At the time of opening, the yard was handling 3,000 wagons a day. Incoming trains were split in the 11 reception sidings, propelled over the hump in the yard, from where the individual wagons rolled down a slope and were automatically sorted into new trains on the yard's 50 main sorting sidings. The yard had its own dedicated class of shunting locomotive (British Rail Class 13) for this purpose as BR's standard class of shunting locomotive was not powerful enough. Each of the main sorting sidings was fitted with computer-controlled retarders to either slow the rolling wagons down before they hit other wagons already on the siding, or give wagons rolling too slowly a boost to move them along to the correct position in a particular siding. This wagon-control system, manufactured by Dowty, was very complex, needed almost constant maintenance, and crucially could not handle the longer wheelbase wagons that were already becoming prevalent and required individual shunting. There was an express freight and departure yard of 10 sidings, and a 25-road secondary yard for local freight trains (with its own hump).