moggie
Member
Sure most, if not all, AHB crossings say that those in charge of a slow moving or abnormally-loaded wagon/trailer have to phone the signaller before using the crossing?
Yes, and its a mandatory requirement.
This is going to be the key question of the investigation imo. The requirement stems from the Hixon disaster back in 1968 and is intended to ensure a train is not on the approach to an AHBC before a potentially slow moving road vehicle attempts to cross on the crossing. The requirement placed on the road vehicle driver is not optional.
In so far as the signalling is concerned, the crossing is designed to function independently. There is normally no direct proving of the AHB in 'protecting signals', which may be located some distance away from the crossing. Hence the need for the driver of the road vehicle to contact the signaller if there is a possibility they may not clear the crossing in the time from crossing initiation by a train to the commencement of barrier lowering, normally satisfied by the amber / red wig-wag traffic light sequence.
If, as in this case a signal is located within the normal strike in for the crossing for other signalling reasons, the rail signal clearance may be automatically delayed for a period until the crossing has reached a point in the standard crossing sequence thereby ensuring a train does not arrive over the crossing before sufficient warning time / barrier lowering has been given.
A bad day for all concerned, thankfully not far worse.