 10.3 Interlocking of level crossing gates (Railway Board’s Circular number 2000/Sig/LX/

2/Pt. Dated 5.5.2003): 10.3.1 Interlocking of `Special’ & `A’ class level crossing gates:

A) Within Station Limits: All Special’ & `A’ class level crossing Gates, falling within station Limits are required to be:

i) Interlocked, ii) Where the level crossing gate is operated from a place other than place of operation

of the signal protecting the gate, arrangement of interlocking should be such that the last operation before taking the signal ‘Off’ should be closing of the gate and first operation after the train has cleared the gate and the signal has been put back to `On’, should be opening of the gate by the gateman.

iii) Normally open to road traffic, iv) Provided with lifting barriers, v) Provided with telephone communication with ASM’s office. B) Out side station Limits: All Special’ & `A’ class level crossing Gates, falling out

side station Limits are required to be: i) Interlocked, ii) Warning Bell operated by the approach of train shall be provided on `Special ‘ class

gates. However in case of `A’ class gates warning bell shall be provided on suburban or Automatic Block signalling sections while at other sections individual railways my provided this facility as and where considered desirable,

iii) Normally open to road traffic, iv) Provided with lifting barriers, v) Provided with telephone communication with ASM’s of the adjoining station.

10.3.2 Interlocking of ‘B’ class level crossing gates:

A) Within Station Limits: All `B’ class level crossing Gates, falling within station Limits are required to be:

i) In suburban section, Interlocked, ii) In non suburban section where the gates are operated by cabin staff of cabins

adjoining the level crossing gate, the level crossing gate should be interlocked with the station signals,

iii) Normally closed to road traffic, iv) Provided with lifting barriers, v) Provided with telephone communication with ASM’s office. B) Outside Station Limits: All `B’ class level crossing Gates, falling out side station

Limits on sections other than Automatic Block Signalling are required to be: i) In suburban section, Interlocked, ii) Normally closed to road traffic, iii) Provided with lifting barriers,

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iv) Provided with telephone communication with ASM’s of adjoining station on Rajdhani Express routs and on suburban sections. On other routes such communication shall be provided at those level crossing gates which are situated on curves obstructing the view of the level crossing from the approaching train or vice versa.

10.3.3 Interlocking of ‘C’ class level crossing gates: A Within Station Limits: All `C’ class level crossing Gates, falling within station

Limits are required to be: i) Where the gates are operated by cabin staff of cabins adjoining the level crossing

gate, the level crossing gate should be interlocked with the station signals, ii) Normally closed to road traffic, iii) Provided with telephone communication with ASM’s office. B Outside Station Limits: All `C’ class level crossing Gates, falling out side station

Limits on sections other than Automatic Block Signalling, are required to be: i) Action shall be taken to upgrade such Level crossing gates on suburban section to

upgrade them to `Special’ or `A’ class. Till the gates are upgraded, provisions of ‘Special’/’A’ Class gates shall be made. If these gates do not qualify for up gradation to `Special’ or `A’ class based on TVUs, these may be considered for up gradation to `B’ class and provisions of `B’ class gates shall be done.

ii) Normally closed to road traffic, iii) Provided with telephone communication with ASM of adjoining station on Rajdhani

Express routs and on suburban sections. On other routes such communication shall be provided at those level crossing gates which are situated on curves obstructing the view of the level crossing from the approaching train or vice-versa.

10.4 Level crossing gates falling in the section provided with Automatic Block

signalling: All level crossing gates falling in the Automatic Block signalling section shall be: i) Interlocked irrespective of its class, ii) Provided with warning bell operated by approaching trains, iii) Approach locked.

11. Schedule of Dimensions (SOD): Signalling equipment are provided indoors and outdoors both. Outdoor equipment are installed by the side of the track preferably as near as possible such as signal posts, point machines and track lead junction boxes; In between two rails viz. facing point locks, Automatic Warning System (AWS) equipment; Equipment attached to track viz. lock bars, holding bars, Axle counter transducers; And some systems superimposed on the rails such as DC track circuits, AC track circuits, Audio frequency track circuits, Jeomont track circuits etc. To ensure that these equipment do not infringe with the moving train, a Schedule of Dimensions is issued by the Railway Board. The gauge of the track is measured between inner faces of both rails forming the track. There are three gauges of track in prevalent on Indian railways, the Broad gauge 1676 mm (5 feet.6 inches), Metre gauge (3 feet 3.3 inches) and narrow gauge 610 mm (2 feet 0 inch) besides tracks on hilly terrain with special gauge.

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The schedule of dimensions was issued by Railway Board in 1922 in Foot Pound Second (FPS). These schedules of dimensions were in two parts one was schedule of maximum and minimum dimensions and other was schedule of recommended dimensions. In 1926 Railway Board gave directions that schedule of recommended dimensions shall be followed in all future works and alteration to new works. These orders were modified on 26th April 1926 allowing relaxation in case of certain recommended dimensions which involved heavy expenditure in remodelling work. Major changes were done in schedule of dimensions issued in 1939 and there have been reprints thereafter. The SOD is therefore is known as SOD 1939. With the change in measurement scale system from (FPS) to Metre Kilogram Second (MKS), the gauges of the track were also converted to MKS in1964. The Schedule of Dimensions 1973 version was based on requirement of 25KV AC traction and all future works were to be carried out to these dimensions except in cases where it was considered that there was no chance of the line being subsequently converted to 25 KV AC traction. The present Schedule of Dimensions (Revised, 2004) is revised version of Schedule of Dimensions 1939 reprinted in 1973. This schedule is only metric units. In this only two schedules have been kept. Schedule-I consists of those items which are mandatory and have to be observed on all 1676mm Gauge railways in India. It is mandatory and contains the items of schedule –I & certain selected items of Schedule-II of 1973 version. Schedule-II consists of items included in Schedule-III of 1973 version. These items contain the infringements to dimensions prescribed in Schedule-I, which may, subject to restrictions of speed as considered necessary, be permitted on existing railways with the understanding that when structures are altered they will be rebuilt to comply with Schedule-I, except in case of dimensions of `building and structures, chapter -I, `General’ of Schedule of dimensions 1676mm Gauge (revised 2004), Item A, 2 of the table given below. Dimensions under Schedule-II have not been dealt with here. It is important to note that the dimensions show minimum clearance from the track centre as such are measured between track centre and outermost edge of the equipment being installed. The dimensions are applicable to fixed structures only. The schedule of dimensions for broad gauge 1676 mm (5 ft.6 in. Gauge) track (BG) are tabulated below: SN Equipment Existing

works New works

A Dimensions in General 1 Spacing of Tracks Minimum distance between centre to centre of tracks 4265mm 5300mm 2. Building & structures: 2.1 Minimum horizontal distance from centre of track to any

1675mm 1905mm

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structure from rail level upto 305mm above rail level 2.2 Minimum horizontal distance from centre of track to any

structure except a platform

i) From 305mm above rail level to 4420mm above rail level 2135mm ii) From 305mm above rail level to 1065mm above rail level - - 1905mm

increasing to 2360mm

iii) From 1065 mm above rail level to 3355mm above rail level

- - 2360 mm

iv) From 3355 mm above rail level to 4420mm above rail level

- - 2360 mm decreasing to 2135mm

v) From 4420 mm above rail level to 5870mm above rail level

- - 2135mm decreasing to 915mm

vi) Below the rail level up to the formation level of the track on straight and curves upto radius of 875m

- - 2575mm

vii) Below the rail level up to the formation level of the track on straight and curves with radius less than 875m

- - 2725mm

Note: 1. With reference to spacing of tracks new /additional works cover laying of new lines

and new running loops. Extension of existing line or replacement of points & crossings will not be treated as new work.

2. Under item number 2.1 &2.2 as above, any material stacked by the side of line is to be considered a structure in the sense in which the word is used here. These items also apply to projections of rock etc., from the side of cutting.

3. Light structures such as ladders, thin posts etc erected along side the track at a distance of less than 2360mm from centre of the adjacent track should be blanked off to a height of 300mm between 2060mm and 2360mm above rail level.

4. Required clearances as mentioned in items vi) & vii) above, will be applicable in case of new lines/doubling/electrification.

5. Various fixtures which are attached to the track like traction bonds etc. and are required to be fitted with the rail can be provided and the clearance as mentioned in items vi) & vii) above will not be applicable to these fixtures.

6. Item 2.2 is applicable for the structures out side station yards. 3. Minimum horizontal distance of any telegraph post

measured from the centre and right angles to the nearest track.

The height of the post plus 2315mm

The height of the post plus 2360mm

Note: When the line is cutting a telegraph post erected outside the cutting, must be at a distance from the edge of the cutting not less than the total height of the post.

4 Interlocking and signal gear: Maximum height above rail level of any part of

interlocking or signal gear for a width of 1600mm or 1830mm in case of tunnels, through and semi-through

64mm - -

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girder bridges on either side of centre of track subject to the restriction embodied in the note (a) below:

Note: (a) For distance of 229mm outside and 140mm inside the gauge faces of the rail, no

gear or track fittings must project above rail level except such parts as are required to be actuated by the wheels or wing rails and point rails of special crossing leading to snag dead ends or elevated ends or elevated check rails of crossing or check rails/check flats of diamond crossings.

(b) Signal wires or supports for signal wires may be allowed at not less than 1600mm or 1830mm in the case of tunnels or through or semi through girder bridges on either side of the centre of track provided that they are not more than 203mm above rail level.

(c) Metal covers with ramps on both sides must be provided over all interlocking gear projecting above rail level between the rails of a track to prevent hanging couplings from damaging the gear.

B Tunnels, through & semi through girder bridges: 1 Track centre Minimum distance between centre to centre of tracks 4495mm 4725mm 2 Minimum horizontal distance from centre of track to any structure shall be as follows: (a) Height above rail level from 0.0mm to 305mm 1905mm - - (b) Height above rail level from 305mm to 1065mm 1905mm

increasing to 2360mm

- -

(c) Height above rail level from 1065mm to 3355mm 2360mm - - (d) Height above rail level from 3355mm to 4420mm 2360mm

increasing to 2135mm

- -

(e) Height above rail level from 4420mm to 5870mm* 2135mm decreasing to 915mm

- -

*Where D.C. electric traction is in use height above rail level from 4420mm to 5410mm shall be

2135mm decreasing to 915mm

- -

C Station yards Station limits, as defined under GR1.02 (52) shall be taken into consideration for the

purpose of station yard. 1 Spacing of Tracks Minimum distance between centre to centre of tracks 4265mm 5300mm New /additional works cover laying of new lines. Extension of existing line or

replacement of points & crossings will not be treated as new work 2 Maximum gradient in station yards unless special

safety devices are adopted and/or special rules enforced to prevent accidents in accordance with approved special instructions.

1 in 400 1 in 1200

a) It may not be possible to provided yard gradients of 1 in 1200 while executing works in connection with gauge conversion, doubling and new crossing station etc. Railway

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should, however make effort to provide grades as flat as possible in the station yards but not steeper than 1 in 400. In case gradient steeper than 1 in 400 are required to be provided in exceptional cases, condonation for the same should be obtained from Railway Board

b) For the purpose of above rule a station yard shall be taken to extend: i) On single line to a distance of 50 meters beyond outermost points at either end of the

station. ii) On double line where two aspect signalling is provided, from Home signal to a

distance of 50 meters beyond outermost facing points at the trailing end, or where there are no lops, to the last stop signal of each line.

iii) On double line where multiple aspect signalling is provided, to a distance 50 meters beyond outermost points at either end of the station or where there are no loops, from Block Section Limit Board to last stop signal of each line.

c) No siding should join a passenger line on a steeper grade than 1 in 260, except where it is unavoidable and then only with the previous sanction of the Railway Board obtained through Commissioner of Railway Safety when slip siding or any other arrangement is made sufficient to prevent accidents.

d) Except in Hump or Gravity yards or provisions of adjustment of super-elevation in item 22 of chapter –II of Schedule of Dimensions revised 2004, there must be no change of grades within 30 meters of any points or crossings.

e) At stations with grades steeper than 1 in 400 beyond 45m (150 ft) of outermost points, trains should not be drawn upto last stop signal and held up on steep gradient in order to clear the reception line for giving permission to the following train.

No shunting beyond outermost points on the steep gradient side should be allowed unless a locomotive is attached at the lower end of the lead from the point of view of gradients

f) This item does not apply to flag or Halt stations. Building and structures 1 Minimum horizontal distance of any building on a passenger platform from centre

line of track: i) From platform level to 305mm above rail level 5180mm

increasing to 5330mm

- -

ii) From 305mm above platform level to 3430mm above 3430mm above rail level

5330mm - -

iii) From 3430mm above platform level to 4115mm above rail level

5330mm decreasing uniformly to 3810mm

- -

iv) From 3430mm above platform level to 4610mm above rail level

- - 5330mm decreasing uniformly to 3810mm

2. Minimum horizontal distance of any building or longi- tudinal boundary fence from the face of the platform

5485mm 10210mm

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coping of passenger platform which is not on island platform (for new works or alteration to existing work)

Note: This also shall apply o buildings and isolated structures not readily removable, erected on ground over which it is anticipated that a platform may be extended in future.

3. Minimum horizontal distance from centre line of track to pillar, column, lamp or similar isolated structure on a passenger platform or any building on a goods platform.

i) From platform level to 305mm above platform level 4570mm increasing uniformly to 4720mm

- -

ii) From 305mm above platform level to 3705mm above rail level

4720mm - -

iii) From 3705mm above rail level to 4115mm above rail level

4720mm decreasing uniformly to 3810mm

- -

iv) From 3705mm above rail level to 4610mm above rail level

- - 4720mm decreasing uniformly to 3810mm

4. Minimum horizontal distance from centre line of track to pillar, column, lamp or similar isolated structure on a goods platform.

i) From platform level to 305mm above platform level 39600mm increasing uniformly to 4110mm

- -

ii) From 305mm above platform level to 4310mm above rail level

4110mm - -

iii) From 3980mm above rail level to 4115mm above rail level

4110mm decreasing uniformly to 3810mm

- -

iv) From 3980mm above rail level to 4610mm above rail level

- - 4720mm decreasing uniformly to 3810mm

Note: A pillar or column, with reference to item numbers 3 & 4 above, which covers more than 3716sq.cm. in plan, must be classed as `building’ and not as an `isolated structure’.

5. Minimum horizontal distance from centre of track to any structure:

i) From rail level to 305mm above rail level 1675mm 1905mm ii) From 305mm above rail level to 1065mm above rail level - - 1905mm

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increasing to2360mm

iii) From 1065mm above rail level to 3355mm - - 2360mm iv) From 305mm above rail level to 3355mm above rail level 2135mm v) From 3355mm above rail level to 4115mm above rail

level 2135mm decreasing to 1980mm

- -

vi) From 4115mm above rail level to 6250mm above rail level on main line

1600mm - -

vii) From 3355mm above rail level to 4420mm above rail level

- - 2360mm decreasing to 135mm

viii From 4420mm above rail level to 4610mm above rail level

- - 2315mm decreasing to 1980mm

ix) From 4160mm above rail level to 6250mm above rail level

- - 1600mm

x) Below rail level upto the formation level of the track on curves with radius less than 875mm

2725mm - -

6. Minimum clearance between toe of open switch and stock rail

95mm 115mm

7. Minimum length of train protection, point locking or fouling treadle bar.

12800mm - -

Note: This includes lock bar, fouling bar and holding bar. 8. Dimensions of carriage and wagons i) Minimum projection for flange of new tyre , measured

from tread at 63.5mm from wheel gauge face 28.5mm - -

ii) Minimum projection for flange of worn out tyre , measured from tread at 63.5mm from wheel gauge face

35.0mm - -

iii) Maximum thickness of flange of tyre, measured from wheel gauge face at 13mm from outer edge of the flange.

28.5mm - -

iv) Minimum thickness of flange of tyre, measured from wheel gauge face at 13mm from outer edge of the flange.

16.0mm - -

v) Maximum distance apart between any two adjacent axles. 12345mm - - 9. Dimensions of Loco motives: Thickness of tyre flange measured at 13mm from edge of the flange i) Thick flange 32mm - - ii) Standard flange 28mm - - iii) Thin flange 18mm - - 10 DC traction- Minimum distance between live conductor

wire and any structure 130mm - -

11 25KV AC traction- minimum vertical distance between any live bare conductor (overhead equipment or pantograph) and any earthed structure or any other bodies (rolling stock, over bridges, signal gantries)

i) When conductor is at rest 320mm - -

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ii) When conductor is not at rest 270mm - - Note: For extra clearances on curves appendices to Indian Railways Schedule of

Dimensions 1676mm gauge (BG) 2004 shall be refereed to. Split stretcher bars connecting the tongue rails for keeping the points locked, while passage of train, when hit by hanging coupling, disturb the adjustment and when broken having hit hard leave the point unlocked. As such, even though the entire arrangement does not protrude above rail level, it is safe to provide the cover with ramps on both sides.

*****

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Chapeter II Self Assessment

1. Multiple Choice Questions: 1 Approved special instructions are approved

by: a) Commissioner of Railway Safety* b) Authorised officer c) Any one of them d) None of them

2 As per SOD recommended placement of signal post from centre of track is(mm): a) 1905 b) 2315* c) 1675 d) 2360

3 Mounting of track devices of axle counters on rail, do not infringe schedule of dimensions because: a) No body bothers fixing any thing on

rail web or flange b) There is a provision in SOD* c) The provision is approved under

special instructions d) It does not come in physical contact

wheel 4 Correspondence between operating units i.e.

levers & buttons and operated units i.e. points & signals is essential to ensure that: a) Signal is ‘On’ when lever is normal* b) Signal is ‘Off’ when lever is normal c) Pulled signal is ‘On’ when lever is

reverse d) All of above

5 Dead approach locking is locking provided to hold the route when: a) The signal is dead with no light b) When there are no track circuits on the

section of track on which train is approaching or standing*

c) When the train has crossed the signal d) None of above

6 Signal overlap is 120 meters in: a) Two aspect signalling territory b) Three aspect signalling territory* c) Semaphore signalling territory d) None of them, It is Block overlap instead

7 Stations can be classified as: a) Block Stations b) Non Block Station c) Both of above* d) None of above

8 Component of TVUs is/are: a) Train, motor vehicle, bullock carts &

Tongas b) Cycles, rickshaw, auto rickshaw c) All of them* d) None of them

9 Back locking is locking provided to hold the route when: a) The train has crossed the signal* b) When the train is being pushed back c) When the train has stopped near the foot of

signal d) None of above

10 Shunt signal on a post of a running signal displays: a) Two lights to form horizontal line to show

‘On’ aspect b) Two lights to form a line include to 45º to

horizontal to show ‘Off’ aspect with main signal showing ‘On’ aspect*

c) Two lights to form a line include to 45º to horizontal to show ‘Off’ aspect with main signal showing ‘Off’ aspect

d) Two lights to form horizontal line when signal is ‘On’ & include to 45º to horizontal when the signal is ‘Off’ with main signal showing ‘On’ aspect

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2. Select the right answer True/False: 1. Station Section & Station Limits are the same thing. True/False* 2. Colour light signals work in two aspect signalling system also. True*/False 3. There is upper speed limit in case of standard IV interlocked station. True*/False 4. Means of isolation need not be interlocked with signals. True/False* 5. Loco pilot must obtain permission to enter the Block section. True*/False 6. On ‘A’ class station the Block Section & Station Section overlap each other. True*/False 7. Intermediate Block Post can be created on single line section also. True/False* 8. A ‘C’ class station is Non Block station. True/False* 9. A calling-on signal can be taken ‘Off’ simultaneously with the main signal on the post of which the

signal is provided. True/False* 10. In a lever frame the lever pulled last is always that of a signal. True*/False 11. ‘Red’ light of the signal is called as Red aspect. True/False* 12. All level crossing gates in automatic signalling territory irrespective of their classification shall be

interlocked. True*/False 3. Answer the following questions: 1. Please give signalling requirements at station interlocked to standard IV with reference to isolation,

signalling, point operation, point locking, point &lock detection, interlocking, track circuit and Block working.

2. Please define Station section & Block section on multiple aspect signalling system provided on double line section. Elucidate your reply supported by diagram.

3. Please detail the procedure of passing a gate signal at danger in Automatic Block Signalling section. 4. Discuss essentials of interlocking. Bring out methods of implementing the provisions thereof, briefly. 5. How can back locking be achieved by mechanical means? Elucidate your answer supported by

sketches wherever needed. Can approach locking be achieved by mechanical means if yes how. How approach locking can be achieved otherwise.

*****

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CHAPTER –III

SYSTEMS OF WORKING ON INDIAN RAILWAYS

1 Systems of Working the trains: As per General Rule [GR 7.01] the System of Working is defined as, “the system adopted for the time being for the working of trains on any portion of a railway”. The trains are worked on any one of the six systems of working on Indian railways which are - Absolute Block system, Automatic Block system, Following train system, Pilot Guard system, Train – staff and Ticket system, or One Train only system. Out of these systems only Absolute Block System and Automatic Block Systems are specified to be used on Indian Railways while other systems of working shall be used under special circumstances as authorised by Railway Board. As per chapter VII of General Rule Book of Indian railways “The Absolute Block and Automatic Block systems alone shall be used on every railway, except any railway or portion of a railway on which the use of any other system of working mentioned in sub rule may be sanctioned under special instructions subject to the conditions applicable to each system as described in these rules”.

2. Absolute Block system: Under Absolute Block System, the trains are run in such a manner that there is only one train on each line, in between two stations. There is no agency to monitor running of trains in between two stations except the train crew, as such the systems of working are designed by framing set of rules for running of trains between two stations. As per General Rule book [GR8.01] of Indian Railways, under this system of working: i) No train shall be allowed to leave a Block station unless Line clear has been received

from the block station in advance; and ii) On double lines such Line Clear shall not be given unless the line is clear, not only up

to first stop signal at the Block Station at which such Line Clear is given, but also for an adequate distance beyond it;

iii) On single line such Line clear shall not be given unless the line is clear of trains running in the same direction, not only up to first stop signal at the Block Station at which such Line Clear is given, but also for an adequate distance beyond it , and is clear of trains running in the direction towards the block station to which such Line Clear is given;

iv) The adequate distance so mentioned above shall under normal circumstances be not less than:

a) 400 metres in case of two-aspect lower quadrant signalling or two- aspect colour

light signalling, and b) 180 metres in case of multiple aspect signalling or modified lower quadrant

signalling.

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2.1 Conditions for granting Line clear at a class `A’ station: [GR 8.02] At `A’ class station on single line or on double line, the line shall not be considered clear and Line clear shall not be given, unless: 2.1.1 The whole of the last preceding train has arrived complete; 2.1.2 All signals have been put back to `On’ behind the said train; 2.1.3 The line on which it is intended to receive the incoming train is clear up to the Starter;

and 2.1.4 All points have been correctly set and all facing points have been locked for the

admission of the train on the said line.

2.2 Conditions for granting Line Clear at a class `B’ station on double line: At a class ‘B’ station on double line, the line shall not be considered as clear and Line clear shall not be given, unless: 2.2.1 The whole of the last preceding train has arrived complete; 2.2.2 All necessary signals have been put back to `On’ behind the said train; and 2.2.3 The line is clear:

(i) At stations equipped with two aspect signalling: Up to Home signal, or (ii) At stations equipped with multiple aspect signalling or modified lower quadrant

signalling- up to the outermost facing point or the Block section Limit Board (if any).

2.3 Conditions for granting Line Clear at a class `B’ station on single line: [GR 8.03]

The line shall not be considered clear and the Line Clear shall not be given unless: 2.3.1 The whole of the last preceding train has arrived complete; 2.3.2 All necessary signals have been put back to `On’ behind the said train; and 2.3.3 the line is clear:

a) At stations equipped with two aspect signalling: • Up to Shunting Limit Board or Advanced starter (if any) at that end of the station

nearest to the expected train, or • Up to the Home Signal if there is no Shunting Limit Board or Advanced starter, or • Up to the outermost facing point if there is no Shunting Limit Board or Advanced

starter or Home Signal; b) At stations equipped with multiple aspect signalling or modified lower quadrant

signalling: • Up to Shunting Limit Board or Advanced starter (if any) at that end of the station

nearest to the expected train, or • Up to the outermost facing point if there is no Shunting Limit Board or Advanced

starter. 2.4 Direct reception of a train from one side: when Line Clear has been given to the block station on the other side; At a class `B’ single line station, above conditions do not forbid direct reception of a train from one side, when Line Clear has been given to the block station on

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the other side provided the distance between the Outer signal and outermost facing points in two aspect signalling, and between the Home signal and outermost facing point in multiple aspect signalling or modified lower quadrant signalling is not less than the sum total of adequate distances prescribed in rule for granting line clear and rule for conditions for taking ‘Off’ Home signal.(Fig.2.4).

STARTER

STARTER HOME

HOME

OUTERWARNER

OUTERWARNER

Fig.2.4 Conditions for direct reception of train, on a single line `B’ class station with two aspect

signalling, from one side when line clear is already granted to other side 2.5 Conditions for granting Line Clear at a class `C’ station: [GR 8.04] At a class `C’ station on single or double line in two aspect, multiple aspect or modified lower quadrant signalling the line shall not be considered clear and Line clear shall not be given, unless: 2.5.1 The whole of the last preceding train has passed complete at least 400 metres beyond the home signal and is continuing its journey; and 2.5.2 All signals taken `Off ‘ for the preceding train have been put back behind the said train; provided that on a single line, the line is also clear of trains running in opposite direction towards the Block Hut from the Block station at the other end.

