The Japanese Soryu class of twelve non-nuclear submarines (SS) was all built in the Kobe shipyards of Mitsubishi and Kawasaki. The first two boats were commissioned in 2009 and 2010: Soryu (SS-501) and Unryu (SS-502). They inherited the names of Japanese aircraft carriers from WWII. This class has the largest tonnage displacement of any JMSDF vessel since the Second World War. Updated from the Oyashio class, diesel-electric Soryu uses four Stirling Air-Independent Propulsion (AIP) engines, two Kawasaki diesel engines and two electric motors. Armament includes Type 89 & UGM-84 Harpoon anti-ship Missiles (AShM).