Specialized bulk carriers began to appear as steam-powered ships became more popular.[6] The first steam ship recognized as a bulk carrier was the British coal carrier SS John Bowes in 1852.[8][9] She featured a metal hull, a steam engine, and a ballasting system which used seawater instead of sandbags.[8] These features helped her succeed in the competitive British coal market.[8] The first self-unloader was the lake freighter Hennepin in 1902 on the Great Lakes.