Summary and Key Points: The Soviet Union’s Typhoon-class was the largest submarine ever built and had a swimming pool. It also displaced 48,000 tons submerged, ran 175 meters long, carried 20 ballistic missiles with up to 10 warheads each — as many as 200 nuclear weapons inside one hull — and could stay under the Arctic ice for 120 days without surfacing. The pool was not decoration. A crew of 160 sealed in steel for four months at a time is a problem no navy had faced at that duration, and the Typhoon’s freakish internal volume let Soviet designers solve it with space: a small pool that could be filled with heated seawater, a sauna, a gymnasium, a solarium. Six were built. The last was decommissioned on 6 February 2023, ending a 42-year run, and nothing like them has been built since, nor is anything likely to be built again.
The Typhoon-Class Was a Massive Submarine for a Reason
The largest submarine ever built announced itself before American intelligence knew what it was. In 1974, Leonid Brezhnev told President Gerald Ford that if the United States insisted on building its Trident submarines, the Soviet Union would build something called Typhoon, a word that meant nothing to Ford or to the analysts who heard it.
What emerged from the Sevmash yard at Severodvinsk over the following decade gave the word its meaning: Project 941, called Akula, meaning shark, by the Soviets and Typhoon by NATO, a class of ballistic missile submarines displacing about 48,000 tons submerged, 175 meters long and 23 meters across the beam, more than twice the submerged displacement of the American Ohio class it was built to answer.
Nothing as it had existed before, and nothing like it has been built since. Six were completed; they served from 1981 until the last was decommissioned in 2023, and they remain the only warships in history whose crews could swim laps and take a sauna between nuclear deterrent duties.
Every part of that sentence had a hard military logic behind it, and the logic is the story.
The Missile Made the Monster
The Typhoon was enormous because its missile was enormous, and its missile was enormous because Soviet chemistry lagged American chemistry.
The class existed to match the Ohio boats and their Trident missiles: a survivable second-strike force, able to ride out an American first strike and answer it, which meant carrying long-range solid-fuel missiles capable of reaching the United States from protected waters near home.
Solid propellant was the hard part.
Soviet solid-fuel technology could not match the energy density the Americans packed into the Trident, so achieving comparable range required a far bigger rocket, and the R-39 that resulted was the heaviest submarine-launched ballistic missile ever put into service, more than twice the weight of America’s Trident I, with a range of roughly 8,300 kilometers.
Each Typhoon carried 20 of them, each missile fitted with up to 10 independently targetable warheads, which put as many as 200 nuclear weapons inside a single hull.
A boat built around 20 rockets of that size could not be a normal submarine, so the designers at the Rubin bureau stopped trying to build a normal submarine. They scaled the vessel to the weapon, and the weapon demanded a giant.
Five Hulls Inside One
The Typhoon’s architecture is often simplified to two submarines welded together, but the truth is stranger.
Inside the outer casing sit two complete parallel main pressure hulls, side by side like a catamaran, with the 20 missile tubes carried between and forward of them, ahead of the sail rather than behind it as on every American boomer.

Typhoon-Class Submarine. Image Credit: U.S. Military/Facebook.
Three additional pressure structures, housing the torpedo room, the command spaces, and the aft steering compartment, bring the total to five separate hulls inside one ship, an arrangement that gave the class extraordinary redundancy and survivability, since damage to one hull did not doom the others. Everything came in pairs: two OK-650 reactors of 190 megawatts each, one per hull, driving two 50,000-horsepower turbine sets and two shrouded screws, good for 27 knots submerged and a test depth of 400 meters.
The design was built for one environment above all. The Typhoons were made to disappear under the Arctic ice cap for months, sitting in protected bastions close to Soviet waters rather than running the Atlantic gauntlet. American boomers never had to run in reverse, and the class carried a massively reinforced sail and enormous reserve buoyancy so a boat could smash upward through meters of ice, surface in the polar night, and launch.

Ohio-Class SSBN. Image Credit: Creative Commons.
The strategy explains the geography of the whole program: the Typhoons never needed to go anywhere.
They needed to survive, wait, and remain undetectable by anyone, within a fortress of Soviet air and naval power, with 120 days of submerged endurance to last.
The Pool, the Sauna, and the Reason for Them
A crew of 160 sealed in steel under the ice for four months is a morale and performance problem no navy had faced at that duration, and the Typhoon’s freakish internal volume let the designers solve it with space: a small swimming pool that could be filled with heated seawater, a sauna, a gymnasium, a solarium, and living quarters roomier than anything in the Soviet submarine force.
Western boats managed long patrols through rotation and culture; the Typhoon managed them through square meters.
Crews called the boats floating hotels, and the comfort had a deterrent logic of its own, because a second-strike weapon only works if its crew remains sharp enough, month after silent month, to execute the one order the entire machine existed to receive. The pool was part of the weapon system.
What It All Cost for the Typhoon-Class Subs
Honestly, the data here is not great in the public record.
What the record does support is scale, from three directions.
First, the comparative: each American Ohio-class boat cost roughly $1.8 billion, and the Typhoon was more than twice the ship by displacement, built with five pressure hulls, two full reactor plants, and a purpose-built construction hall at Severodvinsk with dedicated basing infrastructure at Zapadnaya Litsa, all of which argues for a per-boat burden at or beyond the Ohio’s in real resources, across six hulls and a canceled seventh.
Second, Moscow’s own accounting, delivered decades later: when Russia weighed modernizing the surviving boats, the navy concluded that refitting a single Typhoon would cost as much as building two brand-new Borei-class submarines, and canceled the program in 2012, a statement that prices the class’s appetite better than any archival ruble figure could.

