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Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage

of 103 RSSB GK/GN0675 Issue Four September 2015

Issue record

Issue Date Comments

One March 2011 Original document produced to support GK/RT0075 issue one, Lineside Signal Spacing and Speed Signage.

Two September 2011 Small scale change to correct inconsistencies between GK/RT0075, issue one, Lineside Signal Spacing and Speed Signage, and its associated guidance note GK/GN0675. The only changes to this guidance note are the inclusion of missing word ‘section’ in 3.3.5.5 a), and deletion of section D.2.4.1 d) which was a duplication of D.2.4.1 c).

Three September 2014 Guidance revised to support the reissue of GK/RT0075 from issue two to three arising from project 12/033 to remove the requirement for a risk assessment before an emergency speed restriction is applied (E.2.1). Additional revisions include: Changes made to address typographical errors in

GN Table 1, GN Table 2, Table B.1 and Table X-3. Revisions to clauses 2.1.3b), 3.3.2.4, 3.4.1.4a),

D.1.1.2, D.2.5.1a), D.2.5.2, D.4.2.1 and E.2 (with the addition of guidance GN268).

Removal of GN18b) - GN18c) becomes b). New clause at D.2.5.3. Updates to Figure D-21 (with the addition of guidance

GN242) and Figure D-27. The removal of clause D.4.2.3. New guidance at GN65, GN191a and GN191b. Last sentence of GN263 deleted. Updates to document definitions.

Four September 2015 Guidance revised to support the reissue of GK/RT0075 from issue three to issue four to modify the requirements in 3.4.1.4 for the provision and position of warning boards for temporary speed restrictions (TSRs) with additional changes which include: Minor clarification in clause 1.1. Re-instatement of reference in clause 2.1.3 to excess

signal braking distances. Easement in clause D.2.1.2 for the non-standard

positioning of warning boards (and associated AWS) for TSRs and associated GN202a.

Amendment of Tables X-1, X-2 and X-3 and the corresponding changes to the imperial (yards) braking distances tables at X-11, X-12 and X-13.

Amended or additional parts and / or sections of revised pages have been marked by a vertical black line in the adjacent margin.



RSSB of 103 GK/GN0675 Issue Four September 2015

Superseded documents

The following Rail Industry Guidance Note is superseded, either in whole or in part as indicated:

Superseded Documents Sections

Superseded

Date when sections are superseded

GK/GN0675 issue three Guidance on Lineside Signal Spacing and Speed Signage

All 05 December 2015

GK/GN0675 issue three Guidance on Lineside Signal Spacing and Speed Signage, is withdrawn as of 05 December 2015.

Supply

The authoritative version of this document is available at www.rgsonline.co.uk. Enquiries on this document can be forwarded to [email protected].


http://www.rgsonline.co.uk/

mailto:[email protected]



Contents

Section Description Page Part 1 Introduction 7 1.1 Purpose of this document 7 1.2 Copyright 7 1.3 Approval and authorisation of this document 7 Part 2 Guidance on Requirements for Lineside Signal Spacing 8 2.1 Compatibility requirements for lineside signal spacing 8 2.2 Requirement for signal spacing 9 2.3 Determining minimum signalling braking distances 10 2.4 Acceptable variations in signal spacing 14 2.5 Consistency of signalling braking distances 17 2.6 Four-aspect signalling 18 2.7 Use of attainable speed to determine minimum signal spacing 21 2.8 Requirements at infrastructure manager boundaries 22 Part 3 Guidance on Requirements for Signing of Permissible Speeds and

Speed Restrictions 24 3.1 Compatibility requirements for signing of permissible speeds and speed restrictions 24 3.2 Requirements for permissible speeds and temporary speed restrictions 25 3.3 Signs for permissible speeds 29 3.4 Provision of signs for temporary and emergency speed restrictions 45 Part 4 Application of this Document 50 4.1 Application – infrastructure managers 50 4.2 Application – railway undertakings 50 4.3 Health and safety responsibilities 50 Appendices 51 Appendix A Signalling Braking Distance Data for all Trains 51 A.1 Composite table for all trains (metres) 51 Appendix B Signalling Braking Distances for Passenger Trains 55 B.1 Composite table for passenger trains (metres) 55 Appendix C Signalling Braking Distances for Trains with Enhanced Braking (9%g mean) 59 C.1 Table for trains with enhanced braking (9%g mean) in metres 59 Appendix D Temporary Speed Restrictions 63 D.1 Position of speed indicators and termination indicators 63 D.2 Temporary speed restriction warning boards and AWS equipment 65 D.3 Requirements for adjacent temporary speed restrictions 79 D.4 Altering temporary speed restrictions 83 Appendix E Emergency Speed Restrictions 86 E.1 Management of emergency speed restrictions 86 E.2 Provision of speed indicators, warning boards and AWS equipment 86 Appendix X Deceleration Distances 88 Table X-1 Deceleration distance in metres to speed restriction of 10 mph 88 Table X-2 Deceleration distance in metres to speed restriction of 20 mph 89 Table X-3 Deceleration distance in metres to speed restriction of 30 mph 90 Table X-4 Deceleration distance in metres to speed restriction of 40 mph 90 Table X-5 Deceleration distance in metres to speed restriction of 50 mph 91 Table X-6 Deceleration distance in metres to speed restriction of 60 mph 91 Table X-7 Deceleration distance in metres to speed restriction of 70 mph 92 Table X-8 Deceleration distance in metres to speed restriction of 80 mph 92 Table X-9 Deceleration distance in metres to speed restriction of 90 mph 92 Table X-10 Deceleration distance in metres to speed restriction of 100 mph 93 GN Table X-11 Deceleration distance in yards to speed restriction of 10 mph 93




GN Table X-12 Deceleration distance in yards to speed restriction of 20 mph 94 GN Table X-13 Deceleration distance in yards to speed restriction of 30 mph 95 GN Table X-14 Deceleration distance in yards to speed restriction of 40 mph 95 GN Table X-15 Deceleration distance in yards to speed restriction of 50 mph 96 GN Table X-16 Deceleration distance in yards to speed restriction of 60 mph 96 GN Table X-17 Deceleration distance in yards to speed restriction of 70 mph 97 GN Table X-18 Deceleration distance in yards to speed restriction of 80 mph 97 GN Table X-19 Deceleration distance in yards to speed restriction of 90 mph 97 GN Table X-20 Deceleration distance in yards to speed restriction of 100 mph 98 Appendix Y Key to Symbols Used in this Standard 99 Definitions 100

Abbreviations and Acronyms 102

References 103

Tables Table 1 Exemptions from the compatibility check 9 Figures Figure 1 Example of a permissible speed indicator 29 Figure 2 Example of two or more successive reductions in speed 30 Figure 3 Example of a standard differential permissible speed indicator 32 Figure 4 Example of a standard differential permissible speed warning indicator 32 Figure 5 Examples of a non-standard differential permissible speed indicator 33 Figure 6 Examples of a non-standard differential permissible speed warning

indicator 33 Figure 7 Example of permissible speed indicator at converging junction 34 Figure 8 Example of permissible speed indicator at diverging junction with speed

reduction on diverging route only 35 Figure 9 Example of permissible speed indicator at diverging junction with speed

reduction (equal speed) on both routes 35 Figure 10 Example of permissible speed indicator at diverging junction with speed

reduction on both routes (different speeds) 36 Figure 11 Example of permissible speed indicator at diverging junction with no

straight route 36 Figure 12 Example of permissible speed warning indicator (simple case) 36 Figure 13 Example of permissible speed warning indicator for successive

reductions in speed 37 Figure 14 Example of successive reductions in speed where a further permissible

speed warning indicator is required 38 Figure 15 Example of positioning of permissible speed warning indicator where deceleration distance falls within lower speed section 39 Figure 16 Example of positioning of permissible speed warning indicator where

deceleration distance encompasses lower speed section 39 Figure 17 Example of permissible speed warning indicators at converging junction 41 Figure 18 Example of permissible speed warning indicator for diverging junction

positioned at a signal that displays a cautionary aspect 42 Figure 19 Example of permissible speed warning indicator for speed reduction

on a diverging route 43 Figure 20 Example of movement via crossing not requiring temporary speed

restriction signs 45 Figure 21 Example of a commencement and termination indicator 46 Figure 22 Example of an emergency indicator 47 Figure 23 Example of differential speed indicators 48 Figure D-1 Example of speed indicators at converging junction (D.1.2.1) 64 Figure D-2 Example of TSR over trailing end of crossover (D.1.3.2) 65 Figure D-3 Example of TSR over facing end of crossover (D.1.3.3) 65




Figure D-4 Example of TSR with a higher permissible speed on approach (D.2.1.4) 66 Figure D-5 Example of TSR with a lower permissible speed on approach (D.2.1.5) 67 Figure D-6 Example of TSR with warning board at commencement of higher permissible

speed (D.2.1.6) 67 Figure D-7 Example of warning board positioning at a converging junction (D.2.2.1) 68 Figure D-8 Example of warning board positioning at a diverging junction (D.2.3.1) 68 Figure D-9 Example of a diverging junction with warning board located at the

facing points (D.2.3.2) 69 Figure D-10 Example of a diverging junction where signal is approach released

from red (D.2.3.3) 70 Figure D-11 Example of a diverging junction where signal is approach released from a higher

aspect (D.2.3.4) 71 Figure D-12 Example of a diverging junction where no previous routing advice

is given (D.2.3.5) 72 Figure D-13 Example of usual positioning of AWS magnets. (D.2.4.1a) 73 Figure D-14 Example of critical positioning of AWS magnets (D.2.4.1c) 73 Figure D-15 Example of warning board at signal with signal AWS electromagnet

disconnected (D.2.4.4) 74 Figure D-16 Example of disconnection of suppressor on existing magnet (D.2.4.5) 75 Figure D-17 Example showing use of AWS cancelling indicator (D.2.4.6 / D.2.4.7) 76 Figure D-18 Another example showing use of AWS cancelling indicator (D.2.4.6 / D.2.4.7) 76 Figure D-19 Example showing provision of a warning board on an unfitted line leading

to a fitted line (D.2.4.8) 77 Figure D-20 Example showing disconnection of AWS in advance of protecting signal

leading to a fitted line (D.2.4.9) 78 Figure D-21 Example showing use of repeater warning boards (D.2.5.2) 79 Figure D-22 Example of a lower TSR followed by a higher TSR (D.3.1.1) 80 Figure D-23 Example of a higher TSR followed by a lower TSR (D.3.2.1) 80 Figure D-24 Another example of a higher TSR followed by a lower TSR (D.3.2.1) 80 Figure D-25 Example of co-incident warning boards for diverging routes (D.3.3.2) 81 Figure D-26 Example of successive speed restrictions on the same line (D.3.3.3) 82 Figure D-27 Example showing a moving TSR where the warning board cannot

be moved (D.4.1.2) 83 Figure D-28 Example of a TSR not imposed or withdrawn early (D.4.2.2) 84 Figure E-1 Example of arrangements for emergency speed restriction (E.2.2) 87

Figures (Guidance) GN Figure 1 Spacing of 4-aspect signals – preferred arrangement (see 2.6.1) 18 GN Figure 2 Spacing of 4-aspect signals – alternative arrangement (see 2.6.2) 19 GN Figure 3 Spacing of 4-aspect signals with consecutive double yellows 19 GN Figure 4 Spacing of 4-aspect signals at station with mid-platform signal 20 GN Figure 5 Use of attainable speed at signal beyond converging junction 21 GN Figure 6 Showing the use of excess speed approaching a signal 22 GN Figure 7 Composite curves for all trains (metres) 52 GN Figure 8 Composite curves for all trains (yards) 54 GN Figure 9 Composite curves for passenger trains (metres) 56 GN Figure 10 Composite curves for passenger trains (yards) 58 GN Figure 11 Curves for trains with enhanced braking (9%g mean) in metres 60 GN Figure 12 Curves for trains with enhanced braking (9%g mean) in yards 62

Tables (Guidance) GN Table 1 Composite table for all trains (yards) 53 GN Table 2 Composite table for passenger trains (yards) 57 GN Table 3 Table for trains with enhanced braking (9%g mean) in yards 61




Part 1 Introduction

1.1 Purpose of this document

This document gives guidance on interpreting the requirements of Railway Group Standard GK/RT0075 issue three Lineside Signal Spacing and Speed Signage. It does not constitute a recommended method of meeting any set of mandatory requirements.

Relevant requirements in GK/RT0075 are reproduced in the sections that follow. Guidance is provided as a series of sequentially numbered sections prefixed ‘GN’ immediately below the text to which it relates. Where there is no guidance given, this is stated.

The scope of this document does not include compatibility of lineside signalling and speed signage with train driving processes when an in-cab signalling system is in use.

Specific responsibilities and compliance requirements are laid down in the Railway Group Standard itself.

1.2 Copyright

Copyright in the Railway Group documents is owned by Rail Safety and Standards Board Limited. All rights are hereby reserved. No Railway Group document (in whole or in part) may be reproduced, stored in a retrieval system, or transmitted, in any form or means, without the prior written permission of Rail Safety and Standards Board Limited, or as expressly permitted by law.

Rail Safety and Standards Board (RSSB) members are granted copyright licence in accordance with the Constitution Agreement relating to Rail Safety and Standards Board Limited.

In circumstances where Rail Safety and Standards Board Limited has granted a particular person or organisation permission to copy extracts from Railway Group documents, Rail Safety and Standards Board Limited accepts no responsibility for, nor any liability in connection with, the use of such extracts, or any claims arising therefrom. This disclaimer applies to all forms of media in which extracts from Railway Group Standards may be reproduced.

1.3 Approval and authorisation of this document

The content of this document was approved by the Control Command and Signalling (CCS) Standards Committee on 09 July 2015.

This document was authorised by RSSB on 31 July 2015.




Part 2 Guidance on Requirements for Lineside Signal Spacing

2.1 Compatibility requirements for lineside signal spacing

2.1.1 GE/RT8270 sets out the process for the assessment of compatibility that is required whenever a material change is to be made that affects the interface between the signalling system and railway undertakings or any infrastructure managers that operate stations.

2.1.2 The assessment of compatibility shall check that the signalling spacing data used to determine minimum signalling braking distances (further requirements are set out in 2.3) is compatible with all of the following:

a) The types of rolling stock that will be operated on the route.

b) The maximum speeds that the rolling stock will be authorised to operate on the route.

c) The maximum attainable speeds of the rolling stock, where this is used to determine minimum signalling braking distances.

2.1.3 The assessment of compatibility shall check that the actual signalling braking distance is compatible with the SPAD risk mitigation measures that will be put in place by the railway undertakings, where any of the following apply:

a) There is more than 50% excess signalling braking distance, except where an exemption applies (see Table 1).

b) A variation in excess signalling braking distances means that the distance between the signals displaying the first cautionary aspect and the stop aspect is reduced by 34% or more, compared with the excess signalling braking distance for the preceding sequence of signals on the same line.

c) In four-aspect signalling areas, where the distance between the signals displaying the single yellow aspect and the red aspect is less than one third of the distance between the signals displaying the double yellow aspect and the red aspect.

Situation

Scope of compatibility check where actual signal spacing exceeds the minimum

signalling braking distance by more than 50%

a Where signals control movements in the same direction on parallel lines that have different permissible speeds, and signals are positioned adjacent to each other to minimise the risk of driver misread or disregard

The compatibility check is only required for signalling braking distances on the higher speed line.

Signal braking distances on the lower speed line are exempt from the compatibility check

b Where trains join a higher speed line at a converging junction from a lower speed line or start from a siding, loop or another platform line


Signal braking distances for train movements from the lower speed line are exempt from the compatibility check




Note: Further guidance GN42 to GN50 is provided in 2.4 on the topic of acceptable variations in signal spacing addressed in this Table 1, which is reproduced from GK/RT0075. For ease of reference, extracts from Table 1 have been reproduced in this Guidance Note.

2.2 Requirement for signal spacing

2.2.1 The position of lineside signals shall be compatible with the braking performance of rolling stock so that trains moving at the permissible speed (or attainable speed in the circumstances set out in 2.7) can stop within the actual signalling braking distance.

GN01 The signalling system provides information to the driver by means of the aspects displayed,

to identify that the train is approaching the end of its movement authority.

GN02 The cautionary aspects should be displayed at a sufficient distance on the approach to the signal where the train is required to stop, so that the train can brake from the permissible speed using a full service brake application and stop at the signal.

GN03 Inadequate signal spacing between the first cautionary aspect and the end of the movement authority could be a causal factor of a signal passed at danger (SPAD), if the train cannot stop before reaching the end of its movement authority.

Situation

Scope of compatibility check where actual signal spacing exceeds the minimum

signalling braking distance by more than 50%

c Where trains start from a platform on a through line

The compatibility check is only required for signalling braking distances associated with non-stopping trains.

Signal braking distances for train movements that start from rest are exempt from the compatibility check

d Where the signal spacing is designed using particular signalling braking distance data (for example, Appendix A for a mixed traffic line)

The compatibility check is only required for signalling braking distances associated with the appendix to which the line is signalled

e Where the signal spacing is designed to Appendices B or C, and a differential speed restriction is applied to enable traffic with an inferior braking characteristic to operate


f At the approach to buffer stops at terminal stations or at bay platforms

The compatibility check does not apply to the spacing distance between the approach signals and the buffer stops

Table 1 Exemptions from the compatibility check




GN04 The signal spacing between the first cautionary aspect and the end of the movement authority should take account of the permissible speeds and braking performance of all trains that operate over the route. If appropriate, use may be made of differential permissible speeds, in order to optimise the signal spacing for trains with different braking characteristics (see 2.3.4 and 2.3.5).

GN05 The requirements for signal aspect sequences approaching the end of a movement authority are set out in GK/RT0045.

2.3 Determining minimum signalling braking distances

2.3.1 Minimum signalling braking distances shall be determined using the data in Appendices A to C, as set out in 2.3.3 to 2.3.5. The associated guidance note (GK/GN0675) contains signalling braking distance data in imperial (yards) as well as metric units. Additionally, in respect of Appendices A, B and C, these data are included in graphical form.

2.3.2 Additional requirements for assessing compatibility of the data used and rolling stock performance are set out in 2.1.2.

GN06 The infrastructure manager is responsible for deciding which signalling braking distance

data to use for each line of route.

GN07 The decision is taken at the scheme development stage and should take account of:

a) All types of rolling stock to be operated over the route by each railway undertaking, including braking performance information.

b) The speeds at which trains are to be operated by each railway undertaking.

GN08 The railway undertakings operating trains over the route should provide the information to the infrastructure manager about rolling stock types, braking performance and train speeds.

GN09 The processes set out in GE/RT8270: Assessment of Compatibility of Rolling Stock and Infrastructure should be used to check compatibility between rolling stock and the signalling system before:

a) New or modified trains are introduced onto the network.

b) Any changes are made to the signalling system which could affect the ability of any trains to stop within the available signalling braking distances.

c) Railway undertakings operate any trains at speeds higher than that previously allowed.

GN10 The infrastructure register and rolling stock register (required by the Interoperability Regulations) may be referred to when managing changes.

GN11 Railway Group Standards GM/RT2041: Braking System Requirements and Performance for Trailer Coaching Stock, GM/RT2042: Braking System Requirements and Performance for Traction Units, GM/RT2043: Braking System and Performance for Freight Trains and GM/RT2044: Braking System Requirements and Performance for Multiple Units, specify the braking performance of rail vehicles that is compatible with the signal spacing derived from the data in Appendices A, B and C of GK/RT0075.

GN12 The rolling stock standards specify the braking rates that the trains are designed to achieve. They include various allowances and contingencies to cater for variation in operational performance (for example, errors in speed, and the potential reduction in the available braking rate due to partial failure of the braking system). However, these standards only specify the stopping distance to be achieved on level track; the




corresponding stopping distances for different gradients, which are used in determining minimum signal spacing, are only specified in the appendices to GK/RT0075.

2.3.3 The minimum signalling braking distance shall be established from Appendix A,

based on the maximum permissible speed for freight trains (taking account of standard differential speeds and speed limits imposed by special instructions).

GN13 GK/RT0075 Appendix A is based on the braking rates specified in GM/RT2041 Figure 1,

GM/RT2042 Figure 1, GM/RT2043 Figure 1 and GM/RT2044 Figure 1. These are the minimum braking rates specified for rolling stock (referred to in GM/RT2041 etc as the ‘V’ curve).

GN14 Trains that do not conform to these minimum requirements (for example, engineering trains or abnormal freight loads) are operated only in accordance with special operating rules, which are a condition of allowing them to operate on the network.

2.3.4 Where passenger trains (including those with enhanced braking where specific

non-standard differentials are not provided) are authorised to travel at speeds greater than the permissible freight train speed (by means of standard or non-standard differential speeds), the signalling braking distance shall be equal to or exceed the distance derived from Appendix B, for the maximum permissible speed of those trains.

GN15 GK/RT0075 Appendix B is based on the braking rates specified in GM/RT2041 Figure 2,

GM/RT2042 Figure 2 and GM/RT2044 Figure 2. These are the standard braking rates for all types of passenger rolling stock (often referred to as the ‘W’ curve). Below 100 mph this curve is based on the friction characteristic of cast-iron brake blocks.

GN16 Appendix B is used to determine the signal spacing on lines where it is advantageous to optimise the signal spacing for passenger train operations and either:

a) It is acceptable to impose differential speeds to limit the speed of trains that do not meet the braking performance of Appendix B, or

b) Only trains which meet the braking performance of Appendix B normally operate and it is acceptable either to prohibit the operation of trains which do not meet the braking performance of Appendix B, or to permit such trains to operate only under special operating procedures.

GN17 Where Appendix B is used to establish the signal spacing, the infrastructure manager should also consider the signal spacing required by trains that do not meet the braking performance of Appendix B, unless no such trains are permitted to operate on the line, or impose differential speed restrictions to ensure that the signal spacing is adequate for these trains also to stop, from the lower speed, within the distance available.

GN18 Where it is proposed to resignal a line using Appendix B (or Appendix C) on a route where a differential speed restriction for certain types of trains is currently imposed by an operational rule without the provision of differential speed signs (for example the ‘two-thirds’ rule for freight trains), and the minimum signal spacing does not provide adequate stopping distance for trains operating at a differential speed in accordance with the existing rule, one of the following solutions should be applied:

a) Provide differential speed signs showing the differential speed determined in accordance with GN17 above, or

b) Use Appendix A, which is compatible with all trains.

GN19 In particular, it should be noted that the existing ‘two-thirds’ rule which has been applied to limit the speeds of freight trains on lines of the former Southern Region was based on




signalling set out in Appendix D of GK/RT0034 (now withdrawn), which provided adequate signal spacing for freight trains travelling at two-thirds of the speed set out in Appendix D. The minimum signalling braking distances in Appendix B may not provide adequate spacing at all speeds and gradients for freight trains travelling at two-thirds of the permissible speed, and thus the provisions of GN18 may need to be applied.

GN20 Differential speeds may be imposed for reasons other than restricted signal spacing. For instance, it may be possible to take advantage of differential permissible speeds imposed for other reasons, to optimise the signal spacing in relation to the speed profile and braking capability of different types of trains. The infrastructure manager should record the reason for the imposition of the differential speed, for instance in the Sectional Appendix or an attachment to it.

2.3.5 Where passenger trains with enhanced braking are authorised to travel at

speeds greater than the permissible freight train speed (by means of non-standard differential speeds), the signalling braking distance shall be equal to or exceed the distance derived from Appendix C, for the maximum permissible speed of passenger trains with enhanced braking.

GN21 GK/RT0075 Appendix C is based on the braking rates specified in GM/RT2041 Figure 3,

GM/RT2042 Figure 3 and GM/RT2044 Figure 3. These are the enhanced braking rates achieved by certain types of passenger rolling stock (referred to in GM/RT2041 etc as the ‘Y’ curve, and sometimes referred to as the ‘9%g curve’).

GN22 Appendix C is used to determine the signal spacing on lines where it is advantageous to optimise the signal spacing for trains meeting the enhanced braking performance of Appendix C and either:

a) It is acceptable to impose differential speeds to limit the speed of trains that do not meet the braking performance of Appendix C, or

b) It is acceptable either to prohibit the operation of trains which do not meet the braking performance of Appendix C, or to permit such trains to operate only under special operating procedures.

