Kasatka-class submarine

The Kasatka class was a class of submarines built for the Imperial Russian Navy. The six boats were built between 1904 and 1905. They were designed by I. G. Bubnov and were based on the Delfin. The first boat, Kasatka, experienced significant problems with stability on trials and had to have extra flotation added. In 1905, four of the class were transferred from Western Russia to Vladivostok with the outbreak of the Russo-Japanese War. Initially powered by a kerosene/electrical system, the boats were re-built around 1910 with a diesel-electric power plant following the end of the war. The class remained in service throughout World War I. Two were captured by the German Empire in 1918 and handed over to the British following the German surrender. They were scuttled by the British in 1919 to prevent their capture by the Soviets. The remaining four were broken up for scrap in 1922.