scope:

This technical specification covers the performance requirements for the supply of new designs of stretcher bar assembly and the technical requirements that must be met for the supply of both new and current designs of stretcher bar assembly fitted between blades of switch rails of bull head and flat bottom switches.

For the purposes of this technical specification a stretcher bar assembly is deemed to comprise:

a) stretcher bar;

b) attachments to the stretcher bar to accept drive forces from point actuation equipment;

c) insulating materials (where applicable);

d) stretcher bar brackets for connection of the stretcher bar to the switch rails;

e) fasteners and bolt head retaining plates.

Purpose

The purpose of this technical specification is to set out the requirements for stretcher bar assemblies, comprising the parts listed in clause 2.2, fitted between blades of switch rails of bull head and flat bottom switches. These requirements are based upon the recognised safety criticality of stretcher bar assemblies.