scope:

This Level 2 standard contains a sample Verification Test Specification of the activities required to demonstrate that an Interlocking constructed broadly in accordance with Network Rail's Standard Free-Wired Interlocking system or Electronic Interlocking System meets the Application Logic requirements required of Network Rail's Fixed Block signalling systems in the UK. The method of detailing the Application Logic Requirements is as defined in NR/L2/SIG/11202 Signalling Control Tables.

It should be noted that this Test Specification does not describe a comprehensive and absolute Standard for application to every 'Relay-based' or Electronic signalling system. Certain systems eg. geographical systems, may require more or less specific testing of Control Tables as appropriate. Such special requirements should be detailed in the Testing Plan.

Also detailed here are guidelines to be considered for Validation activities.

When track circuits are mentioned this also refers to axle counters or other train detection devices

Purpose

This Level 2 standard mandates the application of the sections of the Signalling Works Testing Handbook which provides instruction and guidance to signalling works testers on the mandatory procedures and process controls so that new signalling installations, and alterations to existing installations, are independently tested in a manner that assures:

• Compliance with the project Concept Design and Engineering Details, and fitness for purpose before the signalling system is offered for entry into service.

This handbook also, as far as practicable, specifies consistent procedures and process controls are consistent across Network Rail Infrastructure.

The Signalling Works Testing Handbook has been created to collate together all the documents describing the procedures and process controls for signal works testing, and to remove the need for signal works testing related Technical Instructions.