2.6 Obstruction on a block station on double Line section when a train is approaching the station: [GR 8.05] 2.6.1 Class `A’ station: When Line Clear has been given, no obstruction shall be permitted outside the Home signal, or, on the line on which it is intended to admit the train, up to the starter pertaining to the said line. 2.6.2 Class `B’ station: When Line Clear has been given, no obstruction shall be permitted outside the Station Section but shunting within the station section may go on continuously, provided the necessary signals are kept at `On’. When signals have been taken `Off’ for an approaching train on a line, which is not isolated, no shunting movement shall be carried out towards the points over which the incoming train will pass. 2.7 Obstruction on double line, in the block section: [GR8.06] 2.7.1 When Line Clear has been given, no obstruction shall be permitted in the block section in rear.

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2.7.2 Shunting or obstruction for any other purpose shall not be permitted in the block section in rear unless it is clear and blocked back. 2.7.3 Shunting or obstruction for any other purpose shall not be permitted in the block section in advance unless it is clear and is blocked forward: Provided that when the block section in advance is occupied by a train travelling away from the station, shunting or obstruction may be permitted behind the train under special instructions taking into consideration the speed, weight and brake power of the train and the gradients on the section, and as soon as intimation has been received that the train has arrived at the block station in advance, the line shall be blocked forward if it is still obstructed. Block back or Block forward shall be done in accordance with the procedure prescribed by special instructions.

2.8 Obstruction on single line in block section:

Class `A’ stations 2.8.1 Obstruction on single line at a class `A’ station when train is approaching : [GR 8.07] when Line Clear has been given, no obstruction shall be permitted outside the Home signal, or, on the line on which it is intended to admit the train, up to the Starter which controls the train. 2.8.2 Obstructing the block section at a class `A’ station on single line: [GR8.08] The block section shall not be obstructed for shunting purposes, unless: i) The Station Master has received Line Clear from the Station Master at the other end of

the block section, or ii) The Block Section is blocked back, or iii) Is occupied by a train travelling away from the block station at which the shunting is to

be performed which shunting may be permitted under special instructions taking into consideration the speed, weight and brake power of trains and gradients on the section. As soon as intimation has been received that the train has arrived, the block section shall be blocked back, and

iv) The Loco Pilot or other person in charge of the shunting operation has received distinct orders from the Station Master to shunt in a manner directed by special instructions.

2.8.3 Obstruction in face of an approaching train at a class `B’ station on single line: [GR 8.09] The line outside the Home signal in two-aspect signalling territory or facing point in multiple aspect or modified lower quadrant signalling territory in the direction of a train for which line Clear has been given, shall only be obstructed when a Shunting Limit Board or Advanced starter signal is provided and under special instructions which take into consideration the speed, weight and brake power of train, the gradients, the position of first Stop signal and the distance from which that signal can be seen by Loco Pilot of an approaching train. 2.9 Obstruction within station section at a class `B’ station on single line: [GR 8.10] 2.9.1 If the necessary signals are kept at on shunting may be carried on within the station section, provided the provisions of paragraph 2.8.3 of this chapter as given above, are complied with for shunting up to Shunting Limit Board or Advanced Starter, where provided.

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2.9.2 When signals have been taken ‘Off’ for an incoming train on to a line, which is not isolated, no shunting movement shall be carried on towards the points over which the incoming train will pass. 2.10 Obstructions outside station section at a class `B’ single line station equipped with two-aspect signals: [GR 8.11]The line outside station section and up to Outer signal shall not be obstructed unless a railway servant specially appointed in this behalf by the Station Master is in charge of the operations, and unless:

2.10.1 The block section into which the shunting is to take place is clear of an approaching train and all relevant and necessary signals are at on position, or 2.10.2 If an approaching train has arrived at Outer signal, the Station Master has personally satisfied himself that the train has been brought to a dead stand at the signal, provided that the line shall not be obstructed under this para, in thick, foggy or tempestuous weather impairing visibility or, in any case unless authorised by special instructions. 2.11 Obstructions outside station section at a class `B’ single line station equipped with manually operated multiple aspect signals: [GR 8.12] The line outside station section and up to first stop signal shall not be obstructed unless a railway servant especially appointed in this behalf by the Station Master is in charge of the operations, and unless the block section into which the shunting is to take place is clear of an approaching train. 2.12 Obstruction out side the first stop signal at a class `B’ station on single line: The line outside the first stop signal shall not be obstructed unless the line has been blocked back. 3. Automatic Block system: [GR 9] 3.1 Essentials of Automatic Block System on double line: [GR 9.01] Where trains on a double line section are worked on Automatic Block System: 3.1.1 The line shall be provided with continuous track circuiting or axle counters; 3.1.2 The line between two adjacent Block Stations may , when required, be divided into a series of Automatic Block Signalling sections each of which is the portion of the running line between two consecutive stop signals, and the entry into each of which is governed by a stop signal, and 3.1.3 The track circuits or axle counters shall so control the stop signal governing the entry into an automatic block Signalling section that: (i) The signal shall not assume an `Off’ aspect unless the line is clear not only up to the

next stop signal in advance but also for an adequate distance beyond it, which unless otherwise directed by approved special instructions, shall be not less than 120 metres, and

(ii) The signal is automatically placed to `On’ as soon as it is passed by the train. 3.2 Passing an Automatic Block signal at `On’ on double line section: [GR 9.02] Whenever a Loco Pilot finds an Automatic signal `On’, he shall stop near the foot of signal and wait for one minute in the day and two minutes in the night. If the signal does not assume `Off’ aspect during this waiting period, he shall give a prescribed code of whistle and exchange

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signals with the Guard and then proceed ahead, as far as the line is clear, towards the next signal in advance exercising great caution so as to stop short of any obstruction. 3.3 Essentials of Automatic Block System on single line: [GR 9.03]

Where trains on a single line are worked on Automatic Block System: 3.3.1 The line shall be provided with continuous track circuiting or axle counters, 3.3.2 The direction of traffic shall be established only after Line Clear has been obtained from the block station in advance. 3.3.3 A train shall be started from one Block Station to another only after the direction of traffic has been established. 3.3.4 It shall not be possible to obtain line clear unless the line is clear, at the Block Station from which Line Clear is obtained, not only up to the first Stop Signal but also for an adequate distance beyond it, which unless otherwise directed by approved instructions, shall be not less than 180 metres. 3.3.5 The line between two adjacent Block Stations may, where required, be divided into two or more of Automatic Block Signalling sections by provision of Stop signals. 3.3.6 After the direction of traffic has been established movement of train into, through and out of each Automatic Block Signalling section shall be controlled by the concerned Automatic Stop signal and the said Automatic Stop signal shall not assume `Off’ position unless the line is clear up to the next Automatic Stop signal: Provided further that where the next Stop Signal is a manual Stop signal, the line is clear for an adequate distance beyond it, which unless otherwise directed by approved instructions, shall be not less than 180 metres and 3.3.7 All stop signals against the direction of traffic shall be at ‘On’.

3.4 Minimum equipment of fixed signals in Automatic Block territory on single line: [GR 9.04] The minimum equipment of fixed signals to be provided for each direction shall be as follows: 3.4.1 Manual Stop signals at a station:

(i) A Home, (ii) A Starter.

3.4.2 An automatic stop signal in rear of the Home signal of the station. Note: Under approved special instructions, the Automatic Stop signal may be dispensed with.

3.5 Additional fixed signals in Automatic Block territory on single line: [GR 9.05] 3.5.1 Besides the minimum equipment prescribed in paragraph 3.4.1 above, one or more additional Automatic stop signals, as are considered necessary, in between Block stations, may be provided. 3.5.2 In addition, such other fixed signals as may be necessary for the safe working of trains may be provided.

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3.6 Conditions for taking `Off’ Manual stop signals in Automatic Block territory on single line: [GR 9.06] 3.6.1 Home signal: when a train is approaching a Home signal, otherwise than a terminal station, the signal shall not be taken `Off’ unless the line is clear not only upto the Starter but also for an adequate distance beyond it. 3.6.2 Last stop signal: The Last Stop signal shall not be taken `Off’ for a train unless the direction of traffic has been established and the line is clear upto the next Automatic Stop signal, or when the next stop signal is a manual stop signal, for an adequate distance beyond it. 3.6.3 The adequate distance as mentioned above shall never be less than 180 metres and 120 metres in case of two aspect signalling and multiple aspect signalling sections respectively unless otherwise directed by approved special instructions. A sand hump of approved design or subject to the sanction of the Commissioner of Railway Safety, a derailing switch shall be deemed to be an efficient substitute for the adequate distance.

3.7 Person in charge of working of trains in Automatic Block system on single line: [GR 9.08] 3.7.1 Except where Centralised Traffic Control is in operation, the Station Master shall be responsible for the working of trains at and between stations. 3.7.2 On a section where Centralised Traffic Control is in operation, the Centralised Traffic Control Operator shall be responsible for the working of trains on the entire section except when the station has been handed over to the Station Master, when he shall be responsible for the station and between the stations. 3.7.3 On a section where Centralised Traffic Control is in operation, the working of trains at a station or part of a station may be taken over by or handed over to the Station Master during emergency or as prescribed by special instructions. When such emergency control is transferred, the Station Master shall be the person in charge of working trains at the station or part of the station and the station shall be worked accordingly. 3.8 Passing Automatic Signal at `On’ on single line section: [GR 9.07] Whenever a Loco Pilot finds an Automatic signal `On’, he shall stop near the foot of signal and wait for one minute in the day and two minutes in the night. If the signal does not assume `Off’ aspect during this waiting period, he shall contact the Station Master of the next station or the Centralised Traffic control Operator (CTC Operator) on a telephone provided near the signal and seek his advise. If the Station Master or the CTC Operator, having ascertained clearance of the track ahead, permits him to move ahead, the Loco Pilot shall move to the next signal observing extreme caution and in case of visibility being poor due to curvature, rain dust storm or fog, he shall move at an speed of not more than 8 kilometres per hour, even if the next signal is found `Off’. The Loco Pilot shall act upon the aspect of next signal only after he has reached that signal. When no telephone is provided near the signal or it is not functioning the Loco Pilot shall whistle on prescribed code and exchange signals with Guard. The Guard shall show a stop signal towards the rear to warn the approaching train. In case there is no Assistant Loco Pilot with the Loco Pilot, the Loco Pilot may seek assistance of the Guard by giving prescribed code of whistle. In that case the Guard shall accompany Loco Pilot on the engine cab in keeping sharp look out.

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3.9 Passing a Gate stop signal at `On’ in Automatic signalling territory: [GR.9.15] 3.9.1 If `A’ marker is illuminated: The Loco Pilot shall observe the procedure for passing an Automatic signal at `On’ in double line section or single line section as described under paragraph 3.2 & 3.8 respectively of the same chapter of this book. 3.9.2 If `A’ marker is not illuminated: The Loco Pilot shall sound the prescribed code of whistle to warn gateman and bring his train to stop at the foot of the signal., wait for one minute during day and two minutes during night and if the signal is not taken `Off’, he shall proceed with caution upto the level crossing and proceed further passing the level crossing gate if the Gate man is present and exhibiting the hand signal. If the gateman is not available or is available but not exhibiting the hand signal, the Loco Pilot shall stop his train in rear of the level crossing and proceed after ascertaining that the gate is closed against road traffic and on getting hand signal from the gateman. In absence of the Gateman he shall get the hand signal displayed by the Assistant Loco Pilot, shall sound the prescribed whistle code and cautiously proceed upto next signal. 4 Following train system: 4.1 Essentials of the Following Train System: [GR 10.01] 4.1.1 Where trains are worked on the Following Train system, they may be despatched from one station to the next, following each other in succession in the same direction on the same line in such a manner and at such interval of time as may be prescribed by special instructions. 4.1.2 Trains shall not be worked on Following Train system unless the Station Master of the block station in advance has exchanged messages regarding his readiness to receive the trains and has, in addition, given his assurance that no train will be allowed to leave his station for the station from which the following trains are to be despatched, until the latter have all arrived his station and until he as received permission to despatch trains in the opposite direction. i) Report to the commissioner of railway Safety: [GR 10.02] When the Following Train

System is introduced on any portion of a railway under Rule 7.01of GR, a report shall be sent the Commissioner of Railway Safety.

ii) Conditions to be observed in working Trains on the following train System: [GR10.03] When the Following Train system is adopted, the following conditions shall be observed, namely: a) No train shall start until the Loco Pilot has been given written authority to proceed

in the form prescribed for the purpose and a written acknowledgment there of has been obtained from him , the train being stopped for the purpose, if not booked to stop,

b) The authority to stop shall state the station at which the train is next to stop, the speed at which it is to run and actual time of departure of the preceding train,

c) The Loco Pilot and Guard of each preceding train shall have been informed of the fact that a train will follow, and of the probable period which will elapse before the following train shall start,

d) A train shall not follow another from a station unless there has elapsed since the departure of previous train, an interval of not less than 15 minutes, or such shorter interval as may be fixed by special instructions.

e) All the trains following the first train shall be timed to run at the same speed and such interval as maybe fixed by special instructions,

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f) The actual time of departure of each train shall at once be intimated to the block station in advance and the actual time of arrival of each train shall at once be intimated to the block station in rear, and

g) The number of following trains running at the same time between any two Block stations shall not be more than one for each 5 kilometres of station interval; and unless permitted by special instructions, shall never exceed four, whatever may be length of the station interval.

5 Pilot Guard System: 5.1 Essentials of the Pilot Guard System: [GR 11.01] Where trains are worked on the Pilot Guard System: 5.1.1 A railway servant ( herein after called a Pilot Guard) shall be specially deputed to pilot trains; and 5.1.2 No train shall leave a station except under the personal authority of the Pilot Guard. 5.2 Conditions to be observed for following trains on the Pilot Guard system: [GR11.02] Trains shall not follow one another in the same direction between stations, unless: 5.2.1 The Loco Pilot has been properly warned of the preceding train and of the place at which it will next stop; 5.2.2 All the trains are timed to run at the same speed, and such speed shall not exceed 25 Kilometres an hour except under special instructions; and 5.2.3 An interval of fifteen minutes has elapsed since the departure of the preceding train. 5.3 Pilot Guard’s dress or badge: [GR 11.03] The pilot Guard shall be distinguished by red dress or badge. 5.4 Pilot Guard to accompany every train or give authority to proceed: [GR 11.04] 5.4.1 No train shall be started from a station unless the Loco Pilot sees that it is accompanied by, or that the authority to proceed is given personally by the Plot Guard wearing the dress or badge prescribed in GR 11.03. 5.4.2 The pilot Guard shall accompany every train: “Provided that when it is necessary to start two or more trains from one end of the section before a train has to be started from the other end, the Pilot Guard shall accompany only the last of such trains.” 5.4.3 When accompanying a train, the pilot Guard shall ride on the footplate of the engine. 5.5 Pilot Guard’s Tickets: [GR 11.05] 5.5.1 When the Pilot Guard does not accompany a train, he shall deliver to the Guard (or, if there be no Guard, to the Loco Pilot) a Pilot Guard’s ticket on a printed form properly filled up and signed in ink, as the authority to proceed. 5.5.2 Every such ticket shall apply only to the single journey to the station named on it. 5.5.3 If the train is in charge of a Guard, he shall, before the train is started, deliver the ticket to the Station Master who shall at once cancel it.

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5.6 Protection of train on Pilot Guard system: [GR 11.06] In the event of a train, which is followed by another train, stopping on the line between stations, the Guard and the Loco Pilot shall take action to protect the train in accordance with the provisions of General Rule 10.09. 6. Train Staff and Ticket System: 6.1 Essentials of the Train Staff and Ticket System: [GR 12.01] Where trains are worked between two stations on Train Staff and Ticket System: 6.1.1 A single Train – staff shall be kept at one of such stations, and 6.1.2 No train shall start from either of such stations to the other unless the said Train Staff is at the station from which the train starts and has either been handed to or shown to the Loco Pilot by the Station Master when giving such permission. 6.2 System where applicable: [GR 12.02] Trains may be worked on the Train Staff and Ticket system only when the line is single and only between such stations as have been declared by special instructions to be Train staff Stations. 6.3 Conditions to be observed for following train on the Train Staff and Ticket System: [GR 12.03] Trains shall not follow one another in the same direction between Train Staff stations, unless: 6.3.1 The Loco Pilot has been properly warned of the time of departure of the preceding train and of the place at which it will next stop; 6.3.2 All the trains are timed to run at the same speed, and such speed shall not exceed 25 kilometres an hour except under special instructions ; and 6.3.3 An interval of fifteen minutes has elapsed since the departure of the preceding train. 6.4 Loco Pilot to have Train Staff or Train Staff Ticket: [GR 12.04] No train shall be started from a station unless the Loco Pilot has in his possession to be carried with him on journey, either the Train Staff or Train Staff Ticket, for the section of the line over which the train is about to travel. 6.5 Train Staff or Train Staff Ticket to be delivered to: The Train Staff Ticket shall be delivered to the Loco Pilot by Station Master or by some railway staff servant appointed in his behalf by special instructions. 6.6 Train Staff or Train Staff Ticket to be delivered when: Train Staff or Train Staff Ticket shall be delivered to the Loco Pilot when: [GR 12.06] 6.6.1 When no other train is intended to follow before the Train Staff is required for a train in opposite direction, then subject to the provisions of the rule given under paragraph 6.6.3 of this chapter as below, the Train staff shall be delivered to the Loco Pilot. 6.6.2 When other trains are intended to follow before the Train Staff can be returned, then, subject to the provisions of following rule given under paragraph 6.6.3 of this chapter, a Train staff ticket indicating that the Train Staff is following, shall be delivered to the Loco Pilot of each train except the last; and the Train Staff shall be delivered to the Loco Pilot of the last train.

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6.6.3 A train is assisted by second engine in rear, a Train Staff Ticket shall be delivered to the Loco Pilot of the front engine and the Train Staff shall be delivered to the Loco Pilot of the rear engine: Provided that if both the engines attached to the train travel over the entire length of line to which Train staff applies, and the train is to be followed by the trains, a Train Staff Ticket shall be delivered to the Loco Pilot of each of the engines attached to the first mentioned train. 6.6.4 When a train is assisted by a second engine in front, the Train Staff or Train Staff Ticket, as the case may be, shall be delivered to the Loco Pilot of leading engine. 6.6.5 When a material train has to stop between stations, the Train Staff shall be delivered to the Loco Pilot. 6.7 The Train Staff or Train Staff Ticket shall not be delivered to the Loco Pilot of any train until the train is ready to start. 6.8 The Loco Pilot shall not accept a Train Staff Ticket unless he sees the train staff at the same time in possession of the person who delivers the Train Staff to him. 6.9 Train Staff to be kept on engine: When the Train Staff is delivered to the Loco Pilot of a train, he shall place it in a conspicuous place provided for the purpose on the engine. 6.10 Trains not to be started until Train Staff returned: When the Train Staff has been taken away from a station by the Loco Pilot of a train, no other train shall be started from that station to follow the first mentioned train until the Train Staff has been returned to the station. 6.11 Train Staff or Train Staff Ticket to be given up and Ticket to be cancelled on arrival of train: [GR 12.09] 6.11.1 Upon the arrival of a train at the station to which the Train Staff or a Train Staff Ticket extends, the Loco Pilot shall immediately give the Train Staff or Train Staff Ticket to the Station Master, or to some railway servant appointed by special instructions to receive it. 6.11.2 The person to whom any such Train Staff Ticket is to be delivered shall immediately cancel the same. 6.12 Procedure when engine is disabled on the Train Staff and Ticket system:[GR 12.10] 6.12.1 If an engine, which carried the Train Staff, breaks down between two stations, the Assistant Loco Pilot shall take the train staff to the staff station in the direction where assistance can best be obtained, in order that the Train Staff may be available at the station for delivery to the Loco Pilot of assisting engine. 6.12.2 If an engine which carries a Train Staff Ticket breaks down between two stations, assistance shall ordinarily be obtained only from the station at which the Train Staff has been left but if assistance can more readily be obtained from another station in the opposite direction, immediate steps shall be taken to have the Train Staff transferred to the other end of the section. 6.12.3 Whenever an engine has broken down between two stations the assistant Loco Pilot shall accompany the assisting engine to the spot. 6.13 Train staff Tickets, how kept: Train Staff Tickets shall be kept in a ticket box provided for the purpose and fastened by an inside spring, the key to open the box being the Train Staff to

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which the tickets apply. Train Staff when at a station shall not be left in the box but shall be kept by the Station Master in safe custody. 6.14 Distinguishing marks on Train staff Tickets and boxes: 6.14.1 Each train staff shall have shown upon it the name of the Train staff station at each end of the portion of line to which it applies. 6.14.2 The Train staff and Train staff Tickets and boxes for the different portion of the line shall be distinguished by different colours. 6.14.3 `UP’ and Down Train staff Tickets shall also have distinguishing marks. 6.15 Form of Train staff Ticket: Every Train staff Ticket shall be in following form: The Loco Pilot shall not accept this ticket unless he sees the Train staff for the portion of line, which he is about to enter. This ticket shall be given up by the Loco Pilot, immediately on arrival, to the Station Master or other person authorised to receive it, and such person shall immediately cancel it. 6.16 Record of Train staff Tickets issued: The Station Master shall keep a record in a book of each Train staff Tickets issued, showing the number of each ticket and the particular train for which it was issued. A sample of back of the Ticket is given below.

(Back of Ticket) Ticket No.-------------- ----------Railway

TRAIN – STAFF TICKET (UP or DOWN)

Train No.--------------Time ----------Hours------------Minutes From---------------------------------To--------------------------------- To Loco Pilot and Guard, You are authorised to proceed from--------------------------station To ----------------------station and the Train staff will follow. Train No.------------------in front left------------hours----------minutes

Signed---------------------- Station Master at-----------

(Station Stamp) Date:--------------------------

6.17 Obstruction outside the Home Signal: The line out side the Home signal shall not be obstructed unless the Train Staff of the portion on the line to be obstructed is at that station. 7. One train Only System: 7.1 Use of One Train Only System: [GR 13.01] Trains may be worked on the One Train Only System, only on short terminal branches on the single line.

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7.2 Essentials of the One Train Only System: [GR 13.02] Where the trains are worked on the One Train Only System, only one train shall be on the section on which this system is in force, at one and the same time. 7.3 Authority to enter the section: [GR 13.03] A Loco Pilot shall not take his train into the section unless he is in possession of the authority to proceed as prescribed by special instructions.

