Axle Counters : Code of Practice for Resetting and Restoration to Service

Transcription

1 Axle Counters : for Resetting and Restoration to Service Synopsis This gives the best practice requirements for the resetting and restoration to service of axle counters, in support of Railway Group Standard GK/RT0027. Signatures removed from electronic version Submitted by R. Genner Nominated Responsible Manager Authorised by Philip Wiltshire Chairman, Train Control & Communications Subject Committee Michael Harwood Chairman, Operations Standards Subject Committee This document is the property of Railtrack PLC. It shall not be reproduced in whole or in part without the written permission of the Controller, Railway Group Standards, Railtrack PLC. Published by Safety & Standards Directorate, Railtrack PLC, Floor 1, Railtrack House, Euston Square London NW1 2EE Copyright 1998 Railtrack PLC

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3 Axle Counters : Resetting and Restoration to Service Page 1 of 5 Contents Section Description Page Part A Issue Record 2 Responsibilities 2 Health and Safety Responsibilities 2 Supply 2 Part B 1 Purpose 3 2 Definitions 3 3 Requirements 3 RAILTRACK 1

4 Page 2 of 5 Withdrawn Document Axle Counters : Resetting and Restoration to Service Issue Record Part A This will be updated when necessary by distribution of a complete replacement. Amended or additional parts of revised pages will be marked by a vertical black line in the adjacent margin. Issue Date Comments One June 1998 Original Document. Text drawn from GK/RT0027 Distribution Controlled copies of this shall be made available to all personnel who are responsible for the design, testing & commissioning, maintenance and faulting of axle counter systems, and to personnel responsible for writing instructions (e.g. signal box instructions) relating to the resetting and restoring to service of axle counters. Health and Safety Responsibilities In issuing this, Railtrack PLC makes no warranties, express or implied, that compliance with all or any Railway Group Standards or Codes of Practice is sufficient on its own to ensure safe systems of work or operation. Each user is reminded of its own responsibilities to ensure health and safety at work and its individual duties under health and safety legislation. Supply Controlled and uncontrolled copies of this may be obtained from The Catalogue Secretary, Safety and Standards Directorate, Railtrack PLC, Floor 1 Railtrack House, Euston Square, London, NW1 2EE. Telephone Facsimile or (BT) or (BT) 2 RAILTRACK

5 Axle Counters : Resetting and Restoration to Service Page 3 of 5 1 Purpose Part B This supplements the application of Railway Group Standard GK/RT0027 to the resetting and restoration to service of Axle Counters which control signals, in order to achieve safe operation at initialisation, following failure, incorrect operating sequence, or maintenance disconnection. 2 Definitions It should be applied to all axle counters which require manual resetting and restoration to service, where the evaluator is separate from the signalling interlocking processor. Where the axle counter evaluator is an integral part of the signalling interlocking processor, suitable procedures should be prepared and implemented in compliance with this, taking account of the configuration of the system. Axle Counter A method of train detection. Track mounted equipment counts the number of axles entering and leaving a track section at each extremity. A calculation is performed to determine whether the track section is occupied or clear. Axle Counter Evaluator A unit that takes the outputs from the track mounted equipment at each end of the track section and determines whether the track section is occupied or clear by counting the detection signals corresponding to the wheels as they enter and leave the section. Count The number of axles stored within the count memory of the Axle Counter Evaluator. Resetting Placing equipment or systems into a state which is suitable for restoration to service. (Note In the context of this resetting is described as a step towards restoration to service. The Engineer may however reset for other reasons, such as fault finding and testing). Restoration to Service Accepting reset equipment or systems back into service. Track Section The section of track contained between associated axle counter detection points. 3 Requirements 3.1 General Procedures or instructions should be approved by Railtrack who should ensure that the means of communication required by the resetting and restoration to service processes are available, adequate and minimise the risk of misunderstanding. The procedures detailing the signaller s actions should be published in the signalbox special instructions. 3.2 Requirements for the production of Procedures and Instructions Failure or Maintenance Disconnection Mode[s] It is essential for safe resetting and restoration to service that the state of any failure, and the effect of any disconnection is fully understood. All anticipated train movements should be catered for, and consideration given to the operation of engineers trains and trolleys, and the use of wheel skates. The effect of engineering RAILTRACK 3

