On 24th March 1936 the completed Queen Mary left the Clyde and commenced her sea trials to test her sea-worthiness. The Queen Mary sailed on her maiden voyage on 27th May 1936 and she soon captured the westbound and eastbound Blue Riband for the fastest North Atlantic crossing. Following the outbreak of the Second World War in September 1939 the Queen Mary and her sister ship the Queen Elizabeth were converted to troop ships. The Queen Mary's exemplary war service was marred when she collided with and sank the HMS Curacoa in 1942. 338 people aboard the escort cruiser lost their lives. During the Second World War the Queen Mary carried some 765,429 military servicemen and steamed some 569,429 miles in the service of her country. After the war, and a much needed refit for commercial service, she returned to serve on the North Atlantic on 31st July 1947.