*****

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Chapter- III Self Assessment

1. Multiple Choice Questions: 1 In ‘A’ marker on manual stop signal, when

illuminated indicates that: a) The signal is non functional b) The signal can be passed at ‘On’ aspect

at full speed c) The rules for Auto Block section shall

be followed* d) The signal shall be treated as

Automatic Block signal only when it is ‘On’

2 On a ‘B’ class station on double line section, line clear can be granted when: a) The shunting is being performed with

the station section b) Only after shunting is stopped on the

line on which the train is scheduled to be received

c) Both a) and b) are correct d) Only a) is correct*

3 In normal course only two of the following systems can be used, for any system other than which, Railway Board’s approval shall be required: a) Absolute Block system & Train

following system b) Train following system & Automatic

Block system c) Absolute Block system & Automatic

Block system* d) Automatic Block system & One train

only system 4 Automatic Block signal shall assume ‘Off’

aspect as soon as: a) The track circuit ahead of signal is

clear b) Not only the track circuits ahead of the

signal but the overlap track circuit beyond next signal is also clear *

c) All track circuits ahead of signal & next signals are clear

d) None of the above

6 Under Pilot Guard system the normal permitted speed of the train shall be: a) 25 kmph* b) 20 kmph c) 15 kmph d) 50 kmph

7 Under Pilot Guard system the Pilot Guard shall be distinguished by: a) Navy blue dress or badge b) White dress or badge c) Orange dress or badge d) Red dress or badge*

8 At ‘C’ class station on double line section, line clear can be granted only when: a) Preceding has left the station b) The preceding train is still moving having

cleared 400Mts beyond the home signal c) The preceding train is still moving having

cleared 400Mts beyond the home signal or has left the station & the Home signal has been put to ‘On’*

d) The train has passed home signal & the signal has been replaced to ‘On’

9 On single line section provided with Automatic Block signalling, direction of traffic shall be established only when: a) Line clear has been obtained from station

in advance b) All trains in the direction opposite have

cleared complete Automatic Block section between the two stations

c) Both a) and b) are correct d) Only a) is correct*

10 In Automatic Block signalling section the ‘A’ marker provided on gate signal is illuminated when: a) The Gate signal is working as an

Automatic Block signal b) The Gate may not be Closed & locked c) Both a) and b) are correct d) Only a) is correct*

5 Under Absolute block system of working on an ‘A’ class station on double line section, line clear can be granted only when: a) All shunting at the station has been stopped b) Line on which train is scheduled to be received is clear upto Starter signal c) Both a) and b) are correct d) Only b) is correct*

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2. Select the right answer True/False: 1. There are nine systems of operating on Indian Railways as per GR. Chapter-VII. True/False* 2. In Automatic Block Signalling section the normal aspect of the signal in ‘Off’. True*/False 3. The control of the station can not be transferred by CTC controller to Station Master. True/False* 4. Any of the operating system can be provided on Indian Railway without reporting to Commissioner of

Railway Safety. True/False* 5. Under train staff & ticket system of working the Loco Pilot shall accept the ticket when delivered by

Station Master. True/False* 6. While using Following Train System a train shall not follow another from a station unless a fixed

prescribed period has lapsed after the departure of previous train. The normal period is not less than 15 minutes. True*/False

3. Answer the following questions: 1. Discuss Essentials of Absolute Block system of working including minimum equipment to be provided

at the station on double line section. 2. Discuss essentials of Automatic Block system of working including minimum equipment to be

provided at the station on single line section. 3. Discuss advantages and disadvantages of Absolute Block system compared to Automatic Block

Signalling. 4. Write short notes on:

a) One Train Only System b) Pilot Guard System

*****

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CHAPTER –IV

INSTALLATION & BRINGING IN USE, OF SIGNALLING SYSTEMS

1. Construction Organisation: A vibrant organisation is continuously in progress mode. So is Indian Railways. Progress is usually associated with construction activities. Rightly so each Zonal railway has dedicated construction organisation. The organisation is headed by Chief Administrative Officer (CAO) Construction, who is responsible to General Manager of the railway concerned. The CAO is assisted by Chief Engineer, Chief Electrical engineer, Chief Signal & Telecommunication Engineer and FA&CAO, with suitable supporting paraphernalia supporting them. All other supporting departments like Personal, and Operating etc are also under CAO, at levels suitable to bear responsibilities for discharge of their duties depending upon volume of work and to make the organisation compact and independent. Some times the duties of one or more departments are shared with open line when the work load does not warrant the requirement of dedicated officers and staff. Some times Construction organisations are headed by General Manager also. Central Organisation for Railway Electrification (CORE) is another organisation headed by General Manager, is dedicated to Railway Electrification all over Indian Railways. With the electrification, the signalling and telecommunication installations have to go for radical system changes. The affect of electrification on signalling and telecommunication has been discussed in ensuing chapter-VI of this book. CORE is a major organisation undertaking provision of AC traction and changes to signal and telecommunication system. Apart from the dedicated construction organisation under CAO, some low value construction works are also taken up by open line to meet their local and small needs by posting officers against work charge posts. Some high value capital intensive works are outsourced to IRCON, Rail Vikas Nigam Ltd. (RVNL), Indian Railway Project Management Unit (IRPMU) and other Public Sector Units (PSUs). The work of freight corridor has been taken up by Dedicated Freight Corridor Corporation. The Chief Commissioner of Railway Safety is posted under Ministry of Surface Transport, Central Government of India. There are Zonal Commissioners of Railway Safety who are responsible for one or more Zonal railways. It is prescribed in the General Rule 3.26 that `Fixed signal shall not be brought into use until they haven passed by Commissioner of Railway Safety as being sufficient to secure the safe working of trains,’ accordingly concerned Commissioner of Railway Safety is required to be approached for requesting permission for opening of a railway or a portion thereof, for public use. 2 Finances for construction organisation: Pursuant upon recommendations of Acworth Committee (1920-1921), railway finances were separated in 1924 from general finances primarily to secure stability for civil estimates by providing for an assured contribution from

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railway revenues and also to introduce flexibility in the administration of railway finance. Review of this arrangement kept on getting postponed on one or the other reason till a new convention 1949 was adopted with effect from the 1st April, 1950, after independence. 2.1 Revenue receipts: Major portion of revenue of the railway is received from the transport of goods, passengers which includes earnings from defence warrants, vouchers, other rail travel such as MPs etc, parcels, animals and other merchandise. Remaining is received from catering and advertisement fees etc. 2.2 Revenue expenditure: The public money can be spent in two ways only. It may be either `charged Expenditure’ or `Voted Expenditure’. The Charged expenditure is done against Judicial awards and any other expenditure is `Voted Expenditure’. For expenditure against judicial awards parliament’s sanction is not required. The parliament represents public, as such for any expenditure other than Charged expenditure, sanction of parliament is required, which is voted by parliament. The expenditure is also approved by president. The sanction of parliament’s or the President is requested in the form of `Demands for Grants’. The approval by the parliament is granted in the form of `Grants’ after the same has been voted, while the approval by the President is granted in the form of `Appropriations’ [SEM 1988-4.1.3]. The revenue expenditure is requested through demand numbers 1 to 15. Demand number 1- is for Railway Board, 2 – for Miscellaneous expenditure(General), Railway Recruitment Board & survey, 3- is for general superintendence, services & administration, 4- is for Repairs and maintenance (R&M) of Permanent way & works including Ballast, 5- is for R&M of Motive Power, 6- is for R&M of C&W, 7- is for R&M of plant & equipment, 8- is for Operating expenses, rolling stock & equipment, 9 & 10- are for Operating expenses, 11 – is for Staff welfare and amenities, 12- is for Miscellaneous expenses, 13- is for P.F., pension & other retirement benefits, 14- is for Appropriation to funds and 15- is for Dividend to general revenue. The main expenditure from the revenue receipts is on working expenses of railways which includes salaries of employees, all expenditure on fuel, operation, repairs & maintenance of assets, locomotives, coaches, S&T equipment etc; 2.3 Capital source of fund and expenditure: The expenditure on railways by Central Government is financed through a) loans raised specifically for railway purpose; b) Out of revenue surplus of railway which is at the disposal of Government, and c) Contributed by Indian states and District Boards etc. Capital expenditure is done out of grant for demand number 16 under the heading `Asset Acquisition, Construction & Replacement’. The demand for grants number 16 is further grouped under five subheads: 2.3.1 Capital fund (Cap): The amount granted against this fund is financed by Central Government only when rate of return is 14% or more. Railway is required to pay interest to Central Government at a specified rate.

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2.3.2 Capital fund (CF): The expenditure against this fund is done out of surplus railway’s own earnings. 2.3.3 Depreciation Reserve fund (DRF): Allocation to Depreciation Reserve Fund, started from 1st April, 1924 for renewals of the assets which have time bound normal life. The amount of this fund remains in deposit with the Central government; 2.3.4 Development fund (DF) -1: The Development Fund started with effect from 1st April, 1946, with the name of Railway Betterment Fund, modified to be named as Development Fund on 1st April, 1950, and to be used for Passenger Amenities only, which included amenities for all users of railway transport, labour welfare works such as class III staff quarters and un-remunerative project for improvement of operational efficiency. It is further regrouped as: i) DF-1: Fund for passengers and other railway users amenities, ii) DF-2: Fund for staff welfare, iii) DF-3: Fund for Operating improvement, iv) DF-4: Fund for safety works. 2.3.5 Open Line Works (Revenue): Other open line works are carried out under this head. 2.4 Safety fund (SF) and Special Railway safety Fund (SRSF) have now been merged with DF-4 & DRF respectively, with effect from 1st April 2008. 2.5 Construction organisation is broadly required to carry out works generated under Capital supplemented by Development fund, Deprecation Reserve Fund and open line revenue works. 2.6 All new works such as laying of new lines or provision of Electric traction is carried out financed by Capital. The work is undertaken only when it is found to be remunerative with a predetermined Rate of Return (RoR). The present RoR is 14% to justify the work. While planning works under Capital it often implies to incorporate certain development or renewal work to save cost of duplication and as such these works are also clubbed and funded from these funds as well. 3. Execution of works: Indian Railways absorbed huge work force which was working as casual labour for long periods. Railway also decided to reduce its work force gradually. With this depleting work force available for construction works, railway had to resort to contractual system for execution of works. The work may be of execution on running lines or New Lines and Electrification. In both the cases safety of the travelling public is ensured by the rules laid down in: [SEM 1988- 9.1.1] i) The Indian Railway Act, ii) The General Rules for all Open Line Railways, iii) The Rules for Opening of a Railway or a section of Railway for public carriage of

passengers, and iv) Indian Railway Schedule of Dimensions.

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These rules provide for legal authorisation that shall be obtained for any work which affects the running line, before the work is started or brought into use and before a new section of a line opened for public traffic. {SEM 1988-9.1.2]. 3.1 Tenders: besides many meanings of Tender’ in the Dictionary, one is “`to make an offer to carry out work”. So a tender is the offer for service by a tenderer for carrying out the work at the rates agreed with him. Tenders are invited through advertisement in news papers, directly advising working contractors of the organisation, and web site of the organisation, from those interested in execution of the work, out of which one tenderer, which is most economical offer from adequately experienced and financially sound qualifying other eligibility conditions is chosen. To begin with, the work content is decided. The work could be got executed through contractor on “Turn Key Basis” where all elements such as supply of all material required for execution of entire work, designing ,planning etc of work content are included in the contract. In other case a part of the material supply and other elements of work such as planning & designing is retained by railway with itself and balance is included in the contract. 3.1.1 Cost of work: According to the scope of work the entire work content is divided into units of workable activities. The rates of each activity are calculated, this process of working out rates of each activity is called Rate Analysis. Rate Analysis has three basic elements, i) Working out cost of material: The latest cost of all material scheduled to be supplied and used by contractor for the activity is worked out. This shall not include the cost of material scheduled to be supplied by Railway if any, ii) Labour cost: Cost of all labour is worked out; iii) Contractors profit over material and labour cost combined together @ 10% to which overheads and taxes are added: Taxes shall be worked out on material part only while overheads such as supervision etc is worked out on material and labour combined. The total of Material and Labour cost, Overheads and contractor’s profit shall become the cost of each activity independently for one unit of work. This is called `Unit Rate’ of the activity. The unit rate becomes SOR of the year in which the same is adopted. The quantities against activities, which are to be operated in the given tender are filled. The cost of each such activity is worked out by multiplying the quantity of the activity & unit rate and the cost of all activities added together shall be the cost of total work or cost of contract. This document containing all activities with associated rates is called `Schedule of Rates’ (SOR) and also some times `Bill of Quantities’ (BOQ). In certain cases when an activity which is not available in the SOR, the activity required to be operated in a given contract, the cost of the activity is either prepared through rate analysis or from the rates of latest accepted contract. Such items of activity are called Non Schedule items. It is pertinent to note that the cost of each activity has to be realistic as this cost shall become the basis for deciding cost of the work as offered by the tenderer being reasonable, high or low. It shall be seen later that any exaggeration in framing the cost of activities shall result in paying higher cost for the work, and conservative calculation shall lead to a situation where it shall appear that the cost offered by the tenderer is high to which it shall be difficult to accept. The

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consent of associated finance i.e. concurrence, shall be obtained for rate analysis of each such activity independently as well as for complete schedule of rates. Rate analysis shall be approved by an authority competent to do so in conformity to Schedule of Powers. A sample rate analysis is given as below:

Rate analysis for preparation of signal foundation in station area.

Description of the work: Digging earth, casting foundation as per drawing attached along with foundation bolts and plastering surface with sand cement and stone chips (25MM) of 1: 3: 6, ratio with fine finish, quenching the foundation for six days minimum, ramming the earth around the foundation clearing and cleaning the area to its original shape. = 20 Numbers Specifications: Size of the foundation ……Cu Mts Ratio of Sand: Cement: Stone chips. Size of stone chips = …. SN Material Quantity Rate in

Rs. Cost in Rs.

Reference of rate

1 Sand coarse …Cum ….. Rate * qty Builder’s book for the month of ……

2. Cement …Cum ….. Rate * qty Builder’s book for the month of ……

3. Stone chips …Cum ….. Rate * qty Builder’s book for the month of ……

4 Foundation Bolts with two nuts and washers

1 set ….. Rate * qty Budgetary quotation number…….dated…. from ……attached as Annexure-1

5 Pipe for cable entry One piece Lump Sum

A TOTAL COST …. VAT @ .....% ….. TOTAL COST OF

MATERIAL …..

1 Meson one ….. Rate * 1 Rates issued by labour commissioner dated…

2 Labour 4 ….. Rate * 4 Rates issued by labour commissioner dated…

B TOTAL COST OF LABOUR

…

C Supervisor 10% One …. Rate * 1x 10%

Rates issued by labour commissioner dated…

D Overhead charges @ 15% of A+B+C

….

E Cost of work = A+B+C+D X F Contactor’s profit 10% X*10% Unit cost of Work X /20 =Y Approved by ……… Vetted by ……… Prepared by………

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3.1.2 Schedule of Rates SOR: In organisations where the work is of repetitive nature, preparation of SOR is done once. The rates for all possible activities are prepared once by a committee consisting of one executive member and one member from associated finance. The fiancé concurrence is obtained for all such rates as worked out by the committee, which is sanctioned by the Chief Signal & Telecommunication Engineer in case of SOR for S&T department, to become SOR of the year in which the same is adopted for implementation. A sample schedule of rates is shown as follows:

Rate in Rs. SN Schedule of work UnitIn figures

In words

1 Digging earth, casting foundation as per drawing number …… attached, along with foundation bolts and plastering surface of the foundation with sand cement of 1: 3 ratio to fine finish, quenching the foundation for minimum six days, ramming the earth around the foundation, clearing and cleaning the area to its original condition.

Job Y ….

2. 3. 4.

3.1.3 Items not covered in SOR: It is possible that some items are not covered in SOR. Under such a situation the job content is identified and rates analysed and concurred by associate finance. Such items are known as Non- Scheduled items as these are not taken out of SOR but are prepared for the specific contract. 3.1.4 Inviting tenders: Once the schedule of rates is ready including SOR and Non SOR items, the quantities are filled in for the work proposed, for each activity to prepare schedule of quantities and rates for the work on the format as shown below bringing out total cost of the proposed work:

Rate in Rs. SN Schedule of work Unit Quantity In figures In words

Cost in Rs.

1 Digging earth, casting foundation as per drawing number …… attached, along with foundation bolts and plastering surface of the foundation with sand cement of 1: 3 ratio to fine finish, quenching the foundation for minimum six days, ramming the earth around the foundation, clearing and cleaning the area to its original condition.

Job 20 Y …. Y*20

2 - - 3 Non Schedule item of work 3.1 - - TOTAL COST OF WORK Rs.

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This statement, after taking approval of the authority competent to accept the tender shall be put-up for finance concurrence. After the finance concurrence is received, a Tender Notice, giving adequate information of the work content, total cost of work, earnest money amount, which is a given % of the cost of work decided from time to time, to be deposited giving accurate information about the form in which the amount is to be deposited and the name in favour of whom (The associated finance officer at appropriate level) the instrument shall be prepared, the time and date by which the tenders shall be accepted indicating place or person where the tenders shall be received, shall be i) circulated through daily Hindi and English news papers having good circulation in the area of work and the area where the tenders are to be deposited; ii) pasted on the notice board in the office; iii) placed on the web site of the organisation, giving not less than 30 day’s time for receipt of the tenders, except under special circumstances where time may be reduced to not less than 15 days, under approval of competent authority. The tenders invited with such reduced time are called as `Short Tenders’. 3.1.5 Tender documents: The Schedule of Rates shall be accompanied with i) Instructions to the tenderer for filling in the tender documents, ii) Specifications and drawings for execution of the work iii) Specifications for the materials to be supplied and used by the contractor and agency for inspection, iv) Special conditions of the contract including Arbitration clause, v) General conditions of contract issued by the railway in the zone of which the work shall be executed. 3.1.6 Opening of tenders: Usually a `Tender Box’ closed and sealed with an opening in the cover of the box, is kept in the office of the executive at an appropriate safe place, easily accessible to bidders. With information of the name of work and tender number displayed on the box indicating last date and time of receipt of the tenders. There has to be a gap between closing time of receipt of the tenders and the time of opening of tenders. The box shall be closed and sealed immediately on lapse of the scheduled time of receipt of the tenders and opened by one representative of the executive not below the rank of Assistant Signal & Telecommunication Engineer jointly with associated finance representative not below in rank of Section Officer. All tenders shall be stacked in one room, and opened jointly by the two officers in presence of those tendereres or their representatives who may chose to participate in opening of tenders, possessing adequate authority from the tenderer. The cover/envelops containing the tender documents shall be numbered from 1 to the last, not necessarily in any sequence and signed by both the officers having encircled the number put on the envelope. Wherever signed both officers shall jointly sign, using only red ink pen for the entire process of opening. Each signature shall be with date. The covers/ envelops shall be opened one by one in the numbered sequence , tender documents taken out and covering letter, each page of schedule of rates and any special remarks or the conditions put on by the bidder shall be similarly marked with the same number as put-on the cover/envelop. Each and every rate offered in figures and words including any special remarks in offer letter as well as otherwise any where and any corrections or overwriting, shall be encircled and signed. In case more than one correction or overwriting, each such correction and overwriting shall be marked as 1, 2, 3 etc and finally totalled as … corrections. Each page of the

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tender shall also be signed. The rates of each item of schedule of all the tenderers shall be announced clearly and distinctly if even one representative of any tenderer is participating in the opening process. The basic idea of entire process of opening of the tenders is that i) it shall not be possible to modify, alter or replace any part of tender document without being known, ii) rates of all the tenderer are made open and known to other bidders, and iii) late & delayed tenders are separated out. 3.1.7 Delayed tenders: The tenders received after the lapse of time of receipt of the tenders but before opening of the tenders are ‘Delayed Tenders’. 3.1.8 Late tenders: The tenders received after the scheduled time of opening, are ‘Late Tenders’. Delayed as well as late, both types of tenders shall not be considered for award under normal circumstances. However these shall be numbered last and marked conspicuously with red ink as Delayed or Late tender. These tenders may be considered if approved from Railway Board on recommendations of Head of the Department in association with finance, under extreme circumstances such as non-availability of bidders, under extreme emergency or heavy financial implications benefiting railways. 3.1.9 Award of Contract: A tender becomes a contract once an agreement is signed between Railway authority concerned and the tenderer. The procedure for award of tender and signing of contract agreement is discussed in ensuring paragraphs. 3.1.10 Last Accepted Rates (LAR): The cost of work is required to be decided before inviting tenders as the Ernest money to be called with tenders is based on the cost of work while at the same time the cost of work is also the basis for deciding the reasonability of the cost tendered by different tenderers. The cost of work is calculated based on the Rate Analysis of all items of schedule at the time of calling the tenders as discussed under preceding paragraph `Inviting tenders’. However there may be two situations i) Rate Analysis for all items might not have been required to be done there being some items of schedule, the rates of which might have been analysed and accepted for some earlier contract at that time, ii) time may have elapsed between inviting the tenders and evaluating the same for reasonableness, and iii) some other contract bearing the same schedule of quantities having been awarded in between inviting the tender in question and evaluation of the reasonability of its cost. As such it becomes important to work out the cost of the contract again some times just before opening of the tenders based on latest accepted rates and other relevant information such as increase in rates of certain items scheduled to be supplied by the contractor such as steel, cement etc. It is pertinent to note that the LAR shall be prepared before opening of the bids to eliminate possibility of charge of any biases. The LAR so prepared shall be got concurred by associated finance.

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3.1.11 Briefing note: A note to brief the tender committee, containing statement of Last accepted Rates duly concurred by finance, a tabulated comparative statement of the rates offered for all items, by all the bidders, all special remarks or conditions as mentioned by the bidder and any other matter effecting the nature of the offer, duly vetted by associate finance, along with all tender documents, shall be put up to the tender committee by an officer one level below the level of the tender committee member of the department of which the tender pertains. It shall be specifically mentioned in the briefing note if there is any one of the Public Sector Unit (PSU) amongst tenderer with a note that the PSU is entitled for purchase preference benefit. The purchase preference benefit means that if the total cost of the work as offered by the PSU is within 10% of the valid tenderer’s total cost of work, the PSU shall get priority over the other lowest bidder i.e. PSU, shall be considered as lowest tenderer. 3.1.12 Tender Committee: Usually a standard tender committee is nominated by the General Manager at different levels depending on the cost of work. The level of Tender committee is however decided based on the cost offered by lowest valid bidder in case of two packet system where the valid bidders are decided through credential bid before opening of the price bid. However in one packet system, the level of Tender Committee shall be decided on the cost of work offered by the lowest bidder. In case the Tender Committee finds that the lowest bidder does not quality on credentials & he is declared to be invalid bidder on this ground or on grounds of other eligibility criteria, the Tender Committee shall see if the cost of work offered by the next valid bidder falls with in the range of consideration of the committee. In such a situation it shall go ahead & draw tender committee minutes & recommendations. If the next lowest valid bidder does not fall with in the consideration range of the Tender Committee it shall not deal with the rates offered, but shall forward the complete case to next higher level Tender Committee with minutes & recommendations bringing out facts, jointly signed by all Tender Committee members. An officer from Finance and an officer from the department for which the tenders are invited shall essentially be the member of any tender committee. There may be more than two members in the tender committee basically depending upon the cost of work and other reasons. The third member shall be from a technical department other than the one for which the tenders are invited. The committee shall go through the briefing note and all documents, put-up to the committee. It shall ensure that all documents required to be concurred or vetted by finance have been done so. All tender documents submitted to the committee are intact and not tempered. The tender not accompanied with the Ernest money shall be summarily rejected. For the works costing more than Rs.10 lakhs, one of the major qualifying criteria is that the tenderer should have completed at least one similar single work for a minimum value of 35% of advertised tender value during preceding 5 years. The committee shall then evaluate the credentials of the tenderers with reference to the conditions incorporated in the tender documents and decide the tenderers qualifying the eligibility criteria. The tenderers having qualified the eligibility criteria are the eligible tenderers. The committee shall then consider the

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rates offered by the lowest, valid, eligible and technically acceptable tenderer only while simultaneously comparing the rates offered by other bidders in the same tender. The committee shall then see rates of all items through the comparative statement vis-à-vis the LAR and examine each item of schedule for reasonability of rates. Following situations may arise: i) Over all rates are within reasonable limits of acceptance but rates of some of the items

of schedule are high; ii) Over all rates are higher than acceptable limits and there is a scope of bringing down the

rates of some of the items of schedule, with which overall rates shall come down to acceptable limits;

iii) Over all rates are lower and considered to be unworkable i.e. it may not be possible to execute the work by the bidder at the rates quoted by him.

Under first situation where Over all rates are within reasonable limits of acceptance but rates of some of the items of schedule are high, the committee may recommend the acceptance of the tender with rider that the rates which are high shall not be taken as LAR for future tenders. It shall be kept in view that the rates quoted high are not very much disproportionate with respect to other items of work. In second situation the Lowest Eligible bidder shall be invited to negotiate the rates. Here it is pertinent to note that i) The tender committee can deal with lowest eligible bidder only, ii) discharge of tender because of high rates has two serious repercussions, first being that the work shall get delayed and the second that in case of re-tendering the Tender Committee shall be placed defensive if the rates offered by the lowest eligible bidder in the second tender turn out to be higher than the first tender’s lowest rates. It is recommended that the tender committee exhausts all possible channels of awarding the contract before recommending discharge of the tender. Under third situation, if the contract is awarded and contractor fails to complete the work thereby the railway falling into the situation of processing award of another contract to get the balance part of the work executed by another agency at the Risk and Cost of the failed contractor. In this case too discharge of the tender, is fraught with the danger of similar situation as in case of second one, as such in this case too it must be ensured that the rates are really unworkable before recommending discharge. Risk & cost contract: In case a contractor fails to carry out the awarded work within given time, despite of best efforts of railway, the balance part of the work is required to be executed by another contractor at the risk and cost of the failed contractor. In such a situation, the process of award of contract for the balance part of the work (risk and cost contract) is same as a normal contract. The risk and cost tender shall be under the same type and terms and conditions as that of original tender for floating risk and cost tender. It shall be ensured that the contractor against whom risk and cost tender is being floated is also be advised of the notice the risk and cost tender against him. When the cost of balance work is higher because of higher rates, the difference shall be realised from the failed contractor. For realisation of the difference cost, the

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failed contractor shall be given notice to deposit the cost within given time. In case he fails to do so, the money shall be realised by advising all Indian railways to withhold the amount due to be paid by the failed contractor and release the extra amount, if any, after realising the amount due to the railways, with in the preview of tender conditions. The Tender Committee shall record its minutes of meeting, discussions and deliberations clearly bringing out the reasons for recommending award, negotiations or discharge of the tender. In doing so all members shall be unanimous and come to conclusion and sign jointly. In case of a dispute the coordinating member (member of the department for which the tenders were invited) shall sign his views and down below the other member or members shall record their descent note and sign. 3.1.13 Accepting Authority: shall either accept or reject the tender committee recommendations. In case he does not accept Tender Committee recommendations he shall record his reasons in writing for not accepting the recommendations of any Member. In case he accepts the tender committee recommendations a Letter of acceptance shall be prepared in favour of the tenderer, got concurred by finance and delivered through registered dak. Through this Letter of Acceptance the contractor shall be advised to deposit `Security Money’ by a given time and to sign the agreement. He shall also be advised the completion period of work. With this the contract is established pending signing of the Contract agreement. The contract agreement shall be signed by an officer next below in rank to the accepting authority, on behalf of the President of India, and by the contractor. The agreement document shall include, i) Letter of Acceptance, ii) the original bid of the contractor with the negotiated rates and conditions as mentioned if any by the bidder with his tender, and iii) All other documents issued by railways to the tenderer which cover Special Conditions of Contract (SCC), Instructions to the tenderer, specifications for work , specifications for material to be supplied by the contractor and the General Conditions of Contract (GCC) for the railways in the zone of the work is to be execute, as annexure.

3.1.14 Two Packet System: As per Railway Board’s directives for the works tenders having cost more than Rs. 1 crore and upto Rs. 8 crores, as far as feasible, to call the tender on Two Packet System. The powers to decide the matter has been vested with the General Manager. In this system the tender document is divided into two parts. First part is the Credential Bid covering qualifying criteria and Earnest money and the second bid is financial bid covering Schedule of quantities and rates. The tenderer has to submit two envelops at the same time, accordingly. The Credential bid is opened first, on which Tender committee after deliberations shall decide the list of, valid, eligible and technically acceptable tenderer only. After the acceptance of recommendations by Accepting Authority, the second bid shall be opened and deliberated and accepted by the Tender committee and Accepting Authority respectively in the same manner as ordinary tender. The biggest advantage of this system is that no biases can be assigned for deciding a bidder to be eligible or not. In private sector, concept of Q1 (Best Quality offer) has been adopted in place of L1 (lowest cost offer). In this system only the best quality offer is accepted from the lowest cost bidder.

