scope:

Introduction

This document details the method to be used for installing equipment associated with a Train Operated Points System on Network Rail infrastructure. Where only part of an existing system is being replaced, the relevant steps in this instruction can be used to supplement the information already provided in the SMTH.

The Train Operated Point System consists of a hydraulic unit mounted in the four foot adjacent to the toe of the normally closed switch, which maintains the switch in the closed position using the accumulator actuator, which applies a constant pressure to the switch. The whole mechanism is enclosed in a tough weatherproof case that is fixed in the four foot through holes pre-drilled in the sole plate.

To operate the points, the train wheel flange applies a pressure, greater than that applied by the accumulator which 'drives' the points to the reverse position, thus known as 'Train Operated Points'. The points can be cranked to the reverse position, by use of a hand pump unit, which is positioned adjacent to the accumulator, when in the reverse position the points require to be clipped and scotched in order to maintain the minimum switch opening.