He reduced speed and later stopped the train in a gale-force wind while it was snowing at Garsdale, but was unable to find the cause of the noise.
The fireman on the right of the train then saw sparks from the side of the locomotive as ballast began to be thrown up against the cab.
As the driver made a full brake application, a 20-wagon goods train, hauled by LMS Hughes Crab no.
Eventually the entire connecting rod had ploughed into the ballast near the adjacent line; wrecking the track in front of the oncoming goods train.
[4] The root cause was the failure of maintenance staff to properly secure the slide bar nuts; a problem which had been reported several times previously on that locomotive and on others in the same class but without fatal consequences.