scope:

This standard shall be used by all those responsible for the procurement, planning, design, installation or commissioning of alterations to the Signalling System.

It shall be used when procuring, planning, designing, installing or commissioning of alterations to the Signalling Systems

Purpose

This standard defines the requirements that must be followed when making any planned physical change to the vital signalling system where that change involves either:

a) a departure from the existing design, or

b) a change of component type or version.

Note: In this document the terms 'alteration' and 'change' are equivalent, and mean any departure from the existing design, either in respect of component types or versions, or in their electrical or mechanical arrangements.