Group : Attack Submarines
Status : Active
Also Known As : Oyashio, SS 590
Origin : Japan
Contractors : Kawasaki Shipbuilding, Mitsubishi Heavy Industries
Initial Operational Capability (IOC) : 1998
Total Production : 11

The Japan Marine Self Defense Force (JMSDF) Oyashi, also known as Oyashio or Class 590, is an entirely new design of diesel-electric powered submarine with the diving control surfaces at the sail. Like their predecessors these boats are intended to perform both anti-submarine (ASW) and anti-surface warfare (ASuW) missions in blue waters. The Japan Maritime Self-Defense Force (JMSDF) commissioned 11 Oyashio-class submarines from 1998 through 2008. These ships are the quietest and largest submarines of the Japanese Navy ever.

The diesel-electric powered Oyahio-class boats can achieve a top speed of 20 knots while submerged and displacing 2,750t. The diesel engine develops up to 7,700-shp of power. The improved Oyashio ships feature Stirling AIP air independent propulsion system from Kockums. The lead ship, JS Soryu, equipped with such a propulsion system was launched December 2007 at Mitsubishi Heavy Industries in Kobe, Japan. Oyashio-class boats can be equipped with 20 Type 89 torpedoes as well as Harpoon (UGM-84D) anti-ship missiles and mines (40) all of them launched through six 533mm torpedo tubes.