provision of cost effective block working solutions using ... · application of ufsbifor block...

Provision of Cost Effective Block WorkingSolutions Using

Universal Fail-Safe Block Interface(as per IRS: S-104/2012)

Deltron Equipment & Systems Pvt. Ltd.An ISO 9001:2008 Company

Office26, Convent Road, Kolkata-700014

Works17, Canal Street, Kolkata-700014

Contact DetailsPh: (033)-22651778 / 22176467; Fax: (033)-22655903

Email: [email protected]

This documents explores the Cost& Implementation benefits ofworking Absolute, Intermediate &Automatic Block Signaling on OFC/ Radio using RDSO approvedFail-Safe (SIL-4) Mux - UFSBI(as per IRS:S-104/2012)

Provision of Cost Effective Block Solutions using UFSBI

Deltron Equipment & Systems Pvt. Ltd.

About UFSBI

Universal Fail-Safe Block Interface (UFSBI) as perRDSO/SPN/147/2005, is a fail-safe digital triplemodular redundant (TMR) multiplexer capableof transferring 16+16 i.e. a total of 32 On-Offrelay states between locations physicallyseparated by a distance but connected through avoice/data channel over OFC/Microwave orQuad cable. The UFSBI can be effectively used toreplace the signalling cables required forrepeating relays between mid-section block hutsand end stations.

The system development had been initiated byMinistry of Information technology, undertechnical guidance from IIT, Delhi & Centre ofKnowledge Base Systems, Jadavpur University,along with railway expertise and field trialfacilities that was provided by South EasternRailways.

The complete hardware and software areindigenously developed by our team ofengineers and manufactured at our facilities inKolkata, thereby, ensuring prompt after salesservice and availability of spares over the entireequipment life period.

The system had been initially designed andapproved by the Research Design & StandardsOrganization of Indian Railway for interfacingconventional Single & Double line BlockInstruments on OFC voice / data channels. But,eventually it found its utility in repeating relaystates in Intermediate Block Signaling andAutomatic Block Signaling applications wherehundreds of copper conductors were replaced bya pair of optical fiber cables and the UFSBIequipment.

UFSBI is now being extensively used forproviding push button type block instrument asper IRS Spn. No. IRS:S-105/2012 and forIntermediate Block Signalling applications as areplacement of laying signalling cables which hasproven to be cost effective and reliable.

The UFSBI



Fail-Safety Approvals UFSBI has been validated and approved by RDSO for use in railways, as per

RDSO/SPN/147/2005 (with latest amendments).

Center of Knowledge Based Systems, Jadavpur University, has validated the systemSoftware as per CENELEC SIL-4 standards

Hardware is evaluated and independently validated by Electrical Engineeringdepartment of IIT, Delhi

Advantages Provides high level of reliability and fail-safety. Signalling relay states once exchanged

through UFSBI can be worked interchangeably on OFC or Microwave (voice/datachannel) with Automatic Media Changeover facility, to increase system availability incase of cable disruptions.

A single set of UFSBI mux system comprising of a pair each between IB hut and eachstation, caters for IBS section both Up/Dn lines.

{ A typical IBS section approximately 12 Km long needs a dedicated 6-Quad / 24 Coremin. Signalling cable with cutting relays for exchanging IB states between IBH &stations costing approx. Rs.30,00,000 and at least two month’s time. While with UFSBIthe same have been achieved by railway in less than 50% of cost and within 7 days, asonly indoor work is involved. Rate references from different zonal railways are annexedfor reference.

Avoids additional block section cable laying, maintenance time and cost.

Can work over very long Block Sections using OFC Mux / E1 channel or even using 1-Quad copper cable up to 30 Km distance approximately.

The same OFC fiber, that is used for inter-station link can be intercepted at IB Hut byintroducing a STM mux. The E1 thus derived between each station and the IBH, if used,with a suitable dedicated VF mux (Maple-4 or similar), as backup media of UFSBI andprimary media being 1-Quad, then on the event of cable cut, the path protected E1 canbe used for seamless backup for relay repetition through UFSBI. In fact the same E1 toVF mux can cater for back-up channel for Digital Axle Counter. Therefore IBS failureowing to cable cut can be completely avoided.

High level of noise and electro-magnetic immunity making the system suitable to workin railway electrified area and hence is a onetime investment for the Railways.

It reduces the cost of ownership as equipment forms can be changed just by merechange of relay logic (placed in detachable relay racks) and the same set of cards canbe used for various applications.



Usage of UFSBI:

The diagrams below represents the block working in Single and Double Line Sectionsrespectively.