GN23 The use of Appendix C for low/medium speed mixed traffic lines should be avoided as the speed differentials are generally excessive.

GN24 Where Appendix C is used to establish the signal spacing, the infrastructure manager should also consider the signal spacing required by trains that do not meet the braking performance of Appendix C (unless no such trains are permitted to operate on the line) and impose differential speed restrictions to ensure that the signal spacing is adequate for these trains also to stop, from the lower speed, within the distance available.

GN25 Differential speeds may be applied using non-standard differential permissible speed indicators (see 3.3.2.1) showing a higher speed for a category of train which applies only to trains with braking compatible with Appendix C (for example HST).

GN26 Where differential speeds are applied using non-standard differential permissible speed indicators (see 3.3.2.1) showing a category of train which is not restricted to trains with braking compatible with Appendix C (for example MU or SP), Appendix C can be used to determine the signal spacing for trains running at the speed indicated on these signs only if means are taken to ensure that only those trains with braking compatible with Appendix C are permitted to run at this speed. If other trains in this category, which do not have braking compatible with Appendix C, are permitted to run on the line, they must be restricted to lower speeds, for example by an instruction in the Sectional Appendix.

GN27 Where it is proposed to resignal a line using Appendix C on a route where a differential speed restriction for certain types of trains is currently imposed by an operational rule




without the provision of differential speed signs, the minimum signal spacing may not provide adequate stopping distance for trains operating at a differential speed in accordance with the existing rule. When this is the case, one of the following solutions should be applied:

a) Use differential speed signs in place of the operational rule, or

b) Change the operational rule to impose speeds compatible with the actual signalling braking distance, or

c) Reposition the signal to provide the signalling braking distance compatible with the existing operational rule.

GN28 Some changes to differential speeds have to be applied in conjunction with changes to entries in the ‘Route Clearance Table’ in the Sectional Appendix. For example, multiple unit differentials can only be used for Appendix C signal spacing if non-9%g braked multiple units are restricted.

GN29 Differential speeds may be imposed for reasons other than restricted signal spacing. For instance it may be possible to take advantage of differential permissible speeds imposed for other reasons, to optimise the signal spacing in relation to the speed profile and braking capability of different types of trains. The infrastructure manager should record the reason for the imposition of the differential speed, for instance in the Sectional Appendix or an attachment to it.

2.3.6 The minimum signalling braking distance shall be determined using:

a) The permissible speed at the signal displaying the first cautionary aspect, and

b) The average gradient of the line between the signals displaying the first cautionary aspect and the stop aspect.

2.3.7 For gradients between two values shown in the tables, the signalling braking distance for that gradient shall be calculated by linear interpolation between the signalling braking distances for the two adjacent gradient values.

2.3.8 Where a falling gradient varies and the mean gradient is 1 in 200 or steeper, the minimum signalling braking distance to be used shall be the shorter of either:

a) The distance for the mean gradient plus 10% of that distance, or

b) The distance for the steepest falling gradient.

GN30 There are two SPAD traps associated with falling gradients:

a) Where the gradient steepens on the final approach to the end of movement authority.

b) Where an initial rising gradient is followed by a steep falling gradient.

In both cases because the driver may not be able to initiate a brake application at the caution aspect sufficient to bring the train to a stand at the red, the provision of a reminder (for instance a lineside sign or banner repeating signal) should be considered, located at the commencement of the more steeply falling gradient.

GN31 Locations which include combinations of rising and falling gradients, both steeper than 1 in 100, within the distance between the first caution and the associated stop signal, require special consideration. Each case should be considered separately in relation to the performance of trains authorised to operate on the route, to ensure that signals are spaced to enable all such trains to be stopped safely.




2.4 Acceptable variations in signal spacing

2.4.1 The position of signals shall be designed so that the actual signalling braking distance is no less than the minimum signalling braking distance.

GN32 The signalling should be designed such that the distance from the first caution aspect to

the limit of movement authority, for each train travelling at its permissible speed, should be not less than the signalling braking distance quoted in the relevant appendix (A, B or C) to this document.

2.4.2 Wherever practicable, the position of signals shall be designed so that

excess signalling braking distance does not exceed 50%.

GN33 It is good practice to design signal positions with some excess spacing over the minimum

required so that drivers do not have to use the full service brake in order to stop at signals. Also, some variation in actual signal spacing arises because signals have to be positioned to provide good sighting, and positioned appropriately in relation to stations, junctions and other constraining features. This also allows for adjustment of the signal positions to cater for sighting difficulties or other constraints not fully identified at the initial design stage.

GN34 Excessive signal spacing may be a causal factor of a SPAD. Ideally, the first cautionary aspect identifies the point at which the driver should apply the brake.

GN35 If the distance between the first cautionary aspect and the end of the movement authority is significantly greater than the distance required for braking, drivers may not apply the brake at the cautionary aspect, but may delay braking until they reach a point that they judge to be the required braking point. This could potentially lead to a driver error in judging the position that the brakes need to be applied, resulting in a SPAD.

2.4.3 Additional requirements for assessing compatibility of actual signalling braking

distances and train operations, where there is more than 50% excess signalling braking distance, are set out in 2.1.3.

GN36 Signals should, wherever possible, be positioned with no more than 50% excess over the

minimum spacing distance. However, there are circumstances where excess spacing greater than 50% may be preferable to the alternatives.

GN37 Nevertheless, it may be necessary to accept excessive signal spacing if its avoidance would result in signals being positioned such as to be non-compliant with other requirements.

GN38 Whereas inadequate signal spacing significantly increases the likelihood of a SPAD, and is therefore unacceptable, excessive signal spacing is only one of a number of potential factors that can lead to an increased risk of a SPAD.

GN39 On a route where rolling stock operates with differing permissible speeds and braking characteristics, the degree of excess in respect of a particular signal may vary widely between different trains, and this should be reflected in the professional driving policies of railway undertakings that operate over the routes concerned.




GN40 Where the excess signal spacing exceeds 50%, the infrastructure manager should assess the SPAD risk arising from excessive signal spacing, taking account of the balance of the various factors, including:

a) Factors that contribute to a SPAD risk (see below).

b) Factors that mitigate the SPAD risk (see below).

GN41 The assessment of SPAD risk should include (but not be limited to) the following factors:

a) Driver distraction (particularly between the caution signal and the point where trains need to start braking).

b) Signal sighting.

c) Aspect sequences.

d) Signal spacing and location.

e) Junction signalling controls.

f) Effect of rising and/or falling gradients.

g) Effect of intervening changes in permissible speed.

GN42 Table 1 sets out a number of circumstances where it is often not practicable to avoid excess spacing greater than 50%. Guidance on each of these circumstances is addressed in the following extracts:

Situation

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50%

a Where signals control movements in the same direction on parallel lines that have different permissible speeds, and signals are positioned adjacent to each other to minimise the risk of driver misread or disregard


Signal braking distances on the lower speed line are exempt from the compatibility check

Table 1 extract (a) Parallel lines

GN43 GK/RT0045 includes a requirement to position signals on parallel lines adjacent to each

other to minimise the risk of misreading, even when this results in excess spacing on the slower speed line. Where there are parallel lines with different signal spacing requirements (due to different permissible speeds), the excess signal spacing on a slower line is a secondary issue to the requirement in GK/RT0045.

GN44 Where there are parallel fast and slow lines and 4-aspect signalling is provided on the fast lines, 3-aspect signalling at the same spacing may provide adequate signalling braking distance for trains at the slower maximum permissible speed applicable on the slow lines. However, if provision of this arrangement requires extension of the signalling braking distance to provide the required spacing for the 3-aspect signalling on the slow line and this results in excess signal spacing for the 4-aspect signalling on the fast line, the excess signal spacing on the fast line should be subject to a risk assessment. In addition, the risk assessment should consider the alternative of providing 4-aspect signalling on both fast and slow lines.




Situation


b Where trains join a higher speed line at a converging junction from a lower speed line or start from a siding, loop or another platform line


Signal braking distances for train movements from the lower speed line are exempt from the compatibility check

Table 1 extract (b) Converging lines

GN45 Where trains join a through line from another line, including from a siding, loop or platform, and the permissible speed through the connection is lower than that on the through line, the signal spacing is determined using the higher permissible speed on the through line. This may result in excess signal spacing in relation to the lower speed of trains on the connecting line.

Situation


c Where trains start from a platform on a through line

The compatibility check is only required for signalling braking distances associated with non-stopping trains.

Signal braking distances for train movements that start from rest are exempt from the compatibility check

Table 1 extract (c) Starting from platforms

GN46 Where trains may start from rest (for example, from a station platform on a through line), the signal spacing is determined by trains running through the station at permissible speed. This results in excess signal spacing when considered in relation to the lower speed of trains starting from rest.

Situation


d Where the signal spacing is designed using particular signalling braking distance data, (for example, Appendix A for a mixed traffic line)


Table 1 extract (d) Trains with better braking characteristics

GN47 Wherever trains with different braking capabilities (conforming to the different appendices of GK/RT0075) operate, except where differential speeds are used to match the different




braking performances to the signal spacing, the signal spacing is determined by the trains with the lowest braking rate. This results in excess signal spacing when considered in relation to the required braking distance for trains with better braking performance.

Situation


e Where the signal spacing is designed to Appendices B or C, and a differential speed restriction is applied to enable traffic with an inferior braking characteristic to operate

The compatibility check is only required for signalling braking distances associated with the appendix to which the line is signalled.

Table 1 extract (e) Differential permissible speeds

GN48 Where the signalling system is optimised for a particular type of operation (for example, passenger), in most cases the differential permissible speed is determined by the reduced signal spacing and should be compatible with the excess signal spacing requirements.

GN49 Where a lower differential permissible speed is applied for other reasons (for example, axle load), it is not necessary to consider trains restricted to a lower permissible speed than that required to conform to the signal spacing requirements.

Situation


f At the approach to buffer stops at terminal stations or at bay platforms

The compatibility check does not apply to the spacing distance between the approach signals and the buffer stops.

Table 1 extract (f) Terminal platforms

GN50 On lines where the minimum signalling braking spacing is less than 500 m, a maximum

signalling spacing distance of 1000 m is permitted, subject to a compatibility/risk assessment as set out in 2.1.3. Where signals are closely spaced, speeds will be moderate and drivers will probably be able to see several signals ahead at the same time.

2.5 Consistency of signalling braking distances

2.5.1 Variation in the excess signalling braking distances between successive signals shall be kept to a minimum in order to control the risk associated with signals passed at danger (SPAD).

2.5.2 Additional requirements for assessing compatibility of variation of excess signalling braking distances and train operations are set out in 2.1.3.

GN51 Variation in excess signal spacing is also a causal factor of a SPAD risk. A particular risk may arise where one or more signal sections with a large excess of spacing are followed by a signal section with little or no excess. Large variations in signal spacing, when combined




with minimum yellow to red distance in a four aspect sequence (see 2.6) can be particularly hazardous.

GN52 Existing good practice has established a desirable limit for the maximum variation of 34% in excess signal spacing between successive signals, above which a risk assessment is required to determine whether there is an unacceptable increase in SPAD risk. Any relaxation in this limit would need to be justified. The distance between a red-green stop signal and the next isolated distant signal is not relevant as it is not involved in braking.

GN53 At locations where there is a reduction in permissible speed from one signal section to the next, the required signal spacing between successive signals reduces. Thus, the actual signal spacing between one signal section and the next may reduce substantially without any significant variation in excess spacing. While this does not fall within the scope covered by 2.5.1, requiring a SPAD risk assessment, it should be recognised that there may still be a potential SPAD risk, particularly if the reduction in spacing is not expected, and any potential risk should still be considered.

GN54 On the approach to a major terminal station, or other significant area where permissible speeds are low, the reduction in actual signal spacing is more likely to be expected by the driver and therefore SPAD risk may be less.

2.6 Four-aspect signalling

2.6.1 In areas of 4-aspect signalling, the distance between the single yellow aspect and the red aspect shall be no less than one-third of the actual signalling braking distance between the double yellow aspect and the red aspect, unless the criteria set out in either 2.6.2 or 2.6.3 apply.

GN55 Variation in the distance between consecutive signals in a 4-aspect sequence may be

misleading to drivers. A particular SPAD risk may arise where the distance from the single yellow to the red aspect is significantly less than the distance from the double yellow to the single yellow aspect. This could lead to the driver not reducing speed adequately before passing the single yellow aspect and not expecting the red aspect to be so close. It should be noted that this is a case of inconsistency of signal spacing (see 2.5 above).

GN56 To avoid this potentially misleading situation, the preferred arrangement set out in 2.6.1, (as shown in GN Figure 1) requires the distance from the single yellow aspect to the red aspect to be at least one-third of the actual signalling braking distance between the double yellow aspect and the red aspect. This means that the distance from the single yellow to the red aspect should not be less than half the distance between the double yellow aspect and the single yellow aspect.

Actual signalling braking distance 101-105 [ASD]

≥⅓ ASD

Minimum signalling braking distance (YY-R) [MSD]

101 105103

GN Figure 1 Spacing of 4-aspect signals – preferred arrangement (see 2.6.1)




2.6.2 It is permissible for the distance between the single yellow aspect and the red aspect to be reduced to no less than one-third of the required minimum signalling braking distance between the double yellow aspect and red aspect.

GN57 Section 2.6.2 permits a relaxation of the arrangement set out in 2.6.1, subject to an

assessment of the additional SPAD risk arising. This permits the distance between the single yellow and the red aspect to be reduced to one-third of the minimum required signalling braking distance, as shown in GN Figure 2.

GN58 If the actual distance between the double yellow and the red aspect includes an excess over the minimum signalling braking distance, this may result in the distance from the single yellow to the red aspect being less than half the distance between the double yellow and the single yellow. The risk assessment should consider any additional risk of a SPAD which may be introduced by this arrangement.


≥⅓ MSD


101 105103

GN Figure 2 Spacing of 4-aspect signals – alternative arrangement (see 2.6.2)

GN59 Where two or more consecutive double yellow aspects are displayed in the aspect sequence approaching a signal at red (see GK/RT0045), the actual signalling braking distance between the single yellow aspect and the red aspect should not be less than one-third of the minimum required signalling braking distance between the first cautionary aspect and the red aspect (as set out in 2.6.2) as shown in GN Figure 3. It is likely that this will be greater than one-third of the actual signalling braking distance between the inner double yellow and the red (since the reason for providing consecutive double yellow aspects is generally that the inner double yellow is less than the required minimum spacing distance from the red aspect).

GN60 Where two or more consecutive single yellow aspects are displayed in the aspect sequence approaching a signal at red (see GK/RT0045), the constraints set out in this section should be applied to the distance between the outer single yellow aspect and the red aspect.

≥⅓ MSD


101 10510399

GN Figure 3 Spacing of 4-aspect signals with consecutive double yellows




2.6.3 It is permissible for mid-platform signals to be located so that the distance from

the single yellow aspect at the mid-platform signal to the red aspect at the platform starting signal is less than one-third of the required minimum signalling braking distance between the double yellow aspect and the red aspect. In this case the permissible speed and the location of the mid-platform signal shall be configured to comply with all of the following requirements:

a) The distance between the running-in platform ramp and the platform starting signal is greater than the minimum signalling braking distance at the permissible speed.

b) The mid-platform signal is sighted so that it is visible to the driver from the running-in platform ramp, as set out in GE/RT8037.

c) The platform starting signal is sighted so that it is visible to the driver from the mid-platform signal, as set out in GE/RT8037.

2.6.4 Additional requirements for assessing compatibility of four-aspect signal spacing and train operations are set out in 2.1.2.

GN61 Section 2.6.3 permits a further relaxation of the ‘one-third rule’ set out in 2.6.1

and 2.6.2 at stations, subject to the specific conditions stated. This arrangement (shown in GN Figure 4) is applicable only at stations where the permissible speed for through trains is low, since the distance between the running-in platform ramp and the platform starting signal should be greater than the minimum braking distance at the permissible speed. While this arrangement contravenes the principle set out in the preceding sections, by allowing what could be an unexpectedly short distance between the single yellow and the red aspect, this is mitigated by the visibility requirements stated.


May be <⅓ MSD

Minimum signalling braking distance (YY-R) at speed PS1 MSD]

101 105103

PLATFORM

Permissible speed = PS1 Permissible speed = PS2

≥ Minimum braking distance at speed PS2

GN Figure 4 Spacing of 4-aspect signals at station with mid-platform signal

GN62 If this relaxation was not permitted, and it was not possible to meet the spacing requirements set out in 2.6.1 or 2.6.2 in respect to the distance between the mid-platform signal and the platform starting signal, a standard YY-Y-R aspect sequence up to the platform starting signal would not be possible. The alternative arrangement which would have to be implemented would require a (YY)-Y-R sequence up to the mid-platform signal at red, which could then be approach released to single yellow to allow the train to continue to the platform starting signal. This arrangement would have the disadvantage of requiring a cautionary (double yellow) aspect to be shown at an earlier signal than necessary. It also introduces an additional risk, since the aspect sequence approaching the station would be the same whether the train is to stop at the mid-platform signal or the platform starting signal. If drivers are expecting to be allowed to proceed to the starting signal when the train is in fact required to stop at the mid-platform signal, they may expect and anticipate the clearance of the mid-platform signal as they approach it, resulting in a SPAD if it remains at danger.




2.7 Use of attainable speed to determine minimum signal spacing

2.7.1 Where attainable speed is used to determine minimum signalling braking distances, the maximum attainable speed shall be derived using current acceleration data for the appropriate types of rolling stock. Additional requirements for assessing compatibility of minimum signalling braking distances and rolling stock performance are set out in 2.1.2.

GN63 Where attainable speed is used to determine signal spacing, the infrastructure manager

should review all types of rolling stock that operate over the route to ensure that the greatest possible acceleration rate is identified and used. GE/RT8270 sets out the requirements and responsibilities for assessing the compatibility between rolling stock and infrastructure assets, including control, command and signalling equipment and their operations.

GN64 Where differential permissible speed limits apply, it is permissible for these to be taken into account when determining the required signalling braking distances.

GN65 Where attainable speed is used to determine signal spacing, consideration should be given to making this attainable speed a permanent speed restriction (PSR) and signing it accordingly.

2.7.2 On a 4-aspect signalled line, at a converging junction, the distance between the

first signal beyond the junction and the next stop signal shall be compatible with both of the following:

a) The permissible speed and aspect sequence through the junction on the straight route.

b) The permissible speed and aspect sequence on the converging route.

GN66 Where a connection onto a 4-aspect signalled line has a permissible speed which is lower

than the permissible speed on the through line, the attainable speed at the signal beyond the connection should be used to determine the required signal spacing between that signal and the next stop signal.

GN67 If the distance provides adequate signal spacing for a train travelling at the attainable speed, the signal on the converging line on the approach to the connection may be a 3-aspect signal. An example is shown in GN Figure 5. This can apply where the converging line is a running line with 3-aspect signalling or a bay platform, siding or depot exit line.

≥ Minimum signalling braking distance at attainable speed (50 mph)

101 105103

201

Permissible speed through junction

= 30 mph X

Attainable speed at X for train from converging line

= 50 mph

GN Figure 5 Use of attainable speed at signal beyond converging junction

GN68 Where the spacing from the signal beyond the connection to the next stop signal does not provide adequate spacing for a train travelling at the attainable speed, the signal before the connection on the converging line should be a 4-aspect signal.




2.7.3 Where the converging route is a 3-aspect signalled line and the permissible

speed through the convergence is lower than the permissible speed on the straight route, one of the following shall apply:

a) The attainable speed at the first (4-aspect) signal beyond the junction (taking account of any permissible speed restriction through the junction) shall be compatible with the actual signalling braking distance to the next signal so that the train can stop when the signal is displaying a single yellow aspect, or

b) The last signal on the converging route shall be a 4-aspect signal.

GN69 Where the converging line is a crossover from a parallel line with 3-aspect signals, it is

undesirable to provide an isolated 4-aspect signal at the junction solely for moves over the crossover. Particular care is therefore needed in the positioning of the first signal beyond the crossover to ensure that a movement onto the 4-aspect line is not underbraked. Permissible arrangements, allowed by GK/RT0045 are:

a) Provide a minimum signalling braking distance for the attainable speed from 103 to 105, as set out in GN Figure 5.

b) Imposing a lower permissible speed over the crossover to ensure that the attainable speed at 103 is compatible with the minimum signalling braking distance from 103 to 105. Although this is undesirable, it is considered preferable to the provision of an isolated 4-aspect signal on the slower speed line.

c) Control the aspect of 103, so as to give a caution aspect at 201.

2.7.4. Where there is signalling braking distance from the commencement of an

existing reduction of permissible speed and the stop signal, it is permissible to use the attainable speed at the first caution.

GN70 In GN Figure 6, the YY is not at the required signal braking distance for 125 mph, but the

25 mph lower permitted speed imposes a speed at the YY sufficient to stop at the red signal without the need for an additional warning indicator.

P125 25 25

MSD 25

GN Figure 6 Showing the use of assessed speed approaching a signal 2.8 Requirements at infrastructure manager boundaries

2.8.1 The requirements for signal spacing set out in this document shall apply also to the transitions between different signalling systems that are part of Network Rail managed infrastructure.

GN71 This covers transitions between conventional lineside signalling and other signalling

systems, including cab-signalling [Transmission Voie-Machine (TVM), European Train Control System (ETCS)], as well as transitions to other forms of lineside signalling (such as metro-type signalling) which do not conform to the signal spacing requirements set out in GK/RT0075.




2.8.2 Where a signalling braking distance crosses a boundary between infrastructure

managers, the minimum distance between a caution signal and the associated stop signal (or equivalent end of movement authority) shall be determined using the signalling braking criteria specified by the infrastructure manager controlling the stop signal (or responsible for the end of movement authority).

GN72 The principle is that the signal spacing for the aspect sequence leading up to a stop signal

should always be determined in accordance with the requirements applicable to that stop signal, as determined by the infrastructure manager who controls it, regardless of the ownership of the preceding signals which provide the cautionary aspects.

GN73 There may be variations in requirements arising from the different types of rolling stock using the line. For example, requirements for Network Rail signals leading up to a London Underground (LUL) controlled stop signal differ between those locations where main line trains (conforming to the braking characteristics set out in the appendices to GK/RT0075) run onto the LUL line, and those locations where only LUL trains (conforming to LUL braking standards) use the LUL line.




Part 3 Guidance on Requirements for Signing of Permissible Speeds and Speed Restrictions

3.1 Compatibility requirements for signing of permissible speeds and speed restrictions

3.1.1 GE/RT8270 sets out the process for the assessment of compatibility that is required whenever a material change is to be made that affects the interface between the signalling system and railway undertakings or any infrastructure managers that operate stations.

3.1.2 The assessment of compatibility shall check that permissible speeds and temporary speed restrictions are compatible with existing and planned train operations on each route, including a check of all of the following:

a) The permissible speed profile.

b) The configuration and position of permissible speed indicators and permissible speed warning indicators.

c) The provision of additional speed signs, where this is a permitted option to manage operational risk, including:

i) Additional permissible speed warning indicators (see 3.3.1).

ii) Repeater permissible speed indicators at converging junctions (see 3.3.3).

d) Where the nature of engineering work results in complex signage arrangements. The propose configuration and position of temporary speed indicators and warning boards and the arrangements for their implementation and withdrawal.

e) The configuration and position of signs that display standard and non-standard differential speeds, where trains compatible with the signalling braking distances set out in Appendices B and C are authorised to operate at higher permissible speeds (see 3.3.2).

f) The omission of differential speed signs, where differential speeds are implemented by instruction (see 3.3.1).

g) The display of metric speed information, where this is required (see 3.2.1).

h) The overall presentation of information to the driver (further requirements are set out in 3.2.2).

3.1.3 The assessment of compatibility shall check that the deceleration distances (see 3.2.3) used, which are the minimum spacing distances between the warning indicator and the speed indicator, are compatible with all of the following:

a) The types of rolling stock that will be operated on the route.

b) The maximum speeds that the rolling stock will be authorised to operate on the route.

c) The maximum attainable speeds of rolling stock, where these are used to determine the signal spacing.

d) The permissible speed(s) on every signalled approach to the speed reduction, including differential speeds which are authorised for different types of rolling stock.




e) The speed reduction(s) required on every signalled approach.

f) The applicable speed restriction, including differential speeds.

g) The average gradient on the approach to the speed indicator/board.

