Lisbon Maru () was a Japanese cargo liner built at Yokohama in 1920 for a Japanese shipping line. During World War II, the ship was turned into an armed troopship. On her final voyage, Lisbon Maru was being used to transport prisoners of war between Hong Kong and Japan when it was torpedoed on 1 October 1942, sinking with a loss of over 800 British lives. Construction and commercial service Lisbon Maru was completed on 8 July 1920 at the Yokohama Dock Company shipyard in Yokohama, Japan as Yard No. 70, entering service for a major Japanese shipping line, Nippon Yusen Kabushiki Kaisha, and registered at the port of Tokyo. The ship was long, with a beam of and a depth of . It measured and 4,308 NRT. Twin propellers were powered by a pair of triple expansion steam engines with a combined rating of 632 nhp, giving a service speed of . The engines and four boilers were made by the shipbuilder. Sinking On her final voyage, the Lisbon Maru was carrying 700 Japanese Army personnel and 1,816 British prisoners of war captured after the Battle of Hong Kong in December 1941. The POWs were held in "appalling conditions ... [those] at the bottom of the hold ... showered by the diarrhea of sick soldiers above". On 1 October 1942, the ship was torpedoed by the submarine while travelling through the South China Sea. The Japanese troops were evacuated from the ship but the POWs were not; instead the hatches were battened down above them and they were left on the listing ship. After 24 hours, as it became apparent that the ship was sinking, the POWs were able to break through the hatch covers. Some were able to escape from the ship before it sank. The ladder from one of the holds to the deck failed, and the Royal Artillery POWs in the hold could not escape; they were last heard singing "It's a Long Way to Tipperary". Survivors reported that Japanese guards first fired on the POWs who reached the deck; and that other Japanese ships used machine guns to fire at POWs who were in the water. Later, however, after some Chinese fishermen started rescuing survivors, the Japanese ships also rescued survivors. The British government insisted that over 800 of these men died either directly as a result of the sinking, or from being shot or