Closure of Kawatana Naval Arsenal and Nagasaki A-bomb Survivor Relief (1945)

Kawatana Town in Higashisonogi District, Nagasaki Prefecture, faces Omura Bay and had been a centre of Imperial Navy torpedo work since the Katashima torpedo testing range opened in 1918. During the Pacific War the Navy built the Kawatana Naval Arsenal there and the town's population rose sharply; in 1942 the water between Katashima and the shore was filled in. In 1944 the Navy also moved its torpedo boat training school from Yokosuka to Kawatana to train crews for Shinyo explosive motorboats and other special attack weapons. By the end of the war the town thus housed torpedo production, test firing and special attack training.

After the atomic bombing of Nagasaki on August 9, 1945, the national railway ran relief trains to carry the injured out of the city; press accounts state that four such trains carried about 3,500 casualties, mainly to Isahaya and Omura, where there were naval hospitals. In the days following the bombing, casualties and severely burned survivors were also transported to Kawatana by rail. The arsenal's buildings were repurposed as emergency medical facilities, with female high school and junior high school students mobilized as volunteer nurses to care for the atomic bomb victims. The number of people received at Kawatana could not be confirmed from the sources consulted.

The Kawatana Naval Arsenal ceased torpedo production with Japan's surrender on August 15, 1945. This transformation from weapons factory to humanitarian relief center marks a poignant chapter in the facility's history. The torpedo testing range at Katashima was abandoned and gradually reclaimed by forest. After the war, factories of several large companies were attracted to the former arsenal land along the shore.

The remains at Katashima survive. Four structures — the observation post, the oil store, the machine room and torpedo adjustment room, and the jetty — are registered as national Registered Tangible Cultural Properties under the name 'Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range', and the town laid out the surrounding area as Katashima Park in 2015. Elsewhere in the town are the site of the torpedo boat training school and a special attack memorial, erected on 27 May 1967, inscribed with the names of the dead.