GN74 The consultation in respect of permissible speed signing should cover all permanent

arrangements for the application of, or changes to, speed restrictions and the associated signs. Consultation should include the use of signal sighting committees to agree the position and sighting of permissible speed signs (see 3.3.1.1).

GN75 It is not practicable for the infrastructure manager to consult with the railway undertaking(s) in respect of the implementation and withdrawal of all temporary speed restrictions. However, consultation should be carried out in cases of complex engineering work, particularly where the configuration and positioning of signs could be confusing to drivers or could create a risk of misunderstanding.

3.2 Requirements for permissible speeds and temporary speed restrictions

3.2.1 Display of speed information

3.2.1.1 The infrastructure manager shall provide lineside operational safety signs to display permissible speeds and temporary speed restriction information, applicable to each running line, for each direction that trains can be operated under signalled movement authorities for main running movements.

3.2.1.2 Speed signs shall display speed information in units of miles per hour.

3.2.1.3 Where trains are operated using speedometers calibrated in kilometres per hour, speed signs shall also display speed information in units of kilometres per hour.

3.2.1.4 Speed signs that display differential speeds shall display the lower (or lowest) speed above the higher speed(s).

3.2.1.5 Speed signs shall be positioned on the left-hand side of the line in the direction of travel, unless they cannot be accommodated there.

3.2.1.6 Speed signs shall be configured so that all applicable speeds (including differential speeds) over the same section of track are displayed together at the same position and location. It is permitted for nominally co-located signs to be separated by a short distance where readability would not be impaired.

GN76 Section 3.2 sets out the general requirements for the display of speed information to drivers, including the requirement to provide appropriate speed signs and the position and format of the speed information that is displayed.

GN77 Section 3.3 sets out the provision and positioning requirements for permissible speed signs, including the circumstances in which a permissible speed warning indicator and automatic warning system (AWS) should be provided.

GN78 Section 3.4 sets out the requirements for provision of speed signs in connection with temporary and emergency speed restrictions. Because of the potential complexity associated with implementation of temporary and emergency speed restrictions, the detailed requirements for the positioning of the speed signs are set out in the following appendices:

a) Appendix D sets out the positioning requirements for speed signs on plain line areas and at junctions.




b) Appendix E sets out the requirements for emergency speed restrictions.

GN79 Speed signs always display speeds in units of miles per hour because these are the units by which the railway is currently operated and signed in lineside signalled areas. Where trains are operated using speedometers calibrated in kilometres per hour and lineside speed signs are required, the speed signs should additionally display speed information in units of kilometres per hour because drivers have to correlate the speed information displayed at the lineside with the speed information displayed on the speedometer.

GN80 Where dual speed signage in mile/h and km/h would result in a multiplicity of signs, compatibility should be checked in accordance with 3.2 1 above.

3.2.2 Overall presentation of information to the driver

3.2.2.1 Speed signs and associated automatic warning system (AWS) equipment shall be positioned so that the totality of information (including lineside signs, signal aspects, indications and lineside equipment) displayed to the train driver is not liable to cause confusion.

3.2.2.2 Where train protection systems are in use, the position of speed signs shall be compatible with the warning and intervention functionality of these systems so that a driver obeying the lineside signs does not receive unwarranted warnings or interventions.

GN81 In some complex layouts, strict application of all the requirements in this standard may not

achieve the objective of providing clear and unambiguous information to the driver. In such cases, the infrastructure manager should seek an alternative solution, which meets this objective. Possible solutions include:

a) Alterations to the proposed geographical limits of the permissible speeds or speed restrictions.

b) Alterations to the speed value(s) of the permissible speeds or speed restrictions.

c) Alteration to the signalling arrangements.

3.2.3 Deceleration distances

3.2.3.1 Where attainable speed is used to determine the deceleration distance (only permitted for temporary speed restrictions), the maximum attainable speed shall be derived using current acceleration data for the appropriate types of rolling stock. Additional requirements for assessing compatibility of deceleration distances and rolling stock performance are set out in 3.1.3.

GN82 Permissible speed warning indicators are only necessary for some reductions in

permissible speed, where the required speed reduction meets the criteria set out in 3.3.1.4.

GN83 Warning boards should be provided on the approach to all temporary speed restrictions. (Exceptions are permitted as set out in GK/RT0075, 3.4.1.4.)

GN84 Permissible speed warning indicators and temporary speed restriction warning boards should be positioned at a sufficient distance on the approach to the point where the reduced speed commences, to ensure that each train can brake from its permissible speed, using normal service braking rate, to achieve the required speed reduction. The permissible speed for certain trains may be limited by:

a) Differential speed limits.

b) Maximum speeds applicable to particular types of train.




c) Other speed restrictions applied by instruction (for example, the two-thirds rule for freight trains in operation on former Southern Region lines).

GN85 Every type of train authorised to operate over the route should be considered where differential speeds apply, including the following speed transition combinations:

a) One differential speed to another differential speed.

b) A standard speed to a differential speed.

c) A differential speed to standard speed.

3.2.3.2 Where differential speeds are associated with a speed reduction to a lower permissible speed or a temporary speed restriction (whether they are applicable to the permissible speed on the approach, the lower permissible speed or temporary speed restriction, or both), the deceleration distance shall be determined for each type of train, taking account of:

a) The applicable speeds for that train, and

b) The longest deceleration distance required.

GN86 Where differential speeds apply, all applicable combinations of differential approach speed

and differential speed restriction should be considered so that the correct speed differentials are used to determine the required deceleration distance.

GN87 There may be circumstances in which a different type of train with better braking performance is to be operated over an existing route (for example, a train compatible with Appendix C, which is to be operated on a route signalled to Appendix A). In this case the braking performance of the train should be checked against the signalling braking distances and the position of speed signs, before an increased speed is authorised.

GN88 The higher permissible speed should be signed as a differential speed unless all other trains that may be operated over the route are also compatible with the signalling braking distances and the position of speed signs.

GN89 GE/RT8270 sets out the procedure to be followed between the railway undertaking and the infrastructure manager to enable the latter to verify the braking performance of trains that are authorised to operate on any given route.

3.2.3.3 Deceleration distances shall be determined using one of the following:

a) The deceleration data set out in Appendix X, which is compatible with Appendix A (composite data for all trains).

b) The signalling braking distance, where minimum signalling braking distances have been determined using Appendix B (composite data for passenger trains), and the deceleration distance derived from Appendix X is greater than the minimum signalling braking distance.

c) The signalling braking distance, where minimum signalling braking distances have been determined using Appendix C (data for trains with enhanced braking), and the deceleration distance derived from Appendix X is greater than the minimum signalling braking distance.




GN90 The deceleration distances set out in Appendix X are compatible with the train braking performance used to determine the signalling braking distances in Appendix A. Use of the distances in Appendix X, therefore, provides adequate deceleration distances for all trains.

GN91 Deceleration tables for trains with higher braking rates (based on the braking performance used to determine the signalling braking distances in Appendices B and C) have not been published. On lines where signalling braking distances are based on Appendices B or C, the deceleration distance set out in Appendix X for some speed reductions is greater than the required signal spacing (from the first caution aspect to a signal at danger).

GN92 Where the signalling braking distance set out in Appendices B or C for the applicable approach speed is less than the deceleration distance set out in Appendix X, the appropriate signalling braking distance from Appendices B or C should be used as the required deceleration distance, instead of the distance set out in Appendix X.

3.2.3.4 Appendices B or C shall only be used to determine deceleration distances for permissible speeds and temporary speed restrictions where all of the trains that operate over the route have a braking performance that is compatible with the required reduction in speed, taking account of the following factors:

a) The permissible speed, including enhanced permissible speeds and differential speeds, and

b) The authorised speed limits applicable to each category and type of train.

GN93 Signalling braking distances from Appendices B or C should be used as deceleration

distances only for the types of trains, for which those signalling braking distances are applicable.

GN94 Trains with a lower braking performance (that is to say, compatible with Appendix A) may be restricted to a maximum operating speed that is lower than the permissible speed on the approach to the warning indicator or warning board, even where differential speed restrictions are not specifically applied. Where this is the case, the deceleration distance should be based on signalling braking distances from Appendices B or C, for trains approaching at a higher speed, provided that this also gives sufficient deceleration distance in accordance with Appendix X, for trains to which Appendix A is applicable at their maximum operational speed. Similar considerations apply to trains restricted to a speed that is lower than the permissible speed for other reasons, for example, freight trains that are limited to 75 mph.

GN95 Where differential speeds apply on the approach to a reduction in speed, and the higher approach speed requires a higher braking rate in order to conform to the required speed reduction, the higher speeds should only apply to those categories of trains which have the required braking performance.

GN96 The maximum attainable speed should only be used to determine the deceleration distance for temporary speed restrictions where none of the rolling stock authorised to use the line is capable of achieving the permissible speed (or the differential permissible speed applicable to that type of train).

GN97 Attainable speed should not be used to determine the deceleration distance approaching reductions in permissible speed. Instead, the designed permissible speeds should be compatible with the attainable speed of trains.

GN98 Since the use of attainable speed is applicable only to temporary speed restrictions, it is not generally practicable for the infrastructure manager to request validated acceleration data from the railway undertakings for each specific application.




GN99 The positioning and sighting of signs for permissible speeds should be agreed by signal sighting committees. These signs should be considered in the context of the overall arrangement of signals and operational signs.

3.3.1.2 Permissible speed indicator(s) shall:

a) Display the relevant speed(s).

b) Be provided for every increase or decrease of permissible speed, except where differential speeds applying to certain types of train are implemented by instruction. This applies where speed is required to be restricted for particular types of train that do not constitute a recognised category for which differential speed signs are specified in the Rule Book.

c) Be positioned where the change of permissible speed occurs (see Figure 1).

40

4090

Figure 1 Example of a permissible speed indicator

GN100 Where differential speeds apply (see 3.3.2), there may be a change in permissible speed at a particular location for some categories of trains, but not for others. In this case a permissible speed sign should be provided, which displays all the differential speeds.

GN101 In some circumstances, speed restrictions are imposed using operating instructions, instead of lineside signs. Typically, these speed restrictions may be associated with:

a) Specific train movements (for example, degraded operations).

b) Axle load criteria associated with particular vehicle types.

c) Defined classes of train (for example, the ‘two-thirds’ rule – see GN19).

GN18 sets out additional guidance on determining signalling braking distances where differential speed restrictions are imposed using operating instructions.

GN102 On sections of line where it is not possible for trains to achieve the maximum permissible speed, for example on the approach to a reduction in permissible speed or immediately beyond an increase in permissible speed, the infrastructure manager should determine appropriate maintenance requirements based on the maximum attainable speed on that section of line. Where attainable speeds are used solely to determine maintenance specifications, it is not necessary to advise these speeds to drivers as changes in permissible speed, and in this case they will not be shown either in the Sectional Appendix or on lineside signs.

3.3 Signs for permissible speeds

3.3.1 Position and sighting of signs

3.3.1.1 A signal sighting committee (as set out in GE/RT8037) shall agree the position and sighting of:

a) Permissible speed indicators.

b) Permissible speed warning indicators.




GN103 The criteria for provision of permissible speed warning indicators and associated AWS

magnets (sometimes referred to as the ‘Morpeth rules’) were introduced following a number of incidents where drivers entered a section of line with a severe speed restriction at excessive speed, in some cases leading to derailment. The criteria are intended to ensure that drivers cannot approach a severe speed reduction without being aware of it.

GN104 Where differential speeds apply, either on the approach to a speed reduction or to the speed beyond the reduction, the speed reduction applicable to each category of train should be considered. A permissible speed warning indicator is required when any category of train has a permissible approach speed of 60 mph or greater and a required speed reduction of one-third or more.

GN105 The additional criteria set out in 3.3.1.4b) apply where there is a series of successive speed reductions, each of which, considered individually, does not come within the conditions of 3.3.1.4a), but together still result in a risk of a driver approaching a low-speed area at excessive speed.

GN106 See 3.3.5.3 and 3.3.5.4 for further details of the positioning of the permissible speed warning indicators in these cases.

GN107 Additional permissible speed warning indicators may be provided for speed reductions falling outside the criteria of 3.3.1.4, where this increases safety and does not cause confusion to drivers. Such provision should be applied consistently on each section of route.

3.3.1.3 Permissible speed indicators shall be provided at converging and diverging

junctions in accordance with 3.3.3 and 3.3.4. 3.3.1.4 Except where the criteria in 3.3.1.5 apply, a permissible speed warning

indicator shall be provided on all signalled approaches to each permissible speed reduction, where either:

a) The permissible speed on the approach, including any differential speed, is 60 mph or greater and the required speed reduction is one-third or more, taking account of any differential permissible speeds that apply, or

b) There are two or more successive reductions in permissible speed within a distance of 3.2 km (2 miles), none of which individually represents a reduction of one-third, but which together require a speed reduction of one-third or more from an approach speed of 60 mph or greater (see Figure 2).

Figure 2 Example of two or more successive reductions in speed

50 65 65 90

125 90 P

90 65 50

125

< 3.2 km (2 miles)

Note: Depending on spacing of speed reductions and relevant deceleration distances, the warning indicator for the second speed reduction could fall before the speed indicator for the first speed reduction




3.3.1.5 Permissible speed warning indicators shall not be provided for:

a) A speed reduction over a diverging route where the signalling system is configured to display signal aspects that provide for the required speed reduction (see 3.3.7).

b) A speed reduction over a level crossing where a Level Crossing Warning Sign (St Georges Cross) is provided.

GN108 Where a junction signal is approach controlled from red for a diverging route, the aspect sequence may be used to inform the driver of the need to control the speed of the train approaching the divergence. In this case, a permissible speed warning indicator would not provide any additional value and is not required. The driver should use route knowledge of the permissible speed at the divergence.

GN109 Where the speed reduction required for a divergence is within the criteria of 3.3.1.4, and an aspect sequence other than approach control from red is used for the diverging route, a permissible speed warning indicator is used to advise the driver of the necessary speed reduction. See 3.3.7 for further details.

3.3.1.6 Where provided, permissible speed warning indicators shall be positioned in accordance with 3.3.5, 3.3.6 and 3.3.7, using the appropriate deceleration distance set out in 3.2.3.3.

GN110 Detailed requirements concerning the positioning of permissible speed warning indicators, for simple cases and for diverging routes, are set out in 3.3.5, 3.3.6 and 3.3.7.

3.3.1.7 Only one permissible speed warning indicator shall be provided on each approach to a permissible speed indicator, unless an additional indicator is required to mitigate safety risk and will not cause confusion to drivers. Further requirements are set out in 3.1.2.

GN111 To avoid confusion, a train should normally only pass one permissible speed warning indicator associated with a particular permissible speed indicator. Section 3.3.6 sets out the arrangement normally provided at converging junctions to achieve this.

3.3.2 Display of differential permissible speeds

3.3.2.1 Permissible speed indicators and permissible speed warning indicators shall display a maximum of three differential speeds (applicable to different categories of trains), including standard and non-standard differential speeds. For the purposes of this section, an enhanced permissible speed as defined in GE/RT8012 shall be considered as a non-standard differential speed. The only permitted combinations are:

a) Two displayed speeds, each for one of two standard categories of train, where standard differential speeds apply.

b) One displayed speed for a standard category of train and either one or two displayed non-standard speeds applicable to the train categories set out in GE/RT8000 Rule Book module SP.

c) Two displayed speeds for the two standard categories of train (standard differential speeds), together with one displayed non-standard differential speed applicable to a train category set out in GE/RT8000 Rule Book module SP.




3.3.2.2 Further requirements applicable to differential speeds are set out in 3.1.2.

3.3.2.3 Where standard differential speeds apply, the two speeds shall be displayed on a single permissible speed indicator (see Figure 3) and, where a warning indicator is provided, on a single permissible speed warning indicator (see Figure 4).

20

20/509050

Figure 3 Example of a standard differential permissible speed indicator

20 50

Figure 4 Example of a standard differential permissible speed warning indicator

GN112 ‘Standard’ differential speeds are shown on speed indicators and warning indicators by two speed values, one above the other (see 3.2.1.4), without any specific indications to identify particular categories of trains. The bottom figure (which shows the higher speed) applies to passenger trains (loaded or empty), parcels and postal trains (loaded or empty), and light locomotives; the top figure (which shows the lower speed) applies to all other trains.

GN113 The arrangement for displaying ‘standard’ differential speeds, with the lower speed value shown by the top figure and the higher speed value by the bottom figure:

a) Provides a consistent display.

b) Means that the lower speed value, which is a safe speed for all trains, should be read first by the driver.

3.3.2.4 Non-standard differential permissible speeds shall be displayed by a separate speed sign, which shall incorporate an indication of the applicable train category. The meanings of letter abbreviations for non-standard speeds are set out in Rule Book Module SP. The classes of train that apply in a given situation are set out in the Sectional Appendices.

3.3.2.5 A non-standard permissible speed indicator shall be mounted on the same post as the associated standard permissible speed indicator (see Figure 5) and:

a) Where the non-standard speed is higher than the standard speed(s), it shall be displayed below the standard speed(s).

b) Where the non-standard speed is lower than the standard speed(s), it shall be displayed above the standard speed(s).




60

60/9090

HST90

50/75/9090

HST90

5075

75/90 90

90

CS 75

Figure 5 Examples of a non-standard differential permissible speed indicator

3.3.2.6 Where a permissible speed warning indicator is required, non-standard differential speeds shall be displayed by a separate speed sign, which shall incorporate an indication of the applicable train category. Further requirements about train categories are set out in GE/RT8000 Rule Book.

3.3.2.7 A non-standard permissible speed warning indicator shall be mounted on the same post as the standard permissible speed warning indicator (see Figure 6) and:

a) Where the non-standard speed is higher than the standard speed(s), it shall be displayed below the standard speed(s).

b) Where the non-standard speed is lower than the standard speed(s), it shall be displayed above the standard speed(s).

60HST90

HST90

5075

90

CS 75

Figure 6 Examples of a non-standard differential permissible speed warning indicator

GN114 ‘Non-standard’ differential speeds are shown on speed indicators and warning indicators by

an additional speed value on a separate sign, with additional letters above the speed value that identify the category of train to which the speed applies. The letters used to indicate the different categories of trains are set out in the Sectional Appendices.

GN115 Most non-standard differential speeds (for example, HST, MU, SP) apply to categories of trains that are permitted to travel at a higher speed than the standard permissible speed(s)




applying at that location. The sign showing a non-standard differential speed that is higher than the standard permissible speed(s) is placed on the same post, but below the standard speed indicator, for the same reason that this arrangement is used for signing of standard differential speeds (see 3.3.2.3).

GN116 There are cases where a non-standard differential speed (for example, CS) applies to a particular category of train that is required to travel at a lower speed than the standard permissible speed(s) applying at that location. In this case the sign showing a non-standard differential speed that is lower than the standard permissible speed(s) is placed above the standard speed indicator.

3.3.3 Permissible speed indicators at converging junctions

3.3.3.1 A permissible speed indicator shall be provided at converging junctions if the permissible speed beyond the converging junction is different from the permissible speed on the higher speed route (see Figure 7).

70

20

90

90

Figure 7 Example of permissible speed indicator at converging junction

GN117 A permissible speed indicator is provided so that the different permissible speed beyond

the converging junction is displayed to all trains after they have passed the junction.

3.3.3.2 It is permissible to provide a miniature permissible speed indicator as a repeating sign immediately after a converging junction, where all of the following apply:

a) The permissible speed beyond the junction is the same as the permissible speed of the approach on the higher speed route, and

b) The permissible speed beyond the junction is higher than that on the converging route, and

c) The junction is not located within the deceleration distance approaching a lower speed for which warning has already been given.

GN118 A miniature permissible speed sign positioned immediately beyond a converging junction

may be provided for operational performance purposes.

GN119 A miniature speed indicator is considered sufficient for use as a repeating sign because it is not critical for the driver to observe the higher permissible speed and it is only relevant to the train approaching from the converging route.

GN120 The decision on whether to use a miniature permissible speed sign involves co-operation between the infrastructure manager and railway undertakings in assessing the compatibility between the signage arrangements and train operations.




3.3.4 Permissible speed indicators at diverging junctions

3.3.4.1 A permissible speed indicator with an arrow indicating the direction of the diverging (lower speed) route shall be provided immediately before a diverging junction (including a facing crossover) over which there is a reduction in permissible speed (see Figure 8). Where the permissible speed of the straight route does not change at the junction, a speed indicator shall not be provided for the straight route.

90

50

90

50

Figure 8 Example of permissible speed indicator at diverging junction with speed reduction on diverging route only

GN121 A permissible speed indicator with an arrow applies only to the diverging route (or routes)

in the direction indicated by the arrow. Where only an indicator with an arrow is provided, drivers understand that the permissible speed on the straight route does not change at the junction.

GN122 Where a position light junction indicator is provided, the direction of the arrow should correspond with the orientation of the indicator. This is particularly important where the speed over the straight route is lower than that over the diverging route.

3.3.4.2 Where a lower permissible speed applies equally to both routes, a single permissible speed indicator shall be provided without directional arrows (see Figure 9).

40

40

90

40

Figure 9 Example of permissible speed indicator at diverging junction with speed reduction (equal speed) on both routes

GN123 It is not necessary to provide a permissible speed indicator at a diverging junction where

the permissible speed through the junction is the same for all routes, and is the same as the permissible speed that applies on the approach to the junction. Typically, this applies in low-speed areas such as on the approach to a large station.

3.3.4.3 Where different permissible speeds commence for each route at a diverging junction or crossover, two permissible speed indicators shall be positioned side-by-side. Arrow(s) shall be incorporated into the sign to indicate any divergence (see Figures 10 and 11).




125

40

90

4090

Figure 10 Example of permissible speed indicator at diverging junction with speed reduction on both routes (different speeds)

4040

50

50

125

Figure 11 Example of permissible speed indicator at diverging junction with no straight route

GN124 Permissible speed signs applying to different routes should be placed side-by-side, not

vertically on the same post. This is so that drivers do not interpret the indicated speeds as differential speeds for the same route.

GN125 Where space is limited and it is not practicable to position the signs side-by-side, a signal sighting committee may decide to position the two signs one after the other.

3.3.5 Positioning of permissible speed warning indicators

3.3.5.1 Where provided, permissible speed warning indicators shall:

a) Be positioned as close as practicable to (but not less than) the deceleration distance from the permissible speed indicator taking account of the longest deceleration distance required (see Figure 12), and

b) Not be positioned between a signal or other sign applicable in the same direction of travel and the AWS equipment associated with that signal or sign.

Figure 12 Example of permissible speed warning indicator (simple case)

GN126 Section 3.3.1.4 sets out the circumstances in which a permissible speed warning indicator

is required to be provided.

GN127 The permissible speed warning indicator should provide sufficient deceleration distance for all types of trains. Where differential speeds apply, the longest deceleration distance applies.

DD 70–40

40

40 70

40

70 P




GN128 The longest required deceleration distance may be significantly greater than the distance required by some trains, and this is acceptable.

GN129 The distance between the permissible speed warning indicator and the speed indicator may need to be increased to provide adequate sighting, or to avoid AWS conflicts or positions where it is not practicable to site the warning indicator.

3.3.5.2 Where two permissible speed indicators are located at the same position (for example, at a diverging junction) and permissible speed warning indicators are required for both, the position of the permissible speed warning indicators shall be determined using the greatest deceleration distance required.

GN130 If speed indicators are at the same position, the associated warning indicators should also

be at the same position; if the speed indicators are in different places the warning indicators should be considered separately for each. It is not acceptable to have warning indicators at different locations applying to permissible speed indicators at the same location, since this could be misleading to drivers. However, it is permitted for nominally co-located signs to be separated by a short distance, as permitted by 3.2.1.6, where space is limited.

GN131 Where a warning indicator is required only for the lower speed diverging route, and the speed reduction for the higher speed route is not great enough to require a warning indicator to be provided, it is permissible to provide the warning indicator only for the lower speed (diverging) route.

