THE excursion from the South Wales community of Treherbert to Paddington on Sunday, November 20, 1955 at 9.30am was filled with members of local women’s groups looking forward to a day out in the capital.

It was made up of nine former GWR coaches and an ex-LMS cafeteria coach, and was hauled by BR-built Britannia Pacific no. 70026 POLAR STAR.

The driver was 55-year-old WT Wheeler and the fireman was AP Marsh, based at Cardiff Canton.

The guard was from Treherbert, surname of Wall.

There were many route diversions due to Sunday maintenance works but Driver Wheeler had read the weekly engineering notice which listed all the restrictions on the route.

What he hadn’t noticed was that the diversion 2.5 miles west of Didcot to take the train into the Milton Goods Loop had a 10mph speed limit.

The Automatic Train Control audible sound was not working correctly so would have been difficult to hear above the other noises on the footplate of a steam locomotive.

The train ran through the 15mph restriction at Wantage Road and accelerated towards Didcot. The signals were placed on the right of the line, visible to drivers of GWR engines but Polar Star was a BR-built locomotive with the driver positioned on the left-hand side.

Wheeler would have had to rely on fireman Marsh to see the yellow signal.

The train flew past Milton signal box just after 1pm and signalman Granville Burt looked out in horror as the train shot across the points at 50mph.

The engine careered down the embankment on the left, falling on its side.

The Milton signalman sent out the six bells warning meaning 'obstruction danger' to the two signal boxes either side of the accident at Steventon and Foxhall Junction, Didcot.

Although, because of the location in fields (now part of Milton trading estate), it was difficult for the emergency services to get access, rescuers were on hand quickly as the accident was near to the Didcot Ordnance Depot and RAF Milton. Both their fire brigades attended at the scene.

The first coach had followed the engine down the embankment and came to a stop in the field.

The second had smashed on top of the engine and was crushed under the third.

The fourth and fifth coaches came off the rails and ended up at 90 degrees across the running lines, throwing the passengers out of the damaged coaches.

The cafeteria car ploughed into the wreckage but the last four coaches remained on the track and the occupants survived.

Of the 293 passengers, there were 11 dead and 62 injured.

But note, only 18hours later trains were running past the incident!

The Ministry of Transport report found the driver at fault, but also the guard as he was aware of the restriction at Milton but was afraid to undermine the driver’s 40 years’ experience of driving.

There were also technical differences in the braking system between GWR locomotives and BR locomotives and the position of the driver on the footplate meant he visually missed the signals at 'caution' and 'stop' as the train approached Milton Goods Loop.

All Saints Church in Didcot has cemetery gates as a memorial to the tragic event. Acknowledgements must go to to the BR report and Adrian Vaughan for help in writing this article.