It turned out that the reason the 7:10 was still stopped was that there was a faulty signal. The signalman at the interlocking had tried to clear the signal to allow the train to continue, but it was stuck in the danger position due to wet or frosty weather causing the mechanism to stick. The signalman was on his way from the signal box at Ballymacarrett Junction to the 7:10 train to signal it in person when the accident occurred.
