OVERVIEW: The Type 97 (development code G‑RX4) is a Japanese lightweight, submarine/aircraft/ship-launched anti-submarine torpedo introduced in 1997. It features a closed-cycle turbine engine and acoustic homing guidance, optimized for deep-water submarine threats.

DETAILS: Type 97 (“Type” indicates 1997 adoption; G‑RX4 was the R&D project code) was developed by Japan’s Technical Research and Development Institute and built by Mitsubishi Heavy Industries. It is 324 mm in diameter, 2.832 m long, and weighs approximately 320 kg. Propelled by a closed-cycle steam (Otto Fuel II) turbine with pump-jet propulsion, it uses active and passive acoustic homing via a digital seeker. Its shaped-charge warhead is designed to defeat double-hulled submarines at depths beyond 600 m, with an approximate 15 km range .

TYPE: Lightweight anti-submarine torpedo

FUNCTION: Launched from surface ships (Mark 32 torpedo tubes, Type 07 VLS), ASW aircraft, or helicopters, the Type 97 homes on submarine targets using acoustic sensors, delivering a high-energy shaped-charge warhead upon terminal guidance.

NOTE:
IOC: 1997
Manufacturer: Mitsubishi Heavy Industries (Japan)
Operators: Japan Maritime Self‑Defense Force 

SOURCE: Jane’s Underwater Warfare Systems 2006–2007; WeaponSystems.net: https/www.weaponsystems.net/system/1423-Type+97; Kaijinsha Ships of the World Jan 2015; Ministry of Defense of Japan HQ whitepaper: https/www.clearing.mod.go.jp/hakusho_data/2000/photo/frame/ap123025.htm