From the
RAIB▸ website:
The Rail Accident Investigation Branch (RAIB) has released its report into an incident at Greenhill Upper Junction, near Falkirk on 22 March 2009. The RAIB has made six recommendations.
The incident occurred on 22 March 2009 when the 09:17 hrs passenger train from Alloa to Glasgow Queen Street traversed Greenhill Upper Junction, where the line from Larbert and Stirling joins the Edinburgh and Glasgow line.
One of the trailing point ends, which were part of a set of switch diamonds, was in the incorrect position and as the train trailed through them, it forced the switch blades to the correct position causing damage to the mechanism.
The train was not derailed and continued normally to its destination. There were no injuries caused to either train crew or passengers, and there was no damage to the train.
The incident followed overnight work to renew a point machine at Greenhill Upper Junction. As part of this work, the point machine controlling the point end that was trailed through was switched to manual operation. On completion of the work, this point end was not restored to power and the signaller was able to set a route across the switch diamonds for the Glasgow train despite the fact they were in the incorrect position.
The subsequent investigation by Network Rail immediately after the incident found that additional wiring had been incorrectly installed in the point machine fitted to the other end of the switch diamonds and which had been fitted on site on the night of 17/18 January 2009. The additional wiring affected the working of the detection contacts within the point ends that were trailed through resulting in a wrongside signalling failure.
The fault remained undiscovered between 18 January 2009 and the time when the incident occurred.
