scope:

Introduction

The electric point machine is basically an electric motor connected to a gear chain and mechanical linkages so that the final output is the linear movement of a rod or bar which can be coupled up to the points. The whole mechanism is enclosed in a tough weatherproof case that can be fixed down to the track.

The motor can be designed to work on any suitable voltage. The most commonly used on Network Rail infrastructure is 110 volts d.c. This is usually supplied from a trickle charged secondary battery, but sometimes the machine is fed directly from a transformer/rectifier unit.

Although point machines exist that run off a.c., low voltage d.c., or a hand generator, these machines are comparatively rare and this module will concentrate on the high voltage d.c. machine.