GN132 Where the speed reduction required for a diverging route is enforced by the signalling system approach releasing the junction signal from red (see 3.3.1.5 and 3.3.7.1), a warning indicator is not provided for the speed on the diverging route. Where there is also a speed reduction on the straight route which commences at the same point and requires a warning indicator, the warning indicator should be provided only for the speed reduction on the straight route with no warning indicator for the speed reduction on the diverging route.

3.3.5.3 Where the circumstances set out in 3.3.1.4b) apply, the deceleration distance used to position the permissible speed warning indicator shall be determined using the permissible speed applicable prior to the commencement of the series of reductions in speed (see Figure 13).

DD 125-65

Figure 13 Example of permissible speed warning indicator for successive reductions in speed

50 65 65 90

125 90 P

90 65 50

125

< 3.2 km (2 miles)

Note: depending on spacing of speed reductions and relevant deceleration distances, warning indicator for second speed reduction could fall before speed indicator for first speed reduction




GN133 The criteria for provision of permissible speed warning indicators and associated AWS magnets (see 3.3.1.4) are intended to ensure that drivers cannot approach a severe speed reduction without being an AWS warning. If the driver fails to respond to the warning, the AWS applies the brakes.

GN134 Where a series of successive speed reductions apply, as shown in Figure 13, the first speed reduction (from 125 mph to 90 mph) is not considered severe enough to cause a significant risk of derailment if the driver continues at the approach speed (125 mph), and therefore a warning indicator is not provided. Similarly, if the driver correctly reduces speed to 90 mph but fails to observe the further reduction to 65 mph, the risk from overspeeding is again small. It is only if the driver fails to observe both reductions in speed, and continues at the approach speed (125 mph) into the second (lower) speed restriction (65 mph), that a significant risk arises.

GN135 To provide protection against this possibility, the permissible speed warning indicator (and associated AWS) for the second speed reduction to 65 mph are positioned to provide deceleration distance from the initial approach speed of 125 mph. This should enable drivers (or the AWS brake application if they fail to respond) to reduce speed to 65 mph before reaching the start of the 65 mph restriction, even if they have failed to observe the earlier reduction to 90 mph.

GN136 Where application of these criteria (or those in 3.3.5.5), might result in a potentially confusing arrangement of signs, for instance where the warning indicator for a reduction in speed would be required to be positioned before the speed indicator for a previous reduction in speed, consideration should be given to providing a warning indicator (with AWS) for the first speed reduction even though the requirements set out in 3.3.1.4 do not apply.

3.3.5.4 Where further permissible speed reductions occur beyond a reduction for which a permissible speed warning indicator and associated AWS magnet is provided, these shall be assessed separately. A further permissible speed warning indicator shall be provided if the criteria set out in 3.3.1.4 are met (see Figure 14).

50658080

125

P

80 65 50

125

< 3.2 km (2 miles)

50

65

P

125

DD 125–80 DD 80–50

Figure 14 Example of successive reductions in speed where a further permissible speed warning indicator is required

GN137 The principle applied in 3.3.5.3 is extended to cover further reductions in speed, based on

the assumption that the driver responds to the speed reduction for which a warning indicator and AWS are provided.

GN138 Therefore, in Figure 14 it is assumed that the driver has responded to the reduction from 125 mph to 80 mph (for which a warning indicator and AWS are provided). The subsequent reduction from 80 mph to 65 mph, even if it is within the two-mile zone, is assessed in relation to an approach speed of 80 mph, and therefore does not require a warning indicator. The further reduction from 65 mph to 50 mph is also assessed for an approach speed of 80 mph (since no warning indicator was provided for the reduction to 65 mph), and the warning indicator for this should be located to provide the required deceleration distance from 80 mph to 50 mph.




3.3.5.5 Where exceptionally the speed profile is such that the deceleration distance would either:

a) Position a permissible speed warning indicator within a section of line with a lower permissible speed than that immediately preceding the speed reduction (see Figure 15), or

b) Encompass a section of line with a lower permissible speed (see Figure 16), and this lower speed is equal to or less than the speed displayed on the permissible speed warning indicator, one of the following arrangements shall be used:

c) The permissible speeds shall be adjusted to avoid this arrangement (preferred), or

d) The permissible speed warning indicator shall be positioned at the end of the lower speed section, beneath the permissible speed indicator for the higher speed (non-preferred).

125 40

40

40

40

70

70

40

40

DD 70–40

40

Figure 15 Example of positioning of permissible speed warning indicator where

deceleration distance falls within lower speed section

125 30

30

70

70

40

40 40 DD 70–40

125

40

Figure 16 Example of positioning of permissible speed warning indicator where deceleration distance encompasses lower speed section

Note The arrangements shown in Figures 15 and 16 are non-preferred. Where practicable, permissible speeds should be specified to obviate such arrangements.

GN139 In the example shown in Figure 15, the deceleration distance from 70 mph to 40 mph is

longer than the length of line to which the 70 mph permissible speed applies, and this would position the warning indicator within the previous 40 mph section. In this case the 40 mph warning indicator is placed at the end of the previous 40 mph section, below the 70 mph permissible speed indicator. This should provide adequate warning to drivers, who should then accelerate only to a speed from which they can decelerate back to 40 mph before reaching the start of the subsequent 40 mph section.




GN140 In the example shown in Figure 16, the deceleration distance from 70 mph to 40 mph is again longer than the length of line to which the 70 mph permissible speed applies; in addition it would extend through the previous 30 mph section into the preceding section of line on which the permissible speed is 125 mph. However, as trains are restricted to 30 mph in the intervening section, placing the 40 mph warning indicator at the end of the 30 mph section, below the 70 mph permissible speed indicator, provides adequate warning to drivers to accelerate only to a speed from which they can decelerate back to 40 mph.

GN141 In the above cases it may not be appropriate to sign the intermediate section for 70 mph, particularly where this section is short and it is not possible for any trains to accelerate to this speed before decelerating again to the 40 mph restriction. The signed speed should be compatible with the acceleration and braking performance of trains.

3.3.5.6 If the permissible speed on the preceding lower speed section is higher than the permissible speed displayed on the permissible speed warning indicator and there is an intermediate higher permissible speed, the permissible speed warning indicator shall be positioned either:

a) At not less than the deceleration distance, or

b) At the end of the lower speed section, beneath the permissible speed indicator for the higher speed

whichever is the greater distance. In this case the intermediate higher permissible speed shall be disregarded when determining the position of the permissible speed warning indicator.

3.3.5.7 Further requirements for checking the provision, position and configuration of permissible speed warning indicators are set out in 3.1.2.

GN142 Where the deceleration distance for the preceding lower speed would position the

permissible speed warning indicator within the intermediate higher speed section, the permissible speed warning indicator should be positioned below the permissible speed indicator for the higher speed section, as set out in 3.3.5.5. This provides adequate warning to drivers, who should then accelerate only to a speed from which they can decelerate to the appropriate speed before reaching the start of the permissible speed restriction for which the warning indicator applies.

GN143 Where the deceleration distance for the preceding lower speed requires the permissible speed warning indicator to be positioned within the lower speed section, the warning board should be placed at not less than the deceleration distance.




3.3.6 Permissible speed warning indicators at converging junctions

3.3.6.1 Where the criteria set out in 3.3.1.4 apply at converging junctions, permissible speed warning indicators shall be provided:

a) On each signalled approach to a permissible speed indicator (see Figure 17).

b) So that all approaching trains receive one warning for each permissible speed reduction.

4040

125 125P

P40

90DD 90–40

DD 125–40

Note: 125 repeater sign omitted intentionally (3.3.3.2 refers) Figure 17 Example of permissible speed warning indicators at converging

junction

GN144 It is undesirable for a driver to pass more than one warning indicator for the same

permissible speed indicator. Therefore, if the deceleration distance required for the higher speed approach places the warning indicator before a converging junction, the warning for a lower speed approach should also be placed before the converging junction.

GN145 In the example shown in Figure 17, the deceleration distance for the lower speed approach (90 mph to 40 mph) also requires the warning board to be placed before the converging junction.

GN146 If the speed on the lower speed approach was such that the deceleration distance for this speed would place the warning board on the main line beyond the converging junction, the warning board should still be placed on the approach to the converging junction, so that it is not passed by a train on the main line that has already passed a warning board for the same speed indicator.

3.3.7 Permissible speed warning indicators at diverging junctions

3.3.7.1 A permissible speed warning indicator incorporating a directional arrow shall be provided to indicate a permissible speed on a diverging route over or beyond a diverging route ahead, where:

a) The junction signal is not approach controlled from red (see GK/RT0045), and

b) The required speed reduction meets the criteria set out in 3.3.1.4

GN147 Except where approach control of the junction signal from red enforces a reduction in

speed, a warning indicator is required for the speed reduction over a diverging junction where it meets the normal criteria for provision of a warning indicator.




3.3.7.2 Where a permissible speed warning indicator incorporating a directional indication is positioned at a signal that displays a cautionary aspect for the diverging route to which the warning indicator applies:

a) The caution indication given by the AWS magnet associated with the signal shall also apply to the warning indicator.

b) A separate AWS magnet shall not be provided for the warning indicator (see Figure 18).

40

125

DD 125–40 Not approach controlled from red

125

4040

>

Figure 18 Example of permissible speed warning indicator for diverging junction positioned at a signal that displays a cautionary aspect

GN148 It is good practice to locate the permissible speed warning indicator, applying to a diverging

route, at a signal which displays a cautionary aspect for the diverging route (see GK/RT0045).

GN149 In this case the same AWS inductor gives a caution indication for the signal and the warning indicator. This has the following advantages:

a) It avoids the need for suppression of the AWS, which would be required for a separate AWS magnet (see 3.3.7.3).

b) The driver receives information about the turnout speed, to supplement the signal aspect which advises him of the diverging route.

GN150 It is permissible for the warning indicator to be located at either the outer (flashing YY) or the inner (flashing Y) signal, depending on the required deceleration distance. If the deceleration distance is less than the Y to R spacing, the preferred arrangement is to locate the warning indicator at the inner signal.

3.3.7.3 Where a permissible speed warning indicator incorporating a directional indication is not positioned at a signal that displays only a cautionary aspect for the diverging route to which the warning indicator applies:

a) A separate AWS magnet shall be provided for the permissible speed warning indicator, and

b) The AWS magnet shall be suppressed when the junction signal and any intervening signals between the permissible speed warning indicator and the junction signal have been cleared for a route for which the warning indicator does not apply.

GN151 Except where the arrangement of 3.3.7.2 is applied, a separate AWS magnet should be

provided to alert the driver to the permissible speed warning indicator for the diverging route.




GN152 Except where the arrangement of 3.3.7.2 is applied, the AWS magnet associated with the speed warning indicator for the diverging route is suppressed when the signals have been cleared for the straight route at the junction, to avoid giving the driver an AWS caution indication which is not applicable when the train is approaching the junction under green signals.

GN153 When the signal at the junction has not been cleared for either route, an AWS caution indication is received. As this is associated with a permissible speed warning indicator incorporating a directional arrow, the driver should understand that this only applies to the diverging route ahead.

3.3.7.4 A permissible speed warning indicator, incorporating a directional arrow, shall be positioned adjacent to the permissible speed indicator (with directional arrow) at a diverging junction, or crossover (see Figure 19) where:

a) A reduction in permissible speed on the diverging route beyond the diverging junction (or crossover) requires a permissible speed warning indicator; or

b) The deceleration distance would position the permissible speed warning indicator in the vicinity of the diverging junction or crossover; or

c) Either it is not practicable to locate the warning indicator within the diverging junction or crossover, or it is necessary to make it clear to which line the warning indicator applies.

90

2060

60

20

DD 60–20>60

Figure 19 Example of permissible speed warning indicator for speed reduction on a diverging route

GN154 Where the deceleration distance would position the permissible speed warning indicator in

the vicinity of a crossover, the arrangement shown in Figure 19 should be applied because it is not normally practicable to position a speed sign part way through a crossover.

GN155 Because the warning indicator with directional arrow is located adjacent to the permissible speed indicator (also with a directional arrow), which indicates the speed through the crossover, drivers should understand that the warning indicator applies to a further speed restriction on the diverging route beyond the crossover.

GN156 This warning indicator is not positioned on the approach side of the permissible speed indicator, because drivers would interpret the warning indicator with a directional arrow as an indication of the speed through the diverging route at the crossover (as set out in 3.3.7.1), rather than a speed restriction beyond the crossover.

GN157 If the speeds and distances shown in Figure 19 are such that the deceleration distance approaching the 20 mph speed indicator would require the warning indicator for the move through the crossover to be situated before the crossover, a possible solution would be to reduce the speed through the crossover, such that the deceleration distance is reduced to equal to, or less than, the distance between the crossover and the speed indicator. The arrangement shown in Figure 19 could then be applied.




3.3.8 Provision of AWS magnets for permissible speed warning indicators

3.3.8.1 An AWS magnet shall be provided on the approach to all permissible speed warning indicators provided to satisfy the criteria set out in 3.3.1.4, except

a) Where the AWS magnet associated with a signal displaying a cautionary aspect is configured to provide an equivalent warning (see 3.3.7.2).

b) On lines not fitted with AWS.

c) In AWS gap areas.

d) In respect of additional warning indicators.

GN158 The AWS system should be configured so that a caution indication is given to the driver on

the approach to every permissible speed warning indicator, except as shown above.

3.3.8.2 The AWS magnet shall:

a) Be positioned 180 m on the approach to the permissible speed warning indicator.

b) Be positioned not less than 4 seconds running time from any other AWS equipment.

c) Not be positioned between any other AWS equipment and its associated signal, board or indicator.

The constraints in b) and c) do not apply to other AWS equipment which is provided for movements in the opposite direction and which is suppressed for movements in the direction to which the permissible speed warning indicator applies.

GN159 GE/RT8075: AWS and TPWS Interface Requirements permits the distance from the AWS

magnet to the permissible speed warning indicator to be reduced to a minimum of 3 seconds running time. This accounts for the 1 second delay after passing over the permanent magnet before the AWS equipment gives a warning indication and provides the driver with a minimum of 2 seconds to respond to the AWS indication, observe the speed sign and acknowledge the warning.

GN160 The 4 seconds requirement in 3.3.8.2b) is necessary so that the AWS receiver has time to reset, and be ready to respond correctly to the next AWS magnet following a caution indication, which could be acknowledged at the end of the acknowledgement delay period.

GN161 It is important that each AWS indication is directly associated with the signal or indicator that the driver is approaching, which means that AWS magnets provided in connection with permissible speed warning indicators should not be positioned between any other AWS magnet and the equipment associated with it.

3.3.8.3 The AWS magnet shall be configured to generate an AWS caution indication in the driving cab.

3.3.8.4 The AWS magnet shall be suppressed for signalled running movements for which it does not apply, unless AWS cancelling indicators are provided (see GE/RT8075).




GN162 Where independent AWS equipment is provided on the approach to a permissible speed warning indicator (there being no signalled movements in the opposite direction), it should incorporate a permanent magnet only.

GN163 GE/RT8075 specifies the circumstances in which it is acceptable to provide AWS which is not suppressed for signalled movements in the opposite direction, together with AWS cancellation indicators. In these circumstances the AWS magnets provided for permissible speed indicators do not have to be suppressed. In all other cases the AWS magnet should be suppressed for any signalled movements in the opposite direction.

3.3.9 Publication of alterations of permissible speeds

3.3.9.1 Details of alterations to permissible speeds shall be published in:

a) The Weekly Operating Notice (WON), prior to implementation, and

b) The next available Periodical Operating Notice (PON), pending re-issue of the appropriate Table A entry in the Sectional Appendix.

GN164 GO/RT3215: Requirements for the Weekly Operating Notice, Periodical Operating Notice

and Sectional Appendix, sets out the requirements for publication of weekly operating notices, periodical operating notices and sectional appendices. Alterations to permissible speeds are published by the infrastructure manager so that driver route knowledge, with respect to permissible speeds, can be managed by railway undertakings.

3.4 Provision of signs for temporary and emergency speed restrictions

3.4.1 Commencement and termination indicators and warning boards

3.4.1.1 The commencement of each temporary speed restriction shall be indicated by a speed indicator displaying the required speed(s) for all signalled movements entering the speed restriction (see Figure 21), except where:

a) Movements cross over a temporary speed restriction, via a ladder or diamond crossing, and

b) The permissible speed for the movement via a ladder or diamond crossing is less than or equal to that of the temporary speed restriction (see Figure 20).

T

20

20

100

20

20

50

110

110

Figure 20 Example of movement via crossing not requiring temporary speed restriction signs

GN165 Section 3.2.1 mandates provision of speed signs for all speed restrictions, including

temporary speed restrictions. Normally, speed indicators should be provided, but where a route via a ladder or diamond crossing already incorporates a permissible speed indicator




that is equal to or less than the temporary speed restriction, a speed indicator is not required.

GN166 Figure 20 sets out a typical example where a crossing movement is limited to 20 mph; therefore a 20 mph temporary speed restriction need not be signed for that movement.

3.4.1.2 Except in the case of abutting restrictions (see Appendix D, D.3), a termination indicator, displaying the letter ‘T’, shall be positioned at the end of each temporary speed restriction (see Figure 21).

Commencement of Speed Restriction Indicator

(Speed in mph)

Termination of Speed

Restriction Indicator

20 9090

20

T

Figure 21 Example of a commencement and termination indicator

3.4.1.3 Speed indicators shall be positioned in accordance with Appendix D.

3.4.1.4 Warning boards shall be provided for all signalled running movements towards temporary and emergency speed restrictions, except where trains always start from rest (for example, a siding or terminal station platform line) and the commencement of the speed restriction is less than 300 m ahead.

In these cases the WON shall specify:

‘A warning board is not provided on the ___ line for trains proceeding to the ___ line for the temporary speed restriction at ___ miles ___ chains.’

GN167 See also the requirements for repeater warning boards set out in Appendix D, D.2.5, which

may be provided in some cases for trains starting from rest at a distance of greater than 300 m.

3.4.1.5 Warning boards shall be positioned in accordance with Appendix D, using the deceleration distance criteria in Appendix X.

3.4.1.6 Only one warning board shall be provided on each approach to a temporary speed restriction, except where repeater warning boards are provided in accordance with Appendix D, D.2.5.

GN168 To avoid confusion, a train should normally only pass one warning board associated with a

particular speed indicator. Appendix D, D.2.2, sets out the arrangement normally provided at converging junctions to achieve this.




3.4.1.7 Where an emergency speed restriction is to be imposed, an emergency indicator shall be provided in addition to the warning board (see Figure 22), and positioned in accordance with Appendix E.

90 90

20

90

emergency indicator

Figure 22 Example of an emergency indicator

GN169 Emergency speed restrictions are signed in the same way as temporary speed restrictions,

with the addition of the emergency indicator and the additional AWS magnet associated with it. This is provided to draw the driver’s attention to the warning board, because details of the speed restriction have not been published in accordance with 3.4.4.

3.4.1.8 Speed signs provided for temporary and emergency speed restrictions shall be positioned on the left-hand side of the line in the direction of travel, except where:

a) It is not practicable to accommodate a speed sign on the left-hand side of the line, and

b) The applicability of a sign positioned on the right-hand side of the line is unambiguous.

3.4.1.9 Where temporary speed restriction speed indicators or warning boards are positioned to the right of the track in the direction of travel, the WON shall specify either:

‘The temporary speed restriction equipment for trains travelling in the up/down direction on ___ line between ___ miles ___ chains and ___ miles ___ chains is situated to the right of the track,’ or

‘The warning board _________________ (for example, IN THE TUNNEL) on the ___ line at ___ miles ___ chains is situated to the right of the track.’

GN170 Drivers are generally aware of the normal speed profile of a route as part of their route

knowledge, and only need to use the permissible speed signs as reminders. In the case of temporary and emergency speed restrictions, drivers are more dependent on the clarity of signage to give them the information they need. It is therefore important that the signs provided for temporary and emergency speed restrictions give clear and unambiguous information about the speed restrictions.

GN171 It is important that the driver understands which line each speed sign applies to, particularly where temporary speed signs are positioned between running lines. The normal position for speed signs is to the left of the line to which they apply, and signs should be placed on the left-hand side wherever practicable.




GN172 If signs are placed on the right-hand side of the line on a multiple track railway, it may not be clear to the driver which line they apply to. The driver should, generally, be looking for signs on the left-hand side of the line, and may possibly miss a sign on the right-hand side if it is not drawn to his / her attention.

GN173 Temporary speed restriction signs should only be placed on the right-hand side where their application is clear and the driver has been alerted by the entry in the operating notice.

GN174 As the position of emergency speed restrictions is not published in the WON, there is an increased risk that a driver could miss a sign that is positioned on the right-hand side of the line and therefore this should be avoided wherever possible.

3.4.2 Display of differential speeds at temporary speed restrictions

3.4.2.1 Speed indicators and warning boards shall only display the two standard differential speeds.

GN175 The signs specified for use at temporary and emergency speed restrictions only cater for

standard differential speeds (see 3.3.2). Non-standard differential speeds are not displayed at temporary and emergency speed restrictions, to simplify the implementation and publication of these restrictions, which are usually imposed in connection with engineering work or because of infrastructure degradation or failure.

3.4.2.2 The two standard differential speeds shall be displayed (see Figure 23) using:

a) A speed indicator displaying both speeds.

b) A warning board displaying both speeds.

T

Differential Speeds (20 over 50) 2050

20 50

20/50 90 90

Figure 23 Example of differential speed indicators

GN176 Standard differential speeds are shown on speed indicators and warning boards by two

speed values, one above the other, without any specific indications to identify particular categories of trains. The bottom figure (which shows the higher speed) applies to passenger trains (loaded or empty), parcels and postal trains (loaded or empty), and light locomotives; the top figure (which shows the lower speed) applies to all other trains.

GN177 The arrangement for displaying standard differential speeds, with the lower speed value shown by the top figure and the higher speed value by the bottom figure:

a) Provides a consistent display.

b) Means that the lower speed value, which is a safe speed for all trains, should be read first by the driver.




3.4.3 Provision of AWS permanent magnets for temporary speed restriction warning boards

3.4.3.1 An AWS magnet shall be provided on the approach to:

a) All warning boards, in accordance with Appendix D.

b) All emergency indicators, in accordance with Appendix E.

3.4.3.2 Except where the criteria in Appendix D, D.2.4 apply, the AWS magnet shall:

a) Be positioned 180 m on the approach to the warning board or emergency indicator.

b) Be positioned not less than 4 seconds running time from any other AWS equipment.

c) Not be positioned between any other AWS equipment and its associated signal, board or indicator.

The constraints in b) and c) do not apply to other AWS equipment which is provided for movements in the opposite direction and which is suppressed for movements in the direction to which the permissible speed warning indicator applies.

3.4.3.3 AWS magnet(s) shall be configured to generate an AWS caution indication in the driving cab.

GN178 GE/RT8075 permits the distance from the AWS magnet to the warning board to be

reduced to a minimum of three seconds running time. This accounts for the 1 second delay after passing over the permanent magnet before the AWS equipment gives a warning indication and provides the driver with a minimum of 2 seconds to respond to the AWS indication, observe the speed sign and acknowledge the warning.

GN179 The 4 seconds requirement in 3.4.3.2b) is necessary so that the AWS receiver has time to reset and is ready to respond correctly to the next AWS magnet following a caution indication, which could be acknowledged at the end of the acknowledgement delay period.

GN180 Each AWS indication should be directly associated with the signal or indicator that the driver is approaching, which means that AWS magnets provided in connection with warning boards should not be positioned between any other AWS magnet and the equipment associated with it.

3.4.4 Publication of temporary speed restrictions

3.4.4.1 Details of temporary speed restrictions shall be published in the WON prior to implementation.

3.4.4.2 Where this is not practicable, the speed restriction shall be implemented as an emergency speed restriction, as set out in Appendix E.

GN181 GO/RT3215 sets out the requirements for publication of WONs. Details of temporary

speed restrictions are published by the infrastructure manager, so that drivers are aware and alert to temporary speed restrictions along the route.

