scope:

The intervals detailed in this standard relate to the maintenance tasks defined in the Network Rail Signal Maintenance Specification suite of documents, or that need to be applied Risk Based Maintenance. Details of the Network Rail Signal Maintenance Specifications are contained in NR/L2/SIG/10663. The existing maximum and normal intervals are included below.

The intervals shown are intended to maintain the designed safety and reliability by detecting and correcting deficiencies to signalling infrastructure before there is deterioration or failure. The intervals have been derived from best practice over a wide range of operating use and environment but their inclusion in this standard does not endorse them as appropriate for every item of equipment in every operational circumstance. Where specific operating use and environment can be identified a case may be made to propose a change to the intervals shown. T

The Risk Based Maintenance intervals defined apply to the specific work instructions identified within this document.

The Reliability centred maintenance Of Signalling Equipment intervals and criteria can be found in NR/L3/SIG/10665

Purpose

This specification defines the maximum and normal intervals currently applicable to signalling maintenance tasks. It includes the assessment criteria and frequencies of Reliability centred maintenance Of Signalling Equipment regimes. It also details the intervals, work instructions and risk categorisation criteria for Risk Based Maintenance.