Typically 10-20 Km

UFSBI - 1

Block InterlockingCircuit with

Q-type relays(designed by RDSO)

2/3 Fail-Safe DigitalMux - UFSBI ( as perRDSO/SPN/147/05)

Push Button typeBlock OperatingPanel (designed

by RDSO )

Status of VitalRelay (through

potentialfree contacts)

AXLESENSOREVALUATOR

SSDAC - 1

4 4

UFSBI - 2


Q-type relays(designed by RDSO )



by RDSO )

Status of VitalRelay (through


AXLESENSOR EVALUATOR

SSDAC - 2

44

STATION - A STATION - BBLOCK SECTION

Block Proving with single section Digital Axle Counter & UFSBI

Station InterlockingSystem (MACL, RRI,

PI, SSI


PI, SSI

1 Quad Cable or 4 Wire VoiceChannel on OFC

1/2 Quad Cable or2 Wire Voice

Channel on OFC

Block Panel - 1 Block Panel - 2

Relayinterlocking ckt.-2Relay

Interlocking ckt.-1 1/2 Quad Cable or2 Wire Voice

Channel on OFC

Block Telephone Block Telephone

Typically 10-20 Km

UFSBI - 1


Q-type relays(designed by RDSO)



by RDSO )

Status of Vital Relayfor UP & DN Line(through seperate


AXLESENSOREVALUATOR

SSDAC - 1 (DN)

4 4

UFSBI - 2


Q-type relays(designed by RDSO )



by RDSO )

Status of Vital Relay for UP &DN Line (through seperate

potential free contacts)


SSDAC - 2 (DN)

44

STATION - A STATION - BBLOCK SECTIONStation InterlockingSystem (MACL, RRI,

PI, SSI


PI, SSI

1 Quad Cable or 4 Wire VoiceChannel on OFC


Channel on OFC

Block Panel - 1

RelayInterlocking ckt.-1

Typically 10-20 Km

AXLESENSOREVALUATOR

SSDAC - 1 (UP)

4 4


SSDAC - 2 (UP)

44

STATION - A STATION - BBLOCK SECTION


Channel on OFC


Channel on OFC

Block Telephone Block Telephone

RelayInterlocking ckt.-2

Block Panel - 2

Block Proving with single section Digital Axle Counter & UFSBI

Block Proving through Digital Axle Counter using Single Section Digital AxleCounter with UFSBI & Block Panel as per IRS Spn. No. IRS:S-105/2012

It is a non-co-operative, user-friendly push button type Block Instrument. The unique design of interlocking circuits and input/outputs through Q-series

relays provide galvanic isolation, making the system usable in both RE & Non-REsections.

The use of UFSBI with Automatic Media Changeover Facility additionallyharnesses the true benefits of using HA-SSDAC.

Can be easily converted from one form to another (Single Line to Double Lineand vice versa) by just mere change of detachable relay racks and block panels.



Design Features

i) The Interlocking circuits as well as the UFSBI inputs are taken through Q-series relays(conforming to spec. BRS: 930), providing galvanic isolation, thus making the systemusable in both RE and Non-RE sections.

ii) The system is designed to work with MACL, PI, RRI or SSI installations.iii) Triple Modular Redundant fail-safe multiplexer working on 2 out of 3 logic ensures

greater level of safety and availability.iv) The automatic TOL and LINE CLOSED features considerably reduces the

operational time of the Station Master over any other block instrument used inIndian Railways till now.

v) The software coding for inter-station signal transmission takes care of noise disruptionsgenerally encountered in the transmission system. It ensures safety of operation againstthese noises by use of fail-safe data structure, message redundancy, minimum Hammingdistance of 5, etc.

UFSBI as a 16- Input & 16-Output Multiplexer

In the busiest sections of railway traffic movement, the signal & telecom department isentrusted with the responsibility of increasing the line capacity without physicallyincreasing the number of railway tracks.

To implement this S&T experts have come up with Block Signalling schemes likeIntermediate Block Signalling (IBS) and Automatic Block Signalling (ABS). In order toachieve this Single or Multi Section Digital Axle Counters are generally used for trackoccupancy detection. Further outdoor signalling cables with cutting relays after every 2 Km(approx.), are used for track/signal relay state transmission between block hut and stations.

As such throughout the block section a thoroughly knit network of cables and relay huts areset up. This not only involves an immense cost but also difficult to maintain the systemthroughout the year and protect against theft or acts of vandalism. In case of cable or relayfaults it becomes increasingly difficult to troubleshoot the distributed relay statetransmission system.

Acceptability of usage of UFSBI

Research Design & Standards Organization has closely observed the faultless performanceof UFSBI over different zones of Indian Railways for over last 7-8 years and hasrecommended the usage of the same in the schemes of Intermediate Block Signalling (IBS)and Automatic Block Signalling (ABS).



/ OFC VF 4W- E&M. / OFC VF 4W- E&M.