GN182 Where a speed restriction has to be imposed at short notice (for example, as a result of a failure), and it cannot be published in accordance with 3.4.4.1, it should be implemented as an emergency speed restriction (see 3.4.1.7 and Appendix E).




Part 4 Application of this Document

4.1 Application - infrastructure managers

4.1.1 Scope

4.1.1.1 The requirements in Part 2 of this document apply to all work that affects the design of new or altered lineside signalling arrangements relating to signal spacing. Where it is known, or becomes known, that existing lineside signal spacing does not comply with the requirements of this document, action to bring it into compliance is required when the signalling is renewed, the signal spacing is modified or permissible speeds are amended.

4.1.1.2 The requirements in Part 3 of this document apply to alterations to the speed profile, including the speed signage for temporary and emergency speed restrictions. Where it is known, or becomes known, that existing lineside speed signage does not comply with the requirements of this document, action to bring it into compliance is required when the speed signage is modified or renewed.

4.1.2 Exclusions from scope

4.1.2.1 There are no exclusions from the scope specified in 4.1.1 for infrastructure managers.

4.1.3 General compliance date for infrastructure managers

4.1.3.1 This Railway Group Standard comes into force and Parts 2 and 3 are to be complied with from 05 December 2015.

4.1.3.2 After the compliance dates or the date by which compliance is achieved if earlier, infrastructure managers are to maintain compliance with the requirements set out in this Railway Group Standard. Where it is considered not reasonably practicable to comply with the requirements, authorisation not to comply should be sought in accordance with the Railway Group Standards Code.

4.1.4 Exceptions to general compliance date

4.1.4.1 There are no exceptions to the general compliance date specified in 4.1.3 for infrastructure managers.

4.2 Application - railway undertakings

4.2.1 There are no requirements applicable to railway undertakings.

4.3 Health and safety responsibilities

4.3.1 Users of documents published by RSSB are reminded of the need to consider their own responsibilities to ensure health and safety at work and their own duties under health and safety legislation. RSSB does not warrant that compliance with all or any documents published by RSSB is sufficient in itself to ensure safe systems of work or operation or to satisfy such responsibilities or duties.

GN183 There is no guidance associated with Part 4.




Appendix A Signalling Braking Distance Data for all Trains

The content of this appendix is mandatory

A.1 Composite table for all trains (metres)

DISTANCE (METRES)

GRADIENT (mm/m)

Rising Falling

INITIAL SPEED (mph)

20 (1 in 50)

15 (1 in 67)

10 (1 in 100)

5 (1 in 200)

2.5 (1 in 400)

Level Level

2.5 (1 in 400)

5 (1 in 200)

10 (1 in 100)

15 (1 in 67)

20 (1 in 50)

10 62 65 69 75 78 82 89 97 118 146 190

15 100 107 117 128 136 144 156 168 200 244 311

20 155 165 180 200 210 220 238 255 295 365 480

25 220 235 260 290 303 325 345 375 445 575 770

30 295 315 350 390 418 445 485 530 645 820 1305

35 375 405 445 505 540 585 640 715 925 1265 2046

40 455 505 570 660 730 795 895 990 1300 1740 2046

45 580 650 740 855 945 1035 1185 1315 1520 1740 2046

50 629 684 747 855 945 1035 1185 1315 1520 1740 2046

55 704 760 824 899 955 1035 1185 1315 1520 1740 2046

60 776 833 896 970 1020 1070 1190 1315 1520 1740 2046

65 810 870 938 1019 1066 1116 1220 1315 1520 1740 2046

70 897 961 1033 1117 1165 1218 1280 1353 1520 1740 2046 75 953 1015 1084 1164 1215 1258 1320 1382 1534 1740 2046 80 953 1015 1084 1164 1215 1258 1320 1382 1534 1740 2046 85 1047 1110 1180 1261 1310 1354 1415 1471 1614 1788 2046 90 1181 1254 1334 1428 1485 1537 1610 1674 1842 2049 2330 95 1333 1418 1511 1621 1680 1750 1835 1913 2113 2366 2713

100 1528 1630 1745 1880 1960 2041 2143 2245 2503 2835 3312 105 1528 1630 1745 1880 1960 2041 2143 2245 2503 2835 3312 110 1528 1630 1745 1880 1960 2041 2143 2245 2503 2835 3312 115 1528 1630 1745 1880 1960 2041 2143 2245 2503 2835 3312 120 1585 1655 1745 1880 1960 2041 2143 2245 2503 2835 3312 125 1714 1789 1869 1957 2000 2054 2143 2245 2503 2835 3312

For gradients greater than 1 in 50 rising – use distances for 1 in 50 rising. For gradients greater than 1 in 50 falling – seek derogation.




GN Figure 7 Composite curves for all trains (metres) GN184 GN Figure 7 presents the graphical representation of the data of composite signalling

braking distances for all trains in metres.




DISTANCE (YARDS)

GRADIENT

Rising Falling

INITIAL SPEED (mph)

2.0% (1 in 50)

1.5% (1 in 67)

1.0% (1 in 100)

0.5% (1 in 200)

0.25% (1 in 400)

Level

0.25% (1 in 400)

0.5% (1 in 200)

1.0% (1 in 100)

1.5% (1 in 67)

2.0% (1 in 50)

10 68 71 75 82 86 90 98 106 129 160 208 15 109 117 128 140 149 158 171 184 219 267 340 20 170 180 195 215 228 240 258 275 320 395 520 25 240 255 280 315 335 355 383 410 485 625 840 30 320 340 380 425 455 485 530 575 700 895 1425 35 405 440 485 550 592 635 707 780 1010 1380 2237 40 495 550 620 720 792 865 972 1080 1420 1903 2237 45 630 710 805 935 1032 1130 1282 1435 1660 1903 2237 50 688 748 816 935 1032 1130 1282 1435 1660 1903 2237 55 770 831 901 984 1057 1130 1282 1435 1660 1903 2237 60 849 911 980 1061 1113 1165 1300 1435 1660 1903 2237 65 886 952 1026 1115 1168 1221 1328 1435 1660 1903 2237 70 981 1051 1129 1222 1276 1331 1405 1479 1660 1903 2237 75 1042 1110 1185 1273 1324 1375 1443 1511 1677 1903 2237 80 1042 1110 1185 1273 1324 1375 1443 1511 1677 1903 2237 85 1145 1214 1290 1379 1430 1481 1545 1609 1765 1956 2237 90 1292 1371 1459 1561 1621 1681 1756 1831 2014 2241 2548 95 1458 1550 1652 1772 1843 1914 2003 2092 2311 2587 2967

100 1671 1783 1908 2056 2144 2232 2343 2455 2737 3100 3622 105 1671 1783 1908 2056 2144 2232 2343 2455 2737 3100 3622 110 1671 1783 1908 2056 2144 2232 2343 2455 2737 3100 3622 115 1671 1783 1908 2056 2144 2232 2343 2455 2737 3100 3622 120 1734 1810 1908 2056 2144 2232 2343 2455 2737 3100 3622 125 1874 1957 2044 2140 2193 2246 2343 2455 2737 3100 3622

For gradients greater than 1 in 50 rising – use distances for 1 in 50 rising. For gradients greater than 1 in 50 falling – seek derogation.

GN Table 1 Composite table for all trains (yards) GN185 GN Table 1 presents the corresponding signalling braking distances for all trains in yards

and GN Figure 8 presents the graphical representation of these data.




GN Figure 8 Composite curves for all trains (yards)




Appendix B Signalling Braking Distances for Passenger Trains


B.1 Composite table for passenger trains (metres)

DISTANCE (METRES)

GRADIENT (mm/m)

Rising Falling

INITIAL SPEED (mph)

30 (1 in 33)

25 (1 in 40)

20 (1 in 50)

15 (1 in 67)

10 (1 in 100)

5 (1 in 200)

2.5 (1 in 400)

Level Level

2.5 (1 in 400)

5 (1 in 200)

10 (1 in 100)

15 (1 in 67)

20 (1 in 50)

25 (1 in 40)

30 (1in 33)

10 27 28 29 30 31 32 32 33 33 34 36 38 40 43 46 15 42 44 45 47 49 51 52 53 54 56 59 63 67 72 78 20 62 65 67 70 73 76 78 80 82 84 89 95 101 109 118 25 86 89 93 97 101 106 109 112 115 118 127 136 147 159 174 30 114 120 125 132 138 146 150 154 159 164 175 187 201 218 239 35 150 157 165 173 182 192 197 203 209 215 230 246 265 287 314 40 198 207 215 225 235 246 252 258 266 274 292 312 336 364 399 45 251 263 274 287 300 315 323 332 342 353 377 404 437 476 525 50 313 327 342 359 377 396 407 418 433 447 479 516 561 615 686 55 381 399 418 439 461 487 500 515 533 551 593 642 702 774 871 60 460 483 506 533 562 595 614 632 660 679 734 799 879 979 1117 65 537 564 592 624 658 698 720 742 770 798 864 942 1040 1162 1333 70 624 656 689 728 769 816 843 870 904 938 1018 1113 1234 1387 1607 75 727 766 807 853 904 963 995 1030 1075 1115 1216 1338 1496 1700 2007 80 832 877 925 980 1040 1110 1150 1190 1245 1291 1413 1561 1755 2013 2412 85 940 992 1047 1110 1180 1261 1310 1354 1410 1471 1614 1788 2021 2334 2834 90 1058 1118 1181 1254 1334 1428 1485 1537 1605 1674 1842 2049 2330 2715 3361 95 1190 1260 1333 1418 1511 1621 1680 1750 1835 1913 2113 2366 2713 3207 4100

100 1357 1440 1528 1630 1745 1880 1960 2041 2143 2245 2503 2835 3312 4044 5668 105 1357 1440 1528 1630 1745 1880 1960 2041 2143 2245 2503 2835 3312 4044 5668 110 1357 1440 1528 1630 1745 1880 1960 2041 2143 2245 2503 2835 3312 4044 5668 115 1357 1440 1528 1630 1745 1880 1960 2041 2143 2245 2503 2835 3312 4044 5668 120 1461 1522 1585 1655 1745 1880 1960 2041 2143 2245 2503 2835 3312 4044 5668 125 1579 1646 1714 1789 1869 1957 2000 2054 2143 2245 2503 2835 3312 4044 5668




GN Figure 9 Composite curves for passenger trains (metres)

GN186 GN Figure 9 presents the graphical representation of the data of composite signalling

braking distances for passenger trains in metres.

Level 0.5% 1.0% 1.5% 2.0% 2.5% 3.0%0.5%1.0%1 in 100

1.5%1 in 67

2.0%1 in 50

2.5%1 in 40

3.0%1 in 33 1 in 200 1 in 200 1 in 100 1 in 67 1 in 50 1 in 40 1 in 33

125 Mile

/h

120 Mile

/h

100, 105, 1

10, 115 M

ile/h

95 M

ile/h

90 M

ile/h

85 M

ile/h

70 M

ile/h

65 Mile

/h

60 Mile

/h

55 Mile/h

50 Mile/h

45 Mile/h

(ME

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2600

2500

200

FallingRising GRADIENT

75 M

ile/h

80 M

ile/h

35 Mile/h

30 Mile/h

25 Mile/h

15 Mile/h

10 Mile/h

20 Mile/h

40 Mile/h




DISTANCE (YARDS)

GRADIENT

Rising Falling

INITIAL SPEED (mph)

1 in 33 3.0%

1 in 40

2.5%

1 in 50 2.0%

1 in 67 1.5%

1 in 100 1.0%

1 in 200 0.5%

1 in 400 0.25%

Level Level

1 in 400 0.25%

1 in 200 0.5%

1 in100 1.0%

1 in 67 1.5%

1 in 50 2.0%

1 in 40 2.5%

1 in 33 3.0%

10 30 31 32 33 34 35 36 36 37 37 39 42 44 47 50 15 46 48 49 51 54 56 57 58 60 61 65 69 73 79 85 20 68 71 73 77 80 83 86 88 90 92 97 104 110 119 129 25 94 97 102 106 110 116 120 123 126 129 139 149 161 174 190 30 125 131 137 144 151 160 164 168 174 179 191 205 220 238 261 35 164 172 181 189 199 210 216 222 228 235 252 269 290 314 344 40 217 226 235 246 257 269 276 283 291 300 319 341 367 398 436 45 275 287 300 314 328 345 354 363 374 385 412 442 478 520 574 50 342 358 374 392 412 434 446 458 473 488 524 564 614 673 750 55 416 436 457 480 504 532 548 563 583 603 649 702 767 846 953 60 503 528 554 583 615 651 671 692 717 743 803 873 962 1071 1222 65 587 616 648 682 720 763 787 812 842 873 945 1030 1137 1270 1458 70 682 717 754 796 841 892 921 951 988 1026 1113 1217 1350 1517 1758 75 795 838 882 933 989 1053 1089 1126 1172 1219 1330 1463 1636 1860 2195 80 910 959 1012 1072 1137 1214 1257 1301 1356 1412 1545 1707 1920 2201 2637 85 1028 1085 1145 1214 1290 1379 1430 1481 1545 1609 1765 1956 2210 2552 3099 90 1157 1222 1292 1371 1459 1561 1621 1681 1756 1831 2014 2241 2548 2969 3676 95 1302 1378 1458 1550 1652 1772 1843 1914 2003 2092 2311 2587 2967 3508 4484

100 1484 1575 1671 1783 1908 2056 2144 2232 2343 2455 2737 3100 3622 4423 6198 105 1484 1575 1671 1783 1908 2056 2144 2232 2343 2455 2737 3100 3622 4423 6198 110 1484 1575 1671 1783 1908 2056 2144 2232 2343 2455 2737 3100 3622 4423 6198 115 1484 1575 1671 1783 1908 2056 2144 2232 2343 2455 2737 3100 3622 4423 6198 120 1597 1665 1734 1810 1908 2056 2144 2232 2343 2455 2737 3100 3622 4423 6198 125 1727 1800 1874 1957 2044 2140 2193 2246 2343 2455 2737 3100 3622 4423 6198

GN Table 2 Composite table for passenger trains (yards) GN187 GN Table 2 presents the corresponding signalling braking distances for passenger trains in yards

and GN Figure 10 presents the graphical representation of these data.




GN Figure 10 Composite curves for passenger trains (yards)

(YA

RD

S)

Min

imu

m S

ign

al S

pac

ing

Dis

tan

ce

(YA

RD

S)


Level0.5%1.0%1 in 100

1.5%1 in 67

2.0%1 in 50

2.5%1 in 40

3.0%1 in 33 1 in 200

0.5% 1.0% 1.5% 2.0% 2.5% 3.0%1 in 200 1 in 100 1 in 67 1 in 50 1 in 40 1 in 33

100

0

300

400

1200

1300

1400

2000

1900

2100

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125 Mile/h

120 Mile/h

100, 105, 110, 115 Mile/h

95 M

ile/h

90 M

ile/h

85 M

ile/h

70 M

ile/h

65 Mile/h

60 Mile/h

55 Mile/h

50 Mile/h

45 Mile/h

75 M

ile/h

80 M

ile/h

40 Mile/h

35 Mile/h

30 Mile/h

25 Mile/h20 Mile/h15 Mile/h10 Mile/h




Appendix C Signalling Braking Distances for Trains with Enhanced Braking (9%g mean)


C.1 Table for trains with enhanced braking (9%g mean) in metres

DISTANCE (METRES)

GRADIENT (mm/m)

Rising Falling

INITIAL SPEED (mph)

30 (1 in 33)

25 (1 in 40)

20 (1 in 50)

15 (1 in 67)

10 (1 in 100)

5 (1 in 200)

2.5 (1 in 400)

Level Level

2.5 (1 in 400)

5 (1 in 200)

10 (1 in 100)

15 (1 in 67)

20 (1 in 50)

25 (1 in 40)

30 (1 in 33)

10 23 24 25 25 26 27 27 28 29 30 31 33 34 37 40 15 37 38 40 41 43 45 46 47 48 49 52 55 59 64 70

20 55 57 60 62 65 68 72 72 74 76 81 86 92 100 110

25 78 81 85 89 93 98 100 103 106 109 117 126 136 149 164

30 105 110 115 121 128 135 139 143 148 153 164 176 191 208 230

35 139 146 153 162 170 180 185 191 197 204 218 235 254 277 306

40 188 196 205 214 224 234 240 246 254 262 279 298 321 347 380

45 232 243 253 264 276 289 296 304 313 322 343 366 393 425 464 50 282 294 306 320 334 351 359 368 379 390 415 442 475 511 557

55 336 350 365 381 399 418 428 438 451 464 493 525 563 606 660 60 395 411 429 448 468 490 502 514 529 544 578 615 659 709 770

65 458 478 497 519 543 568 582 597 614 631 670 712 762 819 890

70 526 548 571 596 623 652 668 684 703 723 767 816 873 937 1017 75 598 624 650 678 708 742 762 779 801 823 872 927 991 1064 1153

80 676 704 734 766 800 838 860 879 904 929 984 1046 1118 1199 1299

85 758 790 823 859 897 940 963 986 1014 1042 1103 1172 1252 1343 1455

90 846 882 919 959 1002 1049 1075 1101 1132 1163 1232 1309 1398 1499 1623

95 939 979 1020 1065 1112 1165 1193 1223 1257 1291 1368 1453 1552 1664 1802

100 1031 1075 1119 1168 1220 1278 1309 1341 1377 1415 1498 1590 1698 1819 1968

105 1132 1179 1228 1282 1339 1402 1437 1472 1514 1553 1644 1745 1862 1994 2157 110 1237 1289 1342 1401 1463 1532 1570 1608 1653 1697 1796 1905 2033 2177 2354

115 1346 1403 1461 1525 1593 1668 1709 1751 1799 1847 1955 2074 2212 2369 2561 120 1461 1522 1585 1655 1728 1810 1855 1900 1952 2004 2121 2250 2400 2569 2777

125 1579 1646 1714 1789 1869 1957 2005 2054 2111 2167 2293 2432 2594 2777 3001




105 Mile

/h

65 Mile/h

60 Mile/h

55 Mile/h

50 Mile/h

45 Mile/h

75 Mile

/h

80 Mile

/h

85 Mile

/h

90 Mile

/h

95 Mile

/h

100 Mile

/h

110 Mile

/h

115 Mile

/h

120 Mile

/h

125 Mile

/h

Level 0.5% 1.0% 1.5% 2.0% 2.5% 3.0%0.5%1.0%1 in 100

1.5%1 in 67

2.0%1 in 50

2.5%1 in 40

3.0%1 in 33 1 in 200 1 in 200 1 in 100 1 in 67 1 in 50 1 in 40 1 in 33

(ME

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)


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30 Mile/h

25 Mile/h

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15 Mile/h

10 Mile/h

GN Figure 11 Curves for trains with enhanced braking (9%g mean) in metres GN188 GN Figure 11 presents the graphical representation of the data for trains with

enhanced braking (9%g mean) in metres.




DISTANCE (YARDS)

GRADIENT

Rising Falling

INITIAL SPEED (mph)

1 in 33 3.0%

1 in 40 2.5%

1 in 50 2.0%

1 in 67 1.5%

1 in 100 1.0%

1 in 200 0.5%

1 in 400 0.25%

Level Level

1 in 400 0.25%

1 in 200 0.5%

1 in 100 1.0%

1 in 67 1.5%

1 in 50 2.0%

1 in 40 2.5%

1 in 33 3.0%

10 25 26 27 27 28 30 31 31 32 33 34 36 37 40 44 15 40 42 44 45 47 49 50 51 53 54 57 60 65 70 77 20 60 62 66 68 71 74 77 79 81 83 89 94 101 109 120 25 85 89 93 97 102 107 110 113 116 119 128 138 149 163 179 30 115 120 126 132 140 148 152 156 162 167 179 193 209 228 252 35 152 160 167 177 186 197 203 209 216 223 238 257 278 303 335 40 206 215 224 234 245 256 263 269 277 286 305 326 351 380 415 45 254 265 276 289 302 317 325 333 343 353 375 400 430 464 507 50 308 321 335 350 366 383 393 403 415 426 453 484 519 559 609 55 367 383 399 417 436 457 468 479 494 508 539 575 616 663 722 60 432 450 469 489 511 536 550 563 579 595 632 673 721 775 842 65 501 522 544 568 593 622 638 653 671 690 732 779 834 896 973 70 575 599 624 652 681 713 731 748 770 791 839 892 954 1025 1112 75 654 682 710 742 775 811 831 851 876 900 954 1014 1084 1163 1261 80 739 770 802 837 875 916 939 962 989 1016 1076 1144 1222 1311 1421 85 829 864 900 939 981 1028 1053 1079 1109 1139 1207 1282 1370 1469 1591 90 925 965 1005 1049 1096 1148 1176 1205 1238 1272 1347 1431 1529 1639 1775 95 1027 1071 1115 1164 1216 1274 1305 1337 1375 1412 1496 1589 1697 1820 1970

100 1128 1175 1224 1278 1334 1397 1432 1467 1507 1548 1639 1739 1857 1989 2152 105 1238 1290 1343 1402 1464 1533 1571 1609 1654 1698 1798 1908 2036 2181 2359 110 1352 1409 1468 1532 1600 1675 1717 1759 1807 1855 1964 2084 2223 2381 2574 115 1472 1534 1598 1668 1742 1824 1869 1914 1967 2020 2137 2268 2420 2590 2800 120 1597 1665 1734 1810 1890 1979 2028 2078 2135 2192 2319 2460 2625 2810 3037 125 1727 1800 1874 1957 2044 2140 2193 2246 2308 2370 2507 2659 2837 3037 3282

GN Table 3 Table for trains with enhanced braking (9%g mean) in yards GN189 GN Table 3 presents the corresponding signalling braking distances for passenger for

trains with enhanced braking (9%g mean) in yards and GN Figure 12 presents the graphical representation of these data.





100

0

300

400

1200

1300

1400

2000

1900

2100

2200

500

800

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700

900

1500

1600

1800

2300

2400

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3000

3100

2900

2800

2700

200

1700

1100

100

0

300

400

1200

1300

1400

2000

1900

2100

2200

500

800

1000

600

700

900

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2400

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2700

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1100

105 Mile

/h

65 Mile/h

60 Mile/h

55 Mile/h

50 Mile/h

45 Mile/h

75 Mile

/h

80 Mile

/h

85 Mile

/h

90 Mile

/h

95 Mile

/h

100 M

ile/h

110 M

ile/h

115 Mile

/h

120 M

ile/h

125 M

ile/h

70 Mile

/h

(YA

RD

S)

Min

imu

m S

ign

al S

pa

cin

g D

ista

nce

(YA

RD

S)

Level0.5%1.0%1 in 100

1.5%1 in 67

2.0%1 in 50

2.5%1 in 40

3.0%1 in 33 1 in 200

0.5% 1.0% 1.5% 2.0% 2.5% 3.0%1 in 200 1 in 100 1 in 67 1 in 50 1 in 40 1 in 33

40 Mile/h

35 Mile/h

30 Mile/h

25 Mile/h

20 Mile/h

15 Mile/h10 Mile/h

GN Figure 12 Curves for trains with enhanced braking (9%g mean) in yards




Appendix D Temporary Speed Restrictions


D.1 Position of speed indicators and termination indicators

D.1.1 General requirements

D.1.1.1 Where temporary speed restriction speed indicators are required (see 3.4.1.1), they shall be positioned:

a) On the approach to the temporary speed restriction, and

b) As close as practicable to the location where the temporary speed limit commences.

D.1.1.2 Additional speed indicator(s) shall be provided within a temporary speed restriction in the following circumstances:

a) At a position where trains are permitted to reverse direction (for example, at the signal at which the train may reverse direction). In this case the WON shall specify:

‘The speed indicator on the ___ line at ___ miles ___ chains is provided for trains turning back at this location.’

b) Where there is an operational requirement to change drivers (for example, at stations). In this case the WON shall specify:

‘The speed indicator on the ___ line at ___ miles ___ chains applies to changing crews at this location.’

GN190 Drivers should normally observe only one speed indicator for each temporary speed restriction, positioned at the location where the speed restriction commences.

GN191 Where a train may stop part way through a temporary speed restriction, an additional indicator should be provided to display the applicable temporary speed restriction to the driver before the train is restarted, if either a different driver may take over or the train may reverse direction.

