Sonny is a well tank engine who used to work at a coal mine and was brought to Sodor by two criminals named Baz and Bernie, but later joined the North Western Railway. Before arriving on the Island of Sodor, Sonny worked at a coal mine, pulling heavy trucks of coal up steep hills. He was one of the first engines to be built with piston valves, allowing him to control the amount of steam he used.[1] At some point after being withdrawn, he was acquired by Baz and Bernie and first came to Sodor wit