OVERVIEW: The Tp 617 is a heavyweight, wire-guided anti-ship torpedo developed by Sweden as an export variant of the Tp 613, introduced in 1982. It retains Tp 613's high-speed HTP/ethanol propulsion and wire-guidance system with acoustic homing.

DETAILS: “Tp” stands for Torped, and “617” identifies the export model of the Tp 613 torpedo family. It shares the 533 mm diameter, approximately 7 m length, weight around 1 850 kg and 300 kg warhead used in Tp 613, powered by an HTP/ethanol piston engine and featuring two-speed capability exceeding 60 kn. The Tp 617 incorporates two-way wire guidance for mid-course navigation, an active/passive acoustic seeker, and wake-homing during terminal phase. Differences in the export version include downgraded software parameters for hydrophone and proximity fuse performance, maintaining interoperability with surface ships and submarines.

TYPE: Heavyweight Wire-Guided Anti-Ship Torpedo (Export Variant)

FUNCTION: Launched from 533 mm tubes aboard surface ships or submarines, it travels under wire guidance with two-way data link enabling mid-course adjustments. In the terminal phase it employs acoustic and wake-homing to strike fast-moving surface vessels.

NOTE:
IOC: ca 1982 (Tp 617 export model)
Manufacturer: Sweden (Förenade Fabriksverken / Saab Bofors Underwater Systems)
Operators: Denmark, Norway, Yugoslavia (confirmed export users) 

SOURCE:
Miller & Jordan “Modern Submarine Warfare” (Torped 617 export details); Jane’s-like torpedo spec via torp.esrc.unimelb.edu.au P00002814; Naval-Int News “Tp 617 export version”; Wikipedia “Torped 613” – https://en.wikipedia.org/wiki/Torped_613