GN191a The rationale for the provision of additional speed indicators is to remind the driver that the train is subject to a TSR.

GN191b Clause D.1.1.2a) applies only to locations where trains are booked to reverse direction; it does not apply to shunting movements. Clause D.1.1.2b) applies only to locations where trains are booked to change drivers. This information should be obtained locally.

D.1.1.3 Where differential speeds apply, all the required speed indicators and

directional indicators shall be positioned together.

D.1.1.4 It is permitted for nominally co-located signs to be separated by a short distance where this would not impair readability.

GN192 Where differential speeds apply to a temporary speed restriction, the two applicable

speeds are shown on the same sign at the warning indicator and at the commencement indicator. Where a directional arrow is required, this also should be on the same sign as the speed indicators, in order to convey the correct meaning to the driver.




GN193 Where space is restricted (for example, where a sign has to be mounted between adjacent tracks), there may be insufficient room for a speed indicator or warning indicator with differential speeds and a directional arrow. If it is not practicable to provide appropriate signage to allow the application of differential speeds, it may be necessary to impose a single speed limit (the lowest applicable speed) for all trains.

D.1.2 Position of speed indicators at converging junctions

D.1.2.1 Where lines converge within a temporary speed restriction, a speed indicator shall be provided at each entry to the speed restriction before the convergence, so that trains pass only one speed indicator applicable to the restriction (see Figure D-1).

Additional indicator

for converging lineT

90 20 20 90

2050 20

20

Figure D-1 Example of speed indicators at converging junction (D.1.2.1)

GN194 The principle that a driver should normally observe only one speed indicator for each temporary speed restriction is the same as that applied for permissible speed warning indicators as set out in 3.3.6.1.

GN195 By exception, where the temporary speed restriction applicable through the converging junction is higher than the permissible speed for the converging line at the junction points, the speed indicator for trains from the converging line should be positioned beyond the junction points to avoid conflicting speed indications approaching the junction. In this case drivers on the higher speed route pass a second speed indicator within the speed restriction.

D.1.3 Position of speed and termination indicators at diverging junctions

D.1.3.1 A speed indicator, with an arrow indicating the direction of divergence, shall be provided on the approach to any diverging junction or facing crossover on or over which there is a temporary speed restriction.

GN196 The speed indicator should be provided close to the diverging turnout so that it is obvious that it applies to the turnout, but it may be necessary to position it clear of existing signs (for example, permanent permissible speed indicators) adjacent to the turnout.

D.1.3.2 Where a temporary speed restriction only applies to the trailing point end of a crossover and the speed indicator cannot be placed at a position within the crossover, the speed indicator (with directional arrow) shall be placed before the facing point end (see Figure D-2). In this case the WON shall specify:

‘The speed indicator on ___ line at ___ miles ___ chains applies only to trains using the crossover to ___ line.’




90

110

20

90

20 9020 50

110

20

T

5020

Directional indication required

Commencement of 20 speed restriction

Figure D-2 Example of TSR over trailing end of crossover (D.1.3.2) GN197 In the example shown in Figure D-2, the speed indicator for the 20 mph temporary speed

restriction is placed before the facing points of the crossover (adjacent to the existing permissible speed indicator), even though the temporary speed restriction has been applied only to the line through the trailing end of the crossover.

GN198 Drivers observing the speed indicator and arrow should understand that the speed restriction only applies to the crossover move.

D.1.3.3 Where a temporary speed restriction applies only over the facing point end of a

crossover, a termination indicator (or, if entering another adjoining temporary speed restriction, a speed indicator displaying the value of that speed restriction) shall be placed adjacent to the trailing point end (see Figure D-3). In this case the WON shall specify:

‘The termination indicator on ___ line at ___ miles ___ chains applies only to trains using the crossover from ___ line.’

90

90

11020

5020

50

T

20

T

2090

110

Termination of 20 speed restriction

Figure D-3 Example of TSR over facing end of crossover (D.1.3.3)

GN199 In the example shown in Figure D-3, the termination indicator for the 20 mph temporary

speed restriction (which applies only to the line through the facing end of the crossover) cannot be placed part way through the crossover, and is placed adjacent to the trailing end. Trains on the straight line through the trailing end of the crossover, therefore, pass this termination indicator, although it does not apply to them; the WON entry explains the situation.

D.2 Temporary speed restriction warning boards and AWS equipment

D.2.1 General requirements for warning boards

D.2.1.1 Warning board(s) shall be positioned as close as practicable to (but not less than) the deceleration distance from the associated speed indicator.

D.2.1.2 Where the temporary speed restriction commences at an increase of permissible speed, and the speed of the TSR is the same as, or higher than, the speed on the approach, the warning board(s) shall be positioned at a minimum distance from the associated speed indicator equivalent to a running time of four seconds at the permissible speed.




GN200 The temporary speed restriction warning board should provide sufficient deceleration distance for all types of trains. Where differential permissible speeds apply on the approach to the temporary speed restriction, the longest deceleration distance required should be allowed for.

GN201 The longest deceleration distance required may be significantly longer than the distance required by some trains. Such excess spacing is undesirable, but unavoidable, given that Appendix X needs to accommodate the worst braked trains.

GN202 The distance between the warning board and the speed indicator should not be significantly greater than the longest deceleration distance required, because this may make it difficult for train drivers to judge where they need to begin braking. This could lead to early or late brake application by drivers. Therefore, the warning board should be positioned as close as possible to the position that provides the longest deceleration distance from the speed indicator.

GN202a Four seconds provides the driver with enough time to comply with the TSR before the train reaches the speed indicator, including time to:

a) Interpret that the train is approaching the TSR. b) Decide what action, if any, is needed to comply with the TSR. In this case, the required action may be a change to the usual operation of increasing the speed of the train at that location. c) Take the necessary action, if any.

D.2.1.3 The distance from the warning board to the speed indicator shall be extended:

a) Where this is necessary to avoid AWS conflicts (see D.2.4).

b) So that a warning board is not positioned between existing AWS equipment and the equipment to which the AWS applies.

GN203 The distance between the temporary speed restriction warning board and the speed

indicator may need to be increased to provide adequate sighting, or to avoid AWS conflicts or positions where it is not practicable to provide the warning board.

D.2.1.4 Where the required deceleration distance from the permissible speed on the immediate approach to the temporary speed restriction would result in the warning board being positioned in a section of line with a higher permissible speed, the deceleration distance shall be determined using that higher permissible speed (see Figure D-4).

DD 40 – 20

60 20 20

20

20 40

406060

DD 60 – 20

Figure D-4 Example of TSR with a higher permissible speed on approach (D.2.1.4)




D.2.1.5 Where the required deceleration distance from the permissible speed on the immediate approach to the temporary speed restriction would result in the warning board being positioned in a section of line with a lower permissible speed, the deceleration distance required for this lower permissible speed shall be determined. If the revised position of the warning board still falls within that lower permissible speed section, it shall be positioned at that distance (see Figure D-5).

DD 40 – 20

40 20 20

20

20 60

604040

DD 60 – 20

Figure D-5 Example of TSR with a lower permissible speed on approach (D2.1.5)

D.2.1.6 If the revised position of the warning board as set out in D2.1.5 lies between the permissible speed indicator at the commencement of the higher permissible speed section and the temporary speed restriction speed indicator, the warning board shall be positioned at the permissible speed indicator for the higher speed section to prevent acceleration (see Figure D-6).

(> DD 30 – 20)

30

DD 60 – 20

20 60 20 20

2060603030

20

DD 30 – 20

Figure D-6 Example of TSR with warning board at commencement of higher permissible speed (D.2.1.6)

GN204 In the examples shown in Figures D-4, D-5 and D-6, the initial calculation of warning board

position for the 20 mph temporary speed restriction would result in either insufficient braking distance (Figure D-4), excess braking distance (Figure D-5) or in a confusing arrangement (Figure D-6). This is due to the variations in permissible speed on the approach to the temporary speed restriction. The aim of sensible positioning of the warning board is to avoid driver confusion and to enable them to drive their trains in the optimum manner.




D.2.2 Requirements for warning boards at converging junctions

D.2.2.1 Where the deceleration distance requires a warning to be given on the approach to a converging junction, a warning board shall be positioned at the appropriate deceleration distance on each line approaching the speed indicator (see Figure D-7).

50

90

50

20

20 20

20

#

#

DD 50 – 20

DD 90 – 20

Figure D-7 Example of warning board positioning at a converging junction (D.2.2.1)

D.2.2.2 Where the required deceleration distances would position one of the warning boards on the approach to a convergence, then all warning boards shall be positioned before the convergence so that a train passes only one warning board on any approach to the temporary speed restriction.

GN205 It is undesirable for a driver to pass more than one warning board for the same temporary

speed restriction. Therefore, if the deceleration distance required for the higher speed approach places the warning board before a converging junction, the warning for a lower speed approach should also be placed before the converging junction.

D.2.3 Requirements for warning boards at diverging junctions

D.2.3.1 Where a temporary speed restriction applies over or beyond a diverging junction, and the required deceleration distance places the warning board before the junction (see Figure D-8), the warning board shall incorporate an arrow indicating the direction of divergence. In this case the WON shall specify:

‘The warning board situated on the ___ line at ___ miles ___ chains applies to trains proceeding to the ___ line.’

20 60

20

20

110110

60

< DD 60 – 20

Figure D-8 Example of warning board positioning at a diverging junction (D.2.3.1)




D.2.3.2 Where the deceleration distance would provide a warning board on a diverging line at a position that would cause the associated AWS permanent magnet to be located at or before the facing points, all of the following arrangements shall apply (see Figure D-9):

a) The warning board shall incorporate a directional arrow.

b) The warning board shall be positioned at the facing points.

c) The AWS magnet shall be positioned at the required distance on the approach to the warning board.

Figure D-9 Example of a diverging junction with warning board located at the facing points (D.2.3.2)

GN206 In certain cases the deceleration distance for a temporary speed restriction would place the

warning board a short distance beyond the facing points of a diverging junction, and the associated AWS magnet would require to be positioned before the facing points. That arrangement would be unacceptable, since a train on the straight route would receive a warning on passing over the AWS magnet, but would not pass the warning board.

GN207 In such cases the arrangement shown in Figure D-9 should be adopted. The warning board is placed at the facing points, and in most cases is adjacent to the permissible speed indicator for the diverging route. All trains should pass over the AWS magnet and should also pass the warning board, which has a directional arrow to identify that it applies to the diverging route only.




D.2.3.3 Where the deceleration distance would provide the warning board on the approach to a junction signal that is approach controlled from red (permanent or temporary approach control) all of the following arrangements shall apply:

a) The deceleration distance shall be determined using the junction speed.

b) The warning board shall be positioned at or after the sighting point of the signal (including the route indicator), or of the splitting banner repeating signal, where provided (see Figure D-10).

c) The WON shall specify:


90

11040

DD Junction Speed – 20

110

90 20

20

20

Warning board positioned

after the sighting point of signal & route indicator

(or splitting banner where provided)

#

Figure D-10 Example of a diverging junction where signal is approach released from red (D.2.3.3)

GN208 The arrangement in Figure D-10 relies on the fact that, when a train is to be routed to the

diverging route, the aspect sequence causes the approach speed of the train to be reduced. The driver should be prepared to stop at the junction signal until the proceed aspect (or the splitting banner repeating signal, where provided) is observed for the diverging route.

GN209 Because the warning board is positioned after the sighting point of the signal, the driver knows that if the signal displays a proceed aspect for the diverging route, it is necessary to control the speed of the train for the permissible speed restriction on the diverging route, and for the temporary speed restriction beyond the junction.

GN210 It is permissible for the AWS magnet for the warning board to be positioned before the sighting point of the signal.




D.2.3.4 Where the deceleration distance would provide the warning board on the approach to a junction signal and the signalling aspect sequence provides information to the driver on which route has been set (for example, the junction signal is approach controlled from yellow with flashing yellows or splitting distant in rear), all of the following arrangements shall apply:

a) The warning board shall be positioned at the deceleration distance calculated using the permissible speed of the line (see Figure D-11).

b) The WON shall specify:


90

20

110#

90

20

20

110

70

DD 110 – 20

Figure D-11 Example of a diverging junction where signal is approach released from a higher aspect (D.2.3.4)

GN211 A junction signalling aspect sequence using flashing yellow aspects or splitting distant signals provides the driver with advance information about the route that is set, and so allows a train to approach a diverging junction at a higher speed than approach control from red would permit. It is therefore necessary to provide a warning board for a temporary speed restriction on the diverging route at an earlier position than shown in Figure D-10. The driver should be aware that the train is routed towards the temporary speed restriction and should be able to control the speed of the train accordingly.

D.2.3.5 Where the deceleration distance would provide the warning board on the approach to

a junction signal that is not approach controlled or that displays a free single yellow with a standard 4-aspect sequence on the approach, all of the following arrangements shall apply:

a) Temporary approach control from red shall be applied to the signal for the applicable diverging route or straight route (see Figure D-12, which sets out an example of a temporary speed restriction on the straight route).

b) The signal aspect release point shall be at or after the sighting point of the signal (including the route indicator, where applicable), or of the splitting banner repeating signal, where provided.

c) The warning board shall be positioned so that it is visible to the driver when the signal aspect is released from red to display a proceed aspect.




60

20

60#

6020

2060

40

Temporary approach control of appropriate route

Warning board positioned

after the sighting point of signal & route indicator

(or splitting banner where provided)

Figure D-12 Example of a diverging junction where no previous routing advice is given (D.2.3.5)

GN212 A junction signalling aspect sequence without approach control, or using free yellow with a

standard 4-aspect sequence on the approach, allows a train to approach a diverging junction at a higher speed than approach release from red. It does not provide the driver with advance information about which route the train is to take.

GN213 The driver does not know which way the train is to be routed before the junction signal aspect (or splitting banner repeating signal, where provided) becomes visible. It would, therefore, be unacceptable to provide the warning board at full deceleration distance (as shown in Figure D-11) because the driver would not yet know whether the temporary speed restriction applied to that train movement.

GN214 It is therefore necessary to apply temporary approach control from red (where provided) to the junction signal for the route towards the temporary speed restriction (which may be the straight route or a diverging route), and apply a similar arrangement to that shown in Figure D-11. Where temporary approach control facilities are not provided, either:

a) The speed indicator should be repositioned on the approach to the diverging junction, so that the temporary speed restriction applies to all routes through the junction, or

b) A separate temporary speed restriction should be imposed before the diverging junction, of low enough value to allow positioning of the warning board for the required temporary speed restriction on the approach to the AWS magnet for the junction protecting signal.

D.2.4 Requirements for AWS permanent magnets and AWS cancelling indicators

D.2.4.1 Except where D.2.4.2 applies, an AWS permanent magnet shall be positioned:

a) On all lines that signalled running moves approach the warning board, whether or not the line is fitted with AWS (see Figure D-13).

b) 180 m (200 yd) on the approach to the temporary speed restriction warning board, unless the criteria in D.2.4.3 apply.

c) Where the criteria in D.2.4.3 apply, between 45 m (50 yd) and 180 m (200 yd) from the warning board, subject to a minimum of 4 seconds running time at permitted speed (see Figure D-14).




20

DD 90 – 20

90

#

50 #

90

Figure D-13 Example of usual positioning of AWS magnets (D.2.4.1a)

<#

20

DD 90 – 2020

90

(> DD 90 – 20)

#

4 seconds

(min 45 m [50 yd])

Portable AWS not allowed within these limits

Figure D-14 Example of critical positioning of AWS magnets (D.2.4.1c)

GN215 AWS magnet(s) should always be provided for each temporary speed restriction warning

board, including where the line concerned is not fitted with AWS. This is so that the driver is specially alerted to the presence of the warning board, because the driver is not familiar with the position of temporary speed restrictions as part of route knowledge. A limited number of exceptions are set out in D.2.4.2.

GN216 The standard position for these AWS magnets is 180 m on the approach to the warning board.

GN217 Where conditions such as those set out in D.2.4.3 prevent the positioning of an AWS magnet 180 m from the warning board, the magnet should be positioned between 45 m and 180 m from the warning board, subject to a minimum of 4 seconds running time at the permissible speed. The minimum 4 seconds requirement is so that the AWS receiver has time to reset and is ready to respond correctly to the next AWS magnet following a caution indication, which could be acknowledged at the end of the acknowledgement delay period.

D.2.4.2 The AWS permanent magnet shall not be provided, either:

a) In an AWS gap area (see GE/RT8075), or

b) On lines from which trains always start from rest, for example, bay or terminal platforms. In this case the WON shall specify:

‘No AWS at warning board on ___ line at ___ miles ___ chains.’

GN218 AWS magnets for temporary speed restriction warning boards are not provided within

designated AWS gap areas, such as some major stations. While this means that drivers do not receive an AWS indication, AWS gap areas are generally associated with complex infrastructure layouts where train movements are diverse and permissible speeds are low.

GN219 AWS magnets are not provided in bay or terminal platform lines where trains always start from rest, because the AWS cannot be configured to provide 4 seconds advance warning for the stationary train in this situation. If an arriving train were to stop with the receiver on




what would become the leading cab (upon reversal) directly over the magnet applicable to the starting signal, it would not be possible to correctly set up the leading cab.

GN220 Where AWS is not provided, the WON is the means of drawing the driver’s attention to the absence of AWS on the approach to the temporary speed restriction warning board.

D.2.4.3 The AWS permanent magnet shall not be positioned within 4 seconds running

time of the AWS equipment associated with any of the following, which apply in the same direction:

a) A signal (including fixed distant boards and SPAD indicators).

b) A permissible speed warning indicator.

c) A level crossing advanced warning sign (St. Georges Cross).

D.2.4.4 By exception, where no other configuration of warning board and AWS position is practicable:

a) The warning board shall be positioned at a signal.

b) The AWS equipment associated with the signal shall be re-configured to generate an AWS caution indication in the driving cab, regardless of the aspect displayed by the signal (see Figure D-15). In this case the infrastructure manager shall assess the SPAD risk arising from disconnection of the AWS, and ensure that the correct AWS functionality for the signal is restored at the earliest opportunity.


‘Warning Board positioned at signal no. ___ on ___ line, an AWS warning indication will be given irrespective of the aspect exhibited by the signal.’

Disconnect AWS

20

Figure D-15 Example of warning board at signal with signal AWS electromagnet

disconnected (D.2.4.4)

GN221 Wherever practicable, a separate AWS magnet should be provided for a temporary speed

restriction warning board so that drivers receive an AWS caution specifically for the warning board.

GN222 Where it is not practicable to position the warning board so that a separate AWS magnet can be provided for it, the arrangement shown in Figure D-14 could be used. In this arrangement the warning board is positioned adjacent to a signal and makes use of the existing AWS magnet associated with the signal. The AWS electromagnet should be disconnected so that the AWS always gives a caution indication regardless of the aspect displayed by the signal.




GN223 This arrangement has the following disadvantages:

a) When the signal is displaying a cautionary aspect, drivers receive a single AWS caution indication for two different functions (that is to say, the signal and the warning board).

b) When the signal is displaying a green aspect, the driver receives a caution indication at the AWS.

GN224 The risks in this situation are that:

a) Drivers associate the AWS warning with a cautionary aspect shown by the signal, and fail to observe the temporary speed restriction warning board, leading to insufficient deceleration for the temporary speed restriction.

b) Drivers become accustomed to receiving an AWS caution for the temporary speed restriction warning board when the signal is green, and are not alerted by the AWS to the signal when it is showing a cautionary aspect, potentially leading to a SPAD.

GN225 Because of this possibility, the SPAD risk arising from the disconnection of the AWS should be assessed before this arrangement is implemented, and the period for which it is applied should be kept as short as possible.

GN226 This arrangement should not be applied at any signal where the consequences of a SPAD are high (for example, signals protecting converging or crossing movements, or the entry to bi-directional lines), or at a signal that displays a cautionary aspect on the approach to such a signal.

D.2.4.5 On single or bi-directional lines, where it is possible to utilise existing AWS equipment associated with a signal or sign for the opposing direction, which is normally suppressed for movements in the direction towards the warning board (see Figure D-16):

a) The warning board shall be positioned to utilise the existing AWS equipment for the opposing direction.

b) The warning board shall be positioned at the required distance beyond the existing AWS equipment (see D.2.4.1).

c) The suppression shall be disconnected.

d) An AWS cancelling indicator shall not be provided.

90

20

90

#

DD 90 – 20

Disconnect suppression

Figure D-16 Example of disconnection of suppressor on existing magnet (D.2.4.5)

GN227 On lines signalled for movements in the opposite direction to that required for the

temporary speed restriction, the preferred arrangement is to use an existing magnet. Some latitude in the positioning of the warning board is permitted to enable this arrangement to be utilised.

GN228 Where the magnet is suppressed for movements in the direction of the temporary speed restriction, it is necessary to disconnect the suppressor so that a warning is given to trains approaching the warning board.




D.2.4.6 On single and bi-directional lines, except where the arrangement in D.2.4.5 is

used, an AWS cancelling indicator shall:

a) Be provided.

b) Be positioned 180 m (200 yd) beyond the portable AWS equipment when travelling in the direction for which the warning is not applicable (see Figures D-17 and D-18). This distance shall be adjusted to avoid conflict with other equipment so that the AWS cancelling indicator is positioned between 4 and 7 seconds running time from the AWS equipment, subject to a minimum of 45 m (50 yd).

D.2.4.7 On single or bi-directional lines:

a) The AWS permanent magnet and its AWS cancelling indicator shall not be positioned between a signal or a sign (that apply to movements in the same direction as the AWS cancelling indicator), and the AWS equipment associated with that signal or sign.

b) The warning board shall be positioned accordingly (see Figures D-17 and D-18).

90

20

90

# #

Figure D-17 Example showing use of AWS cancelling indicator (D.2.4.6 / D.2.4.7)

90

20

90

# #

Figure D-18 Another example showing use of AWS cancelling indicator (D.2.4.6 / D.2.4.7)

GN229 Because it is not practicable to provide suppression for a temporary AWS magnet on a single or bi-directional line, the restrictions set out in GE/RT8075, (which normally apply to the use of AWS cancelling indicators) are not applicable, and a cancelling indicator should be provided for movements in the opposite direction (see D.2.4.6 and D.2.4.7).

GN230 Where use of existing AWS equipment is not practicable, the position of the AWS magnet (and therefore the warning board) is dictated by the positioning of the cancelling indicator, which should not conflict with other AWS indications, signals or signs.

GN231 Temporary AWS magnets or cancelling indicators should not be located between a signal or sign that applies to movements in the same direction as the AWS cancelling indicator (that is to say, in the opposite direction to movements to which the temporary speed restriction warning board applies) and the AWS equipment associated with that signal or sign. This is because passing a cancelling indicator after receiving a valid AWS indication could mislead the driver.




GN232 Figure D-17 shows a situation where the required deceleration distance places the warning board at a position which allows the temporary AWS magnet and cancellation indicator to be positioned before the existing AWS magnet associated with the signal. This is an acceptable arrangement.

GN233 The distance between the temporary speed restriction warning board and the temporary AWS magnet, and between the temporary AWS magnet and the cancellation indicator, shown by ‘#’ in Figures D-17 and D-18, should both normally be 180 m, but could be reduced, as set out in D.2.4.

GN234 Where the required deceleration distance would place the warning board too close to the signal to permit the arrangement shown in Figure D-17 to be used, the warning board should be positioned as shown in Figure D-18. This allows the temporary AWS magnet to be located beyond the signal for a move towards the cancellation indicator.

GN235 The warning board should not be positioned between the locations shown in Figures D-17 and D-18.

D.2.4.8 Where the deceleration distance means that a warning board is to be positioned

on a line not fitted with AWS, between a junction leading onto an AWS fitted line and the protecting signal, the warning board shall be positioned at the signal and provided with its own portable AWS equipment (see Figure D-19). In this case the WON shall specify:

‘Warning Board positioned at signal no. ___ on ___ line applies to trains proceeding towards the ___ line. An AWS warning indication will be given irrespective of the aspect exhibited by the signal.’

