SS President Coolidge Newport News, Virginia built the two ships, completing "President Hoover" in 1930. The keel for "President Coolidge" was laid 22 April 1930 and the ship was delivered 1 October 1931. They were the largest merchant ships built in the United States up to that time. Each ship had turbo-electric transmission, with a pair of steam turbo generators generating current that powered propulsion motors on the propeller shafts. Westinghouse built the turbo generators and propulsion motors for "President Coolidge" but General Electric built the turbo generators and propulsion motors for "President Hoover". In the "President Coolidge" twelve Babcock & Wilcox superheater
SS President Coolidge SS President Coolidge SS "President Coolidge" was an American luxury ocean liner that was completed in 1931. She was operated by Dollar Steamship Lines until 1938, and then by American President Lines until 1941. She served as a troopship from December 1941 until October 1942, when she was sunk by mines in Espiritu Santo in the New Hebrides, part of current-day Vanuatu. "President Coolidge" had a sister ship, , completed in 1930 and lost when she ran aground in a typhoon in 1937. Dollar Lines ordered both ships on 26 October 1929. The Newport News Shipbuilding and Drydock Company of