scope:

This document shall apply to existing stocks of Field and Grant, Type TY 199, Group 5 Circuit Controllers (Railway Catalogue Number 86/7272). It does not apply to circuit controllers that are currently installed.

This document does not address the general personnel and system safety measures necessary for working on the track with signalling equipment.

PURPOSE

A study into the reliability of circuit controllers used in conjunction with the BR 843 Standard Mk1 or Mk2 lifting barrier has identified problems regarding the pre-setting of some circuit controllers. This code of practice provides advice on the procedure necessary to: 

• check existing stocks
• identify affected circuit controllers

of a barrier machine, or circuit controller replacement will not require on-site circuit controller coarse adjustment, as they are supplied pre-set, from the manufacturer, to comply with the requirements of BR 843 barrier operation and detection. However, fine adjustment may be required to compensate for variations in site foundation levels, road profiles or boom lengths etc. Technical Investigation Report 94060 identified that incorrect settings can contribute to power pack failure. This document includes advice on carrying out adjustment, when this is necessary.