A rail signaller who “forgot” about an train travelling from Manchester to Cardiff before a horror crash left six people injured was exhausted after having just four-and-a-half hours’ sleep, according to a report. The shocking lapse came moments before a passenger train ploughed into a tractor trailer at a farm level crossing near Leominster, Herefordshire. Investigators found the signaller failed to keep track of the train before the smash which left six people injured. Click here to get the biggest stories straight to your inbox in our Daily Newsletter The crash happened at Nordan Farm on May 22 last year as the 8.30am Manchester to Cardiff service slammed into a loaded agricultural trailer being hauled across the tracks. The train was travelling at around 80mph when it struck. The trailer became stuck on the front and was dragged for hundreds of metres before the train ground to a halt. The train was travelling at around 80mph when it struck Passengers were left shaken, with several suffering minor injuries, though no one on board or the tractor …