20

#

40

110

20

> DD 40 – 20

DD 110 – 20

Unfitted

Fitted

#

30

40

30

110 20

20

Unfitted

Figure D-19 Example showing provision of a warning board on an unfitted line leading to a fitted line (D.2.4.8)

GN236 Where it is necessary to position a warning board on a line not fitted with AWS for a

temporary speed restriction that only applies to an adjacent fitted line, and an AWS magnet for movements to the fitted line is provided beyond the signal in accordance with GE/RT8075, the warning board is normally located adjacent to the signal with a separate temporary AWS magnet on the approach.

GN237 The arrangements are similar to those in D.2.3.3. All trains should receive a warning at the AWS magnet, whether or not they are proceeding towards the temporary speed restriction, the applicability of which is indicated by the arrow on the warning board.




D.2.4.9 Where the deceleration distance means that a warning board is required on an AWS fitted line 4 to 7 seconds running time beyond a crossover from an unfitted line, where AWS equipment is provided ahead of the signal for trains proceeding onto the fitted line, all the following arrangements shall apply (see Figure D-20):

a) The existing AWS equipment shall be re-configured so that a caution indication is provided in the driving cab.

b) A permanent magnet shall not be provided.


‘The AWS magnet for signal no. ___ on ___ line will give an AWS warning indication for trains proceeding towards the warning board on ___ line at ___ miles ___ chains irrespective of the aspect exhibited by the signal.’

#

40

110

20DD 110 – 20

Unfitted

Fitted

30

40

30

110

Unfitted

#Disconnect electro-magnet

Figure D-20 Example showing disconnection of AWS in advance of protecting signal leading to a fitted line (D.2.4.9)

GN238 In the case where the warning board is located just beyond the junction from the unfitted

line to the fitted line, it is permissible to disconnect the electromagnet of the AWS magnet, which is provided beyond the signal for movements to the fitted line in accordance with GE/RT8075, so that this gives a warning for the TSR warning board irrespective of the aspect shown by the signal. In this case the normal arrangements for suppression of this AWS magnet for a train proceeding along the unfitted route continues to apply, so that the warning is only received for trains travelling towards the temporary speed restriction.

GN239 The conditions associated with disconnecting the electromagnet at the AWS equipment associated with a signal, as set out in D.2.4.6, also apply in this case.

D.2.5 Repeater warning boards

D.2.5.1 A repeater warning board, showing the restricted speed shall be provided where:

a) The deceleration distance means that the warning board is positioned on the approach to a passenger station, or on a bay platform line or siding, and

b) The associated speed indicator is positioned at least 300 m beyond the station or siding connection.

D.2.5.2 Each repeater warning board shall be configured as shown in Figure D-21 and positioned so that it is visible to drivers before trains start from rest.

D.2.5.3 Repeater warning boards shall be provided from any other line where trains always start from rest.

D.2.5.4 AWS permanent magnets shall not be provided for repeater warning boards.




D.2.5.5 Where repeater warning boards are provided, the WON shall specify either:

‘Repeater warning board positioned ahead of ___ station, for temporary speed restriction on the ___ line commencing at ___ miles ___ chains.’ or

‘Repeater warning board positioned at signal no. ___, for temporary speed restriction on the ___ line commencing at ___ miles ___ chains.’

90

20

90 20

20 MAIN LINE

PLATFORM LOOP

GOODS LOOP SIDING

R

R

R

> 300 m

R

20

20

20

20

Figure D-21 Example showing use of repeater warning boards (D.2.5.2)

GN240 Where trains may start from a station or siding situated between the warning board and the commencement of a temporary speed restriction, repeater warning boards, showing the restricted speed (or the ‘spate’ symbol if the speed restriction has been lifted or not imposed), are provided to remind the driver of a train starting from that location of the temporary speed restriction ahead, while avoiding giving multiple warnings to a through train which has already passed the normal warning board.

GN241 Section 3.4.1.4 states that repeater warning boards are not required on lines where trains always start from rest at a distance of less than 300 m from the commencement of the temporary speed restriction.

GN242 The ‘R’ is placed above the speed numeral to enhance drivability. With repeater boards located just beyond platform ramps, the previous arrangement of speed numeral over ‘R’ resulted in drivers seeing the speed first. This could be mistaken for the commencement of the TSR.

D.3 Requirements for adjacent temporary speed restrictions

D.3.1 Where a lower speed is followed by a higher speed

D.3.1.1 Where a temporary speed restriction is immediately followed by another temporary speed restriction with a higher speed all of the following arrangements shall apply (see Figure D-22):

a) A speed indicator for the higher temporary speed restriction shall be positioned at the end of the lower speed restriction.

b) A termination indicator shall not be provided for the lower temporary speed restriction.

c) A warning board shall not be provided for the higher temporary speed restriction.




d) The WON shall specify:

‘No warning board for ___ mph speed restriction on ___ line commencing at ___ miles ___ chains.’

90

TT

90 20 20 50 90

5090

505020

DD 90 – 20 DD 90 – 50

20

(extended 50)

Commencement of work

Figure D-22 Example of a lower TSR followed by a higher TSR (D.3.1.1)

GN243 Where one temporary speed restriction is followed by another which is a higher speed,

there is no requirement for a warning board for the second (higher) speed restriction as trains will already be travelling at the lower speed.

GN244 The second (higher) speed restriction should be extended to commence at the termination of the preceding lower speed restriction, so that the speed restriction board for the higher speed restriction can be located at the end of the lower restriction.

D.3.2 Where a higher speed is followed by a lower speed

D.3.2.1 Where the deceleration distance means that the warning board for a temporary speed restriction falls within or before a higher temporary speed restriction all of the following arrangements shall apply (see Figures D-23 and D-24):

a) The higher temporary speed restriction shall be extended to terminate at the commencement of the lower temporary speed restriction.

b) A termination indicator for the first temporary speed restriction shall not be provided.

c) The warning board for the second restriction, if this is within the higher temporary speed restriction, shall be positioned at the deceleration distance calculated using the speed of the first temporary speed restriction (rather than the permissible speed of the line).

T T

(extended 40)

DD 90 – 40 DD 90 – 20 DD 40 – 20

40 40 20 20 20

20409090 40 90

Figure D-23 Example of a higher TSR followed by a lower TSR (D.3.2.1)

TT

(extended 40)

DD 40 – 20DD 90 – 20DD 90 – 40

90 90

40 20

90

40

40

20 20

20 90

Figure D-24 Another example of a higher TSR followed by a lower TSR (D.3.2.1)

GN245 Where one temporary speed restriction is followed by another which is a lower speed, the

deceleration distance for the second (lower) speed restriction can be based on the speed of the preceding speed restriction, instead of the permissible speed of the line.




GN246 The warning board for the second speed restriction should be placed at this deceleration distance, and the first (higher) speed restriction should be extended so that it continues to the start of the following lower speed restriction. This means that trains do not accelerate from the speed of the first speed restriction before they reach the warning board for the following lower speed restriction.

D.3.3 Where warning boards coincide

D.3.3.1 Where two or more warning boards, for separate diverging routes or successive speed restrictions on the same line, are calculated to fall within 4 seconds running time of each other:

a) The warning boards shall be positioned so that the AWS magnet for the second warning board is positioned immediately after the first warning board in the direction of travel.

b) A separate AWS magnet shall be provided for each warning board.

c) The AWS magnet for each warning board shall be positioned in accordance with D.2.4.

GN247 The two warning boards should, where practicable, be positioned to allow the AWS magnets to be positioned at the standard distance of 180 m on the approach to each warning board. This would require the two warning boards to be 180 m apart.

GN248 Where this is not practicable, the constraints on positioning the AWS magnets in D.2.4 apply. This means that the spacing between the two warning boards should allow for the required minimum distance between the second warning board and its associated AWS magnet, and therefore is not less than 4 seconds running time, subject to a minimum of 45 m (50 yd).

GN249 To achieve this spacing, one (and in some cases both) of the warning boards should be positioned at a distance greater than the required deceleration distance from the speed indicator.

GN250 To avoid driver confusion, it is not permissible to place the warning boards closer together than the minimum distance required between the second warning board and its associated AWS magnet, or to provide only one AWS magnet for the two warning boards.

D.3.3.2 Where the conditions of D.3.3.1 apply to speed restrictions on diverging routes (see Figure D-25):

a) The warning board for the straight route shall be positioned so that the driver passes it first.

b) In the case of the divergence the WON shall specify:

‘The second warning board and associated AWS warning indication on ___ line at ___ miles ___ chains apply only to trains proceeding to ___ line.’

DD 90 – 20 DD 90 – 30

90

20

90

30

#

20

20

30

30

> 45 m (50 yd)

Figure D-25 Example of co-incident warning boards for diverging routes (D.3.3.2)




GN251 Where temporary speed restrictions apply to different routes at a junction, the warning board for the diverging route is placed closer to the junction and positioned at the required deceleration distance.

GN252 If the required deceleration distance for the warning board for the straight route would place it within 4 seconds running time of the warning board for the diverging route (this may be before or after the warning board for the diverging route), it should be positioned on the approach to the warning board for the diverging route, at a sufficient distance to allow the appropriate positioning of the AWS magnet for the second warning board.

GN253 Where the required deceleration distance for the warning board for the straight route would place it more than 4 seconds running time, but less than 180 m, from the warning board for the diverging route, it is permissible to place it at the correct deceleration distance. The AWS magnet for the second warning board would then require to be positioned after passing the first warning board, which means it would be at less than the standard distance of 180 m. Where practicable, the warning board for the straight route should be placed at a greater distance to permit the AWS magnet for the second warning board to be placed at the standard distance of 180 m.

D.3.3.3 Where the conditions of D.3.3.1 apply to successive speed restrictions on the same line, the warning boards shall be positioned in the order in which the speed restrictions are approached (see Figure D-26).

> DD 90 – 30 for TSR(1)

90

20

90

30

#

30 20

20

30

30

DD 90 – 20 for TSR(2)DD 90 – 30 for TSR(1)

> 45 m (50 yd)

Figure D-26 Example of successive speed restrictions on the same line (D.3.3.3)

GN254 In the example shown in Figure D-26, the required deceleration distance for the first (higher) speed restriction would place its warning board beyond the warning board for the second (lower) speed restriction. To provide a logical presentation of information to the driver, the warning board for the first speed restriction is placed on the approach to the warning board for the second speed restriction, with the AWS for the second warning board positioned immediately after the first warning board.

D.4 Altering temporary speed restrictions D.4.1 Moving temporary speed restriction limits

D.4.1.1 It is permissible for the limits of a temporary speed restriction to be moved progressively along a line, provided that the commencement is not moved towards drivers in the direction of travel. Both of the following arrangements shall apply:

a) The speed indicator and termination indicator shall be repositioned as the worksite is moved, and the warning board shall be repositioned at deceleration distance from the repositioned speed indicator.

b) The WON shall specify:

‘Moving temporary speed restriction.’

GN255 Where the worksite moves along the line in the direction of signalled movements, the temporary speed restriction can move with the worksite. The speed indicator is then repositioned as the worksite is moved, and the warning board repositioned accordingly, so that it is still at deceleration distance from the repositioned speed indicator.




GN256 A temporary speed restriction is not moved towards approaching trains, to avoid drivers being conditioned into anticipating a previous commencement location and approaching the new position of the commencement indicator at too high a speed.

GN257 On bi-directional and single lines this means that the speed indicators and warning boards should be set out for the total length of the temporary speed restriction, those for one direction being moved in the direction of traffic as the worksite changes with those for the other direction remaining in the same position. Alternatively, if the worksite contracts from both ends, it is permissible for both sets to be moved in the direction of traffic.

D.4.1.2 If it is not practicable to reposition the warning board (see Figure D-27):

a) The speed indicator and associated warning indicator shall remain in the original position.

b) The termination indicator shall be repositioned so that it indicates the end of the temporary speed restriction at all times.

90 90 20 90 20

20 20

Moving speed restriction Tunnel

Cannot be moved inside tunnel

Speed indicator must remain

right in its original position

T

T

(with restricted clearance)

due to limited clearance

Figure D-27 Example showing a moving TSR where the warning board cannot be moved (D.4.1.2)

GN258 In the case shown in Figure D-27, although the worksite is to be moved along the line in

the direction of travel, the warning board cannot be moved to a new position because of the restricted clearance tunnel. If the speed indicator was moved with the warning board remaining in the same position, this could be confusing to drivers, who might think they had missed the speed indicator, or might assume that the temporary speed restriction had been removed and the warning board left in error.

GN259 To avoid potential confusion, therefore, if the warning board cannot be moved to the appropriate new position, the speed indicator should also be left in the same position even though the start of the actual worksite has moved.

D.4.2 Withdrawing and increasing speeds of temporary speed restrictions

D.4.2.1 If the implementation of a temporary speed restriction is published or notified, and then its speed is raised earlier than planned, the speed indicators, warning boards and repeater warning boards shall:

a) Remain in the same position until the published time and date for their removal, and

b) Be altered to show the higher speed.

GN260 If the speed of a temporary speed restriction can be raised earlier than planned, and

therefore no change to the arrangements has been published in the WON, it is permissible for the speed indicator and warning board to be altered to show the higher speed.




GN261 The raising of the speed would generally require a shorter deceleration distance, which would allow the warning board to be moved closer to the commencement of the speed restriction. However, drivers do not expect any change to the existing arrangement, and if they no longer see a warning board in the expected position, they could assume that the restriction has been removed. To avoid confusion, the warning board should remain in the original position, even though this provides excess deceleration distance for the higher speed.

D.4.2.2 If a temporary speed restriction is published or notified but then does not need to be imposed, or if it is withdrawn earlier than shown in the WON, the speed indicators, warning boards and repeater warning boards, where required, shall:

a) Be erected or retained in the published position, unless a Special Notice cancelling the restriction is issued at least 24 hours before the temporary speed restriction is planned to commence.

b) Where erected or retained, be altered to show the permissible speed of the line or ‘Spate’ indications (see Figure D-28).

Figure D-28 Example of a TSR not imposed or withdrawn early (D.4.2.2)

GN262 If the speed of a temporary speed restriction can be removed earlier than expected, or

does not need to be imposed after details have been published, drivers expect to see the warning board and speed indicator. If the warning board and speed indicator have been removed, they would be expected to assume that the restriction still applies as published, and to report that the board as missing.

GN263 Therefore, the warning board, speed indicator and any repeater warning boards should remain in the published position, but altered to show either the permissible speed or a ‘Spate’ indication (an indicator showing a single diagonal black line which informs the driver that the planned temporary speed restriction does not apply).

D.4.2.3 Where temporary speed restrictions adjoin (see D.3), the first temporary speed restriction shall only be relaxed or removed, which will leave an adjoining restriction in place, when:

a) The warning boards for the remaining temporary speed restriction have been repositioned to take account of the change, and

b) Amended details have been published in the WON.

GN264 Where adjacent temporary speed restrictions have been implemented, as set out in D.3.1 and D.3.2, removal of the first speed restriction, or raising its speed, would result in inadequate deceleration distance for the remaining restriction, since this could now be approached at the normal permissible speed of the line.




GN265 The first speed restriction should therefore remain in place unless revised arrangements for the remaining restriction, including the appropriate positioning of the warning board, have been published and implemented.




Appendix E Emergency Speed Restrictions

The content of this appendix is mandatory.

E.1 Management of emergency speed restrictions

E.1.1 A temporary speed restriction shall be implemented as an emergency speed restriction if:

a) It has not been published in the WON.

b) It has only been published in an amendment to the WON.

c) The actual speed restriction is slower than the speed details published in the WON, or

d) The speed restriction applies at a time that is different to the details published in the WON.

E.1.2 The infrastructure manager shall consistently communicate details of all emergency speed restrictions to the drivers of all railway undertakings that operate over the route.

E.1.3 An emergency speed restriction shall be managed as a temporary speed restriction only after the correct details have been published in the WON.

GN266 If a temporary speed restriction (including a variation to a published temporary speed

restriction) has to be imposed at short notice, for example because of an incident affecting the condition of the line, drivers will not have been advised through the WON. Although measures should be taken to advise drivers of the speed restriction, it cannot be assumed that drivers are aware of it. It is therefore necessary to manage such a restriction as an emergency speed restriction.

E.2 Provision of speed indicators, warning boards and AWS equipment

E.2.1 Emergency speed restrictions shall be implemented as temporary speed restrictions, in accordance with the requirements of this standard, except that a risk assessment is not required for the disconnection of an AWS electromagnet at a signal.

E.2.2 In addition, an emergency indicator shall be positioned:

a) On the approach to the AWS permanent magnet for the warning board.

b) Not less than 180 m (200 yd) before the warning board.

c) Not further than 400 m (440 yd) before the warning board.

E.2.3 An AWS permanent magnet shall be positioned on the approach to the emergency indicator (see Figure E-1).

GN267 To draw drivers’ attention to an emergency speed restriction of which they may be unaware, an emergency indicator, with an additional AWS permanent magnet, is positioned on the approach to the AWS magnet for the warning board. The AWS warning indication is intended to alert them to the presence of the emergency indicator. On observing the emergency indicator, they are reminded that particular attention should be given to the following warning board.




GN268 The erection of signs and the consequent need for trains to continue to be cautioned would be delayed by the requirement to carry out a risk assessment before the AWS magnet associated with a signal is disconnected. A risk assessment is still required when or if the ESR is changed to a TSR.

E.2.4 The emergency indicator and associated permanent magnet shall remain in place until either:

a) The relevant details have been published in the WON, or

b) The speed restriction has been withdrawn.

90 90

20

#

90

# max 400 m

(440 yd)

Emergency indicator shown

positioned at minimum

distance from warning board

Figure E-1 Example of arrangements for emergency speed restriction (E.2.2)

GN269 Unless it is withdrawn, the speed restriction should remain signed as an emergency speed

restriction until the details have been published in the WON, when the emergency indicator and additional AWS magnet can be removed, leaving the restriction signed as a normal temporary speed restriction.

GN270 Although other methods may be employed to advise drivers of an emergency speed restriction, such as communication to the railway undertakings, who should pass the information on to drivers, or publication of a supplementary operating notice, these alternative means of communication do not have the same level of control as the WON to ensure that all drivers have received and understood them. Therefore, even when these other methods have been used to advise drivers, the speed restriction should still be signed as an emergency speed restriction until the details have been published in the regular WON.




Appendix X Deceleration Distances


GRADIENT (mm/m) Initial Speed 1 in 50 1 in 67 1 in 100 1 in 200 1 in 400 Level 1 in 400 1 in 200 1 in 100 1 in 67 1 in 50

(mph) 20R 15R 10R 5R 2.5R 2.5F 5F 10F 15F 20F 10 20 155 165 180 200 210 220 238 255 295 365 402 25 220 235 260 290 303 325 345 375 402 422 523 30 295 315 350 390 402 402 412 422 523 644 770 35 375 402 402 443 473 503 553 604 744 986 1305 40 402 443 503 583 643 704 784 865 1066 1408 2012 45 523 604 664 785 845 905 995 1086 1267 1569 2046

50 523 604 664 785 845 905 995 1086 1267 1569 2046

55 602 652 710 785 845 905 995 1086 1267 1569 2046

60 716 776 845 929 980 1032 1097 1162 1329 1569 2046

65 775 838 910 996 1049 1102 1168 1234 1428 1730 2046

70 862 929 1004 1096 1150 1205 1276 1348 1520 1740 2046

75 945 984 1084 1164 1215 1258 1320 1382 1534 1740 2046 80 945 984 1084 1164 1215 1258 1320 1382 1534 1740 2046 85 1040 1102 1171 1251 1309 1354 1415 1471 1614 1788 2046

90 1173 1246 1325 1419 1484 1537 1610 1674 1842 2049 2330

95 1325 1409 1502 1612 1680 1750 1835 1913 2113 2366 2713

100 1520 1621 1735 1870 1960 2041 2143 2245 2503 2835 3312

105 1520 1621 1735 1870 1960 2041 2143 2245 2503 2835 3312

110 1520 1621 1735 1870 1960 2041 2143 2245 2503 2835 3312

115 1520 1621 1735 1870 1960 2041 2143 2245 2503 2835 3312

120 1574 1643 1735 1870 1960 2041 2143 2245 2503 2835 3312

125 1702 1777 1856 1944 1998 2052 2143 2245 2503 2835 3312

Gradients are shown as ‘R’ for rising and ‘F’ for falling.

Table X-1 Deceleration distance in metres to speed restriction of 10 mph





(mph) 20R 15R 10R 5R 2.5R 2.5F 5F 10F 15F 20F 20 25 220 235 260 290 303 325 345 375 402 402 402 30 295 315 350 390 402 402 402 402 443 543 805 35 375 402 402 402 422 443 483 523 664 885 1267 40 402 402 463 523 573 624 694 764 986 1287 1811 45 483 543 604 704 764 825 925 1026 1207 1489 1971 50 483 543 604 704 764 825 925 1026 1207 1489 1971 55 560 607 662 729 777 825 925 1026 1207 1489 1971 60 674 733 799 880 929 979 1042 1105 1268 1489 1971 65 736 796 866 950 1001 1052 1116 1180 1345 1650 2046 70 826 890 964 1053 1106 1160 1225 1291 1489 1740 2046 75 886 966 1046 1147 1207 1258 1320 1382 1534 1740 2046 80 891 966 1046 1147 1207 1258 1320 1382 1534 1740 2046 85 1013 1075 1143 1222 1275 1328 1398 1469 1609 1788 2046 90 1147 1218 1297 1389 1449 1509 1589 1670 1842 2049 2330 95 1298 1382 1473 1582 1656 1730 1820 1911 2113 2366 2713 100 1492 1593 1705 1838 1925 2012 2112 2213 2503 2835 3299 105 1492 1593 1705 1838 1925 2012 2112 2213 2503 2835 3299 110 1492 1593 1705 1838 1925 2012 2112 2213 2503 2835 3299 115 1492 1593 1705 1838 1925 2012 2112 2213 2503 2835 3299 120 1540 1608 1705 1838 1925 2012 2112 2213 2503 2835 3299 125 1670 1750 1831 1911 1971 2032 2122 2213 2503 2835 3299

Gradients are shown as ‘R’ for rising and ‘F’ for falling






(mph) 20R 15R 10R 5R 2.5R 2.5F 5F 10F 15F 20F 30 35 375 402 402 402 402 402 402 402 523 704 1066 40 402 402 402 422 472 523 593 664 825 1106 1609 45 402 443 523 624 694 765 845 925 1086 1348 1851 50 402 443 523 624 694 765 845 925 1086 1348 1851 55 480 522 570 630 700 770 847 925 1086 1348 1851 60 596 648 709 783 794 805 898 991 1142 1348 1851 65 661 717 781 860 892 925 1000 1075 1230 1529 1971 70 757 817 887 970 1008 1046 1121 1196 1408 1740 1971 75 845 905 986 1066 1126 1187 1285 1358 1534 1740 1971 80 845 905 986 1066 1126 1187 1285 1358 1534 1740 1971 85 964 1023 1089 1165 1216 1267 1312 1358 1549 1750 1971 90 1098 1166 1243 1331 1389 1448 1528 1609 1790 2012 2293 95 1248 1329 1418 1529 1589 1650 1740 1831 2052 2313 2655 100 1440 1538 1647 1777 1864 1951 2051 2152 2434 2796 3219 105 1440 1538 1647 1777 1864 1951 2051 2152 2434 2796 3219 110 1440 1538 1647 1777 1864 1951 2051 2152 2434 2796 3219 115 1440 1538 1647 1777 1864 1951 2051 2152 2434 2796 3219 120 1485 1550 1647 1777 1864 1951 2051 2152 2434 2796 3219 125 1613 1690 1770 1871 1921 1971 2061 2152 2434 2796 3219




