OVERVIEW: The SST-4 Mod 0 Seeaal is a heavyweight, submarine-launched, electric torpedo developed by West Germany for anti-ship missions. It features wire guidance and passive acoustic homing and was introduced to improve performance over the earlier SST-3 model.

DETAILS: "SST" stands for "Super Schwerer Torpedo" (super heavyweight torpedo), and the SST-4 Mod 0 is based on the German DM-2 torpedo family. Developed by Atlas Elektronik and entering service around 1980, the SST-4 Mod 0 introduced improved guidance electronics, a more capable passive acoustic seeker, and longer range via an upgraded silver-zinc battery system. Like its predecessor, it is 533 mm in diameter, uses electric propulsion, and is launched from NATO-standard submarine tubes. Wire guidance is used during the initial and mid-course phase, with passive homing in the terminal phase to strike enemy surface vessels.

TYPE: Heavyweight Anti-Ship Guided Torpedo

FUNCTION: The SST-4 Mod 0 is launched from a 533 mm submarine tube, initially controlled via wire guidance and then switching to passive acoustic homing. It is designed to locate and destroy enemy surface ships with minimal acoustic signature, making it suitable for stealth attacks in contested environments.

NOTE:
IOC: 1972 (SST-3), 1980 (SST-4 Mod 0)
Manufacturer: West Germany (Atlas Elektronik)
Operators: Argentina, Colombia, Turkey, Venezuela
Platforms: Type 209/1200 submarines (Argentina, Turkey, Venezuela), Type 209/1100 (Colombia)
Conflict used in: None confirmed

SOURCE:
Jane’s Naval Weapon Systems ; Federation of American Scientists (FAS): https://man.fas.org/dod-101/sys/ship/weaps/index.html ; GlobalSecurity.org: https://www.globalsecurity.org/military/world/europe/sst-4.htm ; Military-Today: https://www.military-today.com/navy/sst_4.htm ; Wikipedia: https://en.wikipedia.org/wiki/SST_(torpedo)