OVERVIEW: The SST‑4 Mod 3 Seeaal is a heavyweight, submarine-launched, wire‑guided, electric-powered anti-ship torpedo developed in Germany. It enhances the DM‑2 design by integrating modern active/passive acoustic homing for improved performance against surface vessels.

DETAILS: “SST” stands for Super Schwerer Torpedo (“super heavyweight torpedo”), and the SST‑4 line is derived from the DM‑2 series developed by Atlas Elektronik. The Mod 3 retains 533 mm diameter, uses contra-rotating electric propulsion with silver‑zinc batteries, and includes a passive/active acoustic seeker replacing the Mod 0’s basic passive head. The SST‑4 Mod 3 combines wire guidance for mid-course control with terminal homing to target surface ships silently and effectively.

TYPE: Heavyweight Anti‑Ship Guided Torpedo

FUNCTION: Launched from 533 mm submarine tubes, it travels under wire guidance with mid-course targeting updates, then switches to autonomous active/passive acoustic homing to strike surface vessels quietly and accurately.

NOTE:
IOC: 1980 (SST‑4 family)
Manufacturer: West Germany (Atlas Elektronik)
Operators: Confirmed: Argentina, Colombia, Turkey, Venezuela, Greece 
Conflict used in: None confirmed (some SST‑4 series saw use in Falklands War, but Mod 3 specifics unconfirmed)

SOURCE: Jane’s Naval Weapon Systems; Atlas Elektronik official publications; 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; Weaponsystems.net: https://weaponsystems.net/system/1227-DM2%20Seeaal