OVERVIEW: The 53-65N is a Soviet submarine-launched, straight-running heavyweight torpedo introduced in 1971 and equipped with a nuclear warhead. It was developed to destroy enemy carrier groups and naval formations using a high-yield nuclear detonation.

DETAILS: The designation “53-65N” indicates a 53 cm diameter torpedo of the 53-65 family, with “N” signifying its nuclear warhead configuration. NATO reporting name “53-68N” is incorrect in designation but widely used in Western sources. Unlike wake-homing variants, the 53-65N was a gyroscope-stabilized, straight-running torpedo, designed to deliver a single 20-kiloton nuclear warhead against high-value surface targets. It used a kerosene-oxidizer wet-heater propulsion system and was launched from standard 533 mm torpedo tubes aboard Soviet attack submarines.

TYPE: Heavyweight straight-running nuclear torpedo

FUNCTION: After launch, the 53-65N follows a pre-set straight trajectory using an internal gyroscope for directional stability. It is designed to detonate its 20 kt warhead either on impact or via proximity settings to neutralize carrier groups or dense naval formations with a wide-area blast.

NOTE:
IOC: 1965 (53-65 base), 1971 (53-65N)
Operators: Soviet Union
Platforms: Project 627A (November-class), Project 670 (Charlie-class), Project 671 (Victor-class), Project 641B (Tango-class) submarines
Conflict used in: Never used in combat

SOURCE:
Jane’s Underwater Warfare Systems ; Federation of American Scientists (FAS): https://fas.org/nuke/guide/russia/navy/torpedo.htm ; Russian Naval Ordnance Manuals ; Naval Institute Guide to World Naval Weapon Systems ; SIPRI Yearbook (1972–1985): https://www.sipri.org/publications/sipri-yearbook