scope:

This SIN applies to all VT1 relays. The requirements apply to all Signal Engineering functions that maintain, install or commission this type of relay on NR infrastructure.

The requirements also apply to organisations that handle relays serviced by Unipart Rail Crewe (formerly NRS Crewe) and Siemens Mobility Limited (formerly

Westinghouse).

Purpose

The purpose of this Special Inspection Notice (SIN) is to:

a) inspect the vane front-stop assemblies of all VT1 style relays;

b) inspect all the slipper stop and vane stop-plates;

c) replace all the track circuit stabiliser units manufactured by NRS;

d) replace any relays deemed to be defective.