6 Page 4 of 5 Withdrawn Document Axle Counters : Resetting and Restoration to Service possessions, maintenance disconnections and vandalism should also be considered. The systems should be designed to minimise the probability of intermittent, short duration or partial failures and ensure safety in the event that they do occur. All safety critical failures or disconnections should result in a safe state until reset and restored Protection Arrangements The signaller with overall control of protecting signals should be responsible for all manual protection arrangements and these should remain effective until restoration to service is complete. Before starting any work the Engineer should consult with the signaller to evaluate the situation. The Engineer should then operate a device independent from the Axle Counter equipment to isolate the evaluator from the signalling system. This action should be recorded by both signaller and Engineer Indications The indications to the signaller which normally illuminate to show a train occupying the track section, should illuminate with the failure or disconnection The signaller should be provided with a device to restore the axle counter to normal. An associated red indication (or text message) should flash upon initiation of restoration to service by the Engineer and should change to a steady indication (or text message) when the device is operated. Continued operation of the device for a minimum period of 10 seconds by the signaller should then restore the axle counter, thereby extinguishing the light and track indication. An incremental restoration counter should record each operation. Indications may be provided to enable the Engineer to observe progress of the restoration process Resetting The system should be configured such that a reset operation is not possible without the axle counter system first being isolated from the interlocking using an isolation device. When the Engineer has carried out all necessary work following failure or disconnection of the equipment, he should reset the evaluator to zero, at a time when the track section is, to the best of his knowledge, clear of all trains. At this point the Engineer should advise the signaller that the equipment is ready for restoration to service Restoration to Service The signaller on receipt of confirmation that the axle counter has been reset and is ready for restoration to service should ensure that no movements have been agreed or are taking place through the track section. It is the signaller s duty to ensure that the line is clear throughout the period of restoration to service. The Engineer should then initiate the restoration to service by placing the isolation device to normal. Without this action the evaluator should not be reconnected to the signalling system and restoration to service should be prevented. When the signaller has satisfied himself that the track section is clear he should operate the restoration to service device for a continuous period of at least 10 4 RAILTRACK

7 Axle Counters : Resetting and Restoration to Service Page 5 of 5 seconds. Failure to complete the operation should cancel the restoration to service process. The signaller should observe : a) that the associated flashing red indication changes to steady red indicating that the restoration to service control is activated. b) that at the end of the period the track indications and the special restoration to service indication extinguish confirming the return of the axle counter to normal operation. The signaller should then withdraw all protection arrangements and resume normal train signalling and this action should be recorded by both signaller and Engineer. The Engineer should be on site during the passage of the first train through the track section to confirm successful operation of the equipment or, if necessary, to immediately isolate the evaluator should any failure still be present The Restoration Device The restoration device should be configured so that the signaller is required to effect an action for a minimum period of 10 seconds. This configuration should generally be achieved as follows: On signalling panels - by provision of a button on the panel which requires to be pressed continuously for a minimum of 10 seconds. In signal boxes with lever frames - by provision of a plunger on the block shelf which requires to be pressed continuously for a minimum of 10 seconds. On electronic control & display systems (generally VDUs) - by activation and deactivation of a target (with the mouse/cursor & button arrangement) or by activation of a sequence of targets, such that the sequence of operations is a minimum duration of 10 seconds and failure to activate/deactivate a target within a defined period (typically 2 seconds) cancels the restoration to service process. A text message may be used in place of a target Records Records for the following activities should be recorded on Axle Counter Restoration to Service Forms (approved by Railtrack) by both signaller and Engineer, identifying date, time, serial number (or other unique identifier) allocated by the signaller, axle counter track section, restoration counter reading, responsible signaller and Engineer who have been involved in; (a) (b) (c) lsolation of axle counter. Resetting. Restoration to service. Entries should also be made in the Train Register or Occurrence/Log Book. The Serial Number (or other unique identifier) used by the signaller and details of the failure should be recorded on the Failure Report Form or in Fault Control records. One copy of the Axle Counter Reset and Restoration to Service Form should be retained by Railtrack or in accordance with local instructions. One copy of the Axle Counter Reset and Restoration to Service Form should be retained in a file adjacent to the axle counter evaluator or in the relay room log book. RAILTRACK 5