Railway Signalling Version Control

Railway Signalling Version Control

Network Rail Railway Signalling Version Control

Railway Signalling Version Control

Railway Signalling Version Control :- All types of design details shall be uniquely identifiable. Version is primarily the medium for identification of a drawing and also for keeping track of the changes/alterations, the drawing may undergo over a period of time. Version may be a single letter or double letters followed by the digit to indicate the incrementing if necessary.


Every drawing shall have a Title Block which displays the individual identity of the drawing.

Essential contents of the title bocks are:

* Drawing number

* Current Version

* Issue Date

* Date of last correlation and updated version

* Name of infrastructure controller


* Name of records custodian

* Signal box or control point

* Interlocking control area

* Design detail type and/or description

* Scale and other notes as necessary

* Space for use on production copies for design authority name ,reference number and certification


Alteration Letters       

The records custodian (NRG) allocates the Version letters to be used for a commissioning and it will be followed by sequential numbers for each subsequent alterations. Thus, separate alteration letters are given to every alteration to be commissioned on a single occasion. This process is applicable from the correlation, any new work for maintenance alterations , every stage in a major multi-stage scheme and each item of work package within a stage.

e.g : BA, BB, BC etc

The  Standard (RT/E/C/11701 – 3.5.1 ) stipulates that any letter of alteration allotted is not used, a blank AIR should be returned for that alteration.


Change Numbers           

The version letters should be suffixed with a change number, starting from 1 for the original version.Subsequent modifications/amendments to the production copies shall have incremented numbering. e.g. BA1, BA2, BA3 etc.


AIR shall show the versions in a distinctive manner by separate lines to enclose the versions. The version reference consists of the alteration letters and change number (e.g. BA1). Current version on the source record can be found in the bottom right hand corner, and this will be coloured in production copies.


The final version shall consist of all the modifications issued during commissioning. This shall show the details of all final records being returned indicating any new, renumbered or abolished sheets. In two drawing method, Red and Green sheets shall have different change numbers to indicate the previous  and current changes.

 Railway Signalling Version Control,Alteration Letters,Change Numbers 

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