scope:

This standard applies to all track in running lines, depots and sidings.

This standard applies to all switches in London Underground's (LU) permanent way that may at any time or circumstance be used in a facing direction (except as noted below).

This standard shall be applied to all rail grades and to all types of switch machining in both bullhead and flatbottom rail sections, except that the switch wear gauge may be used only on chamfered and undercut switches.

The requirements do not apply to:

a) the switch half sets of trap points which are in the open position for ordinary running

b) switch diamonds (moveable angles)

c) adjustment switches.

Purpose

This standard describes the inspection regime, monitoring procedures, immediate actions and essential maintenance to be undertaken at switches to reduce the risk of derailment.

It identifies the particular derailment hazards associated with switch wear and damage and the remedial measures necessary.