The Orgreave Train Collision occurred on 13 December 1926 near Orgreave Colliery signal box on the Great Central Railway line about east of Sheffield. A goods train had collided with a preceding goods train on the same line, and the wreckage had obstructed the adjacent passenger line. A workmen's train, known as a paddy mail, ran into the wreckage; paddy mails were workmen's trains operated in connection with all three shift changes at the collieries. These were hauled from Sheffield Victoria, as far as Orgreaves Colliery Sidings by the main line company, using whatever locomotive was available. At this point the colliery's own locomotives took over and in connection with this operation 'Rothervale No.6' was fitted with vacuum brakes. The train then ran to Orgreave Colliery platform and Treeton Colliery. Circumstances The line at Orgreaves Colliery was quadruple track, the centre tracks being the Main Lines operated under Absolute Block regulations, and the outer lines were designated Goods Lines, and they were worked under Permissive Block regulations. Whereas the Absolute Block System maintains a space interval between trains to prevent collision, the Permissive Block System permits trains to follow one another into a block section without special protection other than a speed restriction, usually of 4 mph. At about 5 a.m. on 13 December 1926 the Orgreaves Colliery signalman had the 2.50 a.m. Mexborough to Woodford goods train, consisting of around 40 wagons, mostly empty, standing on the Up Goods Line at his home signal, waiting for clearance forward. He accepted the 1.15 a.m. Dewsnap to Nottingham goods train from Darnall West on the Up Goods Line under the Permissive Block regulations. This train collided with the rear of the stationary Woodford train. The weather was said to be foggy, dense in places. In the collision, a number of empty wagons were derailed and some were thrown foul of the Up Main line. Just before 5.30 a.m. a workmen's train colloquially referred to as the Orgreave "Paddy Mail" left Sheffield Victoria, and having called at Darnall and running on the Up Main line ran into the wreckage. The workmen's train consisted of 14 assorted elderly vehicles hauled by an ex-G.N.R. "Atlantic" locomotive driven by Fred Bagley of Neepsend engine shed. The train was carrying around 800 miners travelling to their work at collieries. Consequences The locomotive of the workmen's train hit the wagons at moderate speed, as the train was