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3.2 Limited Tenders: The Chief Signal & Telecommunication Engineer may prepare a list of contractors with known sound credentials and financial health, in consultation with Finance, Obtain approval of General Manger and resort to Limited Tenders. The list is updated and modified from time to time. This system is used to cut short time and to seek contractors with assured known credentials. The notice is issued only to the contractors born on the approved list. However in this system open competition is eliminated and chances of higher rats increase. 3.3 Special Limited Tenders: May be adopted in consultation with FA&CAO for Works of specialized nature (to be approved by the PHOD personally), for Works of Urgent nature (to be approved by the GM personally) and for Consultancy works (to be approved by the GM personally). Four contractors out of the Approved list for Limited Tenders maintained and some more not born on the list of Approved List for Limited Tenderers subject to a minimum of six contractors are selected and notified after Finance concurrence and approval of General Manager. The balance procedure for award of the work is same as for other open tenders. 3.4 Post Contractual matters: The contact is awarded with the condition that the quantities in the schedule are tentative and can vary to the extent of +25% or -25%, of the total cost of contract without causing any change in the rates or any tender condition. The contractor shall be bound to execute work for variation up to +50 %, in the cost of work as per contract with the condition that if the agreement value goes beyond +25%, then for the first 15% increase in value of the agreement, the rates shall be reduced by 2% of the incremental value and the rates shall be further reduced by another 2% for the incremental value of the agreement for the next 10% increase in the value for first 15% of the cost of contract, beyond 15%. 3.4.1 Variation in the items of schedule vis-à-vis cost of contract: One of the common, post contractual matters is variation in the cost of contract. On receipt of the variation from the field, first the vitiation of the contract shall be examined. It may happen that the total agreed cost of contract may become higher than the total tendered cost of other tenderer when the revised quantities are compared with the rates of all legible tenderers due to increase being of high value items of schedule. Which shall mean that had the original quantities been as they are now after variation, one of the tenderers other than the one to whom the contract was awarded, would have been the lowest bidder and the contract would have been awarded to him. This shall vitiate the entire process of award of the contract. To safeguard against such a situation the officer executing the work shall keep a watch and permit variation of quantities only after ensuring that the contract does not vitiate. If the contract does not vitiate the legitimacy and essentiality of the variation shall be examined. Finding the variation to be inevitable, the sanction of the Contract accepting authority shall be obtained. 3.4.2 Grant of extension for completion of work: The other common post contractual matter is grant of extension to the Date of Completion (DOC) of the work as provided in the agreement. The DOC can be granted only when applied by the contractor. There is no provision for grant of DOC suo-moto. The DOC may be granted on account of delays in providing plans or site of work or any other lapse on the part of railway. Such DOC shall be granted without imposing Liquidate Damages and with the condition that neither the contractor shall be entitled for any compensation nor the grant of extension of DOC shall alter any terms and condition of the contract. The DOC extension may also be granted on account of lapses on contractor’s side.

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In this case if the railway is satisfied that the lapses on contractor’s account are condonable, DOC extension may be granted without Liquidated Damages, otherwise Liquidated Damages may be imposed upon the contractor. 3.4.3 Contractor not applying for DOC: It is pertinent to note that a contract is valid and in vogue only within its agreed date of completion. If the contractor does not apply for extension of date of completion in time, railway shall be obliged to take action well before expiry of the validity of the agreement, to terminate the contract against risk and cost of the contractor for getting the balance part of work done without financial loss to the railway. 3.4.4 Request for change in rates or tender condition, from contractor: No change in accepted rates and tender conditions is at all admissible after signing of contract agreement as this shall vitiate the entire tender and require re-tendering. 3.4.5 Addition of new item of work during the course of execution: It may some times happen that while executing the work some new work might be required to be done for completion of the original work. For this a new schedule of work shall have to be prepared, rates analysed and negotiated with the contractor, finance concurrence taken under approval of the Contract Accepting Authority and sanctioned by the Contract Accepting Authority. This part of work shall be allowed to be executed only after the same has been sanctioned. 3.4.6 Arbitration: Arbitration Act 1996 shall be applicable on all arbitration matters arising after application of the Act. i) In case, the contractor feels aggrieved for any reason, he can opt for Arbitration. There

is an arbitration clause embedded in each contract which is usually derived from the General Contract of Contract. It is during the progress of the contract or after completion of the work that the contractor can invoke arbitration clause.

ii) The contractor shall give in writing his claims of disputes and differences to the accepting authority of the contract to be redressed. The accepting authority, within a period of 120 days after receipt of the claims shall make and notify decisions on all matters referred to by the contractor made in writing with reasons for accepting all or some of the claims or rejecting all claims, to the contractor, and also that matters for which provision has been made in clause 8 (a) , 18, 22 (5), 39, 43 (2), 45 (a), 55, 55-A (5), 57 , 57 A, 61 (1) , 61 (2) and 62 (1) (b) of General conditions of contract or in any clause of the special conditions of the contract shall be deemed as `excepted matters’ and decisions of the Railway authority, thereon shall be final and binding on the contractor provided further that `excepted matters’ shall stand specifically excluded from the purview of the arbitration clause and not be referred to arbitration.

iii) The term `Excepted Matters’ means the matters / claims `except’ which, the reaming matters / claims shall be referable and referred to the Arbitrator for arbitration. The matters for which there already is one or more clauses in the agreement i.e. the Special Conditions of Contract (SCC) or clause numbers 8 (a), 18, 22 (5), 39, 43 (2), 45 (a), 55, 55-A (5), 57, 57 A, 61 (1), 61 (2) and 62 (1) (b) of General Conditions of contract of the railway in the zone of which the work is awarded, in which conditions are laid down to deal with such a situation, as under the dispute / claim.

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iv) The reply to the contractor in such a case shall be given in association with Law Officer and Finance and finally having obtained the approval of General Manager. The claims falling within the ambit of `Excepted Matters” shall be specifically mentioned giving grounds and referring to the clause under which the claim is found to be excepted matter. It also shall be mentioned that in case of matter being referred for arbitration the claims falling within the purview of excepted matters shall not be referred for arbitration.

v) On getting the reply from railways, if the contractor is still not satisfied or does not get any reply form the railway within the specified period, the contractor after120 days but within 180 days of his sending letter of claims, shall request to the General Manager who is the sole arbitrator, for appointment of Arbitrator. Single arbitrator or the Arbitral panel of more than one arbitrator shall be appointed by the General Manager depending upon the value of the claims. In case of appointment of arbitral panel of more than one, one member shall be from Finance and if there is another member it shall be of the choice of the contractor seeking Arbitration.

3.4.7 Appointment of Arbitrator and proceeding: The Arbitration proceedings are governed under Arbitration and Conciliation Act 1996. It is advisable that during the arbitration proceedings assistance of an Advocate, born on the panel of railway for arbitration, be taken. Although the arbitration proceedings do not follow the procedure of court but in case either railway or the contractor approaches court of law against arbitration award, any of the legal lapses may not be used against the interest of railways. After hearing both the parties the Arbitrator / or the Arbitral panel shall give award, discussing in details the reasons for having arrived at the reason for accepting or rejecting the claim, claim wise on a stamp paper of the value of Rs.1/- per Rs. 1000/- upto Rs. 5000/- and Rs.0.75/- beyond Rs.5000/- subject to a maximum of Rs. 75/-in Delhi, of the awarded value or of the value as decided from time to time and in different states. The award so received shall be forwarded for General Manager’s approval through Law officer and finance. The General Manager may accept the award in full or decide to appeal against the award. If the award is accepted in full or part thereof, the payments shall be made to the contractor within time as stipulated in the award. For the unaccepted part of the award the appeal in the High Court shall be made by the contract accepting authority. 4. Execution of work on a running line: 4.1 Notification to Railway officials before opening works: [SEM 1988 -9.2] No signalling work affecting the running of trains or working of traffic at a station shall be brought into use until staff of all concerned departments have been notified by means of a circular issued by the Operating Department. Timely intimation of the date of commencement of work, duration of work, arrangements for working of trains during the progress of the work, date of opening of the work, etc., shall be given to the Operating department, whenever any new or revised traffic working instructions are to be brought into use to enable Operating department to give the station and running staff due notice.

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4.2 Works requiring notice to and sanction of the Commissioner of railway Safety: [SEM 1988-9.6] Under section 20 of Indian Railway Act and chapter VI of the `Rules for Opening of a Railway or section of Railway for public carriage of passengers’ (See paragraph 5.3.2 & 5.4 of this chapter) the approval of Commissioner of Railway Safety is required for the execution of any work on the open line which will effect running of passenger train and any temporary arrangement necessary, for carrying it out except in cases of emergency. The following signal and Interlocking works, when they are connected with or form part of a Railway already opened for carriage of passengers, require the sanction of Commissioner of Railway Safety before they are commenced or opened: 4.2.1 Additions, extensions or alterations to existing Block, Signalling and Interlocking installations, 4.2.2 New Block, Signalling and Interlocking installations, 4.2.3 New stations temporary or permanent, 4.2.4 Interlocking of level crossing, catch siding slip siding, etc. 4.3 Application for sanction: When the work as mentioned above is to be executed by Divisional organisation, Application to the Commissioner of Railway Safety shall be made by Divisional Railway Manager and when the work is to be executed by extra Divisional Organisation such as construction organisation, the application shall be made by an officer not below the rank of Deputy Chief Signal & Telecommunication Engineer for signalling works. For joint works the application shall be made by an officer not below Junior Administrative grade of the department which controls the work. The application prepared in the format given below, shall be accompanied with the Signal & Interlocking plan, Interlocking table or selection table and Station working rules for Signalling works and submitted to the Commissioner of Railway Safety at least fifteen days in advance of expected date of commissioning. The sanction shall expire if not brought into use within one year of the date of sanction. The format for making the application is given below:

Application for Sanction ………………..RAILWAY Department……………………..….….. Office………….….....…... No……………………………..…….… Dated…………..……....... From The…………………………. Designation…………....….... To The Commissioner of Railway Safety, ………………………………………. Sir, I hereby apply for your sanction to*……………………………..................................................................... ……………………………………………………………………………..……………….……..……..….……...…… being commenced and opened for the public carriage of passengers when ready. 2. With reference to Chapter VI of the rules for the opening of a Railway, I have to enquire whether you wish to inspect the work prior to its opening for the public carriage of passengers, in which case intimation will be given of the date completion. 3. In the event of your deciding to not inspect the work prior to opening, the Engineer-in-charge will, on

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completion of the work, submit the Safety Certificate, duly signed by him, prior to the opening of the work for public carriages of passengers and when required, also dispatch a telegram ** to your address intimating that the work has been opened and the safety Certificate has been signed by him. 4. The application for the use of locomotives and rolling stock to be drawn or propelled thereby on the proposed line, in accordance with Section 16(1) of the Indian Railways Act (IX of 1890), is sent herewith/not required. 5. The following documents @ are enclosed: I. Temporary Works:

a) Description of proposed work. b) Drawing of temporary work. c) List of infringement to Schedule of Dimensions. d) List of deviations from the Signal Engineering

Manual.

e) List of deviations from General and Subsidiary Rules.

f) Restrictions. g) Rules for Traffic Working. h) Document for Bridges as per Chapter VII of the

Rules for the Opening of a Railway. II. Permanent Works:

a) Description of proposed work. b) Drawing of temporary work. c) List of infringement to Schedule of Dimensions. d) List of deviations from the Signal Engineering

Manual.

e) List of deviations from General and Subsidiary Rules.

f) Restrictions. g) Rules for Traffic Working. h) Document for Bridges as per Chapter VII of the

Rules for the Opening of a Railway.

6. Certified that a detailed examination of the strength and arrangement of the materials to be used in the temporary permanent works in above connection, have been made and that the design and the materials to be used are up to the loads, which they will be required to carry and that their opening for public carriage of passengers will not be attended with any danger. (Delete temporary or permanent work, as the case may be) Yours faithfully Signature….…………………...... Designation.…………………...... Dated…..….…………………...... No………………….. From The Commissioner of Railway Safety, ……………………………………….. Sir,

Your No…………………………………………………… Sanction is accorded to the above work being carried out. % I do not propose to inspect the work prior to its opening for the carriage of passengers. When ready, it may be opened on a Safety Certificate (vide Paragraph 3 of your letter) which should be submitted to me direct without any delay. % I propose to inspect the work prior to its opening for the carriage of passengers. Advice of the date, when work will be ready for inspection should be intimated at least 14 days before it is proposed to open it. ………………………………………………… Commissioner of Railway Safety * Here enter the name of work and mention whether permanent or temporary. ** Form of telegram: “Reference sanction No……………dated……………………work open at for public traffic on …………………………First train to pass………………………No danger to public. Certificate signed.” @ If any to the documents are not sent, then ‘NIL’ to be written against such items. Working rules for extensive re-modelling scheme may be send in not later than one month before the date on which the work is to be brought into use, and in such cases “will follow” should be written instead of “NIL”. % Strike out paragraph not applicable.

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In case of any material deviation from the plan approved by the Commissioner of Railway Safety, which affects yard layout or signalling and interlocking arrangements or system of train working, prior approval of Commissioner of Railway Safety shall be obtained before opening of the work. 4.4 Preparation for Commissioning: 4.4.1 While according sanction the Commissioner of Railway Safety shall advise in writing that whether he proposes to inspect the work before commissioning or not to inspect the work prior to opening. 4.4.2 In case the Commissioner of Railway Safety proposes to inspect the work prior to opening he will communicate his sanction to open the work in writing after inspection. 4.4.3 In case the Commissioner of Railway Safety does not propose to inspect the work prior to opening, the Engineer in charge, after fully satisfying himself that the work has been executed in conformity to approved plans and is safe for public carriage of passengers without endangering safety of the passengers, shall submit Safety Certificate, signed by him prior to opening of the work. The certificate shall be signed jointly in case of joint work. The safety certificate shall be counter signed by the officer who applied for the sanction of the Commissioner of Railway Safety. The formats for both safety certificates are given below:

Safety Certificate

………………..RAILWAY When the Commissioner of Railway Safety does not inspect the work prior to opening, this certificate must be signed before opening temporary or new works. From, The Divisional Railway Manager/Deputy Chief Engineer (Construction)/Deputy Chief Signal and Telecommunication Engineer (Construction),…………………….Division. To, The Commissioner of Railway Safety, ……………………………………….

Description of work..…………………………............................................................................................... …………………………………………………………………………..……………….……..……..….……...…….. Reference: Divisional Railway Manager Chief Engineer/Deputy Chief Engineer (Construction), Deputy Chief Signal and Telecommunication Engineer (Construction). Application………………………………dated………………..Sanctioned under Commissioner of Railway Safety No…………..dated………………..to commence and open the above work. Following Permanent/temporary work has been done- ……………………………………………………………………………..……………….……..……..….……...…….. ……………………………………………………………………………..……………….……..……..….……...…….. I/We do hereby certify that, in the work abovementioned- (i) The schedule of Dimensions has not be infringed* except in regard to the items sanctioned under letter* No…………...dated…………………

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(ii) Engineering work has been carried out in accordance with plan No……………….* except in regard to the alterations sanctioned under letter No……………dated………………. (iii) The weight of rails, strength of bridges and general structural character of the works are such as have been prescribed under the rules. (i) The *Signalling and *Interlocking and Block Signalling has been carried out in accordance with Signalling Plan No………………and the requirements and instructions laid down in the Signal Engineering Manual have been completed* except in regard to the items sanctioned under letter No……………..dated…………….. 2. A certificate form the Divisional Safety Officer/……………………stating that the necessary working rule have been issued and giving reference in regard to sanction to deviation (if any) from General and Subsidery Rules is attached/not required. *To be scored out if not applicable. 3. I/We hereby certify that on the……………………..19……………, I/We have carefully inspected and tested the above work and that I/We have satisfied myself/ourself that it has been properly completed and is in good working ‘order’ *and that the work can be opened for public carriage of passengers without endangering the safety of the travelling public, or of the employees of the Railway subject to the following speed restrictions: @Temporary…………………….km.p.h………………….due to………………………………………….. @Permanent…………………….km.p.h………………….due to………………………….……………….. 4. The work is being opened on……………………………………………………… *Necessary in case of signalling and interlocking works only . @ To be scored out if not applicable.

………………………………………………..….. Assistant Engineer Dated……………………..……..19………….….. ………………………………………………….... Assistant Signal and Telecommunication Engineer. Dated……………………..……..19………….….. No………………………………

Countersigned by: ………………………………….. Dated………………….19……… Countersigned by: ………………………………….. Dated………………….19……… Countersigned by: ………………………………….. Dated………………….19………. Dated………………….19……….

Countersigned and forwarded to Commissioner of Railway Safety for information: 1. 2. 3. 4. 5. Divisional Railway Manager/ Chief Engineer (Construction)

Deputy Chief Signal and Tele- communication Engineer (Construction).

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Safety Certificate for S&T works for introducing Electrification It is herby certified that the Signalling and Telecommunication work to be executed for the purpose of introduction of 25 KV signal phase, 50 cycle AC/1500V DC traction between……………..and………….. on……….. Railway have been carried out properly and that electric traction can be introduced for public carriage of passenger without endangering the safety of the travelling public or of the employees of the Railway subject to maximum value of traction current not exceeding…………Amps. Name: Designation:

Joint Safety Certificate

Certified that it is safe to run………………….(Particulars of locomotives and rolling stock proposed to run) not exceeding………………unit (in the case of locomotives) coupled together on the section (station)……………........... to…………………..(station) from………..……..(Km.) to…………..…..(Km.) of the………..…… Railway at a maximum speed of…………….(Km.p.h.) against a maximum speed of…………….(Km.p.h.) certified by R.D.S.O. subject to the following speed restrictions and conditions: a) Speed Restrictions:

Sl. No. From Km. to Km. Nature of speed restriction Brief reason for restriction

b) Special Conditions: C.M.E. C.E. C.E.E. C.S.T.E. C.O.P.S. Notes: 1) When the speed of a loco/rolling stock is to be increased the C.O.P.S. and C.S.T.E. should be associated when the increase in speed is contemplated over the maximum sanctioned speed for that category of train (Passenger and Goods) over a particular section. 2) C.E.E. should countersign wherever electric traction is involved.

4.4.4 The Engineer in charge shall bring the installation in use by issuing a message on the format given in the application for sanction, marked as **. 4.4.5 The safety certificate along with a certificate from Operating department stating that Station working rules have been issued shall be sent to Commissioner of Railway Safety endorsing copies to Divisional Railway Manager and Chief Signal & Telecommunication Engineer. Copy shall also be endorsed to Chief Engineer if engineering Department is also involved with the work. 4.5 Commissioning of the work: Whenever a new track is laid, it is easier to execute the

work without bothering about the existing rail traffic. However great care is required to be taken while working on a track or station where rail traffic is already there:

i) Safety of men working; arrangements must be made to warn persons working on or around the track by whistling. One person shall specifically be deputed for this purpose.

ii) Safety for existing train traffic: No attempt shall be made to make any alterations to existing system, to suit or to accommodate new installation before switching over from existing to new system of working i.e. wiring, replacement of point machines with another type, interlocking in the lever frame, modifying existing signal to suit future requirements or even shift existing wiring temporarily to another set of terminals to get

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the terminals free for new work etc, howsoever un-important or redundant that may be, and even after observing proper procedure such as under disconnection memo or under the supervision of open line representative. Entire new arrangement should be totally isolated with the existing arrangement.

iii) All new signals shall be provided with a cross on their front side. The size of the cross shall be one metre in length and 200 millimetres in breadth, painted white. See Fig. 4.5.

Fig. 4.5

Signals not in use provided with cross

iv) Temporary Working Instructions shall be prepared for working traffic at the station, during the period the station is non-interlocked for introduction of new system,

4.6 Declaring the station Non-Interlocked: When the entire work is ready for commissioning, the sanction of Commissioner of Railway Safety has been received, and a date for non – interlocking the station has been decided, speed restriction shall be imposed for trains to move at speed of 15 kilometres per hour, across the station during the period of non-interlocking of the station. The station shall be declared non-interlocked with the consent of the Traffic Inspector, by the section Engineer responsible for maintenance of the station. For this a disconnection memo for interlocking of the station, shall be put up to the Assistant Station Master, on the prescribed form. The station shall stand non-interlocked with the acceptance of the disconnection memo. Besides prescribed speed of the section, permanent or temporary speed restrictions are required to be imposed in the Station Section or Block Section. In Station section the speed restriction is required to be imposed for signalling works, when the station is non-interlocked either for overhauling of interlocking or when the existing system is to be replaced with a new system of signalling, affecting the existing interlocking arrangement. In block section the speed restriction is required to be imposed for track renewal works, maintenance of track culverts or bridges or for any other contingencies. The Section Controller of the section shall be intimated at odd hours on the date on which the station is scheduled to be non-interlocked so that notice for the speed restriction may be issued

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to all Loco Pilots passing the said station, at the stopping station, in time without making them stop in between, on stations other than `Notice stations’. 4.7 Fixing of Caution, Speed and Termination Indicator Boards: Caution, speed & termination indicator boards shall be provided at the station simultaneously along with imposition of speed restriction. These boards shall be lighted during night time, the speed restriction being temporary, required during the non- interlock period only. These boards are not required to be lighted during night time in case of permanent speed restrictions: i) Caution Indicator: In each case a caution indicator, 1400mm long and 400 mm wide

with fish tailed at one end and pointed at the other end, painted in yellow and black (see fig 4.7) and mounted on a post painted with black and white strips of 300mm, shall be fixed at 800 metres from the point where restriction of speed has to commence. In case the stop dead restriction is there, the distance shall be 1200 metres instead of 800 metres on Broad Gauge. This indicator shall be used for permanent as well as temporary speed restrictions. When used for temporary speed restriction, the indicator shall display two yellow lights by night, facing approaching train or painted with luminous paint or provided with fluorescent tape. The indicator shall be mounted at the height of 2 metres from the rail level.

ii) Speed Indicator: This indicator shall be followed by a `Speed Indicator’ with speed painted in black on a equilateral triangular board of 1 metre arm, painted yellow, which shall be mounted on a post painted with black and white strips. A lamp shall be provided on the post such that the speed written on the speed board is properly visible to the approaching train Loco Pilot. The Speed Indicator shall be mounted near the foot of first reception signal, at a height of 2 metres from rail level, for signalling works

iii) Termination Indicator: Two Termination Indicators shall be provided, one for passenger trains and other for goods trains painted black as T/P and T/G with 2500mm high and 40 mm thick letters, for passenger and goods trains respectively, on a circular disk of 1 metre diameter, painted yellow and mounted on a post painted in white and black strips of 300 mm. These indicators shall be fixed at a distance of longest passenger train and longest goods train respectively, running on the section, from the point the restriction ends. A distance of 670 meters is considered adequate to cover the length of longest goods train. These indicators shall be suitably lighted by fixing a hand signal lamp on the post at a height of 1650 mm from the rail level.

10 T/GT/P

Fig. 4.7

Caution indicator, speed indicator, passenger train termination indicator & goods train termination indicator respectively from left to right

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Adequate communication between the controlling Station Master and the Assistant Station Masters posted at each point or group of points for ensuring proper and right setting and locking of points, shall be provided.

4.8 Switching over of new signalling system replacing the existing: i) A programme for switching of the old system of interlocking shall be chalked out to

ensure replacement without causing hindrance to train movement maintaining absolute safety during the station is non- interlocked. Switching of new system shall be under taken in accordance to the pre-chalked out programme. Disconnection memos shall be given for equipment for replacement with the new one and reconnected through reconnection memo accompanied with a note that old equipment has been replaced with new one. All these disconnection and reconnection memos duly acknowledged, shall be kept in safe custody by the Section Engineer. The process shall continue till all the existing equipment due to be replaced with the new one, have been replaced.

ii) The Traffic Inspector shall take assurance from all the Assistant Station Masters, proposed to operate the new system of working and have taken learning, on a register meant for the purpose.

iii) After the new system has been introduced, the signals and other equipment rendered surplus and likely to obstruct the visibility or any other function shall be dismantled without delay. New system shall be tested to be in exact conformity with the Signal and Interlocking Plan and the interlocking table or the Selection Table, on which sanction has been accorded by the Commissioner of Railway safety to open the work without inspection by him and that the officer concerned not below the rank of Assistant Signal & Telecommunication Engineer or any other officer authorised under approved instructions, is fully satisfied of smooth and safe working, shall ensure that the assurance from the Assistant Station Masters has been taken by the Traffic Inspector, shall declare the station having been commissioned to new system of working. He shall then issue a telegram form the station itself notifying so and record the number and name of the first train to pass through the station immediately after bringing the new system in use.

iv) The officer concerned declaring the station commissioned shall make entry in the signal failure register mentioning the number of Signal and interlocking plan brought into use, the number of the sanction accorded by the Commissioner of Railway Safety and the numbers of Block instruments if changed and put his signatures with date.

