'Sleet' trains on London's Electric railway system, clearing ice from live rails.. 'Sleet' trains and locomotives with one or two carriages equipped with special wire brushes to sweep the live rail is clear now being used on London's Electric railway system. Ice on exposed live rails holds up trains on the underground. The clearing apparatus consists of a serrated roller which breaks up the ice and a wire brush which clears it away. Photo shows, ice clearing apparatus on a carriage at Northfield Station, Ealing, London. 20 December 1937