Daily Mail: "Russia produces first batch of nuclear-armed Poseidon torpedo drones"

 The article's full headline is: "Russia produces first batch of nuclear-armed Poseidon torpedo drones 'capable of wiping out entire coastlines with radioactive tsunamis' - as Putin cronies call for Britain to be 'demolished from the face of the earth'." From the article:

    Russia has manufactured its first batch of high-speed Poseidon drones said to be capable of wiping out entire coastlines with radioactive tsunamis, it was reported today.

    The weapon, which could reportedly cause a 1,640ft tsunami, is alleged to have a unlimited range, although details of its unique 125mph underwater propulsion system have been a closely guarded Russian secret.

    The development came as a Vladimir Putin loyalist called on state TV for Britain to be 'demolished from the face of the Earth' as it prepares to supply Ukraine with Challenger 2 tanks.

Also:

    The Russian weapon is a giant nuclear-armed torpedo capable of causing radioactive tsunamis that destroy enemy coastlines.

    In October, it was reported that Nato had sent an intelligence note to its member states warning that Putin had deployed its 604ft-long K-329 Belgorod nuclear submarine, carrier of the Poseidon.

    At the time it was believed to be on a mission to test the fearsome weapon.

    A source told TASS today: 'The first batch of Poseidon ammunition has been manufactured and will be soon delivered to special-purpose nuclear-powered submarine Belgorod.'

    The same source from the Russian military and defence industry said trials of core components of Poseidon underwater drones, including the nuclear power unit, had been trialled successfully.

    Putin sees the Poseidon missile as key to his attack on the West, it has been reported.

Related articles:

• "Vladimir Putin's nuclear tsunami: It's called Poseidon - a giant torpedo that could travel thousands of miles undetected before swamping cities with radioactive waves. No wonder fears over the Russian threat are growing, writes TOM LEONARD"--Daily Mail (April 7, 2021).

    The notion is horrendous to contemplate. 

    A nuclear torpedo drone creeps along the ocean floor, slipping under coastal missile defences and detonating with catastrophic effect close to New York.

    A vast wall of water rises from the sea, tearing through the city, obliterating all in its wake and leaving the area flooded with toxic radioactivity.

    When he unveiled plans for his latest military nightmare a few years ago, everyone thought Vladimir Putin was bluffing. 

    Capable of devastating a huge stretch of coastline with a multi-megaton warhead, the Poseidon 2M39 torpedo would set off a chain of deadly radioactive tsunamis that would smash into towns and cities leaving them uninhabitable for decades.

    This 'doomsday nuke' or 'apocalypse torpedo' seemed just the sort of super weapon that the sabre-rattling Russian leader would dream up to scare the wits out of opponents and bend them to his will. 

    At the time, U.S. officials and defence experts dismissed it as fantasy.

    But now the grim truth has emerged from the melting Arctic ice: Russia really is developing the Poseidon, sending a chill through the West. 

• Related: "Russia reveals giant nuclear torpedo in state TV 'leak'"--BBC (Nov. 12, 2015) (h/t Marcus Wynne). From the article:

    Launched by a submarine, it would create "wide areas of radioactive contamination", the document says.

    The "oceanic multi-purpose Status-6 system" 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", the document says.

Also:

    According to state-run Rossiiskaya Gazeta, the destructive power attributed to the new torpedo's warhead would fit the description of a cobalt bomb.

    That would be a type of thermonuclear warhead with a layer of cobalt-59, which on detonation would be transmuted into highly radioactive cobalt-60 with a half-life longer than five years.

    Such a weapon would guarantee "that everything living will be killed", the paper said - there would not even be any survivors in bunkers.

    A cobalt bomb has never been tested because of the devastating radiation it would unleash.

    "But it can be considered as a means of deterrence - like the Perimetr system, which is on combat readiness, which guarantees retaliation with all of Russia's nuclear forces even if command posts and the country's leadership have been annihilated".

    The April 2021 article notes that the Russians have adapted 3 submarines to carry the weapon, describes in the article as "More than 6ft in diameter and 65ft long, the remotely-controlled weapon is 30 times the size of a standard heavy torpedo and estimated to weigh 100 tons" and being both nuclear armed and nuclear powered. The weapon was originally intended to carry a 100 megaton warhead, but is now armed with only a 2 megaton warhead. 

    The same article also mentions that the U.S. had looked into such weapons during the Cold War, but determined that much of the energy would be dissipated when a wave struck the continental shelf. However, the reality is that the U.S. had started looking at tsunamis created by explosions in World War II (see article, "Tsunami Bomb"). I also looked into early research on the effect of underwater nuclear explosions, and a modest sized underwater nuclear blast tested in the Pacific was able to inundate the nearby atoll with 10-foot waves. 

