Project 627

Project 627A

Ship data country  Soviet Union Shipyard Shipyard 402 , Severodvinsk Construction period 1955 to 1964 Decommissioning 1991 Units built 1 project 627 12 project 627A 1 project 645

Ship dimensions and crew length 107.4 m ( Lüa ) width 7.9 m Draft Max. 5.7 m displacement surfaced: 3,075 t submerged: 4,750 t   crew 104 men

Machine system machine 2 × WM-A - nuclear reactors with 2 × 70  MW th 2 × GTZA-601 turbines with 2 × 12,871 kW propeller 2

Mission data submarine Diving depth, normal 300 m Immersion depth, max. 400 m Top speed submerged 28.0 kn Top speed surfaced 15.5 kn

Armament 8 × torpedo tubes ∅ 533 mm Ammunition: 20 torpedoes

Project 627 "Wal" ( Russian Кит ) was the name of the first class of nuclear submarines put into service by the Soviet Union . The NATO designation for this type of submarine, which was produced from 1958, was November class . A total of fourteen units were produced under the project name. After a prototype, twelve modified versions called Project 627A and a heavily modernized boat called Project 645 were built.

history

Project 627

According to a corresponding decree drawn up by the Soviet Council of Ministers and signed by Stalin in 1952, the Soviet Navy began to consider building a nuclear-powered submarine.

The theoretical advantages were obvious: in a possible war with the Western powers, the enemy would be able to maintain air supremacy over most of the seas, making Soviet naval operations impossible. Even a submarine, as the experience of the Second World War had shown, could not move safely under constant air surveillance, because to recharge its batteries or to use its snorkel it had to come to the surface of the water, where it could be detected and attacked from the air could. A drive system based on a nuclear reactor for energy supply eliminated this problem, but presented the designers with new challenges. A sufficiently thick shielding of the WM-A reactors used to protect the crew from radiation and a system that could equalize the pressure conditions in the boat despite the heat of the reactors had to be developed.

The development group SCR-143 founded for this project constructed a submarine that solved these problems and at the same time achieved a favorable ratio of length to width, so that a relatively high speed could be achieved.

The nuclear reactor was developed parallel to the boat by another research group. It was a low-maintenance design that used ²³⁵ U to generate steam that drove a turbine to generate propulsion power. With only one cooling and one steam circuit, construction costs and maintenance work remained relatively low. Distilled water was pumped around the container with the fuel elements and transferred the heat absorbed there to the second circuit, in which the hot steam was created. After the steam had passed through the drive turbine, the pipes of the second circuit were washed in a further step by seawater, which lowered the temperature again so that the process could be repeated.

The use of control rods allowed shutdowns and helped to control the formation of the harmful ¹³⁵ Xe in such cases.

The technical data of the prototype with the project number 627 differed only slightly from the later series model 627A. A shallow draft of 5.65 meters reduced the surface displacement to 3,065 tonnes, while submerged it was 4,750 tonnes, the same as that of Project 627A. Two GTZA 601 turbines each transmitted up to 17,100 hp (12,871 kW) to the shafts.

The originally planned main purpose of the November class was not to hunt down enemy submarines, but to attack ports . The plan was to advance to enemy ports in the event of war and to launch a torpedo with a nuclear warhead against them . For this purpose, the submarine should be equipped with a large torpedo tube in the bow. This housed the T-15 torpedo with a caliber of 1550 mm. This should bring a nuclear warhead with an explosive power of around 1  megaton at a distance of 30-40 km to the target. The project was never implemented and the boats from Project 627 were then used as hunting submarines.

Project 627A

After several weaknesses in the prototype K-3 Leninsky Komsomol had been identified, a revision of the concept was decided. The concrete plans for Project 627A were made from July 1955 to March 1956. First and foremost, the transverse bulkheads and pressure hull cladding of the reactor compartment and the adjacent turbine compartment were reinforced. Furthermore, the electronic equipment was changed and an improved sonar device of the "Artik-M" type was installed.

On August 25, 1956, twelve boats from Project 627A were commissioned from shipyard 402 in Severodvinsk.

effort

The effort that went into planning and building the boats was enormous. Including the planning and construction of various test samples, 135 companies and organizations from all over the Soviet Union were involved in Project 627 until the series version of the boats was built.

technical description

construction

Project 627 was designed as a two-hull boat and had streamlined tail fins. The pressure hull was divided into nine sections:

1. Bow torpedo room
2. Accommodations and batteries
3. bridge
4. Auxiliary diesels and generators
5. reactor
6. Turbine system
7. Electromechanics
8. Accommodations
9. Rear section

The bulkheads between the departments should be able to withstand a pressure of up to 10 atm, so that the individual departments should be locked in an emergency. The outer shell of the pressure hull was made of AK25 steel, which was actually developed for armor. A diving depth of 300 meters was achieved. This was more than twice the depth that other military submarine types of the period could reach.

Armament

The boats were equipped with eight bow torpedo tubes in caliber 533 mm. They were originally designed to carry up to 20 torpedoes of the type SET 53 or 53-61MA.

