In the subsequent inquiry,[1] the accident was deemed to have been caused by a signalman failing to secure a set of points that he had operated manually after an equipment failure.
He thus made the decision that he and another railwayman would walk to the points and move them to the normal position manually, which they did.
[1] Meanwhile, the 15:02 freight train from Drax power station to Lindsey Oil Refinery, composed of a Class 47 diesel locomotive (47299) and nine empty 100-ton oil wagons, had drawn up to the signal which was stuck at danger, and received a green hand-signal from the signal box.
[1] At the same time, the 17:32 Cleethorpes to Sheffield local train, composed of a 2-carriage Class 114 diesel multiple unit, had left the nearby Barnetby station.
[1] The HM Railway Inspectorate inquiry found the accident to be due to the railwaymen failing to secure the points in the position in which they had set them.