(mph) 20R 15R 10R 5R 2.5R 2.5F 5F 10F 15F 20F 40 45 402 402 402 463 523 583 663 744 885 1106 1569 50 402 402 402 463 523 583 663 744 885 1106 1569 55 402 402 426 473 528 583 663 744 885 1106 1569 60 475 518 568 630 668 706 754 803 932 1107 1569 65 545 593 648 714 759 805 865 925 1086 1328 1811 70 648 702 763 845 886 927 996 1066 1247 1529 1831 75 744 805 885 966 1016 1066 1146 1227 1428 1609 1831 80 766 812 885 966 1016 1066 1146 1227 1428 1609 1831 85 887 943 1004 1086 1126 1167 1227 1287 1428 1609 1831 90 1021 1085 1158 1247 1307 1368 1438 1509 1670 1891 2152 95 1171 1247 1332 1431 1500 1569 1649 1730 1931 2193 2515 100 1359 1453 1556 1690 1770 1851 1961 2072 2334 2676 3098 105 1359 1453 1556 1690 1770 1851 1961 2072 2334 2676 3098 110 1359 1453 1556 1690 1770 1851 1961 2072 2334 2676 3098 115 1359 1453 1556 1690 1770 1851 1961 2072 2334 2676 3098 120 1428 1509 1569 1690 1770 1851 1961 2072 2334 2676 3098 125 1569 1629 1710 1811 1851 1891 1982 2072 2334 2676 3098







(mph) 20R 15R 10R 5R 2.5R 2.5F 5F 10F 15F 20F 50 55 402 402 402 402 402 402 402 402 402 422 664 60 402 402 402 409 435 461 494 528 617 740 1046 65 402 422 463 506 544 583 623 664 785 986 1428 70 523 563 604 664 704 744 804 865 1006 1247 1609 75 624 664 744 825 865 905 975 1046 1227 1428 1609 80 658 699 744 825 865 905 975 1046 1227 1428 1609 85 780 830 884 947 986 1026 1086 1147 1267 1428 1609 90 914 972 1046 1127 1177 1227 1287 1348 1509 1710 1931 95 1062 1133 1210 1308 1368 1428 1498 1569 1770 2012 2293 100 1246 1333 1448 1569 1639 1710 1810 1911 2152 2454 2877 105 1246 1333 1448 1569 1639 1710 1810 1911 2152 2454 2877 110 1246 1333 1448 1569 1639 1710 1810 1911 2152 2454 2877 115 1246 1333 1448 1569 1639 1710 1810 1911 2152 2454 2877 120 1368 1428 1489 1569 1639 1710 1810 1911 2152 2454 2877 125 1489 1549 1629 1710 1760 1811 1861 1911 2152 2454 2877




(mph) 20R 15R 10R 5R 2.5R 2.5F 5F 10F 15F 20F 60 65 402 402 402 402 402 402 402 402 402 483 724 70 402 402 402 422 442 463 503 543 644 825 1267 75 463 503 543 583 613 644 704 764 905 1147 1267 80 523 551 586 628 653 678 721 764 905 1147 1267 85 640 682 728 780 810 841 877 914 1026 1147 1267 90 774 824 880 945 985 1026 1076 1127 1267 1428 1650 95 921 983 1050 1130 1178 1227 1297 1368 1529 1730 2012 100 1106 1187 1287 1388 1458 1529 1619 1710 1911 2213 2575 105 1106 1187 1287 1388 1458 1529 1619 1710 1911 2213 2575 110 1106 1187 1287 1388 1458 1529 1619 1710 1911 2213 2575 115 1127 1187 1287 1388 1458 1529 1619 1710 1911 2213 2575 120 1267 1308 1368 1428 1478 1529 1619 1710 1911 2213 2575 125 1388 1448 1509 1589 1629 1670 1720 1770 1911 2213 2575







(mph) 20R 15R 10R 5R 2.5R 2.5F 5F 10F 15F 20F 70 75 402 402 402 402 402 402 402 402 443 583 925 80 402 402 402 418 434 450 469 489 536 590 925 85 483 503 530 570 597 624 646 668 732 808 925 90 600 644 682 744 774 805 834 863 966 1086 1247 95 745 805 851 925 965 1006 1056 1106 1247 1408 1609 100 945 1006 1086 1187 1237 1287 1367 1448 1629 1871 2193 105 945 1006 1086 1187 1237 1287 1367 1448 1629 1871 2193 110 945 1006 1086 1187 1237 1287 1367 1448 1629 1871 2193 115 1006 1046 1086 1187 1237 1287 1367 1448 1629 1871 2193 120 1147 1187 1247 1308 1338 1368 1408 1448 1629 1871 2193 125 1267 1328 1388 1448 1488 1529 1569 1609 1690 1871 2193



GRADIENT (mm/m)

Initial Speed 1 in 50 1 in 67 1 in 100 1 in 200 1 in 400 Level 1 in 400 1 in 200 1 in 100 1 in 67 1 in 50 (mph) 20R 15R 10R 5R 2.5R 2.5F 5F 10F 15F 20F

80 85 402 402 402 402 402 402 402 402 402 402 422 90 402 422 445 478 497 517 540 564 619 685 770 95 563 583 624 664 688 712 748 785 865 966 1106 100 744 785 845 905 955 1006 1056 1106 1247 1428 1650 105 744 785 845 905 955 1006 1056 1106 1247 1428 1650 110 764 785 845 905 955 1006 1056 1106 1247 1428 1650 115 865 905 945 986 1006 1026 1056 1106 1247 1428 1650 120 1006 1046 1086 1127 1157 1187 1217 1247 1308 1428 1650 125 1127 1167 1227 1287 1317 1348 1378 1408 1489 1569 1670



GRADIENT (mm/m)


90 95 402 402 402 402 402 402 402 402 422 463 523

100 503 523 563 604 634 664 694 724 825 925 1086 105 503 523 563 604 634 664 694 724 825 925 1086 110 604 624 644 664 674 684 704 724 825 925 1086 115 704 744 764 805 815 825 845 865 905 966 1086 120 845 865 905 945 965 986 1006 1026 1086 1147 1207 125 966 1006 1046 1106 1126 1147 1177 1207 1267 1328 1408






GRADIENT (mm/m)


100 105 110 402 412 422 443 453 463 468 473 493 513 533 115 523 543 563 583 593 604 614 624 654 684 724 120 644 664 694 724 739 754 774 795 825 865 905 125 785 805 835 865 885 905 930 956 1006 1056 1106



The following Guidance Note Tables (X-11 - X-20) present the corresponding deceleration distances in yards for the data set out in Tables X-1 - X-10 above.

GRADIENT

Initial Speed 1 in 50 1 in 67 1 in 100 1 in 200 1 in 400 Level 1 in 400 1 in 200 1 in 100 1 in 67 1 in 50 (mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F

10 20 170 180 195 215 228 240 258 275 320 395 440 25 240 255 280 315 335 355 383 410 440 461 572 30 320 340 380 425 440 440 451 461 572 704 968 35 405 440 440 484 517 550 605 661 814 1078 1540 40 440 484 550 638 703 770 857 946 1166 1540 2200 45 572 661 726 858 924 990 1088 1188 1386 1716 2237 50 572 661 726 858 924 990 1088 1188 1386 1716 2237 55 658 713 776 858 924 990 1088 1188 1386 1716 2237 60 783 849 924 1016 1072 1129 1200 1271 1453 1716 2237 65 848 916 995 1089 1147 1205 1277 1350 1562 1892 2237 70 943 1016 1098 1199 1258 1318 1395 1474 1660 1903 2237 75 1033 1076 1185 1273 1324 1375 1443 1511 1677 1903 2237 80 1033 1076 1185 1273 1324 1375 1443 1511 1677 1903 2237 85 1137 1205 1281 1368 1430 1481 1545 1609 1765 1956 2237 90 1283 1363 1449 1552 1321 1681 1756 1831 2014 2241 2548 95 1449 1541 1643 1763 1838 1914 2003 2092 2311 2587 2967

100 1662 1773 1897 2045 2144 2232 2343 2455 2737 3100 3622 105 1662 1773 1897 2045 2144 2232 2343 2455 2737 3100 3622 110 1662 1773 1897 2045 2144 2232 2343 2455 2737 3100 3622 115 1662 1773 1897 2045 2144 2232 2343 2455 2737 3100 3622 120 1721 1797 1897 2045 2144 2232 2343 2455 2737 3100 3622 125 1861 1943 2030 2126 2185 2244 2343 2455 2737 3100 3622

Gradients are shown as ‘R’ for rising and ‘F’ for falling.

GN Table X-11 Deceleration distance in yards to speed restriction of 10 mph




GRADIENT Initial Speed 1 in 50 1 in 67 1 in 100 1 in 200 1 in 400 Level 1 in 400 1 in 200 1 in 100 1 in 67 1 in 50

(mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F 20 25 240 255 280 315 335 355 383 410 440 440 440 30 320 340 380 425 440 440 440 440 484 594 880 35 405 440 440 440 461 484 528 572 726 968 1386 40 440 440 506 572 627 682 759 836 1078 1407 1981 45 528 594 661 770 836 902 1012 1122 1320 1628 2155 50 528 594 661 770 836 902 1012 1122 1320 1628 2155 55 612 664 724 797 850 902 1012 1122 1320 1628 2155 60 737 802 874 962 1016 1071 1140 1208 1387 1628 2155 65 805 871 947 1039 1095 1150 1220 1290 1471 1804 2237 70 903 973 1054 1152 1210 1269 1340 1412 1628 1903 2237 75 969 1056 1144 1254 1320 1375 1443 1511 1677 1903 2237 80 974 1056 1144 1254 1320 1375 1443 1511 1677 1903 2237 85 1108 1176 1250 1336 1394 1452 1529 1606 1765 1956 2237 90 1254 1332 1418 1519 1585 1650 1738 1826 2014 2241 2548 95 1419 1511 1611 1730 1811 1892 1990 2090 2311 2587 2697 100 1632 1742 1865 2010 2105 2200 2310 2420 2737 3100 3608 105 1632 1742 1865 2010 2105 2200 2310 2420 2737 3100 3608 110 1632 1742 1865 2010 2105 2200 2310 2420 2737 3100 3608 115 1632 1742 1865 2010 2105 2200 2310 2420 2737 3100 3608 120 1684 1759 1865 2010 2105 2200 2310 2420 2737 3100 3608 125 1826 1914 2002 2090 2155 2222 2321 2420 2737 3100 3608







(mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F 30 35 405 440 440 440 440 440 440 440 572 770 1166 40 440 440 440 461 516 572 649 726 902 1210 1760 45 440 484 572 682 759 837 924 1012 1188 1474 2024 50 440 484 572 682 759 837 924 1012 1188 1474 2024 55 525 571 623 689 766 842 926 1012 1188 1474 2024 60 652 709 775 856 868 880 982 1084 1249 1474 2024 65 723 784 854 940 975 1012 1094 1176 1345 1672 2155 70 828 893 970 1061 1102 1144 1226 1308 1540 1903 2155 75 924 990 1078 1166 1231 1298 1405 1485 1677 1903 2155 80 924 990 1078 1166 1231 1298 1405 1485 1677 1903 2155 85 1054 1119 1191 1274 1330 1386 1435 1485 1694 1914 2155 90 1201 1275 1359 1456 1519 1584 1671 1760 1958 2200 2508 95 1365 1453 1551 1672 1738 1804 1903 2002 2244 2529 2904 100 1575 1682 1801 1943 2038 2134 2243 2353 2662 3058 3520 105 1575 1682 1801 1943 2038 2134 2243 2353 2662 3058 3520 110 1575 1682 1801 1943 2038 2134 2243 2353 2662 3058 3520 115 1575 1682 1801 1943 2038 2134 2243 2353 2662 3058 3520 120 1624 1695 1801 1943 2038 2134 2243 2353 2662 3058 3520 125 1764 1848 1936 2046 2101 2155 2254 2353 2662 3058 3520




(mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F 40 45 440 440 440 506 572 638 725 814 968 1210 1716 50 440 440 440 506 572 638 725 814 968 1210 1716 55 440 440 466 517 577 638 725 814 968 1210 1716 60 519 566 621 689 731 772 825 878 1019 1211 1716 65 596 649 709 781 830 880 946 1012 1188 1452 1981 70 709 768 834 924 969 1014 1089 1166 1364 1672 2002 75 814 880 968 1056 1111 1166 1253 1342 1562 1760 2002 80 838 888 968 1056 1111 1166 1253 1342 1562 1760 2002 85 970 1031 1098 1188 1231 1276 1342 1407 1562 1760 2002 90 1117 1187 1266 1364 1429 1496 1573 1650 1826 2068 2353 95 1281 1364 1457 1565 1640 1716 1803 1892 2112 2398 2750 100 1486 1589 1702 1848 1936 2024 2145 2266 2552 2926 3388 105 1486 1589 1702 1848 1936 2024 2145 2266 2552 2926 3388 110 1486 1589 1702 1848 1936 2024 2145 2266 2552 2926 3388 115 1486 1589 1702 1848 1936 2024 2145 2266 2552 2926 3388 120 1562 1650 1716 1848 1936 2024 2145 2266 2552 2926 3388 125 1716 1781 1870 1981 2024 2068 2167 2266 2552 2926 3388







(mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F 50 55 440 440 440 440 440 440 440 440 440 461 726 60 440 440 440 447 476 504 540 577 675 809 1144 65 440 461 506 553 595 638 681 726 858 1078 1562 70 572 616 661 726 770 814 879 946 1100 1364 1760 75 682 726 814 902 946 990 1066 1144 1342 1562 1760 80 720 764 814 902 946 990 1066 1144 1342 1562 1760 85 853 908 967 1036 1078 1122 1188 1254 1386 1562 1760 90 1000 1063 1144 1232 1287 1342 1407 1474 1650 1870 2112 95 1161 1239 1323 1430 1496 1562 1638 1716 1936 2200 2508 100 1363 1458 1584 1716 1792 1870 1979 2090 2353 2684 3146 105 1363 1458 1584 1716 1792 1870 1979 2090 2353 2684 3146 110 1363 1458 1584 1716 1792 1870 1979 2090 2353 2684 3146 115 1363 1458 1584 1716 1792 1870 1979 2090 2353 2684 3146 120 1496 1562 1628 1716 1792 1870 1979 2090 2353 2684 3146 125 1628 1694 1781 1870 1925 1981 2035 2090 2353 2684 3146




(mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F 60 65 440 440 440 440 440 440 440 440 440 528 792 70 440 440 440 461 483 506 550 594 704 902 1386 75 506 550 594 638 670 704 770 836 990 1254 1386 80 572 603 641 687 714 741 788 836 990 1254 1386 85 700 746 796 853 886 920 959 1000 1122 1254 1386 90 846 901 962 1033 1077 1122 1177 1232 1386 1562 1804 95 1007 1075 1148 1236 1288 1342 1418 1496 1672 1892 2200 100 1210 1298 1407 1518 1594 1672 1771 1870 2090 2420 2816 105 1210 1298 1407 1518 1594 1672 1771 1870 2090 2420 2816 110 1210 1298 1407 1518 1594 1672 1771 1870 2090 2420 2816 115 1232 1298 1407 1518 1594 1672 1771 1870 2090 2420 2816 120 1386 1430 1496 1562 1616 1672 1771 1870 2090 2420 2816 125 1518 1584 1650 1738 1781 1826 1881 1936 2090 2420 2816







(mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F 70 75 440 440 440 440 440 440 440 440 484 638 1012 80 440 440 440 457 475 492 513 535 586 645 1012 85 528 550 580 623 653 682 706 731 801 884 1012 90 656 704 746 814 846 880 912 944 1056 1188 1364 95 815 880 931 1012 1055 1100 1155 1210 1364 1540 1760 100 1033 1100 1188 1298 1353 1407 1495 1584 1781 2046 2398 105 1033 1100 1188 1298 1353 1407 1495 1584 1781 2046 2398 110 1033 1100 1188 1298 1353 1407 1495 1584 1781 2046 2398 115 1100 1144 1188 500 1353 1407 1495 1584 1781 2046 2398 120 1254 1298 1364 1430 1463 1496 1540 1584 1781 2046 2398 125 1386 1452 1518 1584 1627 1672 1716 1760 1848 2046 2398




(mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F 80 85 440 440 440 440 440 440 440 440 440 440 461 90 440 461 487 523 544 565 591 617 677 749 842 95 616 638 682 726 752 779 818 858 946 1056 1210 100 814 858 924 990 1044 1100 1155 1210 1364 1562 1804 105 814 858 924 990 1044 1100 1155 1210 1364 1562 1804 110 836 858 924 990 1044 1100 1155 1210 1364 1562 1804 115 946 990 1033 1078 1100 1122 1155 1210 1364 1562 1804 120 1100 1144 1188 1232 1265 1298 1331 1364 1430 1562 1804 125 1232 1276 1342 572 1440 1474 1507 1540 1628 1716 1826




(mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F

90 95 440 440 440 440 440 440 440 440 461 506 572 100 550 572 616 661 693 726 759 792 902 1012 1188 105 550 572 616 661 693 726 759 792 902 1012 1188 110 661 682 704 726 737 748 770 792 902 1012 1188 115 770 814 836 880 891 902 924 946 990 1056 1188 120 924 946 990 1033 1055 1078 1100 1122 1188 1254 1320 125 1056 1100 1144 1210 1231 1254 1287 1320 1386 1452 1540






GRADIENT

Initial Speed 1 in 50 1 in 67 1 in 100 1 in 200 1 in 400 Level 1 in 400 1 in 200 1 in 100 1 in 67 1 in 50 (mph) 2.0%R 1.5%R 1.0%R 0.5%R 0.25%R 0.25%F 0.5%F 1.0%F 1.5%F 2.0%F

100

105

110 440 451 461 484 495 506 512 517 539 561 583

115 572 594 616 638 649 661 671 682 715 748 792

120 704 726 759 792 808 825 846 869 902 946 990

125 858 880 913 946 968 990 1017 1045 1100 1155 1210






Appendix Y Key to Symbols Used in this Standard

Spate indicator

xx

xx

xx

DD yy–xx

yy/zz

Section of line showing (in upright type) permissible speed (xx mph) (in italics) temporary speed restriction (yy mph)

Section of line with differential temporary speed restriction (yy mph and zz mph)

Permissible speed indicator (xx indicates speed displayed)

Permissible speed warning indicator (xx indicates speed displayed)

Position of warning board at deceleration distance (DD) from speed indicator (for speed reduction from yy mph to xx mph)

AWS magnet for signal

yy

yy

T

Speed indicator marking commencement of temporary speed restriction (yy indicates speed displayed)

Termination indicator for temporary speed restriction

yy

Portable AWS magnet for temporary speed restriction (permanent magnet only)

Warning board for temporary speed restriction (yy indicates speed displayed)

Repeater warning board for temporary speed restriction

Emergency indicator (for emergency speed restriction)

#

AWS cancelling indicator

Distance between warning board and associated AWS equipment

xx

Section of line showing permissible speed (xx mph)

Section of line with differential permissible speeds (yy mph and zz mph)

P AWS magnet for permissible speed warning indicator (“P” indicates permanent magnet only)

GN271 There is no guidance associated with the above appendix.




Definitions

Actual signalling braking distance (ASD) The actual distance between a signal displaying the first cautionary aspect and the signal displaying the associated stop aspect.

Attainable speed (as applicable to this document)

The maximum speed that any permitted type of rolling stock can achieve over a specific section of line, where it is not possible for any rolling stock authorised to operate on the line to attain the permissible speed. Attainable speed can be used as the basis of deceleration distance calculations for temporary speed restrictions or to enable the driver to bring the train to a stand at a stop signal.

Deceleration distance

The minimum distance at which a warning indicator (for a permissible speed) or a warning board (for a temporary or emergency speed restriction) shall be positioned approaching the start of the change in speed to which it applies, in order to ensure that all trains have sufficient warning to be able to conform to the required reduction in speed.

Differential speed

A permissible speed or speed restriction applicable to a particular type of train, where different values of speed are applicable to different types of trains over the same section of line.

Differential speeds include:

a) Standard differential speed − Two values of permissible speed, or two different speed values for a temporary speed restriction, each of which is applicable to one of two standard categories of trains, as defined in the Rule Book.

b) Non-standard differential speed − A permissible speed for a specific type of train, which is different from that for other types of trains on the same section of line. This comprises ‘Permissible speed indicators with letters’ and ‘Enhanced permissible speed indicators’ as described in the Rule Book. Non-standard differential speeds are not applicable to temporary or emergency speed restrictions.

Emergency speed restriction

A speed restriction not shown in the Weekly Operating Notice (WON), or which is more restrictive than shown, or which applies at a time other than that shown in the WON.

Enhanced permissible speed

The permitted speed (higher than the permissible speed) over a section of line which applies to a specific type of train operating at cant deficiencies in excess of those permitted at the permissible speed (see GE/RT8012 and GC/RT5021).

Excess signal spacing The distance by which the actual signalling braking distance exceeds the minimum signalling braking distance.

Lineside operational safety sign

Lineside operational safety signs include speed indicators, warning indicators and emergency indicators, as depicted in GI/RT7033: Lineside Operational Safety Signs, Appendix A, sections AD, AE and AF.

Miniature permissible speed indicator

A reduced size indicator in accordance with GI/RT7033, Appendix A, sections AD and AE showing the permissible speed(s) over a section of line.




Minimum signalling braking distance (MSD) The calculated minimum distance between a signal displaying the first caution aspect and the signal displaying the associated stop aspect.

Overrun

Passing the end of movement authority (the end of movement authority is the point where a train is required to come to a stand on completion of a signalled movement). On lines signalled with lineside signals, the conventional terminology for an overrun is a signal passed at danger (SPAD). The definition includes both failure to come to a stand at a signal at danger and starting from rest against a signal at danger.

Permissible speed

The authorised maximum speed over a section of line, either for all trains or (where differential speeds are applied) for specific types of trains, as set out in the Sectional Appendix.

Permissible speed indicator

An indicator in accordance with GI/RT7033 showing the permissible speed(s) over a section of line.

Permissible speed warning indicator

An indicator in accordance with GI/RT7033 showing warning of a reduction of permissible speed over a section of line.

Signal

Throughout this document the word ‘signal’ shall be understood to include any lineside sign that performs the function of a signal.

Signalling braking distance (as applied to this document)

The distance between the signal exhibiting the first caution aspect and the signal at which the train is required to stop.

Spate indicator (Speed Previously Applied Terminated Early)

A trackside indicator which informs the driver that a temporary speed restriction has been withdrawn earlier than published or has not been applied.

Temporary speed restriction

A speed, less than the permissible speed, applied for a pre-planned period not normally exceeding six months.

Weekly Operating Notice (WON)

The Weekly Operating Notice (WON) is the official printed notice which includes advice to drivers of temporary speed restrictions and alterations to permissible speeds. GO/RT3215: Requirements for WON, PON and Sectional Appendix, details requirements for the format and contents of the WON.

Other defined terms are included in GK/GN0802: Glossary of Signalling Terms.




Abbreviations and Acronyms

ASD Actual signalling braking distance

AWS Automatic warning system

ESR Emergency speed restriction

ETCS European Train Control System

LUL London Underground Limited

MSD Minimum signalling braking distance

PSR Permanent speed restriction

PON Periodic Operating Notice

SPAD Signal passed at danger

Spate Speed Previously Applied Terminated Early

TSR Temporary speed restriction

TVM Transmission voice-machine

WON Weekly Operating Notice




References

The Catalogue of Railway Group Standards gives the current issue number and status of documents published by RSSB. This information is also available from www.rgsonline.co.uk.

RGSC 01 Railway Group Standards Code RGSC 02 Standards Manual

Documents referenced in the text

Railway Group Standards

GC/RT5021 Track System Requirements GE/RT8000 Rule Book GE/RT8012 Controlling the Speed of Tilting Trains Through Curves GE/RT8037 Signal Positioning and Visibility GE/RT8075 AWS and TPWS Interface Requirements GE/RT8270 Assessment of Compatibility of Rolling Stock and Infrastructure GI/RT7033 Lineside Operational Safety Signs GK/RT0045 Lineside Signals, Indicators, and Layout of Signals GK/RT0075 Lineside Signal Spacing and Speed Signage GM/RT2041 Braking System Requirements and Performance for Trailer Coaching

Stock GM/RT2042 Braking System Requirements and Performance for Traction Units GM/RT2043 Braking System and Performance for Freight Trains GM/RT2044 Braking System Requirements and Performance for Multiple Units GM/RT2045 Braking Principles for Rail Vehicles GO/RT3215 Requirements for the Weekly Operating Notice, Periodical Operating

Notice and Sectional Appendix RSSB documents

GK/GN0802 Glossary of Signalling Terms


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