5 Execution of new lines and Electrification works:

Rules for Opening of a railway or section of a railway for the public carriage of passengers: ‘Rules for Opening of a Railway or Section of a Railway for the Public Carriage of Passengers’ are issued by Railway Board. It is pertinent to note that these rules cover `public carriage of passengers’. New railway line include extensions of existing railways, new double treble or other running lines laid alongside existing lines and conversion of gauge to another or installation of electric traction on the existing lines. These rules contain fine details essentially required to be known for execution of new works. These rules are not covered elsewhere in other rule books and manuals and the signal engineering is incomplete in absence of knowledge of these rules. Some of the major guidelines

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with reference to the chapter of the book covering `Requirements and Recommendations for Signalling and Interlocking Installations are discussed here: 5.1 Preparation for opening of new railways: 5.1.1 Whenever the General Manager of a Zonal Railway or Chief executive of a non- government railway is of the opinion that any railway or a part thereof is required to be opened for public carriage of passengers, he shall refer the matter to the Chief Commissioner of Railway Safety, for inspection and report on the safety of that railway. 5.1.2 Every Railway administration shall ensure that the railway line or portion thereof to be opened for public carriage of passengers is complete in all respects as per the Indian Railway standard Codes and manuals of practice or as per the Codes and Manuals of Practice as specifically approved by Central Government for that Railway and for such opening all the administrative formalities are complete and that the working of the railway is regulated by the Indian Railway (Open Lines) current General Rules or any other General rules as approved by the Central Government and notified in the Gazette of India. 5.1.3 The Chief Executive of the railway administration of non-Government Railway, before making a reference to the Chief Commissioner of Railway Safety for inspection of any railway, shall obtain a clearance from the Central Government that the railway which is sough to be opened has been constructed and maintained by that administration in accordance with the Indian Railway Standard Codes and Manuals of Practice and working of the railway is governed by the Indian Railway current General rules. 5.1.4 Before a reference to the Commissioner of Railway Safety, it shall be ensured that the railway proposed to be opened, is operationally fit in every respect before inspection and while making a reference to the Commissioner of Railway Safety he is advised of any deviation in design, material & construction of work, rolling stocks or appliances of the railway, instances in which maximum and minimum dimensions have not been observed, or the bridges, tunnels are not capable of carrying the prescribed or standard load without exceeding the stress specified in the Indian railway standard Codes & Manuals of practice. 5.2 Supply of documents to the Chief Commissioner of Railway Safety: 5.2.1 The General Manager of the Zonal railway or the Chief Executive of non- Government railway, while making a reference for inspection to the commissioner of railway safety, shall furnish tabulated details, Index plan & section of railway, Drawing of works, List of question and answers, certificates, List of infringements of Maximum & Minimum dimensions, Working orders to be enforced at each station and Administrative note giving the salient features of the project. The work could be Engineering, Signalling or Overhead traction in nature however all these documents shall be discussed with reference to signalling works here. 5.2.2 Contents of the documents to be supplied as mentioned above: i) Tabulated details shall consist of important characteristics of the railway or the portion

of the railway to be opened for public carriage of passengers and in particular shall include gradient abstract, stations and station sites, station machinery, level crossing abstract, brief particulars of traction installations, power supply installation abstract etc.

ii) Index plan & section sheet shall be prepared as laid down in Indian railway code for Engineering Department as reproduced in schedule and shall include Diagrammatic plans of tracks and particulars of turnout, block working & of any signals & interlocking installed.

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iii) List of questions & answers shall be prepared for signalling items as tabulated below:

SN QUESTIONS ANSWERS 1 Have the requirements and recommendations for Signalling and Interlocking, and the

catechism for signalling and interlocking installations vide chapter VII of these rules, and the appendix thereto, being fully complied with, according to the class of signalling and interlocking installed? If not, in what respect do the arrangements provided fall short of them?

2 Have the requirements and recommendations for Signalling and telecommunication installations in accordance with the instructions issued for the installations of S&T equipment in 25KV 50 Hz electrified sections been complied with? If not, in what respect the arrangements provided fall short of them?

3 Is provision made, whether by trap points or other means, to prevent vehicles standing on sidings, from fouling any running line?

4 Are there any stations situated on a grade steeper than 1 in 400? If so, what special safety devices are adopted and / or special rules enforced at those stations? (No station should be constructed nor should any siding join a passenger line on a grade steeper than 1 in 260, except where it is un avoidable, and then only with previous sanction of the Railway Board obtained through the Commissioner of Railway Safety, when a slip siding or other arrangements are made, sufficient to prevent accidents.)

5 What safety sidings are provided? Are any other necessary? (At any station situated in the immediate neighbourhood of an incline steeper than 1 in 100 falling away from the station and 1 in 80 falling towards the station, a catch siding in former case and a slip siding in later case, should be provided if necessary, in suitable position. The take ‘Off’ points to catch siding or a slip siding should normally be set and locked for the siding except where required to be trailed through.

6 Are station yard so arranged that shunting past junction or level crossings may be avoided as far as feasible?

7 Are shunting necks for goods working provided in large yards, where shunting operations cannot otherwise be carried on without interfering with incoming trains

8 Are means of communication between passengers and the guards provided in all trains carrying passengers?

iv) Certificates of the work shall comprise Maximum & Minimum dimensions,

Communication, System of working, Working order to be enforced at each station on the railway to be opened, prepared in accordance with the rules provided in the chapter V of General & Subsidiary Rules specifying any special conditions that are required to be met with.

The format of the certificate to be given by the General Manager shall be as follows:

I do hereby certify: (i) that the Maximum dimensions for railways in India have in every case been worked to, with the exceptions detailed in the statement herewith annexed, also that the Standard dimensions will be observed in future, and that no work or structure infringing the standard dimensions will hereafter be permitted without the sanction of the Central Government. (In the statement showing the cases in which the maximum and minimum dimensions have been infringed, full details for each case must be given, in the form given below, with the explanation of the necessity for such infringements and a reference to the authority under which it was permitted. If there have been no infringements of the maximum and minimum dimensions the words “with the exception detailed in the statement herewith annexed” should be omitted or struck out. This form XVII shall be annexed to the certificate) ii) that each bridge is of such design, dimension and construction as will enable it to bear the dead load of the structure itself (with flooring, roadway, permanent way etc. complete), and in addition thereto, the equivalents

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of the live loads specified in the rule prescribing Standards of Design and loading for Railway bridges, without exceeding the maximum permissible stress on the available material in any member or portion of the structure. iii) that more than two engines shall not under any circumstances be allowed at one time on the same track of one span of any bridge. iv) that every coaching vehicle constructed or procured for the use of the railway in mail and passenger trains is, and shall be provided with vacuum/air brake and effective means of communication between passengers, guard and driver. (This part of certificate is nor necessary for those light lines on which the use of vacuum or air brake has not been insisted upon.) v) that one compartment or such number of berths or seats, as the railway administration may think fit, of a second class carriage of every train carrying passengers shall be reserved for exclusive use of females. vi) That the railway shall be worked on the system known as Absolute Block System in accordance with the regulations prescribed in Chapter VIII of the General Rules for railways in India. vii) That the electric traction equipment can be used for public carriage of passengers without danger to public and that the rules for design and inspection of equipment for electric traction (of Chapter VIII of these rules) have been complied with. (This shall be included only when applicable.) viii) That the signalling and telecommunication equipment have been installed in accordance with the approved instructions and they are safe for passing traffic. ix) That……….has been delegated to accompany the Commissioner of Railway Safety on his inspection and all information supplied or engagements entered into by him shall bear my authority.

(Signed) The General Manager

FORM XVII

INFRINGEMENT OF MAXIMUM AND MINIMUM DIMENSIONS SECTION: RAILWAY: LENGTH: GAUGE:

Location Prescribed maximum & minimum dimensions

SN

Division Kilometrage

Name of structures which infringe Chapter

item Maximum Minimum

Existing actual dimension

Amount of infringement

Particulars of sanction to infringement & remarks

5.3 Inspection by Commissioner of Railway safety: 5.3.1 Special arrangements shall be made by the General Manager to facilitate the inspection by the Commissioner of Railway Safety and also give all information and assistance in his power, and provide all instruments and apparatus required for making measurements, testing of bridges and electrical and other installations, of the railway, which is to be opened. The General Manager shall, on receipt of the a request from the commissioner of Railway Safety, make arrangement to dismantle any structure on the railway to be opened, with a view to make complete examination of the details or workmanship of the structure as quickly and completely as possible. The Commissioner of Railway Safety, while requesting the dismantling shall be responsible to see that such complete dismantling is essentially required for its proper inspection. The General Manager shall accompany the Commissioner of Railway Safety throughout inspection or under unavoidable circumstances he shall authorise an officer, not below the rank of Under Secretary to the Government of India authorised by general or special order of Central Government issued under section 28, to accompany the Commissioner of Railway Safety during the entire period of inspection.

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During the inspection the engineer or officer, immediate in-charge of the corresponding section may also be present. 5.3.2 Sanctioning of opening of railways and opening of Railway for public carriage of passengers: The Commissioner of Railway Safety shall submit his inspection report to the Central Government along with Index plan, tabulated details, list of question and answers, certificate by the General Manager, & list of infringements as submitted by the General Manger while making the reference along with results of the bridge test. The Central Government after considering the inspection report of the Commissioner of Railway Safety, sanction the opening of the railway or a portion of the railway for public carriage of the passengers giving due consideration to the suggestions or conditions subject to which the Commissioner of Railway Safety has recommended the opening of the railway. Where Commissioner of Railway Safety has not recommended the opening of any railway, or has proposed to cancel the sanction already give, the Central government shall confirm , modify or cancel the sanction given to opening of such railway or a portion of the railway and shall take steps to remove the defects or the shortcomings pointed out by the Commissioner of Railway Safety in his inspection report in case of Government railway, and direct the General Manager concerned to rectify the defects, in case of non- government Railway. In case it is not possible to remove the defects the Central Government shall order closing of the railways for the public carriage of the passengers, which can be reopened unless the same is duly inspected and recommended by the Commissioner of Railway Safety for its reopening. The actual date of opening of the railway line or a section thereof for passenger traffic shall be notified by the concerned General Manager, after consulting the Central Government, by notification in the Official gazette, and in local news papers of the area through which the railway passes. 5.4 Temporary opening of railways by the Commissioner of Railway Safety: The Commissioner of Railway Safety may sanction the temporary opening of new railway lines for public carriage of passengers, subject to such conditions as he may impose during his inspection in the interest of the passengers. The Central Government may confirm, modify or cancel the sanction given subject to such conditions, alterations or relaxations as may be considered necessary, on receipt of inspection report of the Commissioner of Railway Safety. 5.5 Opening of minor works: 5.5.1 Where it is proposed, on the railway which has been opened after inspection, to construct any deviation lines, stations, junctions or level crossings, or to make any addition, alteration or reconstruction materially affecting the character of any work and such work forms part of, or is directly concerned with the working of that railway, the railway administration concerned shall give notice to that effect to the Commissioner of Railway Safety. Every temporary deviation line irrespective of its length and any permanent diversion less than two kilometres in length where no new station is involved shall also be treated as new minor works.

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5.5.2 Before any such work, the execution of which may affect the running of trains carrying passengers, is taken in hand, the concerned railway administration shall furnish drawings or particulars of the work and of any temporary arrangements necessary for carrying it out, to the Commissioner of Railway Safety for his approval. 5.5.3 In case of accident temporary diversions may be opened after responsible person of the concerned railway certifies that the use of such diversion will not cause danger to passengers or to the railway servants. However where the use of the temporary division is likely to be extended to for more than three days, the Commissioner of Railway Safety shall take action to inspect the diversion at the earliest opportunity. 5.5.4 Powers of Commissioner of Railway Safety to open minor works: The Commissioner of Railway Safety may sanction for opening any minor work for passenger traffic, without previous notice, if he is satisfied that work may be allowed to be opened, either with or without inspection. (i) The Commissioner of Railway Safety shall take steps for carrying out inspection

subsequently, for the work opened without inspection. (ii) The authority for opening any work shall be communicated in writing by the

Commissioner of Railway Safety to the concerned railway administration and a record of all works so authorised during each year, with particulars of prior or subsequent inspection, if made, shall be maintained by the Commissioner of Railway Safety.

5.5.5 Infringement of maximum and minimum dimensions: No infringements of Maximum and minimum dimensions shall be permitted without the prior sanction of the Commissioner of Railway Safety or of the Central Government. 5.5.6 In case of application for use of new type of locomotives or rolling stock contemplating increase in the speed of loco/ rolling stock over the sanctioned speed for a specific category of train over a particular section of the railway, the certificate in the application shall also be signed by Chief signal & Telecommunication Engineer & Chief Operating Manager of the Zonal railway concerned; on the railway where both shop maintenance and open line maintenance of electric locos and electric Multi unit rolling stock are under the control of electrical department only, the Chief Electrical Engineer, other wise Chief Mechanical Engineer should also sign; when motive power with chopper control is to be used the Chief Signal & Telecommunication Engineer and Chief Electrical Engineer should sign the certificate, in addition to the signatures of Chief Engineer. 5.5.7 In case railway administration which desires for use of new type of block instruments or main signalling instrument, which is not of approved type, shall apply for sanction of the Commissioner of Railway Safety. The application must be accompanied with (i) A list of requirements which the instrument fulfils, together with the results of the field trial conducted by the railway concerned; (ii) A certificate by Chief Signal & Telecommunication Engineer in the form as given below; (iii) A statement whether the equipment complies with the specifications approved by the Central Government; (iv) A statement giving comments on the performance of the equipment as a result of bench trails (trails done in the laboratory) conducted by Research Designs & Standards Organisation (RDSO) (vi) The circuit diagrams and other relevant diagrams and explanation as may be necessary to give full particulars of the principles of operation and safety features incorporated & (vii) A copy of the instructions approved by the Chief Operating Manager, to be issued for operation of the equipment by the operating staff, including those instructions for working under abnormal or failure conditions.

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CERTIFICATE Certified that it is safe to use (particulars of the equipment) at the station/ on the section of railway, with the following precautions:-

1. 2. 3. 4. etc. ( Sd/-…) The Chief Signal & Telecommunication Engineer. 5.6 Requirements and recommendations for Signalling and Interlocking Installations: 5.6.1 Signals: i) The number of signals provided and their height should be limited to what is actually

necessary for safety and traffic purposes. ii) The distance between Distant/Warner and the first stop signal ahead shall be such that a

train approaching the Distant/Warner signal at the maximum permissible speed with due allowance to weight, braking power, gradient and sighting distance can be stopped before passing the first stop signal.

iii) The subsidiary signals shall be readily distinguishable from running signals. iv) Where a signal or its back light is not visible to the railway servant operating the signals,

the aspect of the signal and the condition of the light shall be repeated at the place of operation.

v) It is desirable that the signalling at all block stations and interlocked level crossing gates in the same section shall conform to the same standard and type.

vi) Signals shall be so designed as to give the most restrictive aspect in the event of failure of any part of the mechanism, which operates them. This feature is called fail safe feature of the signalling system.

vii) The location and type of signals shall be in accordance with the provisions contained in chapter VII of Signal Engineering Manual and Chapter III of General rules 2007.

5.6.2 Points: i) Points must be so located that movement over them shall be within view of the cabin or

other location from which they are worked, unless an approved alternative for direct vision by the cabin man i.e. electric indication is provided.

ii) The points, locks and bars shall not be worked by wire but by rodding or power operation.

iii) Spring points shall not be used. iv) Movable crossings and movable diamond crossings on passenger lines shall be provided

with complete facing point equipment of approved type. v) The requirement of points as stipulated in chapter VII of Signal Engineering Manual

shall be followed. 5.7 Interlocking: 5.7.1 Signal & Interlocking apparatus and installations shall be in accordance with chapter VII of Signal Engineering Manual. 5.7.2 Apparatus provided for operation and control of signals, points etc shall be interlocked

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and arranged to comply with the essentials of interlocking and other requirements as laid down in chapter VII of the Signal Engineering Manual, Part-I. 5.7.3 The operation of the signalling gears may be from a lever frame or a panel with individual operation of points, signals and other functions of a providing operation of a route setting type or other approved means in accordance with the provisions of Chapter VII of the Signal Engineering Manual, Part-I. 5.7.4 When a signal is controlled by more than one agency, it shall be possible for every such controlling agency to replace the signal to ‘On’ position. 5.7.5 The Station Master shall be provided with interlocked mechanical or electrical control of the Home & last stop signals except where i) all reception lines are fully track circuited from Home Signal to corresponding Last Stop Signal on double line and Home Signal to Home Signal on single line, or All reception lines are track circuited from the fouling mark to fouling mark and the non-track circuited portion of the line from the fouling mark to Home Signal is within the range of visibility of the Cabin Assistant Station Maser /Leverman/Switchman, ii) Station Master does not allot the line; and iii) Cabin Assistant Station Master/ Switchman posted in the cabin operates the block instruments and controls reception/despatch signals. 5.7.6 Standards of signalling & interlocking shall be complying with the requirements of the Signal Engineering Manual. 5.8 Siding and trap points: 5.8.1 Siding shall be arranged in such a manner that shunting operations upon them shall involve the least possible use of, or obstruction, to running lines. 5.8.2 Trap points shall be provided upon goods lines & sidings at their junctions with passenger lines, with points normally set against the passenger lines and interlocked with the signals. 5.8.3 Bay and loop platforms line & refuge loops shall be isolated from main through lines. 5.9 Junctions of tracks: bars or other appropriate devices shall be provided in order to

define the fouling points of junctions, loops, siding connections, crossings and the like. 5.10 Isolation at stations: 5.10.1 The speed of trains running through stations shall be governed by the General Rules for all open lines administered by the railway administration, both government and non-government railways and shall be subject also to the restrictions relating to the standards of Interlocking in the Signal Engineering Manual. 5.10.2 At no station at which isolation has not been provided, through running trains shall not be permitted at speed 50 Kilometre per hour or less, unless all shunting has been stopped and no vehicle unattached to an engine or got properly secured by the Station Master, in accordance with provision of special instructions, kept standing on connected line which is not isolated from the through line. 5.10.3 At any station where there is a speed restriction for through running trains different from neighbouring stations, speed restriction board should be erected at the first approach signal or where no signals are provided, at full braking distance outside the first facing point. 5.10.4 In order to maintain safety for through running, points for trap siding must not be inserted in the main line or through line, except under approved special instructions in

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accordance with the Signal Engineering Manual Part-I. 5.10.5 All the passenger running lines may be isolated from all sidings connected thereto. 5.10.6 All goods running lines may be isolated from all siding connected thereto. 5.10.7 It is not necessary to isolate one goods receiving line from another. 5.10.8 Isolation may be accomplished by:

a) Connection to another line or long siding, b) The provision of short dead end siding, c) The provision of trap.

Which ever may be the method for isolation, a starter signal shall be provided except when allowed to be omitted under special approved instructions and when a trap is provided for isolation the trap switch should be located with the heel of the switch in rear of the fouling mark and preferably on straight. The switch shall be in the rail away from the line to be protected. 5.10.9 The various methods of isolation are: Method A: Cases in which the line, on which the train will run when points are set for isolation of the through line, is kept clear for the adequate distance, which shall be 180 metres at stations equipped with two aspect lower quadrant or two aspect colour light signals and 120 metres in case of station provided with multiple aspect signals or modified lower quadrant signals. Method B: When a short dead end siding is provided, it shall not ordinarily be long enough to permit of vehicles being stabled thereon. To obtain the adequate distance prescribed as mentioned in method A above, the points of the dead end siding shall be set for the cross over and against siding, before a train is admitted on a line trapped by this method. Where it is necessary for the dead end siding to be extended for the purpose of stabling vehicles, the above rule shall apply, unless a trap is provided on the dead end siding at a distance of not less than 180 metres (120metres in case of station provided with multi- aspect signalling) from the starter signal where provided or from points leading to the main or through line. No train must be admitted on the running line unless the trap is set and locked against vehicles occupying the further part of the dead end siding. Method C: When a trap is used, a train must not be admitted on to the trapped line unless the trap has been closed, so that the train will not be derailed if the Loco Pilot overshoots the trap. 5.10.10 When Method A cannot be used, and for any reason it s not convenient to use Method B or Method C and to provide adequate distance by setting the points of the short dead end siding or trap for the crossover and against the siding or the trap, a sand hump of the appropriate design should be used as a substitute for adequate distance as provided in rule 3.40(4) of General Rule book. In that case the length of the siding should be at least one rail length and formation should be made up for a short distance beyond the sand hump. 5.11 Summary: It is hazardous for a train running through a station at any speed if any vehicle standing loose on an adjoining line may roll though and infringe upon the line through which the train is scheduled to run through. To safeguard against such a situation to arise, the problem is categorised in two parts one for stations where trains are allowed to run-through at a

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speed of 50 kilometres per hour and other where the trains are allowed to run through at a speed above 50 kilometres per hour.

At stations where trains are allowed to run through at a speed of 50 kilometres per hour or less, though isolation is not required but it has to be ensured that the vehicles on adjoining lines connected with the line on which the train is to run-through, are either attached with a loco or are secured or fastened with track in such a way that they do not roll due to any reason be it vibration of the running train or gradient. At stations where the trains are allowed to run through at a speed of more than 50 kilometres per hour, the lines on which the train is scheduled to run through shall be isolated from all other lines by one of the three Methods described as Method A, Method B and Method C as above. In case of Method A, adequate distance beyond starter or the place at which the train is proposed to stop shall be kept clear. The adequate distance shall be 180 metres in case of two aspect signalling be it semaphore or Colour light and 120 metres be it case of multiple aspect semaphore, modified lower quadrant or colour light signalling. See Fig. 5.7.5.a.

FM

120 mts

Run through line

120 mts

Run through line

Fig. 5.7.5 a

Method A for isolation Fig. 5.7.5 (b-I)

Method B for isolation with short siding In case of Method B, a short siding shall be provided ahead of the starter signal or the place at which the train is proposed to stop. The clear length of the siding shall be the prescribed adequate distance as discussed in method A above. This siding shall under no circumstances be used for shunting or stabling of any vehicles. A long siding may also be provided instead of short siding, however a trap point shall be provided at an adequate distance beyond the starter or at which the train is proposed to stop, here the length upto trap shall invariably be kept clear. However in exigencies when the siding is obstructed for any reason the adequate distance shall be deemed not to be available. See Fig. 5.7.5 (b-I) & Fig 5.7.5 (b-II).

Run through line

120 mts

Run through line

Fig. 5.7.5 (b-II)

Method B for isolation with longer siding & a trap

Fig. 5.7.5 c Method C for isolation with a trap

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In case of Method C, A trap point shall be used for the isolation purpose, which shall be kept open to isolated main line, through which the train has to pass, from loop line to be isolated. However in such case while receiving the train on loop line, the trap must be closed to set overlap towards the run-through line. See fig. 5.7.5 c In case none of the methods is feasible for any reason a sand hump of approved design shall be provided which is considered to be an adequate replacement of short siding, long siding or tarp point. The sand hump shall be connected with the track keeping at least one rail length in between. See Fig. 5.7.5 d Further more, all passenger running lines shall be isolated from all goods lines or sidings; all goods running lines shall be isolated from all sidings and it is not necessary to isolate goods receiving lines from each other. 5.12 General: 5.12.1 The requirement and regulation of Block Instruments shall be in accordance with section “N” and section “R” of chapter VII of the Signal Engineering Manual, Part – I. 5.12.2 The requirement of Centralised Traffic Control (CTC) shall be in accordance with section `Q’ of chapter VII of the Signal Engineering Manual, Part – I. 5.13 Catechism for signalling and Interlocking installation: One of the methods to verify that the all requirements pertaining to the work have been fulfilled, the best is catechism, which is listing out questions, answers to which not only verifies the part of the work done but also reminds of the lapses if any. Interestingly some of the questions provide information otherwise not available elsewhere.

Sand hump

Run through line

fig. 5.7.5 d

Isolation with a sand hump

5.13.1 Inspection at the Signals: i) Are all running signals controlling trains placed in such a height above rail level so that

they can be clearly seen by Loco Pilots in sufficient time and be readily distinguished by night or by day from the subsidiary signals?

ii) Are all signals constructed so that their normal position is at `On’ or most restrictive and that they stand at or return to this position in case of failure of any part of the signals or their connections except in case of Automatic signals, the normal aspect of which is `Off’?

iii) Do all signals come fully `Off’ when worked and return freely to the `On’ position? iv) In case of slotted or controlled signals, can the signals be freely returned to danger by

either of controlling agencies except in case of signals controlled by key transmitter or any such control?

v) Are signal counterweights, where possible, fixed out of reach? vi) Is the facing side of the arm of the semaphore signals, including miniature and disk

signals, but except Calling on signals, painted the same colour as the light exhibited in the `On’ position?

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vii) Are signals not in use fixed at `On’ and distinguished by having to crossed bars attached to them, each bar being not less than one metre long and 100 millimetres wide?

viii) Are all signals of standard type and do they comply with the requirements as laid down in the General Rules and have they been passed by Sighting committee?

Whenever a new signal is installed or the position of an existing signal is changed, the

signal is required to be passed by a Sighting Committee consisting of a Loco Inspector, Section Engineer (Signal) and Traffic inspector, before the signal an be brought in use.

ix) Are all fixed signals, the front light of which cannot be seen from the point from which

they are worked, provided with a small white backlight not larger than is actually necessary and visible only when the signal is at `On’? Also is the fixed green light of every Warner, which is used by it, provided with a white back light?

x) Do all the Distant signals in Multiple Aspect area show two back lights in `On’ position and no light in any other position or where electric lighting of Distant signals is provided, it shows at least on back light in the `On’ position? However colour light signals shall not be provided with back light since these are provided with visual indication.

xi) Do miniature and dwarf signals, used to control shunting show the same front and back lights, as are prescribed for running signals and are the lenses small enough to make them distinguishable from running signals?

xii) Are signal lamp brackets fixed on the posts, and is suitable provision made for lighting and cleaning lamps?

xiii) If any signal is placed at more than 180 metres away from the facing points it controls, is arrangement made to keep the points locked until the train has passed them?

xiv) Are all signal arms placed on the left-hand side of the post as seen by the Loco Pilot of the approaching trains to which the signals refer?

xv) Are all signal posts placed on the left-hand side of the track of the approaching trains to which they refer? If placed otherwise, for what reason?

xvi) Where two or more lines diverge, are signals fixed on a bracket post or on separate doll post carried on Signal Bridge?

xvii) Where two or more lines converge, are signals fixed on altogether separate posts or separate doll posts carried on single bridge?

xviii) Are bracket and the bridge signals arranged so that each signal from left to right, from the point of view of approaching trains, applies to each corresponding line from left to right, and are they distinguished by grouping and by marking the more important signal higher to those of lesser importance? Here the highest signal must always refer to the straight line.

xix) In case of two or more signals referring to parallel lines, are they arranged in transverse line as nearly as circumstances allow?

xx) Does any case occur or more than one signal referring moving in the same direction being placed on the same post, other than Warner, shunt or calling-on signals?

xxi) Are Warner signals fixed 1.5 to 2 metres below stop arm or fixed green light? xxii) Are Co-acting or Calling on signals placed not less than 2.5 metres below the

Semaphore arm above? xxiii) Are Warner signals, which are un-worked, secured in the `On’ position?

