Nuclear torpedo

In the U.S.S.R. and U.S. submarine navies during the cold war, nuclear torpedoes replaced some conventionally weaponized torpedoes.

The U.S.S.R. developed the T15, the T5 and the ASB-30. The only nuclear warhead torpedo used by the United States was the Mark 45 torpedo.^[1] In 2015, there were rumors that Russia was developing a new nuclear torpedo, the Status-6. The Soviet Union widely deployed T5 nuclear torpedoes in 1958 and the U.S. deployed its Mark 45 torpedo in 1963.^[2]:28

The idea behind the nuclear warheads in a torpedo was to create a much bigger and more explosive blast. Later analysis suggested that smaller, more accurate, and faster torpedoes were more efficient and effective.^[3]

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 compatible with the traditional 1550 millimeter 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 millimeter 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.^[4]:239-240 The T-15 project developed a torpedo that could travel 16 miles with a hydrogen bomb warhead. The 1550 millimeter T-15 design was 5 feet in diameter and weighed 40 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 30 knots. The torpedo speed was hindered by the usage of an electric propelled motor to launch the warhead.^[2]

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 percent 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-millimeter 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.^[5]

Project 627 was modified to provide reactors for a new vessel that would be capable of deploying 533mm 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 52Mt 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.^[6]

T-5

From the early 1950s, when the Soviets successfully engineered their own form of a nuclear bomb, an effective means of delivery was sought.^[7] The T-5 torpedo was tipped by a RDS-9 nuclear warhead which had a 5 kiloton payload. The first T-5 test in Semipalatinsk, Kazakhstan, on 10 October 1954 was unsuccessful.^[8] A year later, after further development, a test at Novaya Zemlya on the 21st of September 1955 succeeded.^[2] On 10 October 1957, in another test at Novaya Zemlya, S-144, a Whiskey class submarine, launched a T-5. The test weapon, code named Korall, detonated with a force of 4.8 kilotonnes twenty meters under the surface of the bay sending a huge plume of highly radioactive water high into the air.^[9] Three decommissioned submarines were used as targets at a distance of 6.5 miles.^[2] Both S-20 and S-34 sank completely, and S-19 was critically damaged.

In 1958, the T-5 became fully operational as the Type 53-58 torpedo.^[2]:28 Its nuclear warhead was interchangeable with high explosive, allowing for quick decision making. Like the US Mark 45 torpedo, the T-5 was designed not for direct hits, but for a maximized blast kill zone. In water, a T-5 can send shock waves that are powerful enough to break the hulls of submarines. The T-5 could be outfitted on most Soviet submarines.^[2]

Like the U.S. Mark 45 torpedo, the T-5 was not optimized for deep diving and had limited guidance capability. The thermal range for normal operation required temperature +5 to +25C, which limited its use, particularly in Arctic waters.^[5]

ASB-30

The ASB-30 was a nuclear warhead, deployed by the Soviet Navy in 1962, which could replace high-explosive warheads on 21-inch torpedoes while the submarine was at sea.^[2]:28

VA-111 Shkval

Supercavitating torpedo VA-111 Shkval can be used to carry nuclear warheads.

Russian Federation

Status-6

In 2015, rumors emerged that Russia may be developing a new up to 100 megatons^[10] nuclear torpedo, the Status-6 Ocean Multipurpose System,^[11][12][13] codenamed “Kanyon” by Pentagon officials.^[14][15] This weapon is designed to create a tsunami wave up to 500m tall that will radioactively contaminate a wide area on an enemy coasts with cobalt-60, and to be immune to anti-missile defense systems that might disable an ICBM.^{[12][13][15][16][17]} Two potential carrier submarines, the Project 09852 Belgorod, and the Project 09851 Khabarovsk, are new boats laid down in 2012 and 2014 respectively.^{[14][15][18][19]} Status 6 appears to be a deterrent weapon of last resort.^[17][18][19] It appears to be a torpedo-shaped robotic mini-submarine, that can travel at speeds of 100 knots(185.2km/h).^[17][18] This underwater drone is cloaked by stealth technology to elude acoustic tracking devices.^[12][18]

United States

Rationale

U.S. interest in a nuclear torpedo can be traced to 1943, when Captain William S. Parsons, head of the ordinance division of the Manhattan Project, proposed an air-launched uranium-type nuclear warhead torpedo.^[2] This concept never advanced. It was not until the late 1950s, when deep-diving, fast Soviet nuclear submarines appeared, that heavier weaponry was needed. In 1960, the United States declared its program of nuclear warheads that could be dropped from the delta-winged B-58 Hustler, the first operational supersonic bomber, over target points detected by sonar systems.^[20]

Mark 45

The Mark 45 torpedo, also known as ASTOR, was a United States Navy (USN) nuclear weapon. The Mark 45 replaced the Mark 44 torpedo, which was appreciably smaller, weighing about 425 lbs and 100 inches in length.^[1] The Mark 44 range was around 6000 yards and it could reach speeds of 30 knots.^[21] The initial design was undertaken in 1959 or 1960 by the Applied Research Laboratory, University of Washington, Seattle, Wash., and the Westinghouse Electric Corp., Baltimore, Md.^[21] The torpedo entered service in 1963.

