scope:

The contents of this Part of the SMTH are designed to assist those investigating signalling equipment failures. This includes related information which may be of use, such as requirements for dealing with serious incidents and arranging specialist investigation services.

Wrong side failure investigation Test Guides are provided in the T series and Test Guides for intermittent or obscure fault finding are provided in the U series.

This Part of the SMTH makes reference to Signalling Maintenance Specifications (NR/SMS) and to Special Inspection Notices (NR/SIN).

Purpose

The purpose of this Part 05 of the Signalling Maintenance Testing Handbook (NR/SMTH) is to define the method of investigating reported signalling equipment failures, in support of Parts 02 and 03.

It provides assistance to those investigating reported Wrong Side Failures (WSFs) and to signal engineering staff involved in serious incidents.

It also provides Fault Finding Guides for use where a WSF is not suspected.