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xxiv) Are arrangements made to render it impossible for the Warner arm to be taken `Off’ independently of the stop signal arm above it and when the stop signal arm returns to danger, the Warner if `Off’ automatically returns to danger?

xxv) At diverging junctions, is one Warner signal only provided applying to the through line? xxvi) Do all signal lights show red in the `On’ position, or yellow/double yellow in the case of

Distant signals, or no light in the case of Calling on signals? xxvii) Do all running signal lights show green in the `Off’ position in two aspect signalling

sections and yellow, double yellow/green in multiple aspect signalling section? xxviii) Are signals where necessary effectively guyed? 5.13.2 Inspection at points: i) Is the locking of facing points is such that points can not be or become unlocked while a

train is passing over them? i.e. a) are lock bars provided of a length exceeding the greatest distance between any two adjacent axles likely to be used on the line or alternatively is the point or lock lever electrically controlled by the track circuits? b) In case of key locks, are the locks either under the train and therefore inaccessible or if not placed under the train, is the arrangement such that the key is used to release the signals and that it cannot be brought back to the points until such signals have been up to the `On’ position?

ii) Is the arrangement such that the operation of the facing point lock depends on the correct operation of the lock bar where used, and it is impossible for the lock bar to be forced over while a train is passing over it?

iii) Are the locks of a substantial pattern and make? Are they fixed in such a manner as to ensure the necessary rigidity and are key sufficiently large and strong to minimise the chance of their being mislaid or broken?

iv) Do key locks fitted to facing punts on the passenger running lines lock both switches? v) Are the switches adjusted to come tight against stock rails? Does the insertion of 5 mm

obstruction piece between the switch rail and the stock rail, 150 mm from the toe of the switch prevent the points being locked and prevent the relevant signals from being taken `Off’, the giving of which is preceded by the locking of the points?

vi) Do facing point plungers clear the stretcher bar blade when the points are unlocked and in the event of there being an obstruction at the points, it is impossible for the point lock plunger to enter the stretcher bar blade and for point lock lever to be forced into its normal or reverse position?

vii) Are all facing points fitted with a gauge tie plate where steel sleepers are not provided at the toe of switches, and are they provided with split stretcher bars or other fitting giving equal security?

viii) Are all points, locks and detectors securely fixed? ix) Are detectors fitted to all facing points and do they efficiently detect with both switches,

the signals controlling the movement of the trains over them? x) Are trailing points on passenger running lines used in the facing direction for shunting

movements which are not fitted with facing locks, detected with the relative shunt signals?

xi) Is it possible for any detector slide to enter a notch other than that intended for it?

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xii) Do point indicators show the prescribed indications i.e. white for the straight green for the turnout in both directions and where fitted to trap points red in both directions when trap is open and green in both directions when trap is closed?

xiii) Where point indicators of the directional type have been provided has this been done under approved special instructions?

5.13.3 Inspection on the track: i) Are all through lines isolated from each other, from other running lines and from all

sidings? ii) Are running lines isolated from all sidings and goods lines, either by a) trapping into

dead ends taking off the sidings or goods lines? iii) Are dead ends traps so locked as to prevent any possibility of the running lines being

fouled for which signals have been taken ‘Off’? iv) Are dead ends traps fitted with indicators, or they are protected by signals? v) Are dead ends and traps placed in such a position as to ensure that any vehicle that may

be derailed by them shall not foul any running line? vi) a) Are all points worked by rodding within a distance of 320 metres from the lever

operating them?, b) if the distances are greater than those specified in (a) , are they within the limit of 460 metres , and is a stroke of not less than 200 mm provided at the lever tails?

vii) Is the rodding efficiently laid and properly compensated where necessary, and means of adjustment provided?

viii) Are all signal connections efficiently installed and means of adjustment provided? 5.13.4 Inspection of the cabin or at the lever frame where there is no cabin: i) Is signal cabin provided with the following essentials: a) A clock in cabins where train movements are registered. b) A diagram correctly representing the arrangement of the points and signals worked

from the cabin in their normal position and the number of the points and signals? c) Lights so arranged as not to be mistaken for running signals or interfere with their

sighting? ii) Is there sufficient space in the cabin to allow the man or operator freedom of movements

for manipulating the levers or other apparatus in the cabin? iii) Is the gear leading off from the cabin or frames securely fixed? iv) Are the levers painted with distinguishing colours and in addition to its own number

does each bear the numbers of the levers, which must precede it, and in the proper order?

v) Is the cabin so located and built as to enable the cabin man to have the best possible view of all the points and signals, the working of which he is responsible for and also, for all movements under his control?

vi) Are all signals, which are not visible from the cabin or frame electrically repeated? If so, does the repeater repeat the light as well as the arm?

vii) Have instructions for working have been issued to the staff and included in the Railway Working instructions, and are they correct and sufficient?

viii) Is the Station Master provided with interlocked mechanical or electrical control of the Home and Last Stop Signals?

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5.13.5 Test to be made in the lever cabin or at the Lever frame: It is essential that the interlocking of all signals with the points is so effected as to ensure the following conditions, which may be tested from the cabin or frame by pulling over the levers for each combination allowed by the locking table and checking the security of each such combination by attempting to infringe it: i) Is it possible to take ‘Off’ conflicting signals at the same time? ii) Is it possible to take `Off’ signal until a) all points on the running line including overlap

are correctly set and the facing points locked? b) All points giving access to running line from sidings and goods lines, are set against the running line? c) Level Crossing gates, if included in or controlled by the interlocking, are locked across the roadway?

iii) A signal lever, when operated , locks or back locks as necessary, the levers operating the points and gate locks referred to in this paragraph?

iv) When all signals are `On’ are all points, which would be locked by the taking `Off’ such signals, free for shunting purposes?

v) Is it possible to take `Off’ a Warner signal until all the relative stop signals in advance have first been taken `Off’ and when `Off’ does it back lock such signals?

vi) Does the locking in the frame correspond with that shown in the approved locking table?

vii) Is the locking strong, durable and accurate, i.e. can any tappet enter a notch other than for which it s intended, or can the locking be forced?

viii) Does the locking in the lever frame act on the commencement of the movement of the lever in case of direct locking type of lever frames and on pressing the catch handle in case of catch handle/ Double Wire type of lever frames?

ix) Is release locking not effective before the completion of the movement of the lever? 5.13.6 Power operated points and signals: These questions are to be read in addition to the questions for other signalling and interlocking installations to the extent they are applicable to power operated points and signals: A. Signals: i) Is the mechanism case weather proof and protected for unauthorised interference? ii) Do the indication contacts close if the arm is more than +5 or - 5 degrees from `On’ or

`Off’ Position? iii) Is the signal and hold off mechanism so constructed, that in the event of a failure the

signal shall go to the `On’ position? iv) With the exception of motor commutators, etc is a surface leakage distance of not less

than 6mm provided between any exposed metallic part of the mechanism carrying current and other metallic part thereof?

v) Are the signals so bright as to cause confusion in reading at night? vi) Does the signal give distinct indication to the Loco Pilots when approaching or stopped

at a signal? B Points: i) Is the switch operating mechanism of substantial design securely fixed and protected

from unauthorised interference?

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ii) Is the mechanism provided with means for emergency operation in the event of a failure?

iii) Does the use of the bank or other apparatus for emergency operation disconnect the power supply to the motor and prevent clearance of the signal for such points are required to be set?

iv) With the exception of motor commutators, is a surface leakage distance of not less than 6mm provided between any exposed metallic part carrying current and other metallic part of the mechanism?

v) Is the mechanism so constructed that it can be stopped revered or obstructed at any point of its movement without damage?

vi) Is the mechanism so constructed that it cannot give a `Normal’ or `Reverse’ indication, unless the closed switch be within 5 mm of the stock rail and in the case of facing points, switches are properly locked?

vii) In order to prevent the movement of points while a train is passing over them, are facing points provided with lock bar, alternatively with track circuit locking of the point lever?

viii) Where the movement of trains over the points are not within easy visibility of the cabin, is occupation of the section between the stop signals leading to over the points and the fouling point ahead of such points, electrically indicated in the cabin?

C. Cabin and Lever Frame: i) In the case of power interlocking frames, is the lever frame mechanism completely

enclosed with removable covers giving free access to all parts and provision made for securing such cover against unauthorised opening?

ii) Are all exposed metallic parts carrying current, not less than 6 mm surface leakage distance between and any other metallic parts of the mechanism?

iii) Are the levers operating power worked points provided with `Normal’ and `Reverse’ indication locks, adapted directly to prevent the full the movement of the lever, unless the point mechanism has made the required movement and the point is in a position corresponding to that of the lever and in case of facing points, unless the point is securely locked? This test shall not be required where alternative electrical locking is provided.

iv) Are the levers operating power worked signals provided with `Normal’ indication locks, adapted directly to prevent the full return movement of the normal, unless the arm has returned to the `On’ position? This test shall not apply to a mechanical lever frame, if the signal is repeated at the place of operation through an arm and light repeater.

v) Are all electric locks mechanically replaced to the locking position? vi) Is all the wiring between different parts of the apparatus made with suitably insulated

wire and efficiently protected? vii) Is the lever frame properly earthed and are efficient safeguards provided to prevent

injury to the operator, in the event of a short circuit or other similar circumstances? D. Cables and circuits: i) Do all main cables terminate in properly sealed boxes? ii) Are circuits controlling the operating and indication of signals so arranged that as far as

practicable a cross connection or a short circuit on any of the wires, cannot give a false `Clear’ indication?

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iii) Are circuits controlling the operation and indication of points arranged such that, as far as practicable, a cross connection or short circuit cannot operate the switch or give a false indication of the position of the points?

iv) Is the battery or power supply for line circuits, as far as practicable, arranged at the end of the circuit farthest from the operated unit?

v) a) Are all main track circuits as far as practicable so arranged as to provide the best protection against broken rails, points crossings etc? b) Are the adjacent track circuits staggered in polarity?

vi) Are sidings and junctions track circuited upto the fouling mark? vii) Are hand worked switches in or leading to automatic signalling territory, equipped with

a circuit controller operated by the normally closed switch? viii) Are such switches electrically locked by the approaching track circuits to prevent their

movement in the face of an approaching train? 5.13.7 Signalling and Telecommunication installation in 25 KV 50 Hz single conductor

AC electrified sections: A. Signals: i) Are the signals located in accordance with the approved Instructions as per Manual of

instructions for installation of Signalling and Telecommunication Equipment in 25KV, 50Hz AC electrified section?

ii) Have the protective iron screens as required for signals/fittings within 2 metres of live conductors / parts been provided and earthed?

iii) Where it is not possible to provide protective iron screens, has a caution board been provided on the signal posts in accordance with the approved instructions?

iv) Has the `Signal Sighting Committee’ certified that the Loco Pilot’s view of the signal is clear?

v) Have only multi aspect signals been used in colour light signalling area? vi) Is the AC power supply arrangement for the colour light signals of a type approved for

Railway Electrification areas? B. Points: Have the rodding transmission of points and other apparatus been insulated as per the

approved instructions? C. Electrical Signalling equipment: i) Does the design of Signalling equipment and the circuit used in Railway Electrified

areas provide for safety factor 1.5 against AC interference? ii) Has it been ensured that the signalling equipment not suitable for Railway Electrified

areas on external circuits like banner type indicators, Luminous indicators, Telephone type relays, Electrical Lever locks, rotary key transmitters, DC neutral polar relays of 250 ohms, DC neutral line relays and door coils of IRS block Instrument etc have not been used?

iii) Has it been ensured that all stick relays have at least 4 front and 4 back contacts and their pickup transfer time is not less than 300 milliseconds?

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D. Cabling and wiring circuits: i) Have all telephone circuits, except cabin to cabin to ASM circuits, which may be

retained on signalling cable, been transferred to separate underground telecommunication cable?

ii) Have all overhead wire circuits been shifted or cabled as per the approved instructions? a) Has it been checked that the voltage induced due to parallelism in the

telecommunication cable under normal and short circuit conditions are within safe limits as specified by the consulting Committee of International Telegraph and Telephones?

b) Has it been ensured that the earth return circuits are not retained and have been replaced by metallic return circuits except block circuits?

c) Has the principle of double cutting been used isolated for internal circuits and batteries?

d) Has the external circuits and batteries been isolated from internal circuits and batteries?

e) Has it been ensured that the induced voltages in the length of inter-cabin telephone circuits in signalling cables does not exceed 60V?

E. Batteries: i) Has it been ensured that power supply for internal and external circuits and for each

block instrument are isolated? ii) Has it been ensured that the battery for signalling equipment is separate from the battery

for telecommunication equipment? F. Earthing: i) Have the lever frames and other equipment been earthed in accordance with the

approved instructions? ii) Has it been checked that no earthing pipe is less than 3 metres away from any other

earthing pipe? iii) Has it been tested that the earth resistance does not exceed 10 ohms for the signalling

equipment and 1 ohm for telecommunication copper cable earth? iv) Has the screening of the telecommunication cable terminated at the sectionalising points

and repeater stations been earthed in accordance with approved instructions? G. Track circuits: i) Has it been ensured that track circuits are of approved type? ii) Have measurements of DC stray currents been taken before installation of DC single rail

track circuits and whether these are within permissible limits? iii) Has the longitudinal and transverse bonding in track circuited areas been provided as per

the approved instructions? iv) Have the DC single rail track circuits of closed type been installed in accordance with

the approved instructions? v) Have the protective measures like surge dischargers (Interval of Discharge) been

provided on track circuits, where required as per the approved instructions?

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H. Block Instruments: i) Are the block instruments installed of a type approved for the use in AC electrified

sections? ii) Have block filters for single line and double line block instruments been provided in

accordance with the approved instructions? iii) Are the filter units of an approved design? iv) Have the line terminals of block filters been painted red to caution the maintenance staff

against high voltage? v) Where a block section falls between an electrified and non electrified section, has it

been ensured that bock filters have been provided for block instruments at either ends of such block sections?

vi) Have the block telephones been provided on a separate pair of conductors in accordance with the approved instructions?

vii) Have the block circuits been provided on underground cables as per the approved instructions.

viii) Have three position polarised relays of SGE block instruments been provided in accordance with the approved instructions?

ix) Have the block release and Advanced starter control of block instrument been provided in accordance with the approved circuit?

x) Has it been ensured that the circuits from a non-electrified section approaching an electrified section and vice versa been cabled for a length of 1 kilometre beyond electrified sections?

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Chapter IV Self Assessment

1. Multiple Choice Questions: 1 The amount granted against capital fund is

financed by Central Government only when rate of return is: a) 14% or more* b) 13% c) Both a) & b) d) None of above

2 The tender received after the scheduled time of opening, are: a) Delayed tender b) Late tender* c) Normal tender d) All of above

3 In two packet system, the tender document is divided into: a) Credential bid b) Financial bid c) Only a) d) Both a) & b)*

4 Termination Indicator shall be provided for: a) Passenger train b) Goods train c) Both a) & b) are correct* d) Only b) is correct

5 Demand No.16 is meant for: a) Revenue receipts b) Capital expenditure* c) Revenue expenditure d) Development expenditure

6 The cost of work to be tendered includes the cost of material: a) To be supplied by Railways b) To be supplied by contractor* c) To be supplied by both Rly &contractor d) To be supplied by sub contractor

7 Various methods of providing isolation are: a) Sand hump b) Track circuits c) Long or short siding d) Any one of the above*

8 Catechisms for installation is: a) Requirement of the work before

commissioning b) Listing of questions c) Check list in the form of questions* d) None of above

9 In case of execution of signalling work on running lines, the copy of safety certificate issued by Engineer shall be given to: a) Commissioner of Railway Safety b) Divisional Railway Manager c) Chief Signal & Telecomm Engineer d) All of above*

10 The size of cross to be provided on new signals before they are brought into use, shall be: a) One meter x 200 mm* b) 1.2 meter x 200 mm c) One meter x 250 mm d) 1.2 meter x 250 mm

2. Select the right answer True/False: 1. Construction organisations are headed by General Manager also. True*/False 2. For expenditure against judicial awards, parliament’s sanction is required. True/False* 3. The DOC extension may also be granted on account of lapses on contractor’s side. True*/False 4. Caution indicator shall be mounted at the height of 2 meters form the rail level. True*/False 5. Delayed tenders can be considered for award of work under normal circumstances. True/False* 6. Last accepted rates & SOR both are one and the same thing. True/False* 7. It is not essential to inform the contractor against whom risk & cost tender is being floated. True/False* 8. Late tenders can not be considered for award of work under normal circumstances. True*/False 9. The agreement shall be signal by the same officer who accepts the tender. True/False* 10. Whenever a work, which is not there in contract, is essentially required to be done to progress the main

work in contract, it can be executed pending sanction of the accepting authority in view of emergency. True/False*

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3. Answer the following questions: 1. Describe briefly procedure for execution of work starting with the stage of allotment of tenders for the

work. 2. Give the format for issue of telegram bringing the work into use. At what stage the concerned Engineer

incharge shall issue the safety certificate if CRS has proposed not to inspect the work before commissioning, while according his sanction.

3. Prepare rate analysis for casting of one foundation for colour light signal. The specifications, parameters & rates of various items may be assumed realistically.

4. While you are a member of tender committee, how would you proceed. Give step by step and elucidate the important factors which you shall keep in account while drawing T.C. minutes.

5. A variation in the contracted values takes place during the course of execution of work. Please detail the process for regularising it.

*****

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CHAPTER – V

RAILWAY ACCIDENTS

1 Categories of train accidents: Train accidents may be categorised in: i) Derailments, ii) Collisions, iii) Accident at Level crossing, iv) Parting of train, v) Incomplete arrival of train. vi) Vehicles escaping from the station. 1.1 Different causes of these accidents may be attributed to: i) Failure of station staff, ii) Failure of Loco Pilot, iii) Failure of technical staff, iv) Track defects, v) Vehicle defects, vi) Signalling & Interlocking defects, vii) Other Human failure, viii) Ruthless Driving by road vehicle drivers, ix) Short circuiting in the wiring of coaches, x) Carriage of inflammable materials, xi) Anti-social elements causing fires, xii) Sabotage. A decade wise trend of accidents in these categories are tabulated as below*. This table is an indicator of decreasing trend of accidents:

Years Number of Accidents (Yearly Average)

Million train Kilometres (Yearly Average)

Incidence of train accidents per million train Kms. (yearly average)

1960s (1961-1970) 1393 433.8 3.3 1970s(1971- 1980) 866 480.9 1.8 1980s (1981- 1990) 757 559.8 1.4 1990s (1991- 2000) 464 655.8 0.7 2000- 2003 (av) 412 686.6 0.6 2002 – 2003 only 349 793.8 0.44

2 Intimation of accident: The Loco Pilot or the Assistant Loco Pilot or the Guard of the train involved or any other train passing by or by nearest gate man or by any other means, the section control shall get the information through Emergency control circuit of the details of the accident occurred in the Block Section. In case of accident takes place in the station section, the -------------------------------------------------------------------------------------------------------------------- * Extract from Indian Railway Safety by Arya Bhushan & M.M. Agarwal.

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Station Master on duty, who shall come to know of the accident first shall inform the Section Controller. It is the Test room, situated near the complex where Chief Controller and the Section Controllers are placed, are first to come to know about the incidence for S&T Organisation. The Senior Section Engineer In-charge shall collect the information of site, time, trains involved, casualty if any, extent of damage to the track and S&T equipment. He shall inform S&T officers, SSE, SE JE and other artisan staff to reach the site. A hooter is sounded at the Divisional headquarters station yard to intimate the concerned railway staff to reach the site of accident. The hooter codes also gives vital information about the accident.

3. Accident Relief Train (ART): A train equipped with Tools plants, crane, communication arrangements, coaches to carry staff and officers, medical van, Spares of general nature for S&T and other departments is kept ready to move on short notice to the site of accident, at the divisional headquarters and at such places where the train can be accommodated and shall be able to cover reach of entire division taking minimum time. The ART is inspected by Officers frequently to ensure all tools, equipment and spares are maintained in fit to use condition. 4. Post accident action: 4.1 It is the prime responsibility of each railway officer and the employee associated with the maintenance of the section, to reach to the site of accident as quickly as possible immediately after getting information of the accident. The Senior most Officer or senior subordinate travelling in the affected train whether on duty or on leave and whether or not associated with the section in which the accident takes place shall take charge of the situation till an officer associated with the section reaches the site, and arrange for rescue of the passenger without disturbing the evidence of the accident. 4.2 The officer in charge shall arrange for joint investigations and recording the measurements, a sketch, statements of the station and train crew and other staff concerned with the accident and other vital information to be carried out by Senior subordinates of traffic, Loco/ electric (operation), Civil engineering (P. Way) and of a branch apparently not concerned with the accident. 4.3 He shall arrange simultaneously placement of ART, Establishment of communication with the divisional headquarters other measures for restoration of traffic. 4.4 Action shall be taken to: 4.4.1 Rescue the passengers, arrange first aid to injured and sending them to nearest hospital. All passengers stagnated with the train shall be sent forth to their normal journey as soon as possible.

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4.4.2 Communication shall be established by S&T department i) between site of accident and divisional headquarters using emergency control circuit or administrative line connected through emergency sockets or using BSNL, GSM(Rly.), satellite link or any other service provider and ii) between work force and officers at site of accident using VHF system. 4.4.3 Enquiry into cause of accident: One of the important action to be taken after the accident is to establish the cause of the accident so that remedial measures may be taken to prevent repetition. For this: i) Take measurements, photographs and carryout other observations, prepare a sketch and

other measures to preserve evidence in bringing out cause of accident. ii) Take statements of staff relevant to the accident and who could be helpful in

establishing the cause of accidents. iii) Prepare a preliminary enquiry report jointly by senior subordinates. This shall be done

as quickly as possible as the restoration work shall start only after completion of this activity.

iv) It shall also be ensured by all Officers and Senior subordinates available at site of accident that a) no evidence is tempered, dislocated or shifted, while at the same time b) no evidence is omitted from being put on record howsoever insignificant it may appear to be.

4.4.4 While enquiring into cause of accident the senior subordinates of Traffic, Signalling, P. Way and any other branch of railways who may be concerned with the cause of accident, shall take all actions such as taking statements, measurement s etc, jointly. 4.4.5 Restoration of normal traffic shall be done as quickly as possible. 5. Derailments: 5.1 In Block Section: In normal course there is no involvement of S&T department if train derails in Block section except for assistance in restoration of traffic by way of providing communication. 5.2 In Station section: train may derail in station section on i) the point, due to a gap between switch rail and stock rail. This situation is called no road. ii) points moving in face of the approaching train, when the point is neither set normal nor reverse, in this case also no road situation shall arise, iii) points moving under the wheel, in such a situation some of the wheels shall move on road set for one direction and other on the road set for other direction, iv) on straight route where involvement of point is ruled out. 5.2.1 It is only in case of signalled movements where the interlocking system takes care of the safety of the trains. In case of signalled move, the point is supposed to be properly set and locked at site as well as in the interlocking. Possible reasons may be: i) Mounting or wedging through of any wheel of the train: The wheel flange shall not

be able to wedge through a gap of 5 mm or less between switch rail and stock rail of the point. In a situation of such a signalled move where the wheel has been able to wedge through the point, a no road situation shall arise. It also may happen that effort is made to unlock the point immediately after passing the signal by the Loco, which may result in riding of the wheel over the raised lock bar resting on the upper crest of the radial

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guide. Under such circumstances it becomes the responsibility of S&T to clear its position.

ii) Points moving in face of the approaching train: In case of change in decision to receive the train on a line other than for which signals had been taken ‘Off’ after the Loco Pilot accepts the signal. If the reception signal is put back, the point unlocked and changed but the driver is not in position to bring his train to a stop before the reception signal, he is likely to encounter the points moving, resulting in no-road and as such derailment. In such a situation a controversy shall arise as the Loco Pilot shall be telling that he saw signal `Off’ while approaching the same and then saw signal going back to `On’ but the station staff shall be telling that the signal was `On’ only. The lever position in the cabin shall also support the operating staff‘s version. However it can be established if the Station Master’s log register record is upto-date and the section Controller‘s statement supports the change in decision. This can also be established if the data logger is provided at the station and is functioning well. In this case chances of damage to switch or stock rails are negligible except because of drag after derailment.

fig.5.2.3

Derailment when points are in no road condition.

iii) Points moving under the wheel: situation is not possible in case of signalled movement. In case of rod operated points it may be possible if the lock bar is not effective and it is possible to move the lock bar under the wheels. Lock bar may become non-effective if out of 12 lock bar clips at least three in a row were lying unbolted and not supporting the lock bar thereby reducing the effective length of the lock bar. However if the track locking is achieved through track circuits, the movement of points may take place only due to equipment failure or unauthorised interference. In this case chances of damage to switch or stock rails are negligible except because of drag after derailment.

iv) Investigation:

a) Seizure of records: All records with the train movement in the Station Master’s office, both the cabins and Loco Pilot shall be seized.

b) Statements: statement of Station Master, cabin Masters of both the cabins and Loco Pilot/ Assistant Loco Pilot shall be taken,

c) Inspection & tests: i) If the switch rail area of the point is not damaged the point should be tested with

obstruction piece of 5 mm in between stock and switch rail to see if the point gets locked in the position on which derailment took place. It is important to note that if switch rail toe area is damaged due to accident, obstruction test should not be resorted to as it becomes very difficult to establish the integrity of

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the locking arrangement if the toe area of the switch rail is damaged due to derailment. Sharp wheel flange, is able to wedge through the switch rail or mount the switch rail, as such in either case first wheel derailed should be checked for sharp flange. A wheel flange thinner than 22 mm measured from wheel gauge face at 13mm from outer edge of the flange, is not permitted to be used on high speed trains (IR Safety, by Arya Bhushan and M.M. Agarwal). The shape of a sharp wheel flange is shown in the Fig 5.2.1.

ii) Uneven loaded goods vehicle or shifting of load is also responsible for wheel jumping off the rails.

iii) There have been cases of wheel mounting on the toe of switch rail giving false indication of gap in the switch and stock rail also mounting on heel block. Both the situations become complicated because of damages due to derailment.

