scope:

This Railtrack Line Code of Practice applies to Signal Post Replacement Switches installed on Railtrack's infrastructure.

This document does not address the general personnel and system safety measures necessary for working on the track with signalling equipment.

Purpose

An incident, where a Signal Post Replacement Switch was found to be defective, as it was not possible to rotate the mechanism into the danger position, led to a technical investigation (Technical Investigation Report 98029). This revealed the cause to have been a fractured actuating shaft.

This document has been prepared to discuss known problems affecting the signal post replacement switch and includes advice on the:

• actuating shaft fracture, including checks necessary to identify early signs of failure

• details of the new modified replacement switch.