The Mark 45 was a submarine-launched, antisubmarine, antisurface ship torpedo with wire guidance capabilities.^[3] The warhead was a W34 low-yield tactical nuclear warhead, whose extensive blast radius would destroy an enemy boat by a proximity detonation, rather than precision delivery. To ensure full control was maintained over the nuclear weapon, a wire control carried out the detonation.^[1] The warhead was detonated only by a signal sent along the wire; there was no contact or influence exploder in the torpedo. Target guidance signals, informed by a gyro and depth gear, could also be sent via the wire connection, as the torpedo had no on onboard homing ability.^[22]:71[1] It was 19 inches in diameter, and was launched silently from a standard 21-inch tube by allowing it to swim out. It was 227 inches long and weighed 2300 to 2400 lbs.^[21] There were 3 modules of the Mark 45. The first one, module 0, was a heavier than the other modules, perhaps because it was flooded for most of its life. The 2nd and 3rd modules had increased range.^[21] The nuclear warhead offered a large explosion that could destroy high speed, deep diving submarines. Powered by a seawater battery and a 160ehp electric motor,^[1] it could reach 40 knots and had a maximum range of 15,000 yards (13,650m), uncomfortably close for a vessel launching a nuclear weapon. Approximately 600 Mark 45 torpedoes that were built from 1963 to 1976.

Replacement

The size and weight of the Mark 45's nuclear warhead greatly interfered with the speed the torpedo could reach. From 1972 to 1976, the Mark 45 was replaced by the Mark 48 torpedo, the current USN submarine torpedo.^[23]:161 The Mark 48 is a very fast, deep-diving, acoustic-homing torpedo with a high performance guidance system.^[1][21] The Mark 48 is 21 inches (533 mm) in diameter, has a length of just over 19 feet (5.8 m), and carries a warhead of approximately 650 pounds (295 kg) of high explosives. The weapon is estimated to have a speed of 55 knots and a range of 35,000 yards (32 km). A guidance wire spins out simultaneously from the submarine and the torpedo, enabling the submarine to control the "fish" using the larger and more capable passive sonar of the submarine. The torpedo's gyro places it on an initial bearing to the target. The wire only cames into play if the target’s position and movement suggest a change is needed to correct the torpedo’s gyro course. In such case, the fire control technician makes the alteration through the wire. The wire is then cut and the torpedo’s homing sonar seeks out the target. Subsequent advances to the Mark 48 include the Mark 48 Mod 3, with advances to the homing system, using TELECOM, which provides two-way data transmissions between the submarine and the torpedo, enabling the torpedo to transmit acoustic data back to the submarine. Over 5,000 Mark 48 torpedoes have been produced.^{[23]:161[2]:203–204}

The decommissioned Mark 45 torpedoes were refashioned, replacing the nuclear warheads with conventional warheads. These "Freedom" torpedoes were offered for foreign sale without much success.^[22]:72[24]

Cuban Missile Crisis

The U.S. was initially unaware that the U.S.S.R. possessed nuclear-armed-torpedoes. Although other types of nuclear weapon were well known, it only came to light many years after the Cuban Missile Crisis in October 1962 that the U.S. had been vulnerable to a nuclear torpedo attack.

Before the crisis, the U.S. had been stalking and documenting most Soviet submarines.^[25] During the crisis, the U.S. imposed a blockade to eradicate all Soviet presence in the Caribbean Sea. A dangerous incident may have occurred on Soviet submarine B-59,^[26] although some doubts have been raised. Vadim Orlov, who was a communications intelligence officer, stated that on 27 October, U.S. destroyers lobbed PDCs at B-59. Captain Valentin Savitsky, unable to establish communications with Moscow, with a crew suffering form heat and high levels of carbon dioxide, ordered the T5 nuclear torpedo to be assembled for firing. The Deputy Brigade Commander Second Captain Vasili Arkhipov calmed Savitsky down and they made the decision to surface the submarine.^[27] This narrative is controversial, as other submarine commanders have found it improbable that Savitsky would have given such an order.^[25]

See also

• Supercavitation
• Submarine-launched ballistic missile
• List of supercavitating torpedoes
• ICBM
• Heavy ICBM
• Comparison of ICBMs
• List of ICBMs
• MIRV
• MARV
• RS-28 Sarmat
• Hypersonic cruise missile
• High Speed Strike Weapon (HSSW)
• WU-14 - Chinese hypersonic glide vehicle (HGV)
• Yu-71 - Russian hypersonic glide vehicle (HGV)
• Advanced Hypersonic Weapon (AHW)
• Hypersonic Technology Vehicle 2 (HTV-2)
• Hypersonic Technology Demonstrator Vehicle
• DARPA Falcon Project
• Prompt Global Strike
• Boost-glide
• Ballistic missile
• Intermediate-range ballistic missile
• Anti-ship ballistic missile (ASBM)
• theatre ballistic missile
• B61 Mod 12
• B83 nuclear bomb

References