    However, there didn't seem to be a lot of support for a nuclear weapon being able to produce sizable tsunamis by itself--rather, it appeared that it would need to be a confluence of the blast, the geography of the sea floor, and the depth of the water. The more critical problem, in my mind, is the plume of radiative water that would be produced by the explosion because it would contaminate most everything the water rained down upon. This was demonstrated in the Baker test of Operation Crossroads in 1946 where an underwater atomic bomb was detonated 90 feet below the surface. Arranged around the blast zone was a flotilla of ships representing ships taken from the Japanese and Germans as well as some active duty American vessels located farther from the blast zone.  Wikipedia actually has a good summary of the test, which you can read here. The takeaway, however, is that several of the American vessels that were intended to be scrubbed down and decontaminated ended up being sunk because they couldn't be safely decontaminated. 

    Another descriptive article of the test is "Operation Crossroads: A Deadly Illusion" from the National World War II Museum. It relates:

    The Baker underwater shot was a different story. The bomb, dubbed “Helen of Bikini,” was detonated on the morning of July 25, 1946. According to the government’s Historical Radiological Assessment, “The first effect of the blast was a tremendous bubble of water and steam that broke the ocean’s surface. Then a huge wave, over 90 feet high, later called a base surge, rolled over target and support vessels as well as the islands of the atoll. Vast quantities of radioactive debris, primarily consisting of fission products (radioactive elements resulting from the fission, or splitting, of the bomb’s plutonium), unconsumed plutonium from the bomb’s fissioning core, and radioactive sand and coral that had been irradiated by the intense neutron radiation from the blast rained down on the target and support ships, islands, and lagoon. This unexpected outcome caused contamination of both target and support ships, the extent of which depended on each ship’s position relative to the zero point of the blast. Twelve of the ships in the immediate area of the detonation sank immediately or within hours.”

    No one had experience with decontaminating radioactive ships. Some ships were too radioactive to be boarded at all in the first week and thereafter, for little more than a few minutes. The support fleet itself became radioactively contaminated, as stated in the Nuclear Test Personnel Review, from marine life in the lagoon. By August 10, the decision was made to tow ships to Kwajalein atoll for decontamination and to sink or scuttle others. Eventually, eight major ships and two submarines were towed back to Hawaii and the West coast of the United States for inspection and decontamination. Animals retrieved from the ships that were still alive in August had mostly died of gamma poisoning by November 1946.

    One of the deadly illusions of the 1946 nuclear tests was that a nuclear war could be fought, and maybe even won. The tests demonstrated that some military equipment outside the “red zone” could survive a blast and radiation in some circumstances (a relatively “clean” detonation like Able) but not in others (a dirty one like Baker). The Able shot lulled observers into a false sense of security, whereas the Baker test conveyed the deadlier risks of radiation. A ship could be seaworthy but still untouchable. ...

And, from another article on the Baker test:

    Test Baker was set off beneath the surface, with the bomb suspended from a landing craft. Its shock wave and the following tsunami sank ten ships, including two battleships and an aircraft carrier, and damaged many more (including three that would have sank if they had not been beached). It also threw two million tons of radioactive water into the air, which fell back and created a 900-foot-tall rolling wave of mist, contaminating all remaining vessels within range. 

    Test animals were on board the target vessels for both tests. Survival in Able was good, at about two thirds. None of the hundreds of pigs placed on the range survived Baker.

    Decontamination efforts in the days following showed that none of the ways the Navy thought to clean off radioactive fallout were effective. Plutonium is toxic in microgram amounts, and tests showed that after cleaning, incredibly miniscule but still deadly quantities remained, more than enough to pose a threat to human health. The workers cleaning the vessels even contaminated their own living quarters when they returned to the support ships. After days of trying to warn the Navy command, Colonel Stafford Warren, the Army officer in charge of radiation safety, famously convinced the deputy chief of naval operations to halt the cleaning and any further tests by showing him an x-ray of a fish from the atoll's lagoon – a self-x-ray, as the radiation from the fish was enough to create an image on film.

    The majority of the surviving target ships were too radioactive to clean off and were scuttled. In a top secret report which was kept classified for the next 30 years, the Navy concluded that contamination of the type produced by Baker could not be remediated, and, further, could even be used to "depopulate vast areas of the earth's surface, leaving only vestigial remnants of man's material works.” 

    As I read the articles on the Russian weapon, it appears to me that it is designed to be launched and stealthily approach a coast from perhaps as far as thousands of miles away, then increase its speed to its maximum speed of 80 to 120 mph as a last dash into shallow water before detonating. Depending on the depth of the detonation, the result could produce a wave, produce a giant plume of radioactive water, or both.