Losharik submarine

Losharik is Russia's Project 10831 AS-31 deep-diving nuclear-powered special-purpose submarine for GUGI undersea missions. Open reporting describes a titanium-hulled boat built around seven joined spherical pressure compartments, supported by a mothership, and still being repaired or tested after the 2019 fire.

Various Conflicts🏳️ Unspecified

Losharik submarine, Deep-diving special-purpose submarine, Naval Systems

Image source: Losharik.svg

Profile

Origin: Russia
Built by: Malakhit Design Bureau
Type: Deep-diving special-purpose submarine
Service note: 1990s-present
Designer: Malakhit Design Bureau
Designed: 1988-1990
Produced: 1990s-2003
Number built: 1
Variants: AS-31, AS-12, Project 10831, Project 210, NATO reporting name: Norsub-5

Also Known As

AS-31
AS-12
Project 10831
Project 210
Norsub-5
Losharik
Losharik submarine

submarine nuclear-powered special operationsundersea warfare

Specifications

Length: ~70 m
Beam: ~7 m
Crew: About 25
Propulsion: 1 nuclear reactor driving a single screw
Operating depth: About 1,000 m in one open-source estimate; reporting after repairs said its 6,000 m capability was preserved
Hull: Seven joined titanium spherical compartments

Service And Conflict Use

Service History

In service: Open sources place Losharik in service by the late 1990s or early 2000s, but the exact commissioning year is not consistently reported because the platform is highly secret. It remained under repair after the 2019 fire and was reported due for sea trials in 2024.
Used by: Russian Navy, Main Directorate of Deep Sea Research (GUGI)

Conflict Usage

Side: 🏳️Unspecified

Reuters reported in March 2024 that Losharik was due for sea trials after years of repair work, and The Barents Observer reported the boat returning to service after its 2019 fire. Open reporting confirms continued Russian fielding of the submarine, but not a specific cataloged conflict assignment.

Timeline

Losharik submarine Key Events

Jul 16, 1990
Construction starts
Covert Shores lists Losharik as laid down on 16 July 1990 as a secret special-missions boat.
Sources: Spy Submarine: Russia’s AS-31 Losharik
Aug 26, 1995
Launch date reported in open sources
Covert Shores gives 26 August 1995 as the reported launch date for Project 10831 Losharik.
Sources: Spy Submarine: Russia’s AS-31 Losharik
Jul 1, 2019
Fire during underwater research
The Barents Observer reported that a fire broke out during underwater research activity, killing 14 sailors and sending the submarine into a long repair cycle.
Sources: TASS: super-secret nuclear submarine Losharik soon back in service
Mar 13, 2024
Sea trials reported after repairs
Reuters, republished by The Star, reported that Losharik would go out for testing in June or July after completing years of repairs.
Sources: Russian nuclear-powered Losharik submarine to be tested in June or July after repairs, TASS reports

Losharik submarine Images

Losharik submarine, Deep-diving special-purpose submarine, Naval Systems - view 1 — Source: Losharik.svg

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Sources

Spy Submarine: Russia’s AS-31 LosharikPublisher: Covert Shores | Note: Supports Losharik background, special-missions role, estimated dimensions, propulsion, crew size, and the joined-sphere hull description. | Accessed: 2026-06-25 Losharik – Russia Military AnalysisPublisher: Russia Military Analysis | Note: Supports Malakhit development context, Severodvinsk build references, and the open-source uncertainty around Losharik's exact service timeline. | Accessed: 2026-06-25 TASS: super-secret nuclear submarine Losharik soon back in servicePublisher: The Barents Observer | Note: Supports the 2019 fire, the 2024 sea-trial and return-to-service reporting, and the submarine's continued operational context. It also supports Various Conflicts because the article confirms fielding but does not assign a named conflict. | Accessed: 2026-06-25 Russian nuclear-powered Losharik submarine to be tested in June or July after repairs, TASS reportsPublisher: The Star / Reuters | Note: Supports Various Conflicts because Reuters reported Losharik would go out for testing after repairs, confirming direct operational fielding, but the report does not identify a named conflict. | Accessed: 2026-06-25 Losharik.svgPublisher: Wikimedia Commons | Note: Supports image provenance and CC BY-SA 4.0 licensing context for the primary Losharik schematic. | Accessed: 2026-06-25 Losharik interno.svgPublisher: Wikimedia Commons | Note: Supports image provenance and CC BY-SA 4.0 licensing context for the interior schematic used in the gallery. | Accessed: 2026-06-25