Calmar Steamship Company

Calmar Steamship Company was a proprietary subsidiary of the Bethlehem Steel founded in New York City in 1927.

Calmar Steamship Company closed in 1976, as United States steel manufacture declined in the 1960s.

The ship was run by its crew and 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.

Black Diamond Steamship Company continued to operate after the war, but closed in the 1955.

SS Portmar (1919) sister ship Circinus )
SS Calmar a Type C4-class ship
A VC2-S-AP2 type Victory ship
SS John W. Brown , one of four surviving Liberty ships in 2000