Underwater flame
The fire on the AS-31 Losharik in July 2019 marked a rare tragedy for the Russian submarine fleet since the Nerpa incident in 2008. Official details remain classified, and publicly available information is limited. The Russian Defense Ministry said the blaze started in the battery compartment and that 14 submariners died while preserving the vessel’s survivability. A civilian specialist was evacuated from the burning area, and the hatch was closed to prevent the fire from spreading.
Within weeks, a military industry source suggested the device sustained serious damage across multiple systems, including communications, the control system, the hydroacoustic complex, navigation, and life support. Journalists noted the extent of the damage and the likelihood that these critical components were replaced during the aftermath.
Speculation remains about the actions of the crew during the incident. What is clear is that the Losharik platform itself holds a unique fascination, paralleling the tragedy of its mission. The craft’s unofficial name, Losharik, draws from a Soviet cartoon about a horse composed of cannon parts, a nod to the submarine’s heavily reinforced hull. Externally, submarines appear with two hulls: an outer hull designed to shed water and an inner hull that is sealed to protect the crew and essential machinery. Typical configurations feature a long, rounded shape, with dive depths usually limited to a few hundred meters for standard designs.
Losharik was engineered to operate at depths reaching three thousand meters or more, capable of withstanding pressures around 290 atmospheres. This translates to about 2.8 thousand tons of force per square meter. The ideal shape for resisting compression is a sphere, with a smaller sphere offering better strength. This line of thinking led the Soviet era to explore a multi-spherical deep-sea vehicle design in the 1980s.
An isolated nuclear power plant was installed in one section. The vessel is reported to function without crew intervention in that area, while other compartments connect to the crew and equipment via passages. Losharik is not designed for independent navigation and relies on a carrier submarine. The working procedure is believed to involve the carrier deploying the device to a research area, with the AS-31 then navigating a designated zone and returning later to its base point.
Silent Spy
Public sources do not provide official, detailed descriptions of the tasks assigned to Losharik. Nuclear submarines typically fall into two categories: multipurpose and strategic. Strategic submarines center on a sequence of vertical launch tubes for ballistic missiles and are designed to stay far from allied shores, ready to deliver weapons in a large-scale conflict. They are built for survivability, making a disarming first strike especially challenging for opponents.
Multipurpose submarines cover broader missions, echoing the workhorse role of World War II era boats. They can hunt enemy ships, gather intelligence, monitor carrier groups, conduct sabotage, transport military cargo, and perform numerous stealth operations. Losharik does not fit neatly into these traditional roles and is generally considered unarmed. Still, it has drawn attention as a platform with potential to operate under extreme conditions. Analysts note the unit involved in deep-sea research remains highly confidential, and Western observers frequently speculate about possible objectives, from seabed investigations to strategic reconnaissance.
Some analyses contend Losharik could collect valuable underwater objects or install sensitive reconnaissance capabilities on seabed facilities. Others suggest that such submarines could be adapted to retrieve sensitive items or to establish discreet connections with underwater networks. There is also discussion about the possibility of future variants equipped with retractable wheels to enable seabed travel, which would complicate sonar detection. The idea remains a topic of debate rather than a confirmed program, with experts offering various scenarios based on existing deep-sea research capabilities.
Notably, despite significant civilian engineering advancements, there are no widely publicized equivalents of the Losharik in the United States. Public sentiment often reflects a belief that some systems remain classified, similar to historical precedents where stealth assets existed beyond public knowledge. Such comparisons reinforce the notion that advanced underwater platforms could enable novel capabilities while remaining under tight secrecy. It is worth noting that the recent accident halted major work on Losharik, with restoration continuing after the fire caused extensive damage. The platform is expected to undergo testing in the near term, following repairs and safety assessments in the wake of the incident.