MAY 30, 2021: The Project 955A (Borei A) nuclear-powered ballistic missile submarine Knyaz Oleg sets off on its first sea trial in the White Sea. Oleg Kuleshov/TASS/Russian State Media.
Third, the disposal ledger: when the money ran out, Russia could not even afford to scrap the giants itself, and three of the six were dismantled in the 2000s with American funding under the Cooperative Threat Reduction program, the United States paying to take apart the weapon built to destroy it, an irony with an exact parallel in what warship disposal costs everywhere.
The program consumed a meaningful slice of late-Soviet military industry to produce six hulls, and the fairest per-boat statement is the one the evidence sustains: each Typhoon absorbed resources on the order of the most expensive submarines ever built anywhere, in an economy one-third the size of its rival’s.
The Quiet Career
The operational history is short on drama by design, because the class’s job was the absence of events.
TK-208, the lead boat, was laid down in 1976, launched in 1980, and commissioned in December 1981, with five sisters following through 1989 and a seventh canceled on the ways; the Soviets had once planned a dozen.
All six served with the Northern Fleet, running deterrent patrols under the Arctic through the 1980s, holding American cities at risk from water no NATO force could easily reach, and never firing a shot at anything but test ranges.
The end came not from an enemy but from chemistry and arithmetic.
The R-39 missiles were retired around the turn of the century; their replacement, the R-39M Bark, failed three consecutive test launches and was canceled in 1998; and a giant submarine without a missile is a very expensive hotel.

Typhoon-Class Submarine. Image Credit: Creative Commons.

Typhoon-class Submarine. Artist Rendering.
Russia pivoted to the smaller Bulava missile and the smaller Borei-class to carry it, and the Typhoons became orphans of their own weapon.
The lead boat alone found a second life: rebuilt over a twelve-year overhaul and recommissioned in 2002 as Dmitriy Donskoy, she spent her final two decades as the test platform for the Bulava, the missile of the boats that replaced her, firing the future from tubes built for the past.
Hollywood’s Favorite Submarine
No warship class has a better second career in fiction.
Tom Clancy’s 1984 novel The Hunt for Red October imagined a modified Typhoon whose captain, Marko Ramius, steals the boat to defect, aided by a silent caterpillar drive that renders her invisible to sonar; the 1990 John McTiernan film put Sean Connery in the role opposite Alec Baldwin and made the class the most famous submarine silhouette on earth.
The fiction sat on a real foundation in more ways than one. Clancy drew his mutiny from the actual 1975 revolt aboard the Soviet frigate Storozhevoy, whose political officer, Valery Sablin, seized his own ship, and in inventing his submarine’s navigation gear, the novelist unknowingly described a classified gravimetric system that existed on American boats, one of the episodes that earned Clancy his legendary unwanted attention from the Pentagon.
The caterpillar drive itself was fiction wrapped around real magnetohydrodynamic research that continues at DARPA today.

Typhoon-Class Submarine. Image Credit – Creative Commons.
The class’s cinematic afterlife has outlived the class: the eleven-foot filming model of the Red October, once displayed at Planet Hollywood, was bought at auction and now hangs, turning gently to the right as Ramius would insist, from an office ceiling in Wyoming.
Why They All Went Away
The Typhoons were killed by the same forces that killed the country that built them, in the order of money, missiles, and mathematics.
Post-Soviet Russia could not afford to run 48,000-ton submarines whose upkeep devoured budgets, strategic arms treaties capped the warhead counts that had justified 200-weapon boats, and the death of the R-39 line left the class unarmed for its only mission.
TK-202, TK-12, and TK-13 went to the breakers in the 2000s with American money paying the yards; TK-17 and TK-20 lingered in reserve for years before joining the disposal queue at Severodvinsk; and Dmitriy Donskoy, the first built and last serving, was decommissioned on February 6, 2023, closing the class’s 42-year run, with reports since that she may be preserved as a museum ship in Saint Petersburg, which would leave one giant intact as the monument the class already is.
Russia’s deterrent now rides in the Borei boats, half the size of the Typhoon and quieter, and one of the new hulls has been named Dmitry Donskoy, the legacy passing to a submarine on which the old giant personally tested the missile.

Typhoon-class submarine. Image Credit: Creative Commons.
The design philosophy died with the class, and every navy since has voted the same way, building its best boats smaller and quieter rather than bigger, while the burden of maintaining giant capital ships in small numbers remains a lesson both navies keep learning.
The record the Typhoon set will likely stand forever, because the conditions that produced it cannot recur: a superpower whose missile chemistry forced its hand, whose ideology demanded the answer be visible from space, and whose treasury never had to explain the bill.
Forty-eight thousand tons, a swimming pool, two hundred warheads, and not one shot fired in anger.
As epitaphs for the Cold War go, the biggest submarine ever built is close to perfect.
About the Author: Harry J. Kazianis
Harry J. Kazianis (@Grecianformula) was the former Senior Director of National Security Affairs at the Center for the National Interest (CFTNI), a foreign policy think tank founded by Richard Nixon based in Washington, DC. Harry has over a decade of experience in think tanks and national security publishing. His ideas have been published in the NY Times, The Washington Post, The Wall Street Journal, CNN, and many other outlets. He has held positions at CSIS, the Heritage Foundation, the University of Nottingham, and several other institutions related to national security research and studies. He is the former Executive Editor of the National Interest and the Diplomat. He holds a Master’s degree focusing on international affairs from Harvard University.