scope:

This guidance applies to the signalling assets detailed in section 3.1. All those involved in the construction and undertaking of maintenance regimes should follow this guidance.

Purpose

This document details the routine change intervals for signalling equipment, with potentially unsafe failure modes due to progressive degradation, that cannot be satisfactorily addressed by maintenance and testing of the equipment at its installed position.

Note: This document provides guidance to the requirements of standard S1199 'Signalling and Signalling Control - Operation and Maintenance' in relation to Routine change. Work Instructions cover the detail of what exactly is to be undertaken during Routine change.