Application of UFSBIfor Block Working on Microwave Radio

Inter-Station Block Working using Block Instrument & UFSBI on Radio (as per RDSO/SPN/147/2005)

BLOCK INSTRUMENT

UNIVERSAL FAIL-SAFE BLOCKINTERFACE

BLOCK INSTRUMENT

UNIVERSAL FAIL-SAFE BLOCKINTERFACE

Signalling Cable(24 Core, 0.9mm dia)

1. SGE Double Line2. Diado Handle Type Tokenless Single Line

3. Neals Ball Token Single Line4. Block Panel with SSDAC & UFSBI

BlockTelephone

2-Wire E&M Voice Ch.(Through 0.9 mm,

dia STP cable)

Primary Mux

Tx

Rx


dia STP cable)

BlockTelephone


dia STP cable)

Primary Mux

SM's Room SM's Room

Relay Room

Signalling Cable(24 Core, 0.9mm dia)

Relay Room

Telecom Room Telecom Room

E1 / EthernetRadio Unit

E1/ EthernetRadio Unit

E1E1

Channel Characteristics Reqd by UFSBI:1. SNR: 20dB min.2. Channel loss: 28 dB max.

The Microwave based E1 Radio provides end to end E1(G.703)2.048Mbps connectivity. This when fed to the station Primary-Mux (30Ch.), necessary E&M Voice and Data channel as required by railwaymay be derived.

The Microwave ISM 2.4 / 5.8 GHz Radio can be of Radwin IDU-R / RADAirMux / AprisaXE or similarThe Primary-Mux (30 Ch.) can be RDSO approved products WebfilFleximux / Puncom VMX / MROTEK Maple 4

1. SGE Double Line2. Diado Handle Type Tokenless Single Line

3. Neals Ball Token Single Line4. Block Panel with SSDAC & UFSBI

Tx

Rx


dia STP cable)

SSDACSSDAC

System Layout for Interfacing Conventional Block using UFSBI with E1 Digital Radio & PDMUX

System Layout for Interfacing Conventional Block using UFSBI & Digital Radio Modem withVoice & Data Transmission / Reception Facility



Fig.3a. Tower (30m) at Rangiya at N.F. Railway

Fig.3b. UFSBI at Rangiya at N.F. Railway with2.4 GHz Radio & VOIP adaptor inside

Fig.3c. 24 dBi Grid Parabolic Antenna mounted on 30mTower in Rangiya at N.F. Railway

Fig.3d. 2.4 GHz Microwave Radio and VOIP adaptor placed under physicalLock & Key inside UFSBI cabinet in Rangiya at N.F. Railway

Fig.3e Neals Ball Token Instrument working on Radio inRangiya at N.F. Railway



Scheme of Automatic Block Signalling using MSDAC & UFSBI on Quad/OFC

The scheme, utilizes the MSDAC for track detections, with detection points spread over theentire auto section. Independent Evaluators are used for UP & DN Line. Quad cable (1 pairconductor) is used for connection the each Detection Points to the respective redundantEvaluators. In case the distance of the DP exceeds 5 Km, separate arrangement is used forproviding power supply. Due to the substantial cable requirement of repeating the signalaspects and all vital relay states (SIL-4) pertaining to drive/control of Auto signals from theCentral Interlocking (at station), it has been proposed to use redundant UFSBI (separate for UP& DN line) in lieu of Quad or signaling cable. This not only reduces project expenditure, it alsomitigates the possibility of service disruption owing to cable theft. Avoiding the use of coppercable for relay repetition also eradicates the chances of electrical induction and false feed insignaling circuits.

The scheme has been approved by RDSO and issued as a general guideline (vide publicationdated June 2006 to all zones) and has been largely followed in South Eastern Railway, alongwith use of UFSBI in relay state repetition, over Haur – Panskura – Balichak (Howrah –Kharagpur sub-urban section). The RDSO schematic details are provided below for reference.

Although some zonal railways have proposed the use of Object Controllers of distributedElectronic Interlocking for merely repeating safe signaling relay states from field locations toCentral Interlocking (at station) and vice-versa, it’s an absolute overkill with almost double thecost, as that of use of a simple fail-safe Mux UFSBI.

Further, using the Object Controllers of a particular make limits the user to keep on using thesame make of EI for station interlocking, even though, it may be functionally unimpressive orcostlier alternative. Also the maintenance of Object Controllers is much critical as compared toUFSBI. In case UFSBI is used for relay repeating then railway to use any type of relay orelectronic interlocking.

Media Independent IBS operation simultaneously on OFC/Quad



` ```````````````````````



Scheme of Automatic Block Signalling using Dual HA-SSDAC & UFSBI on dual OFC

The scheme utilizing the MSDAC centralizes the all the track relays at the central location andmakes the maintenance of the critical signaling items at the central location, although it carrieswith it a series of serious limitations.

