HMS Avenger was a Royal Navy escort aircraft carrier during the Second World War. In 1939 she was laid down as the merchant ship Rio-Hudson at the Sun Shipbuilding & Drydock Company yard in Chester, Pennsylvania. Launched on 27 November 1940, she was converted to an escort carrier and transferred under the lend lease agreement to the Royal Navy. She was commissioned on 2 March 1942. Avengers capacity allowed for a maximum of 15 aircraft. In September 1942, she took part in what was the largest and most successful Russian convoy to date. Upon her return home, after observing a number of design faults, Avengers captain drew up recommendations for future escort carrier design. In November 1942 she took part in Operation Torch, the Allied invasion of North Africa, where she suffered engine problems. While leaving North Africa to start the journey home Avenger was sunk by the on 15 November 1942 at 3:20am GMT, 9 hours after leaving Gibraltar for Britain, with a heavy loss of life among her crew. Design and description The s were converted American type C3 merchant ships of the C3 class. Their design was based on the U.S. Navy (AVG1). To differentiate between the two classes, the Royal Navy ships were prefixed with a 'B' (BAVG). HMS Avenger (BAVG2) was built by the Sun Shipbuilding and Drydock Company in Chester, Pennsylvania, south of Philadelphia on the Delaware River. Originally named Rio-Hudson, she was laid down on 28 November 1939 as a passenger cargo ship for the American Moore-McCormack Lines, Inc., and was launched on 27 November 1940. She was then purchased by the United States Navy and converted to an escort aircraft carrier in the Bethlehem Steel yards at Staten Island. Transferred to the Royal Navy on 31 July 1941, she was commissioned 2 March 1942 when the conversion was completed. Avenger had a complement of 555 men (including aircrew) and an overall length of , a beam of , and a height of . She displaced at normal load and at deep load. Propulsion was provided by four diesel engines connected to one shaft, giving 8,500 brake horsepower. This could propel the ship at . Aircraft facilities were composed of a small combined bridge-flight control on the starboard side above the long wooden flight deck, one aircraft lift, one aircraft catapult, and nine arrestor wires. Aircraft could be housed in the half hangar