OVERVIEW: The 65-73 is a Soviet submarine-launched, straight-running heavyweight torpedo developed between 1985 and 1991, equipped with a 20-kiloton nuclear warhead. It was designed to destroy high-value surface groups such as carrier strike formations using a wide-area nuclear blast.

DETAILS: The designation “65-73” indicates a 650 mm diameter torpedo, with “73” corresponding to its project series. Unlike wake-homing or wire-guided torpedoes, the 65-73 followed a purely straight, gyroscope-stabilized course. It carried a single 20-kiloton nuclear warhead and used a kerosene-oxidizer thermal propulsion system, providing long-range and high-speed performance. Its nuclear payload made it capable of eliminating multiple vessels within a task group from a single detonation, though its operational role remained strategic and deterrent-focused.

TYPE: Heavyweight straight-running nuclear torpedo

FUNCTION: Once launched from a submerged submarine, the 65-73 follows a predetermined straight trajectory guided by internal gyroscopes. The 20 kt warhead is set to detonate on impact or via proximity to surface vessels, creating a large-scale blast intended to neutralize carrier groups or surface concentrations.

NOTE:
IOC: 1985–1991 (development period), no confirmed operational service
Operators: Soviet Union (planned), no confirmed active deployment
Platforms: Project 941 (Typhoon-class, designed compatibility), Project 949A (Oscar II-class, torpedo tube compatibility)
Conflict used in: Never used in combat

SOURCE:
Federation of American Scientists (FAS): https://fas.org/nuke/guide/russia/navy/torpedo.htm ; Jane’s Underwater Warfare Systems ; Naval Institute Guide to World Naval Weapon Systems ; Russian Navy Strategic Weapons Digest ; SIPRI Yearbook: https://www.sipri.org/publications/sipri-yearbook