The Birmingham Pullman was already running on a substitute. The luxury Blue Pullman multiple unit normally rostered to the 1 pm departure from Snow Hill had been withdrawn from service that day, and an 11-month-old diesel hydraulic Class 52 locomotive, D1040 Western Queen, had been pressed into duty hauling nine coaches instead. At Knowle and Dorridge station, a routine shunting movement was under way - a hopper wagon, a brake van, an empty flatcar, and a flatcar loaded with new Land Rovers being marshalled in fine summer weather. Such manoeuvres were a normal part of operations, performed before or after expresses passed through. But the signalman in the Knowle and Dorridge box, having already given line clear for the express, somehow held in his mind the impression that the up main was empty. He let the freight train onto the same line. When the "train approaching" bell rang from Bentley Heath, he realised what he had done.

He grabbed a red flag and ran. The freight train's driver saw it, braked hard, and stopped his train on the up main. All four men aboard the freight - driver, fireman, shunter, guard - leapt clear before the impact. But the distant signal that warned Morris of trouble ahead stood only 902 yards from the home signal at Knowle, and 902 yards of braking distance is not enough to bring an express down from 80 mph to a halt. Morris dragged the speed down to 20 mph before Western Queen struck the loaded flatcar. The locomotive's cab was crushed but the engine itself did not derail. Two freight wagons were thrown off the rails, the rest pushed 64 yards down the track by the force of the collision.

Ernie Morris died at his controls. So did Sid Bench, the second driver - on the Pullman workings two drivers were required, and both men were in the front cab. The third man was David Corkery, the second man, who was on the train only because the rostered crewman had gone sick that morning and Corkery had been called in to cover. He was killed too. The men in the freight train were unhurt. The investigation later identified the deeper failure: the signalman had also disregarded Regulation 4A, a standing order that governed sections where the minimum stopping distance for trains was greater than the distance between signals. He should have sent a "blocking back inside home signal" message to Bentley Heath, which would have caused that signal box's distant to be set at caution miles earlier - giving the express time to slow gently rather than discovering trouble nine hundred yards from impact.

Dorridge station today sits in commuter Solihull, the line still busy with Chiltern Railways services between Birmingham and London. The signal boxes are gone, replaced by centralised signalling that does not depend on a single man remembering what he authorised five minutes ago. The Class 52 Westerns were withdrawn from service by 1977, though several survive in preservation. Of the Blue Pullman sets Morris helped pioneer, none remain. The 1962 film he featured in still survives in the British Film Institute archive, a young driver in the cab of a brand-new train, the rails ahead clear and the future seemingly limitless.