Black Diamond Steamship Company

Black Diamond Steamship Company (BDSC) operated passenger and cargo liners from New York City to Rotterdam and Antwerp. It was founded by J.E. Dockendorff in 1919, and named the American Diamond Line by the United States Shipping Board. The company was profitable in the 1920s and early 1930s. Prior to the United States' entry into World War II, the nation's neutrality policy ended much of the lines trade. Dockendorff stepped down as a principal executive in 1934, selling the only one of the company's 21 ships not owned by the government: New Britain, which he had bought in 1918. During World War II the company sold most of its American Diamond Line ships and moved to charter shipping with the Maritime Commission and War Shipping Administration. During the war, the Black Diamond Steamship Company operated Victory ships and Liberty ships. These ships were operated by their own crews; the US Navy supplied United States Navy Armed Guards to man the deck guns and radio. The most common armament mounted on these merchant ships were the MK II 20mm Oerlikon autocannon and the 3"/50, 4"/50, and 5"/38 deck guns. After the war there were many surplus ships and much competition. Black Diamond Steamship Company continued to operate after the war, but finally closed in 1955.