In all the three situations other than derailment on straight route, wheel marks should be located and recorded through sketch also. In case of wheel mounting at heel block there shall be clear dent marks on the inside fishplate joining wing rail and switch rail. In case the wheel flange has mounted on toe of the switch rail clear longitudinal dent shall be observed on the toe of the switch. However this should be distinguished with normal wear on the toe of the switch rail formed over the period due to tight gauge or due to curvature. The marks of mounting of the wheel shall be deep while wear marks shall be in the form of longitudinal scratches. In case the wheel flange wedges in between switch rail and stock rail at the toe of the switch there shall be light scratch marks inside the switch rail at the toe of the switch, besides there shall be scratches on the stock rail also at the same place as on switch rail, facing point lock (FPL) may get shifted and might even shear off the holding bolts of the FPL. In case of electric point machine also the point machine may get shifted, or bolts holding point machine may get sheared off or base of the point machine may get broken at the hole meant for holding bolts. Point machine should be opened after verifying integrity of its locking arrangement to check for status of point locking assembly. Any one of the observations shall be suggestive of that the point adjustments were as such that it could not have been possible to lock the point with 5 mm obstruction in between stock and switch rails. d) Preparing sketch: A sketch shall be prepared showing point of mounting of wheel

point of drop and drag along with other significant information. 5.2.2 Derailment on straight route: Derailment on straight route may take place because of hanging brake block or any other part of vehicle falling in track, tight or slack gauge, rail fracture during winter, track buckling during summer, uneven loading or shifting of load, running over of animals etc.

Fig.5.2.1 profile of the wheel flange

shown in firm line and sharp , in dotted line

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6 Collisions: Collisions may be within station section or in Block section. It may be i) Head-on collision, ii) Head to tail collision, and iii) Side collision. 6.1 Collision in station section: In station section any of the three types of collision may occur. 6.1.1 Head-on or head to tail collisions: Any of the two may occur because of wrong allocation of line or passing a signal at `On’ by Loco Pilot. In extreme exigencies equipment failure or unauthorised interference with the system may result in signal coming `Off’ for an occupied line where flank protection is provided. The yard may be equipped with i) no track circuiting of berthing track in the yard, ii) main line track circuited between fouling mark to fouling mark where loop lines are not track circuited. iii) entire yard track circuited.

i) In fist case where no track circuiting of berthing track is available observing clearance

of line is to be done by the Station Master, manually. In such a case any laxity in checking line clearance may result in head-on or head to tail collision. Another situation may be where the Loco Pilot has passed the signal at `On’. In both the situations it is very difficult to find out the cause if the station staff takes a stand that the Loco Pilot has passed the signal at `On’ and the Loco Pilot says that he saw the signal `Off’. The inference shall be drawn about the cause of accident by the Train Log records of the Station Master and both the cabins along with their `private number’ books , if taken into custody in time, the statements of the Operating staff of the station and the Loco Pilot, Assistant Loco Pilot and the Guard of the affected train.

ii) In second case where mainline is track circuited while loop lines are not track circuited, the collision taking place on non track circuited line shall lead to a similar situation as in first case. However in case the collision occurs on track circuited line it shall not be possible to take `Off’ the signal for the occupied line and hence a train could not be received on occupied line unless the track circuit had been bypassed. In this case also inference can be drawn by observing the same procedure as in preceding paragraph (a), except that in this case the signal failure book, presence of the signal maintainer at the station with specific reference to the relay room should be given additional cognizance.

iii) In case when the entire yard is track circuited usually in case of central panel interlocking or RRI, The system is such that it is not possible to receive a train on a track occupied besides unauthorised interference is almost impossible. The Central panel Interlocked stations are usually provided with data-loggers which, when accounted for with other records and statements of staff it is possible to a large extent to substantiate the cause of accident.

iv) Investigation: a) Seizure of records: Train movement Log register, private number books of the

Station Master and both the cabins, Relay Room key register and Loco Pilots diary of record should be seized under joint signatures.

b) Statements: Position of levers in both cabins and position of slides in SM’s slide frame shall be recorded jointly. Statements of Station Master on duty, Cabin Masters on duty of both cabins, Loco Pilot & Assistant Loco Pilot and the Guard of

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the train, shall be recorded jointly. If the key of the relay room is found to be under issue at the time of accident, the relay room shall be examined for any temporary connections and observations put on record jointly. The data to establish time of taking `Off’ relevant signals shall be retrieved in case data logger is provided at the station. All information thus collected shall be analysed to establish the cause.

6.1.2 Side collision in station section: Side collision may take place in two situations, i) first when a train is standing on a line infringing with the Schedule of Dimensions with the adjoining line on a turnout or crossover and ii) the other case when coaches or wagons of derailed train are fouling with the adjoining track. In this case when a train moves on the adjoining line infringed upon, as mentioned, shall collide by its side with the other train.

i) Side collision when the train is standing on a line infringing with the Schedule of

Dimensions with the adjoining line on a turnout or crossover: The GR4.56 provides that `When a train comes to a stand at a station, the Guard shall see that, whenever possible, the last vehicle of his train has cleared the fouling marks of all points and crossings. If not, he shall inform the Station Master at once and exhibit Stop hand signal to prevent any movement on the fouled line.’

In addition, on stations where point zone is not track circuited, a fouling bar is provided linked with the point in such a way that it is not possible to change the position of the point from the last operated position unless the train clears the fouling bar. With this it shall not be possible to receive next train on adjoining line unless the points are changed from their last operated position. On stations where point zones are track circuited flank protection is achieved by providing track circuits in such a way that the part of the track circuit falling within the fouling mark, if occupied shall not permit taking `Off’ the signal for adjoining line fouling the line on which train is already standing. See `Flank Protection’, Chapter-II, figures 7.3.10 (B-I) & 7.3.10 (B-II).

ii) Side Collision on straight route: Side collision in station section on straight route shall be under similar circumstances as in case of side collision in Block Section and shall be discussed in ensuing paragraphs.

6.2 Collision in the Block section: 6.2.1 Head on or head to tail collisions: i) Head on Collision: In Block section head on collision may take place on single line

section or under special circumstances when single line working has been introduced on double line section due to any reason. In case of head on collision on single line section a) one of the possibility is disregard of `On’ last stop signal at one of the station thereby two trains entering into the block section simultaneously from both ends, b) extraction of tokens at block stations at both ends of the block section, or c) Erroneous issue of authority to proceed the last stop signal at danger when a train is already in section, when the Block Instrument is defective or the Block Working has been suspended for any reason.

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ii) Head to tail collision: In double line section another train could enter the block section due to a) disregard of the `On’ last stop signal, in such as situation the collision may be averted if both the trains maintain equal speed and the leading train does not stop in the Block section. b) Erroneous issue of authority to proceed the last stop signal at danger when a train is already in block section, when the Block Instrument is defective or the Block Working has been suspended for any reason.

iii) Investigation:

a) Seizure of record: Train movement Log register, private number books of the Station Master and both the cabins, Relay Room key register and Loco Pilots diary of record should be seized at both the stations in between which the collision takes place,

b) Statements: Statements of Station Master on duty, Cabin Masters on duty of departure end at both the stations, Loco Pilot & Assistant Loco Pilot and the Guard of both the trains and Section controller, shall be recorded.

c) Inspection & tests: Position of levers in both cabins and position of slides in SM’s slide frame shall be recorded. If the key of the relay room is found to be under issue at the time of accident, the relay room shall be examined for any temporary connections and observations shall be put on record. The position of Block Instruments at both the stations shall be recorded. The Block instruments shall be tested for proper working at both ends and observations shall be put on record.

d) Preparation of sketches of site: A sketch shall be prepared to show point of drop, drag and other significant observations.

e) The data to establish time of taking `Off’ relevant signals shall be retrieved in case data logger is provided at the station. All information thus collected shall be analysed to establish the cause

6.2.2 In case of side collision in Block section, which may occur under similar conditions i.e. a derailed train infringing with the adjoining line, the communication from site of accident should be jointly tested to ensure that there was no communication failure during the period of occurrence of side collision in the Block section, which otherwise could have been saved had there been no communication failure. This should be put on records and signed jointly.

7. Accidents at level crossing gates: Level crossing gates are the intersection pint of railway and road traffic at the same level. In terms of railway Act Railway has first priority between rail and road traffic. Out of about 38000 level crossing gates, 21500 are unmanned on entire railways. Out of remaining manned level crossing gates 40% are Interlocked (Indian Railway safety by Arya Bhushan & M.M. Agarwal). Each interlocked gate is protected by Signals prewarned by a Warner or Distant depending upon the type of signalling in the section. Interlocked level crossing gates may fall within station section and Block section. The level crossing gates falling with in the station section are protected by the signals of the station and the gates falling in the Block section have independent set of Gate signals on either side of the gate. Closing of gates and taking `Off’ of the relevant signal is done by the gate man on duty.

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The gateman is also responsible for protection to the Rail traffic across the gate, which eventually applies to Road traffic as well. In both the cases the Level crossing gate is connected with the Station Master of adjoining station preferably the nearest one. Accidents usually take place due to speeding road vehicles hitting the barriers or the leaves of the gate and infringing with the railway track while the train is approaching the gate. This may be inadvertent or deliberate forcing in the process of closing the gate for road traffic. The Loco Pilot not getting enough braking distance may hit the road vehicle. Accidents at Level crossing gates though result in more casualty but are easier to resolve. 8. Fire in trains: Fire in trains may be the result of crying inflammables, or fire works by passengers getting ignited by a careless smoker. Often the electric conductors wired for fan & light getting short circuited. Whatever may be reason the fire gets wild within no time due to heavy wind. Usually casualties are high in such cases. The communication between train crew and the station master, or Emergency control should be immediately tested jointly for efficient working at the time of accident. 9. Parting of train: Train parting in itself is not as serious as after affect of the same. After parting if the rear end cut-off part does not get braked automatically and continues to roll, it may result in collision with its main part. As such it is necessary that the main part of the train continues to move ahead till the rear truncated part does not come to a stop. In case both parts collide the action shall be taken in the same manner as to be taken in case of collision. 10. In complete arrival of the train at the station: In case a train gets parted in the Block section and the truncated part is left out. The action shall be taken to protect the part of the train left out in the section. 11. Vehicles escaping from the station: If any vehicle escapes from a station, the Station Master shall take immediate steps to warn other stations or persons concerned, as far as practicable, to prevent an accident. [GR 6.11].

*****

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Chapter V Self Assessment

1. Multiple Choice Questions: 1 A derailment on a point could take place due

to: a) Sharp wheel flange b) Improper setting of points c) Movement of point under wheel d) Any one of above*

2 Flank protection is: a) Protection against a side collision of

trains with a train standing fouling adjoining line*

b) Protection of a train against getting hit from the rear end

c) Protection of a train against getting hit head on

d) Protection of a Motor Trolley against getting hit by a train

3 Give the correct size out of the following options of wheel flange below which, it is not permitted to be used on high speed train: a) 22 mm* b) 24 mm b) 26 mm d) 25 mm

4 Fire in train usually takes place because of the following reason: a) Short circuit in electric wiring of coaches b) Carrying inflammable material by

passenger c) Careless smoking by passengers d) Any one of above*

5 Minimum permissible thickness of wheel flange is (see SOD): a) 16 mm* b) 20 mm c) 18 mm d) 15 mm

2. Select the right answer True/False: 1 Main reason of accidents on interlocked level crossing gate are breaking the gate while ruthless driving

by road vehicle driver. True*/False 2 In case of parting of train the Loco Pilot should immediately stop the train attached with the Loco.

True/False* 3 All investigations should be done jointly with the team of departments apparently involved in the

accident including Operating department & Civil Engineer department. True*/False 3. Answer the following questions:

1 Elaborate main reasons of collision & side collision in station section. 2 Write short notes on:

a) Possible causes of head on collision in Block section. b) Riding of wheel on tongue rail at points.

3 Write short notes on: a) Investigation in case of accidents. b) Tests to be conducted after accident to establish that the S&T equipment relevant to the

accident were functioning properly at the time of accident. 4 What is an Accident Relief Train? In what way it serves the purpose in case of accidents? 5 What is the 1st duly of Railway employee & what action shall be taken on having come to know about

an accident.

*****

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CHAPTER –VI

AFFECTS OF TRACTION ON SIGNALLING SYSTEM 1 Affects of Steam and Diesel traction on signalling system: Indian Railway has been using Engines propelled by steam for more than 50 years. Diesel engines were also pressed in service while simultaneously phasing out steam loco motives. Both of these systems of traction were responsible for creation of atmospheric pollution. In both of these locos the foot plate for the Loco Pilot is not in the centre of the length of the loco. In steam loco motives the foot plate was at the end of the main body as the front part contained furnace and the boiler with a tender attached to it carrying coal which was the fuel to create steam. In diesel Loco similar is the orientation. It contains longer hood which carries the diesel engine leading with a smaller hood at the rear end of the loco to accommodate braking system equipment. Wile steam loco hauled the train essentially with longer hood leading, the diesel locos haul the train with shorter hood leading. However there is no constraint in diesel loco hauling the train with longer hood leading except that visibility gets obstructed for shorter distance when the engine hauls the train with longer hood leading. When the loco moves with longer hood leading, the 42 feet lock bar which is mechanical track locking arrangement, is required to be placed between starter signal and the first facing point, for the train starting from loop line. When track locking is through track circuit, the same track circuit also works as signal replacement track. When the loco with longer hood leading, passes the signal the track circuit should start at such a place that the Loco Pilot does not see the signal getting back to `On’ because of occupation of the track circuit by the leading wheels of the loco. This distance is about 13 metre, almost the same as the length of the lock bar. This compels the signal to be placed 13 metre behind the beginning of the track circuit. The position nearest to the first facing point where the track circuit shall start is the stock joint. In both the situations the clear available berthing portion of the loop line is reduced by 13 metre on this account only. If A fouling bar or clearance bar is provided at the entry end of the loop line another 13 metre are reduced.

With the introduction of double ended diesel engines similar to Electric Locos, it shall be possible to eliminate this avoidable loss of berthing space. However till long hood diesel engines are in use the provision shall have to be kept to avoid occurrence of even one incidence of the Loco Pilot observing signal going `On’ before he crosses it. 2 1500 Volt DC traction: DC electric traction with 1500 Volts was introduced in 1925, when the first section of 16 kilometres was brought into use between Bombay- VT to Kurla. It was extended upto Pune and Igatpuri by 1930. The southern Railway Metre gauge line between Madras Beach to Tambaram was electrified in 1931. The Bombay (now Mumbai) and Madras (now Chennai) suburban section of 388 route kilometres was energised by 1936.

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3 3000 Volt DC traction: After a lapse of 20 years, after introduction of 1500 V DC traction, 3000V DC traction was introduced in 1958 in Calcutta (now Kolkata) suburban section in Howrah – Burdwan section.

3.1 The structure to hold the overhead DC traction alignment infringe with the visibility of the semaphore signals as such only colour light signals are required to be used in DC traction area. 3.2 Since in the area provided with DC traction, the traction return current has to pass through rails, a DC track circuit can not be used. In its place either of the following devices shall be used to detect track clearance: 3.2.1 AC track circuits with either two position or three position relays, 3.2.2 Jeomont track circuit with 83 ½ pulse, 3.2.3 Audi frequency track circuits, 3.2.4 Axle Counters. 4. 25 Kilo Volt AC traction: 4.1 France having introduced 25 KV AC traction in 1951 had the enough experience in running trains on 25 KV AC traction as such Indian railways decided to go for appointment of French National Railway (S.N.C.F.) as consultants. First section between Raj Kharsawan & Dongaposi was introduced with 25 KV AC traction on South Eastern Railway in August’ 1960, thereafter 18312 route Kilometres of AC traction has been provided by the end of 2008 financial year which works out to be 28.6 % of 63968 route kilometres on Indian Railways, so far. 4.2 Traction sub-stations: Traction sub-stations are placed by the side of the track, which receive 132 KV three phase power supply from the grid of the respective State Electricity Board. The transformers placed at the traction substation step down 132 Volt supply to 25 Kilo Volt and feed to the Over Head Equipment (OHE). The other end of the transformer winding is firmly earthed to the ground at the substation. 4.3 Single phase: Since the three phase supply received from the grid system is used as single phase for running the trains, the other phases are used in cyclic order with adjacent subsections to avoid unbalance. The subsections are isolated from each other by providing neutral sections of about 41 metres, in between. The neutral section is reduced to 5 metres using special insulators in Automatic Block sections. 4.4 The OHE: The OHE is in three parts i) Contact wire of 107 sq mm cross-section, is grooved Cadmium Copper conductor and is

in contact with the pantograph of the engine, ii) Catenary, a Cadmium Copper conductor of 65 sq mm cross-section is to hold the contact

wire straight by supporting the contact wire by droppers of 5 mm diameter spaced at about 9 metres, to adjust the natural sag of the Contact wire. The current carrying area of both becomes 157 sq mm permitting 600 Amperes current on single track.

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4.5 Support: The entire system is supported by cantilever bars fixed on masts placed at an interval of 72 metres. For BG and 63 metres on MG. The contact wire is staggered by 300mm to have uniform wear and avoid cutting of the pantograph of the loco. 4.6 Anchor: The OHE conductors are terminated at an interval of 1.5 to 2 kilometres, the overlap span is anchored with mast with an insulator in between, while other end is provided with counterweights to maintain equal tension all the time compensating for the expansion and contraction during atmospheric temperature variations. The anchoring is done to facilitate smooth transition of the pantograph of the engine from one contact wire to another. Signal should not be placed under the live anchored conductors without additional precautions and as such signal implantation is required to be reoriented if it falls under the anchored wire.

4.7 Affects of 25 KV AC traction: The signalling system is affected due to: 4.7.1 Impaired visibility of signals obstructed by the OHE structures, 4.7.2 Electrical clearance of the signals with the live conductors, 4.7.3 Traction rail return current, and 4.7.4 Electrostatic and electro magnetic induction. 4.8 Visibility & electrical clearance of the signals from live OHE: The structure to hold the overhead AC traction alignment along with insulators, infringe with the visibility of the semaphore signals. The visibility for Colour light signals is manageable as such only colour light signals are required to be used in AC traction area [SEM 22.2.1] with the following precautions: 4.8.1 Under no circumstances any part of the signal or work man on the signal post shall come within 2000 mm from a live OHE conductor [SEM 22.2.6]. 4.8.2 In case it is unavoidable and any part of the signal or the person working on the signal post has to infringe the zone within 2000 mm from the live conductor, a metallic screen shall be provided between the signal and the OHE conductor and earthed. 4.8.3 The stop signal shall be placed ahead of neutral section at 1600 metres from the neutral section if the gradient in the area is 1 in 300. The distance shall be increased to 2500 metres if the gradient is more but less than 1 in 200. If PTFE type short neutral section is provided, the distance my be reduced to 400 metres [SEM 22.2.8.3]. 4.8.4 If the OHE mast is placed in front of the signal towards and approaching train, it shall affect visibility adversely as such the distance between OHE mast and the signal shall be kept 30 metres at least. In addition it also must be ensured that no OHE mast falls within a distance of 10 metres ahead of signal looking from the direction of approaching train [SEM22.3.1] (Fig 4.8.4).

30 m (min)

OHE MAST

TRAIN

10 m (min)

Fig 4.8.4

Minimum distances between signal and the OHE masts

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4.8.5 The height of the signal post or any part of the signal without route indicator shall not be more than 5.2 metres from the rail level, maintaining the centre point of the red aspect of the signal at a height of 3.65 metres. The rail level is measured from the top of the rail. [SEM 22.3.3.2]. 4.8.6 The OHE masts shall be placed staggered for proper visibility of the signals to the Loco Pilot in the manner given below. Figure 4.8.6.a, 4.8.6.b, 4.8.6.c & 4.8.6.d, show the arrangement for colour light signal, without rote indicator for 1000 metres visibility, without route indicator for 600 metres visibility, with route indicators without horizontal arm for 600 metres visibility and with route indicator with horizontal arm for 600 metres visibility respectively [SEM 22.3.3 & 22.3.5]. If the signal is provided between tracks, no OHE structure shall be provided in the track space at least for a distance of 600 metres in rear of the signal [SEM 22.3.4.1]. The measurement is shown between track centre & the centre of signal post:

Fig 4.8.6. a Placement of OHE masts out side track for Colour light signal without route indicator for

visibility of 1000 meters

CENTER LINE OF TRACK

400

270

190110

800

CENTER LINE OF TRACK

0 50

70115

160

240

Fig 4.8.6. b

Placement of OHE masts out side track for Colour light signal without route indicator for visibility of 600 meters

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CENTER LINE OF TRACK

280

215

170

130

700 Fig 4.8.6.c

Placement of OHE masts out side track for Colour light signal with route indicator without horizontal arm for visibility of 600 meters

250

215

170

125

600

CENTER LINE OF TRACK

310

Fig 4.8.6. d

Placement of OHE masts out side track for Colour light signal with route indicator with horizontal arm for visibility of 600 meters

4.9 Traction rail return current: The system being single phase the electric motors of the loco form circuit with phase being the contact wire through pantograph and the return current through rail, firmly earthed at feeding post to work as neutral. Approximately 300 amperes current flows through rails due to operation of one loco. The return current finds its path through any contact with the earth. This was best meat with the steel trough sleepers to give access to return current through ballast. However with the use of PRC sleepers specifically designed to

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provide electric isolation between rails to enable provision of track circuit, the leakage path to earth also gets obstructed and the return current has to travel through rails only to be earthed at feeder point where the rails are firmly earthed. This leads to: 4.9.1 Use of DC track circuits, to avoid interference with Alternating return current: Only one rail has to be used with the DC track circuits while other rail is used to give path to the return current. For this, accordingly, negative polarity rail of the DC track circuit is shared with the traction current return rail. The polarity of the DC track circuit is required to be staggered to avoid unwanted energisation of the adjoining track circuit in case of damage to the rail insulation joint as the negative rail is already common to all the track circuits. The negative rail of DC track circuit which is traction current return rail also, is connected with the Mild Steel (MS) flat with the adjoining traction current return rail till the last track circuit and after that both the rails are connected together with MS flat to give continuous connectivity to the feeder where the rail is firmly earthed. Fig 4.9.1 a

BOTH RAILS CONNECTED AT THE END OF DC TR. CCT. BY OHE BOND

FEEDER POINT

OHE BONDS FOR

CURRENT PATHTRACTION RETURN

- VE RAIL

- VE RAIL- VE RAIL

- VE RAIL

+VE RAIL

+VE RAIL

+VE RAIL

+VE RAIL

Fig 4.9.1. a

Arrangement showing sharing of one rail of DC track circuits with traction return current rail There always is possibility of traction return current passing through track relay through the wheel of the loco in contact with positive rail to find a path through traction rail return, which may result in picking up or burning of the track relay. For the protection of track circuit equipment a choke of 120 ohms impedance and 3 ohms resistance is provided in the circuit. Fig 4.9.1.b.

R ESISTANCEVARIABLE

- +

C HARG ER

RELAY

CHO KE

FEEDER PO INT+VE RAIL

+VE RAIL- VE RAIL

- VE RAIL

Fig 4.9.1. b

Arrangement showing basic circuit diagram of DC track circuit with protective choke

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4.9.2 Maximum permissible length of DC track circuit on wooden sleepers is 450 meters and on Pre-stressed Reinforced Concrete Sleepers (PRC) sleepers it is 350 metres. 4.9.3 Measurement of stray current and stray voltage: Un-foreseen stray current flow is observed in certain area due to industries in vicinity or other flow of currents through earth which in-turn result in track not getting shunted to drop the track relay. It is therefore important that stray current is measured before commissioning of new track circuits. Both rails of the track circuit are insulated on either end and connected together. Two earths are provided at either end of the track circuited part and a milliamp meter is provided to measure flow of current between both rails electrically joined together and the earth to measure stray current Fig 4.9.3.a. Similarly to measure stray voltage a resistance equal to the resistance of the track relay is inserted between both rails electrically joined together and the earth and voltage is measured across the resistance Fig 4.9.3.b. The length of the track circuit shall be suitably reduced to bring the i) rail to earth voltage measured across resistance to be not more than 100 mili volts, ii) the stray current to be not more than 10 mili amps for the length of the track circuit of less than 100 metres and, iii) 100 mili amps for the length of the track circuit to be more than 100 metres. It is more appropriate to provided electronic or AFTC in such areas where stray voltage or stray current is detected.

milliamp meter

volt meter

Fig 4.9.3.a

Measurement of stray current Fig 4.9.3.b

Measurement of stray voltage 4.9.4 Other track circuits such as Audio Frequency Track Circuits (AFTC) or Jeomont track circuits with impedance bonds to keep the traction current balanced in both the rails thereby keeping the potential difference between the two rails nil or bare minimum not enough to disturb the track circuit system. 4.9.5 Axle counters are also used as alternative to track circuits which are not affected by the traction return current as these do not form any part of the rail structure. 4.9.6 Track in the area of 25 KV AC traction is likely to be on higher potential as compared to earth. The rod run connected to operate points at one end and to the lever frame at the other end is therefore isolated electrically from the track by providing rod insulators between the adjustable crank and the point connecting lug at point end and between the vertical crank and the accommodating crank at the lead out. Similarly rod connection between point and detector, electric point machine and trap or point indicator is also provided with rod insulators to safeguard the maintenance staff against the electric shock. Some more precautions to be taken are:

132

i) In case the length of rod run is more than 300 metres, additional rod insulators shall be provided to restrict the length between two insulators, within 300 metres.

ii) While providing insulators it shall be ensured that insulated part of rod does not come in contact with the un-insulated rod, wire or OHE mast.

iii) Distance between insulator and the nearest standard roller guide shall be more than 300 mm to permit maximum stroke on the tail piece.

iv) In case of large numbers of the rodding in the same alignment, the insulators shall be provided on each rod in the same span of standard roller guides to prevent flow of current through standard roller guides if joints are placed in another span.

v) The distance between any OHE mast and that of rod run shall not be less than be 40 mm.

vi) Wherever the rod passes under the track, the minimum clearance of 25 mm shall be kept between bottom of the rail and top of the rod.

