NR TI 020 ISSUE 2 PDF

Introduction

An incident occurred whereby a barrier boom failed to raise fully after the passage of a train. Investigation revealed that the circuit controller mounting bracket was bent and the detector cam plate was jamming against the circuit controller operating arm.

Further investigation showed that this was as a result of the main pivot shaft displacement longitudinally, by approximately 12mm. (Atkins Rail TIC report 04131 refers). Although not proven, this could have been caused by either transit damage to the pedestal or heavy impact to the side arm, although none had been recorded. Inspection at another site revealed a similar defect although no known failure had at that time taken place.