A REPORT into the derailment of a train at Iarnród Éireann's E60 million Portlaoise depot last January has found that sun shining on a signal light was a contributing factor.
The train was leaving for Heuston Station following a routine service at the Laois Traincare Depot.
It was on the "down loop", a single track which leads directly onto to the busy the Cork to Heuston line. Thousands of commuters travel on the train line each week.
The Railway Accident Investigation Unit (RAIU) concluded that the shunter who was responsible for resetting the track was called to the front of the train to read a signal that the driver couldn't see properly due to sun shining on it.
This led to "a momentary lapse in attention", resulting in the shunter resetting the points as the train was still passing over it, which caused carriages to take diverging routes, derailing two of them.
Drivers had made complaints that signal PL278 which had a filament lamp was unreadable in sunlight, but this hadn't been addressed by the Signal Sighting Committee.
It was also found that it had become standard practice at the depot to leave the points handle - which changed the track direction - in the engaged position, which made it very easy to move by mistake.
Three of the carriages on the six carriage train were damaged as was the track. The train was fitted with an event recorder, but information downloaded was corrupted, so that the speed of the train could not be established.
Iarnrd ireann confirmed last month that the signal had now been replaced by a LED display, and their shunters have been briefed on the accident and on the need to remain focussed on their jobs.