Limitations of Automatic Block Signalling using MSDAC

1. The common mode failure at the central location, viz. a Quad cable damage /cut nearest tostation where Evaluators are placed (which is quite common) or a IPS module breakdown atthe station, geopodizes the complete Auto-Signaling operation over the entire section. Underthat case the trains are forced to mode on caution, reducing the line capacity, to levels evenlesser than Absolute Block working.

2. Use of costly Quad-cable for connecting the DP to central evaluator, is mandatory, owing tothe inability of the same to work OFC VF channel. Further, non availability of mediadiversity in connecting the DP to central evaluator, is a major shortcoming in places wherethe copper cable theft is quite prevalent.

3. Electrical induction from 25 KV traction line on copper Quad cable is many times the causeof link failure in axle counters. Especially supervisory track circuits are seen to auto-heal theauto track sections and even cause failures.

Salient Features of ABS using Dual HA-SSDAC & UFSBI on dual OFC

The same have been critically studied by some railways and complete copper-less scheme forAuto-Signaling is prepared.

1. Dual HA-SSDAC (single detection dual communication link) is used in lieu of dualcentralized MSDAC evaluator. Complicated supervisory tracks for mutual resetting areavoided with mutual auto-healing by the Dual HA-SSDAC.

2. The usage of Quad / signaling cable for relay state exchange is completely avoided by use ofdual redundant hot-standby UFSBI units for UP & DN Line on OFC, thus making thescheme very cost effective and less theft prone.

3. Dual OFC is proposed one on each side of the track, with independent media converter /Mux to achieve spatial / equipment diversity. Additionally it completely does away withthe negative effects of Electrical induction from 25 KV traction line on axle countercommunication

Advantages using Dual HA-SSDAC & UFSBI on dual OFC

1. Much lower cost as signaling / Quad cable usage is completely avoided. An estimated costsaving of 25-30% approx. may be achieved, if compared with scheme with MSDAC oncopper cable.

2. Much higher Reliability, owing to very high level of redundancy provided.

3. Easy Maintenance and less theft prone, thus leading to high MTBF with less MTTR



4.



Automatic Media Changeover for Seamless operation of UFSBI on dual media(OFC/Quad or OFC/Radio or Quad / Radio)

Automatic Media Changeover unit is an intelligent network switcher that continuouslyscans both the communication line / channel connected to it and on the event of failure ofthe working media; it automatically switches over to the backup media. The system is builtaround a powerful 32 bit high speed microcontroller that continuously monitors thenetwork traffic reaching the host from the remote UFSBI. The microcontroller only sniffs onthe data path , without either intervening or modifying the safety data.The data quality is decided by the microcontroller itself while the media switchover is doneby an isolated digital switch, thereby reducing the switching latency to less than 1 ms. Thechangeover time being extremely small in term of UFSBI to sense, the channel switchover ispractically seamless. In order to indicate to the user/maintainer, the working channel, healthof both the working and non-working (secondary) channel etc. LED’s are provided on thefront panel. Further, potential free contacts are provided against each of the referredindications, so that the same can be logged into the Networked Data-logger.The system basically works on digital levels of the communication circuit. It accepts a serialRS232C channel from the UFSBI and physically splits into 2 paths, which are transmittedover 2 media. The Line side of the Automatic Media Changeover unit is front ended byeither a Modem to work through VF 4-wire E&M channel or Quad Cable as media. In case aof direct optical fiber connectivity is provided, suitable media converter may be used. If alow-speed data channel like microwave radio is provided, then the same can be directlyconnected to the Line side serial port of the system.On the receiving end, only one of the channels, both having identical data (since both arecoming from same source, but through different media), is forwarded to the UFSBI. In caseone fails, then only the working channel is shut off from the receiving UFSBI and the backupchannel is connected to the UFSBI.Schematic diagrams provided below, shows the front and back panel view of the equipment,as well and the connectivity details.

The functional advantages of the Automatic Media Changeover

a) Seamless changeover between the primary and the secondary media without humanintervention, only indications provided.

b) Very low latency media switchover (<1 ms), thereby ensuring no link failure ofUFSBI.

c) Continuous monitoring of both working / non-working media through intelligentnetwork processor and providing potential free contact for recording mediaperformance over networked data logger.

d) In-system network performance / failure logger for providing time stamped record(in downloadable form) for network performance figures such as – active channel id.,no. of channel switchover and duration of channel failures for each media.

Note: The same media changeover unit may be used for other devices like digital axle-counter provided thecommunication packet format (like size, speed, number of Start /Stop bit etc. are provided



Schematic related to the connectivity of the Media Changeover are presented hereafter.

Front View Back View

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