RMS Empress of Britain was a steam turbine ocean liner built between 1928 and 1931 by John Brown shipyard in Scotland, owned by the Canadian Pacific Railway Company and operated by Canadian Pacific Steamship Company. She was the second of three Canadian Pacific ships named Empress of Britain, which provided scheduled trans-Atlantic passenger service from spring to autumn between Canada and Europe from 1931 until 1939. In her time Empress of Britain was the largest, fastest and most luxurious ship between the United Kingdom and Canada, and the largest ship in the Canadian Pacific fleet. She was torpedoed on 28 October 1940 by and sank. At she was the largest liner lost in the Second World War and the largest ship sunk by a U-boat. Design and building Work began on Empress of Britain on 28 November 1928 when the plates of her keel were laid at John Brown & Co, Clydebank, Scotland. She was launched on 11 June 1930 by the Prince of Wales. This was the first time that launching ceremonies in Britain were broadcast by radio to Canada and the United States. The ship had nine water-tube boilers with a combined heating surface of . Eight were Yarrow boilers, but as an experiment she was also the first to be fitted with a Johnson boiler. Her boilers supplied steam at 425 lbf/in2 to 12 steam turbines, which drove her four propeller shafts by single reduction gearing and developed a combined power output of 12,753 NHP. Empress of Britains UK official number was 162582. Until 1933 her code letters were LHCB. Her call sign was GMBJ. The ship began sea trials on 11 April 1931 where she recorded , and left Southampton on her maiden voyage to Quebec on 27 May 1931. As the ship would sail a more northerly trans-Atlantic route where there was sometimes ice in the waters off Newfoundland, Empress of Britain was ordered with outer steel plating double the thickness at the stem and for back at either side, up to the waterline. Her sea trials showed her to be "the world's most economical steamship for fuel consumption per horsepower-hour for her day." Her primary role was to entice passengers between England and Quebec instead of the more popular Southampton–New York route. The ship was designed to carry 1,195 passengers (465 first class, 260 tourist class and 470 third class). She was the first