scope:

Introduction

This module applies to traditional electro-mechanical signal boxes. Ground Frames should be considered as the equivalent of the locking frame area of a signal box and so the relevant parts of this instruction also apply to them.

When working near levers and locking frames, beware of being struck or trapped by moving parts. Wear head protection and agree with the signaller that you are to be warned before levers are moved. Care should be taken to avoid working in a position in which the unexpected movement of a lever may cause injury. Positions in the line of travel of backweights, tappets and other moving parts of a lever frame should especially be avoided unless the lever has first been secured.