Freight diesel designed by BREL in the 1980s following the US 'road switcher' style narrow body but with cabs at both ends. The result was dubbed the 'bone' by enthusiasts. These locomotives were intended for MGR coal service as a simpler and more economical alternative to the class 56 with it's traditional strength bodyshell construction. The side access doors did reduce maintenance time and costs, but the simplified bogie with pedestal instead of drop-equalised suspension was notorious for getting stranded in rough colliery sidings with the a centre axle spinning helplessly over a dip in the track! The 58s were later deployed on a range of other block train flows, including 'binliner' waste container trains, though their 60mph maximum speed made them unsuitable for fast freightliner trains.