Noise development

A number of measures have been introduced to minimize noise development. These included a streamlined fuselage with only a few bumps, an anti-sonar coating on the fuselage, vibration damping for the machinery and specially developed screws. Nevertheless, the noise development was significantly higher in the November class compared to contemporary types, both in comparison with American nuclear submarines and with diesel-electric powered submarines. The reason for this lies primarily in the reactors used, which, however, were more powerful and also more compact than their American counterparts. However, it must be considered that such a noise development should be viewed relatively in practice. Even the submarines of the American Thresher class used specifically for submarines could not follow the November class acoustically.

reliability

In technical terms, the submarines were considered to be unreliable. The operating time of the steam generator was particularly problematic, as leaks could occur after several hundred hours of operation, which led to the release of ionizing radiation in the machine area . Such machine problems apparently also prevented the submarines from being used during the Cuban Missile Crisis in autumn 1962. However, during the service period, the vulnerable components could be replaced by more durable versions.

variants

In addition to the original class from Project 627, there was also the variant 627A. This differed in a sonar mounted under the fuselage bow and other hydrophones. Another variant was called Project 645; this version, of which only a single copy (K-27) was built, used liquid metal-cooled reactors of the type WT-1 instead of the pressurized water reactors WM-A . In addition, a conical bow shape and quick-loading devices were used for the torpedo tubes, and the hull was made of anti-magnetic steel. This type was 3 m longer than the previously built boats of the class.

Units built

Project 627

Project 627A

Project 645

All boats were armed only with torpedoes . A modification of this design (referred to as the Hotel class ) allowed the use of ballistic missiles.

In April 1970 one of these boats, the K-8 , sank off the coast of Spain , the K-159 sank in 2003 en route for dismantling. This type of boat was extremely dangerous for the crew, especially due to the high radiation exposure of the leaky cooling systems. The November class was built under massive time pressure regardless of cost and - as is criticized today - put into service immature. Nevertheless, the American models could not compete with the Soviets in terms of speed - although the latter developed significantly more noise emissions.

The K-27 had the November fuselage, but was equipped with liquid metal-cooled reactors and had a serious reactor accident in 1968. Today only a few units are still in service, most of them have been scrapped or broken up.

Project 627 and 627A (NATO: November)

tact. number	Surname	Project	Keel laying	In service since	decommissioned	Remarks
K-3	Leninsky Komsomol	627	September 24, 1955	December 30, 1958	1991
K-5	-	627A	August 13, 1956	December 26, 1959	1989
K-8	-	627A	September 9, 1957	December 31, 1959	April 11, 1970	sunk on April 11, 1970 in the Bay of Biscay
K-11	-	627A	October 31, 1960	December 30, 1961	April 19, 1990	Serious reactor accident on 7.2.1965 while loading new nuclear fuel in Severodvinsk . Eight injured and three killed.
K-14	-	627A	2nd September 1958	December 30, 1959	April 19, 1990
K-21	-	627A	April 2, 1960	November 28, 1961	1991
K-42	Rostovsky Komsomolets	627A	November 28, 1962	November 30, 1963	1985	Badly damaged in a reactor accident involving K-431 on August 10, 1985 and then decommissioned
K-50	-	627A	February 14, 1963	17th July 1964	April 19, 1990	Renamed the K-60 in 1982
K-52	-	627A	October 15, 1959	December 10, 1960	1987
K-115	-	627A	April 4th 1962	December 31, 1962	1988
K-133	-	627A	3rd July 1961	October 29, 1962	May 30, 1989
K-159	-	627A	1962	1963	May 30, 1989	sunk on August 30, 2003
K-181	-	627A	November 15, 1961	December 27, 1962	1987
K-27	-	645	June 15, 1958	October 30, 1963	1979	1982 folded

literature

• Ю.В. Апальков: Подводные лодки советского флота 1945–1991 , том I (for example: JW Apalkow: U-Boats of the Soviet Navy 1945–1991 , Part 1). 2009, ISBN 978-5-903080-55-7 (Russian).
• С.А. Спирихин: Надводные корабли, суда и подводные лодки постройки завода №402. (For example: SA Spirichin: Surface ships, vehicles and submarines built at shipyard No. 402. ) Arkhangelsk 2004, ISBN 5-85879-155-7 (Russian).
• Antonov, Marinin, Walujew: Soviet-Russian nuclear submarines. Brandenburgisches Verlags-Haus, Berlin 1998, ISBN 3-89488-121-6 .

Web links

• National Geographic: November class (English)
• November class on FAS.org (English)
• November class on globalsecurity.org (English)

Individual evidence

1. ↑ Ю.В. Апальков: Подводные лодки советского флота 1945–1991 , том I, p. 93.
2. ↑ ^{a b c d} Владимир Ильин, Александр Колесников: Отечественные Атомные Подводные Лодки . In: Техника И Вооружение - Вчера, Сегодня, Завтра, 2000, issue 05-06
3. ↑ Ю.В. Апальков: Подводные лодки советского флота 1945–1991 , том I, p. 15.
4. ↑ Ю.В. Апальков: Подводные лодки советского флота 1945–1991 , том I, p. 20.
5. ^ Peter Lobner: Marine Nuclear Power 1939-2018. Lyncean Group, 2018. p. 103.
6. ↑ Ю.В. Апальков: Подводные лодки советского флота 1945–1991 , том I, p. 94.
7. ^ Peter Lobner: Marine Nuclear Power 1939-2018. Lyncean Group, 2018. p. 84.