H I SuttonFebruary 25, 2021 3:26 PM
Illustration of Belgorod submarine. H I Sutton Image used with permission
Russia’s latest super-sized submarine, Belgorod, has been a conundrum for interested observers. While its existence is far from secret, Moscow has gone to great pains to keep certain key details out of the public domain. While navies traditionally hide the screw, or propeller, from the cameras, in Belgorod’s case the reverse was true: the screws were on display at the 2019 launch ceremony, but no photographs of the forward section were ever published.
Belgorod’s secret is its arrangement of the primary weapon system: a new class of nuclear-tipped torpedos. Russian state media Izvestia reported on Feb. 11 that Belgorod is being prepared for tests with the new weapon called Poseidon, a massive nuclear torpedo which is shot forward out of the front of the submarine.
The Izvestia article’s timing matches fresh satellite imagery of the submarine in the northern Russian submarine base in Severodvinsk, which may show part of the tests.
In the absence of official photographs, commercial satellite imagery has become a primary source of information. Though the long Arctic nights and thick clouds have limited access to new imagery for many months, now as the Arctic winter is waning, commercial imagery satellites are once again more active over Severodvinsk.
On Feb. 10, an Airbus satellite took a high-resolution image of the harbor. Moored next to the quay is Belgorod with its torpedo tube doors appearing to be open. These tubes are not for ordinary torpedoes but rather the Poseidon nuclear-powered, nuclear-armed torpedo. It is one of Russian President Vladimir Putin’s so-called wonder weapons, together with hypersonic missiles and a nuclear-powered cruise missile.
Poseidon Torpedo. Russian Defense Ministry Photo
The satellite imagery clearly shows two large openings in the bow. Each opening is roughly six feet (two meters) across, approximately three times the diameter of the openings for regular 21-inch (533mm) torpedoes. This is because the Poseidon weapon is about 20 to 30 times the size of a traditional heavyweight torpedo.
Revealed in 2015, the school-bus sized torpedo is a strategic weapon that is designed to slip under the U.S. ballistic missile defense network. The weapon is designed to “destroy important economic installations of the enemy in coastal areas and cause guaranteed devastating damage to the country’s territory by creating wide areas of radioactive contamination, rendering them unusable for military, economic or other activity for a long time,” according to a 2015 translation of the initial document by the BBC.
Previous reports indicate that Belgorod will be armed with six Poseidons. Being so large and nuclear powered, these are likely carried externally to the main pressure hull, so it is unclear whether all six tubes will have their own shutter doors or if they will be able to cycle through the two shutters seen in the satellite images.
One takeaway from the images is Belgorod probably has a forward hull between the two open shutter doors. This could allow regular torpedo tubes to be mounted in the bow, shooting over top of the sonar.
Although some reporting on the Poseidon implies Belgorod will be conducting test launches imminently, this is unlikely. It’s unclear if the submarine has ever conducted submergence testing, and just today the TASS Russian news agency reported the submarine is preparing to sail to sea for the first time.
The tests that the Izvestia article referenced are likely in-port mating and mechanical checks between the submarine and the weapon, which matches the satellite imagery showing the outer shutters open. This would likely be conducted with inert surrogate rounds where possible, given the safety implications of testing a nuclear-powered weapon with what is likely a minimally shielded reactor at the pier.
While the public image of Belgorod is becoming clearer, the particulars of the new Russian boat are still shrouded in mystery. Nope