scope:

The new requirements shall be applied to all Siemens and GE Transportation Systems Electronic Treadle Replacement Systems that have been, or will be installed across the network.

Purpose

This Technical Instruction is being issued to advise of the Signal Maintenance Specification requirements for the newly approved Siemens WSR Electronic Wheel Sensor, and GE Transportation Systems WDD Electronic Wheel Sensor and Treadle Replacement Unit, prior to these instructions being included in the 2009 issue as SMS TQ13 and SMS TQ14. This Technical Instruction also describes the process required for replacement of these sensors and associated component parts which will be mandated within the Signalling Maintenance Testing Handbook at its next update.