Nuclear torpedo

During the Cold War, nuclear torpedoes replaced some conventionally armed torpedoes on submarines of both the Soviet and American navies.

The USSR developed the T15, the T5 and the ASB-30. The only nuclear warhead torpedo used by the United States was the Mark 45 torpedo. The Soviet Union widely deployed T5 nuclear torpedoes in 1958 and the U.S. deployed its Mark 45 torpedo in 1963. In 2015, there were rumors that Russia was developing a new nuclear torpedo, the Status-6.

Soviet Union

T-15

The Soviet Union's development of nuclear weapons began in the late 1940s. The Navy had put itself forward as the most suitable branch of the Soviet armed forces to deliver a nuclear strike, believing its submarine technology and tactics to be superior to the rest of the world. In theory, long-range submarines that can surface just prior to launching a nuclear weapon offer a large tactical advantage in comparison to deploying weapons by long range bomber planes that can be shot down.

In the early 1950s, the Soviet Ministry of Medium Machine Building secretly initiated plans for incorporating nuclear warheads into submarine warfare. One concept, the T-15 project, aimed to provide a nuclear warhead with a diameter of 1,550 mm (61 in), which was completely incompatible with the traditional caliber torpedo already used in Soviet diesel-powered submarines. The T-15 project began in strict secrecy in 1951. Research and testing was contemporaneous with the other concept, the much smaller and lighter 533 mm (21.0 in) torpedo referred to as the T-5. Stalin and the armed forces saw benefits to both calibers of torpedo: the T-5 was a superior tactical option, but the T-15 had a larger blast. Meetings at the Kremlin were so highly classified that the Navy was not informed. The plans for the T-15 torpedo and for an appropriately redesigned submarine, named project 627, were authorized on September 12, 1952, but were not officially approved until 1953, surprising the Navy, which had been unaware of the central government activity. The T-15 project developed a torpedo that could travel 16 miles (26 km) with a thermonuclear warhead. The 1550 mm T-15 design was 1.5 m (5 ft) in diameter and weighed 36,000 kg (40 short tons). The large size of the weapon limited the capacity of a modified submarine to a single torpedo that could only travel at a speed of 56 km/h (30 kn). The torpedo speed was hindered by the usage of an electric propelled motor to launch the warhead.

Discontinuation

The T-15 was intended to destroy naval bases and coastal towns by an underwater explosion that resulted in massive tsunami waves. The front compartment of the T-15 submarines held the massive torpedo, which occupied 22% of the length of the submarine. A submarine could only hold one T-15 at a time, but it was also equipped with two 533-mm torpedo tubes intended for self-defense. In 1953, the T-15 project presented its conclusions to the Central Council of the Communist Party, where it was determined that the project would be managed by the Navy. In 1954, a committee of naval experts disagreed with continuing the T-15 nuclear torpedoes. Their criticisms centered on a lack of need when considered along with existing weapons in the submarine fleet, as well as skepticism that submarines would be able to approach launch points close enough to the coastline to hit targets within 40 km (25 mi).

Project 627 was modified to provide reactors for a new vessel that would be capable of deploying 533 mm caliber torpedoes in the T-5 project. However, the termination of the T-15 program in 1954 was not the last time a large torpedo would be considered as means of deployment. In 1961, Andrei Sakharov revisited the idea after the successful testing of his new 52 megaton bomb, which was too large for aircraft. When he introduced the concept to the navy they did not welcome the idea, being turned off by the wide area effect which would kill so many innocent people. Technological advances led to the weapon selection process favoring more tactical approaches that were amenable to quicker execution. After years of decline and reduction of stockpiles the Russian Federation in recent years seems to tend to lean toward an increase of its stockpile in terms of quantity and yield of nuclear weapons.

T-5

From the early 1950s, when the Soviets succeeded in engineering atomic bombs of their own, an effective means of delivery was sought. The T-5 torpedo carried an RDS-9 nuclear warhead with a yield of 5 kilotons. The first test of this warhead on the Semipalatinsk nuclear proving ground in Kazakhstan on 10 October 1954 was unsuccessful. A year later, after further development, a test on Novaya Zemlya on 21 September 1955 succeeded. On 10 October 1957, in another test on Novaya Zemlya, the Whiskey class submarine S-144 launched a live T-5 nuclear torpedo. The test weapon, code named Korall, detonated with a yield of 4.8 kilotons 20 m (66 ft) under the surface of the bay, sending a huge plume of highly radioactive water high into the air. Three decommissioned submarines were used as targets at a distance of 10.5 km (6.5 mi). Both S-20 and S-34 sank while S-19 received critical damage.

In 1958, the T-5 became fully operational as the Type 53-58 torpedo. The weapon, which could be deployed on most Soviet submarines, had an interchangeable warhead for either nuclear or high explosive. This permitted quick tactical decisions on deployment. The T-5, like the US Mark 45 torpedo, was not designed to make direct hits but to maximize a blast kill zone in the water. The detonation would create shock waves powerful enough to crack the hull of a submerged submarine. However, like the U.S. Mark 45 torpedo, the T-5 was not optimized for deep diving and had limited guidance capability. As its thermal operational range was between 5 and 25 °C (41 and 77 °F), this decreased its effectiveness in the waters of the North Atlantic and Arctic.

On 27 October 1962, at the height of the Cuban Missile Crisis, the Soviet submarine B-59 was pursued in the Atlantic Ocean by the U.S. Navy. When the Soviet vessel failed to surface after broadcast communications, the destroyer USS Beale began dropping signaling depth charges as a warning to surface. The B-59 was armed with a T-5. The Soviet captain was not aware of this recent US to Soviet submarine signal instruction and believing that World War III was under way wished to launch the nuclear weapon. However, his flotilla commander, Vasili Arkhipov, who was using the boat as his command vessel, refused to endorse the command. After an argument, it was agreed that the submarine would surface and await orders from Moscow. It was not until after the fall of the Soviet Union that it was made known that the submarine was armed with a T-5. A fictional Soviet nuclear torpedo was deployed in the 1965 Cold War film The Bedford Incident.

ASB-30

The ASB-30 was a nuclear warhead, deployed by the Soviet Navy in 1962, which could replace high-explosive warheads on 533 mm (21-inch) torpedoes while the submarine was at sea.

VA-111 Shkval

The supercavitating VA-111 Shkval torpedo is allegedly able to carry nuclear warheads.