4.9.7 The wire operated signals are also provided with wire insulators which shall be as close to cabin as possible as well as near signal. Some more precautions to be taken: i) Insulator shall also be provided on detector wire in the same manner. ii) Distance between insulator and the nearest pulley stake shall be more than the stroke at

the lever tail. iii) The distance between two wire insulators shall not be more than 300 metres. In case it is

so, additional wire insulator shall be provided to keep the length between two within 300 metres.

iv) In case of large numbers of the wires in the same alignment, the insulators shall be provided on each wire in the same span of pulley stakes staggered in such a manner that insulators do not entangle with each other.

v) Horizontal distance between two wires shall be not less than 50 mm while vertical distance between two wires shall be not less than 200 mm.

vi) A minimum distance of 40 mm shall be kept between wire and the nearest edge of rail or the mast.

4.9.8 The wire run operating Lifting barriers is provided with wire insulators at winch end as well at lifting barrier end. The boom lock arrangement shall be insulated at both, lever end as well as boom lock end, in either case of wire operation or rod operation. 4.9.9 Installations to be earthed: Equipment to be earthed separately [SEM 22.14.2]: i) Lever frames and other metallic frames, ii) Protection screen provided on signals falling within the range of two meters of live

conductor. iii) All relay-racks inside relay room iv) Apparatus cases where the cables terminate. v) Block instrument circuit working on earth return, through filter unit. vi) The surge arrester provided in block filter unit. vii) Armouring of the tail cables when the length increases beyond the prescribed limit.

133

4.10 Electrostatic and electro magnetic induction: 4.10.1 Electrostatic induction-Over head alignment to be converted to underground cable: Any conductor when charged with a potential with reference to earth, creates an opposite charge on another conductor in its vicinity. The induced potential is directly proportional to the potential on the main conductor and inversely proportional to the distance between the two. This induction of charge is called static induction’. The conductor carrying 25 KV AC accordingly creates static induction on all conductors in its vicinity i.e. track, rod run, wire run cables etc. this induction is substantial when the conductors are running parallel to the OHE. Results of measurements done in Sealdah Division of Eastern Railway is reproduced below:

SN Separation between OHE wire and the alignment from the centre of track

Length of parallelism of overhead alignment

Electrostatic voltage measured

1 9 metres 1KM 950 V 2 109 metres 1KM 3.25 V 3 209 metres 1KM 0.9 V

This suggests that all the circuits on overhead alignment running parallel to the track shall have to be put underground in the form of cables. 4.10.2 Electromagnetic induction – Screening of the cables: Any conductor in which current flows, magnetic lines of forces are created around it. These magnetic lines when very due to change in potential in the conductor and cut another conductor, an induced potential is developed in the conductor cut by the magnetic lines. The potential so generated is called Electromagnetic induction. Since in case of current through OHE conductor is AC, all the conductors including rails get influenced by these magnetic lines of forces and an induced potential is generated there. The magnitude of this induced potential is proportional to the current, rate of change of potential in the main conductor, distance of separation and conductivity of surrounding medium etc. When all of the OHE current passes through track, the induced voltage in the cable running parallel to the track shall be almost nil as induced potential getting due to OHE and rail shall neutralise each other. However there are two situations one where the return current passes through rail as well as through ballast and earth where sleepers other than PRC are provided. In second case where PRC sleepers, which are designed and provided with additional insulators for bearing track circuits, the entire traction return current has no path other than rail. It was decided to provide the cable with lead or aluminium sheath and the sheath to be earthed. The voltage induced in sheath caused flow of current, the sheath being earthed. This resulted in neutralising & as such reduction of induced voltage in cable, & provided screening effect. 4.10.3 Maximum voltage induced on cable: The entire network of flow of current through contact wire, railway track, earth and other metallic conductors in the vicinity, conductivity of earth, cumulatively result in generation of potential 95 Volts per kilometre on unscreened armoured signalling cable used in double line section taking return current as 600 amperes, where 35 is the voltage induced on screened cable per 1 kilometre. The induced voltage on a single line section on unscreened cable is 116 Volts per Km taking return current as 300

134

amperes. [SEM 22.6.2.1]. This has far reaching affect on the entire signalling system in 25 KV AC traction area. 4.10.4 Reduction factor: Rail reduction factor of 0.4 on double line and .56 on single line section, along with other factors taken into consideration results in development of induced voltage of 35 Volts per Kilometre on screened signalling cable. The sheath of the cable was required to be earthed at each termination and the screening effect was depended of the effectiveness of the earth. Over the period it was observed that maintenance of earth was far from satisfactory. A 300 volt signalling system was designed using un-screamed cable. It was difficult to handle as too many precautionary measures were required to be taken and the system was changed soon to use 110 V AC supply using unscreened cable with provision of cutting in relays at shorter intervals, which is in vogue today. 4.10.5 Maximum length of parallelism: Two factors are there to decide maximum length of parallelism. i) Human safety and ii) system safety. i) Human safety: Upto 120Volts can be handled by human being safely. As such

maximum length for unscreened cable has been permitted to be 1.2 kilometres. ii) System safety: The unsolicited induced voltage if not taken care can result in unsafe

conditions: a) Limit for direct feeding of signal lamps: In case of incandescent Signal lamps

which work on 12 Volts AC, the glow of the lamp is proportional to the voltage applied. These lamps glow at 2.3 volts. In case of a typical double earth fault in the cable, where the power to the lamp is extended by HR placed in the cabin if 21 volt is induced in the cable on the primary sided 2.3 volt shell appear on secondary side under transformation ratio of 110:12. This restricts distance for direct feeding of signal lamp as (21/95) x1000=240 metres. This distance, with screened cable is (21/35) x1000= 600 metres. Fig 4.10.6

>>

HR

HR

110:12

SIG. LAMP

BX110

NX110

)

)

)

)

240 METRES (MAX)

21 V

2.3

V

Fig 4.10.6

Maximum permissible distance for direct feeding of signal lamp to protect against glowing of lamp in two earth faults case

Accordingly the maximum permitted length for direct feed of signal prescribed as per SEM 22.7.3 is tabulated below:

110 Volt feed system 300 volt feed system Type of cable Single track Double track Single track Double track

Screened 600 m 600 m - - - - Un- screened 180 m 220 m 500 m 500 m

135

b) Use of AC Immunised relays in outdoor circuits: Indoor circuits are designed with single wire using no-AC immunised relays, while outdoor circuits are designed with double wire using relays which are immunised to 400V AC [SEM 22.6.2.2] to avoid picking up of relays due to induced voltage in the cable.

c) Cutting – in- relays: In view that a potential of 120 Volts is induced through a length of 1.2 metres of unscreened cable, a relay shall be inserted at this distance to cut-in the length to keep 120 Volts limit. The next relay shall be picked up through pickup contact of this cutting in relay with a different source of power supply. All relays used in out side circuits shall be immunised to 120v x 2.5 = 300 Volts AC keeping a factor of safety of 2.5 times of 120 V.

d) Separate power supply source for indoor & outdoor circuits: Since the indoor circuits are designed on single conductor using non-AC immunised relays the power supply source for indoor circuits shall be separate to the power supply source for outdoor circuits [SEM 22.5.5].

e) Power supply source for outdoor circuits: shall be so grouped that at any source the total length of circuit never increases beyond 1.2 kilometres when unscreened cable is used on double line (95v x 1.2m =114m i.e.< 120m) this length may be increased to 3.5 kilometres if screened cable is used (35 x 3.5 = 122.5).

In case signals are placed at a distance beyond 1.2 kilometres when unscreened cable is used and by 3.5 kilometres when screened cable are used, the signals are to be feed from different source of power supply, such as in case of distant signals, a separate source of power than the main outdoor source of power supply shall be used for the same.

f) Equipment not immunised to AC: Some equipment are not immunised to AC. To

take care of this, command for operation of such equipment can not be given directly. One relay which is AC immunised is picked up at the site of such equipment to communicate command and the equipment is operated through local circuit in a manner similar to other indoor circuits. These equipment are listed below [SEM 22.5.3]: i) Luminous indicators, ii) Telephone type relays, iii) Electric Lever Locks, iv) Door coil of IRS Block Instrument, v) 250 Ohms DC neutral line relays, vi) Rotary key transmitters, vii) Arm & Light repeaters, viii) DC neutral polar relays.

g) Relays which release interlocking shall be slow to act with time delay, ranging

between 0.6 to 0.8 seconds so that interlocking is not released due to inadvertent voltage fluctuations. [SEM 22.5.8].

h) Length of DC track circuits terminated on Line relays with unscreened cable shall be restricted to [SEM 22.6.2.5]:

136

Maximum permissible length on* Type of relay AC immunity level in volts Single line Double line

AC immunised shelf type 750 2.1 Km 2.8 Km QNA 1 1000 2.1 Km 2.8 Km K50B 1 170 1.0 Km 1.2 Km K50 130 750 meters 900 meters

* Maximum permissible induced voltage is restricted to 400V for human safety & factor of safety 1.5 has been considered.

j) Electric operation of points: The maximum permissible length for various type of

commonly used point machines is as under [SEM 22.8.2.2]. This is keeping factor of safety as 1.5:

Maximum permissible parallelism in meters between point contactor & point motor

Type of Machine

AC immunity level in volts

Single line Double line IRS-24 160 910 1100 SGE 110V 250 1435 1750 GRS 5E 90 515 630 Style 63 130 745 910 M3 200 1150 1400 M5 70 400 490 Siemens IA 160 910 1100 Siemens IB 300 1650 2100 Siemens IC 400 2200 2800 LM-55 160 910 1100

4.10.6 Block working: In 25 KV electrified area only following type of block instruments can be used: [SEM 22.9.1] i) On single line section:

a) Neal’s token instrument; b) Daido’s Token-less instrument; c) Block working with Axle Counter;

ii) On double line section: a) SGE Block instrument; b) Block working with Axle counter. c) Push button type block instrument may be used on non electrified section taking off

from electrified section if the length of parallelism does not exceed 1.5 Km.

4.10.7 Additional precautions to be taken for Block working: i) Poly Ethylene Tetrachloride (PET) insulated Quad cable shall be used to connect two

block instruments of which one quad shall be used for block instrument and half quad shall be kept as spare. The block instrument shall be connected through a filter unit to protect the system from high induced voltage.

137

ii) Both the half quads of one quad shall be terminated on transformers of ratio with its primary side to match the characteristic impedance of the cable and secondary side to match the characteristic impedance of the equipment i.e. one for Block bell & other for Block telephone see fig. 4.10.7.

iii) The block instrument shall work on earth return phantom circuit. iv) The telephone attached with the block instrument shall be used on one half quad through

the transformer with induction coil. v) The block bell shall work through an independent Block Bell Equipment to be

connected through the transformer connected on the other half quad of the cable. vi) The filter unit consists of two chokes S1 of 50 Ohms resistance & 40000 Ohms

impedance and other S 2 of 40 Ohms resistance & 20000 Ohms impedance. Two capacitors C1 each of 10 mfd and two lightening dischargers LD, connected to common earth. The arrangement is shown in figure 4.10.8.

vii) Ripple free power supply for the line circuit shall be used. For this either primary cells, DC-DC converters of IPS or Battery Charger with dual battery bank shall be used as the three position magnetic polarised relay is not immune to AC.

PE

T C

AB

LE

BL. INST.

EARTH

LINE 1

LINE 2

BELL

BLOCK FILTER

CABLE TERMINATION BOX

T2

T1

LD

LD

C1

C1

S2

S2S1

S1

W

W

TELEPHONE

Fig. 4.10.7

Arrangement of connection between cable termination box and block filter

viii) Another battery set shall be used for working block bell equipment. This may also be clubbed to signalling internal battery set.

4.10.8 Laying of the cables: Cable laying shall be done based on following principles: i) The cable running parallel to the track shall be buried at a depth of 0.8 metres from the

ground level and while crossing under the track shall be 1 metre below the bottom of the rail. In case of rocky soil the depth may be reduced to 0.5 metres.

ii) In case of tail cable the depth shall be not less than 0.5 metres. iii) The distance between OHE mast and the cable trench shall be not less than 3 metres to

maintain depth of the trench more than 0.5 metres.

138

iv) A distance of one metre shall be maintained between the cable and the OHE mast supporting Catenary or any structure that is likely to come in contact with high tension conductors. In this case depth of the cable shall not exceed 0.5 metres. The distance of the cable from OHE mast may be reduced to 0.5 metres by passing the cable through RCC pipes near the OHE mast

v) In vicinity of the traction substation or switching station such as Feeding posts, sectioning posts and sub sectioning posts, the cable shall be laid one metre away from any metallic body of the substation which is fixed in the ground. The distance of one metre shall also be maintained from the substation earth.

vi) All the traction return current flows through sub station earth as such a) the cable shall be laid on the side of track opposite to substation or, b) on the side of substation, through RCC pipe or enclosed brick channels, for a length of not less than 300 metres on either side of the sub station.

vii) The cable shall be laid at least 5 metres away from the switching station earthing which can be reduced to one metre by passing the cable through RCC pipes near the earth.

viii) Signalling, telecomm and power cable can be laid in the same trench observing following requirements: a) 100 mm distance between signalling and telecomm cable shall be maintained. b) Signalling and power cable shall be separated by row of bricks. c) For recognising the cables in the same trench, the telecommunication cable shall be

laid nearest to the track, signalling cable spaced by 100 mm next to telecommunication cable away from track and power cable separated by row of bricks outermost away from the track. If LT and HT both cables are laid in the same trench as signalling and telecom, the HT cable shall be put outermost and LT by the side of bricks.

d) A separation of 50 mm shall be maintained between the power cable and signalling cable when laid in separate trenches.

ix) Cables shall cross the track: a) Right angle to it. b) Shall not cross under the points and crossings. c) Pass through RCC pipes at a depth of one meter below bottom of rails. d) Minimum distance of 0.2 metres shall be kept between signalling and power cable. e) When cable has to cross a metallic bridge it shall be placed inside GI pipe filled

with sealing compound suitable to withstand 6000 V AC.

*****

139

Chapter VI Self Assessment

1. Multiple Choice Questions: 1 Minimum glow voltage of a incandescent

signal lamp is: a) 6.3 Volts b) 4.3 Volts c) 3.3 Volts d) 2.3 Volts*

2 In case of 25 KV AC traction when signalling, telecomm & power cables are laid in the same trench running parallel to track, the power cable shall be laid in the trench placed: a) Nearest to railway track b) Middle of the trench c) Farthest to railway track* d) In between signalling & telecomm

cable

3 Maximum permissible parallelism in meters between point contactor & point motor in case of 25 KV AC traction area, for Siemen’s-lc point machine is: a) 1100 mts b) 2100 mts c) 2800 mts* d) 490 mts

4 With the use of unscreened signalling cable in 25 KV AC traction area the induced voltage per Km on double line section is: a) 75 V b) 95 V* c) 99 V d) 100 V

2. Select the right answer True/False: 1 The Block instruments are the only equipment in 25 KV AC traction area operated on single

conductor circuit through earth return. True*/False 2 Only single rail DC track circuit may be used in case of 25 KV AC traction area. True*/False 3 Relay which release interlocking shall not be slow to release. True/False* 4 In 25 KV AC traction area block bell shall work on alternating current, through a Block bell

equipment. True*/False 5 The three position relay used in series with line circuit due to which ripple Block instrument power

supply can only be permitted on line. True*/False 3. Answer the following questions: 1 List out equipment which are not immunised to AC for use in 25V AC traction area. 2 Discuss salient features of power supply arrangement for signalling system in 25 KV AC traction area. 3 Draw schematic diagram depicting Block Instrument circuit connecting to quad cable through

transformers. 4 Write short notes on:

a) Affect of 1500 & 3000 V DC traction of signalling system. b) Affect of 25 KV AC traction of signalling system.

5 Write short notes on: a) Types of track circuits which can be used in 25 KV AC traction area. b) Compare utility of the track circuits used in 25 KV AC traction area.

6 Detail precautions to be taken while using SGE type double line Block instrument, in 25 KV AC traction area.

*****

140

Bibliography

1. Indian Government Railways General Rules 2007; 2. Compendium on Instructions on matters pertaining to condonation of

infringements to schedule of dimensions, CRS & Railway Opening of Public Carriage of Passenger Rules issued by CORE;

3. Signal Engineering Manual Part-I, 1988 & part – II 2001; 4. Objective Railway Engineering by M.M. Agarwal; 5. Notes on signalling in 25 KV Electrified sections by IRSTE, Secunderabad; 6. Indian Railway Safety by Arya Bhushan & M.M. Agarwal.

*****

141

INDEX

A Marker 26Absolute Block system 59AC traction 25 Kilo Volt 127Accepting Authority (Tenders) 84Accident Relief Train (ART) 117Accidents at level crossing gates 123Addition of new item of work 86Additional fixed signals in Automatic Block territory on single line

64

Additional precautions for block working

137

Advanced Starter signal 34Affects of 25 KV AC traction 128Affects of Steam and Diesel engines on signalling system

126

Application for sanction 88Appointment of Arbitrator 87Approach Locking 37Approved special instructions 7Arbitration 86Aspects of the signal 29Authority to enter the section 71Automatic Block signal 28Automatic block system 63Award of Contract 81Axle counters 46Back locking 39Back Locking by Electrical Means 39Back locking Mechanically 39Block hut 9Block Instruments 113Block overlap 45Block Section 15Block Stations 8Block Working 45,137Briefing note 82Cabin and Lever Frame 110Calling-on signal 24Capital expenditure 75Capital fund (Cap) 75Capital fund (CF) 76Capital source of fund and expenditure 75Catch siding and Slip siding 46Catechism for signalling and Interlocking installation

105

Categories of train accidents 116

Caution Indicator 94Check and Indication Locking 40Class ‘A’ Stations 8Class ‘B’ Stations 8Class ‘C’ Stations 8Classification based on TVUs 47Classification of fixed signal based on usage

22

Classification of fixed signals based on structural design

17

Classification of signals based on placement

31

Classification of Stations 8Classification of stations based on operational requirements

8

Classification of stations based on Standard of Interlocking

9

Clearance bar 42Co-acting signal 27Collision in station section 121Collision in the Block section 122Collisions 121Colour light signalling system 23Commissioning of the work 92Conditions for granting Line Clear at a class `B’ station on single line

60

Conditions for granting Line Clear at a class `C’ station

61

Conditions for granting Line clear at a class ‘A’ station

60

Conditions for granting Line Clear at a class ‘B’ station on double line

60

Conditions for taking ‘Off’ Manual stop signals in automatic Block territory

65

Construction Organisation 74Contractor not applying for DOC 86Correspondence between operating and operated units

36

Cost of work 77Cutting in Relay 136DC traction 1500 Volt 126DC traction 3000 Volt 127Dead Approach Locking 38Declaring the station Non-Interlocked 93Delayed tenders 81Departure signals 34

142

Depreciation Reserve fund (DRF) 76Derailment on straight route 120Derailments 118Development fund (DF) 76Devices to monitor status of the yard 42Different causes of accidents 116Direct reception of a train 60Distant sig. in Modified, two aspect semaphore signalling territory

32

Distant signal in Multiple Aspect Colour Light signalling territory

32

Distant signal in Semaphore Multiple Aspect Upper Quadrant

32

Distant signal in Upper Quadrant 32Dock signal 27Electric Operation of Points 137Electrical Block Instruments of Token or Token-less type

46

Electrical Communication Instruments 46Electrical Signalling equipment 111Electromagnetic induction – Screening of the cables

134

Electrostatic induction 134Enquiry into cause of accident 118Equipment not immunised to AC 136Essentials of Automatic Block System on double line

63

Essentials of Automatic Block System on single line

64

Essentials of interlocking 35Essentials of the Following Train Sys. 66Essentials of the One Train Only System

71

Essentials of the Pilot Guard System 67Essentials of the Train Staff and Ticket System

68

Evolution of Indian Railways 1Evolution of Railway Signalling system 4Execution and commissioning of the work

95

Execution of work on a running line 87Execution of works 76Finances for construction organisation 74Fire in trains 124Fixed Signal 17Fixing of Caution, Speed and Termination Indicator Boards

94

Flank Protection 42

Following Train System 66Fouling bar 42G Marker 25Gate signal 25Generally used terms 7Goods signal 27Grant of extension for completion of work

85

Head-on or head to tail collisions 121,122Holding bar 39Home signal, Routing Home signal & Route indicator

33

Human safety 135In complete arrival of the train at the station

124

Indication conveyed by the Aspect of the signal.

30

Infringement of maximum and minimum dimensions

100

Inspection at points 107Inspection at the Signals 105Inspection by CRS 98Inspection of the cabin 108Inspection on the track 108Installations to be earthed 133Interlocking 101Interlocking in the station section 35Interlocking of ‘B’ class level crossing gates

48

Interlocking of ‘C’ class level crossing gates

49

Interlocking of ‘Special’ & ‘A’ class level crossing gates

48

Interlocking of level crossing gates 48Intermediate block post 9Intimation of accident 116Inviting tenders 79Isolation 44Isolation at stations 102Isolation where to be provided 44Items not covered in SOR 79Joint Safety Certificate 92Junction of tracks 102Last Accepted Rates (LAR) 81Late tenders 81Laying of the cables 138Level crossing Gates

43,47

143

Level crossing gates falling in Automatic Block signalling

49

Lever Lock 43Limit for direct feeding of signal lamp 135Limited Tenders 85Lock bar 39,55Locking of last trailing point by the Last Stop Signal

41

Maximum length of parallelism 135Maximum permissible length of DC Track Circuit

132

Maximum voltage induced on cable 134Means of Isolation 45Measurement of stray current 132Mechanical Semaphore Signal 17Minimum equipment of fixed signals in Automatic Block territory on single line

64

Modified lower quadrant signalling 19Monitoring clearance of the track 42Monitoring devices 41Multiple aspect colour light signalling 20Multiple aspect Upper quadrant Signalling

19

Non-Block Stations or Class ‘D’ Stations

9

Notification to Railway officials before opening works

87

Obstruction on a block station on double Line section

61

Obstruction on single line in block section

62

One Train Only System 70Opening of minor works 99Opening of new Railway 99Opening of tenders 80Outer signal 32Overlap 45Parting of train 124Passing a Gate stop signal at `On’ in Automatic signalling territory

66

Passing an Automatic Block signal at ‘On’on double line section

63

Passing Automatic Signal at ‘On’ on single line section

65

Pilot Guard System 67Points (Inspection of) 109,101,111‘Position’, ‘Aspect’ and ‘Indication’ signals

29

Post accident action 117Post Contractual matters 85Power operated points and signals 109Powers of CRS to open minor works 100Preparation for Commissioning 90Preparation for opening of new railways 96Protection of train on Pilot Guard sys. 68Railway Signalling System. 7Rate analysis for preparation of signal foundation

78

Reception signals 32Reduction factor 135Repeater signal 26Request for change in rates or tender condition from contractor

86

Revenue expenditure 75Revenue receipts 75Risk & cost contract 83Route holding 37Rules for Opening of a railway 95Running Line 7Running train 7Safety Certificate 90Safety Certificate for S&T works for introducing Electrification

92

Schedule of Dimensions (SOD) 49Schedule of Rates SOR 79Sectional route release 41Semaphore signalling system 23Shunt signal 23Shunting 7Side collision in station section 122Siding and trap points 102Sidings 46Signal overlap 45Signals (Inspection of) 109,101,111 Signals at class ‘D’ station 28Special Instructions 7Special Limited Tenders 85Speed Indicator 94Standards of Interlocking 9Starter signal 34Station 7Station Limits 13Station Section 14Station Section and Block Section 14Stop Signal

22

144

Switching over of new signalling system replacing the existing

95

System safety 135Systems of working the trains 59Temporary opening of railways 99Tender Committee 82Tender documents 80Tenders 77Termination Indicator 94Test to be made in the lever cabin or at the Lever frame

109

Track circuits 46Track Locking 40Traction rail return current 130Train Staff & Ticket System 68Train staff Tickets, how kept 69Trap siding 46

Two aspect colour light Warner Signals 32Two aspect lower quadrant signalling 17Two Packet System (of tendering) 84Use of AC Immunised relays 136Use of DC track circuits 131Use of One Train Only System 70Variation in the items of schedule 85Various methods of Isolation 103Vehicles escaping from the station 124Visibility & electrical clearance of the signals from live OHE

128

Visibility of signals 21Warner/Distant signal 22,32Warning Board 22Works requiring notice to and sanction

f the Commissioner of railway Safety o 88

*****

145