OVERVIEW: The Tp 412 is a lightweight, submarine‑launched, wire‑guided anti‑ship torpedo developed in Sweden in the late 1960s and entering service in 1972 on the Sjoormen-class (A12) submarines.

DETAILS: “Tp” is the Swedish designation for Torped, and the Tp 412 is the anti‑ship variant of the Tp 41/42 torpedo family. Produced by Förenade Fabriksverken (FFV), it was specifically customized for Project A12 Sjoormen-class submarines and remained in service until replaced by the Tp 431 in 1988. It measures approximately 2.6 m in length with a 400 mm diameter, weighs ~298 kg, carries a 45 kg high-explosive warhead, and uses electric propulsion with a silver‑zinc battery. It is wire-guided and uses active/passive acoustic homing, optimized for targeting surface vessels in littoral waters.

TYPE: Lightweight Wire-Guided Anti‑Ship Torpedo

FUNCTION: Launched from 400 mm submarine tubes, the Tp 412 travels under wire guidance during the mid-course phase and switches to acoustic homing in the terminal phase to detect and engage surface ships with acoustic signatures.

NOTE:
IOC: 1972 (Tp 412 operational with Sjoormen-class)
Manufacturer: Sweden (Förenade Fabriksverken / FFV)
Operators: Sweden (Royal Swedish Navy)
Platforms: Project A11/Sjoormen-class submarines

SOURCE:
Jane’s Naval Weapons Systems (Sweden Tp 41–46 overview) ; Wikipedia “Torped 41” entry ; Naval‑Warfare.net “HSwMS Sjoormen” history and torpedo fittingshttps://www.torp.esrc.unimelb.edu.au/bib/P00002933.htm