Misplaced Pages

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48-409: Until the advent of nuclear power , submarines were designed to operate on the surface most of the time and submerge only for evasion or for daylight attacks. Until the widespread use of radar after 1940, at night a submarine was safer on the surface than submerged, because sonar could detect boats underwater but was almost useless against a surface vessel. However, with continued radar improvement as

96-856: A "considerable amount" of information regarding submarine design and quietening techniques transferred from the United Kingdom to the United States. The rafting system for the Valiant class provided the Royal Navy with an advantage in submarine silencing that the United States Navy did not introduce until considerably later. Nuclear power proved ideal for the propulsion of strategic ballistic missile submarines (SSB), greatly improving their ability to remain submerged and undetected. The world's first operational nuclear-powered ballistic missile submarine (SSBN)

144-399: A 600 kPa (87 psi) compressed air plant provided power to pneumatic drills , increasing productivity greatly over previous manual drilling methods. Compressed-air drills were applied at mines in the United States in the 1870s. George Westinghouse invented air brakes for trains starting in 1869; these brakes considerably improved the safety of rail operations. In the 19th century, Paris had

192-602: A design team under Vladimir N. Peregudov worked on the vessel that would house the reactor. After overcoming many obstacles, including steam generation problems, radiation leaks, and other difficulties, the first nuclear submarine based on these combined efforts, K-3 Leninskiy Komsomol of the Project 627 Kit class, called a November-class submarine by NATO , entered service in the Soviet Navy in 1958. The United Kingdom 's first nuclear-powered submarine HMS  Dreadnought

240-568: A device named a snuiver ( sniffer ). Germany defeated the Netherlands in 1940; their capture of O-25 and O-26 was a stroke of luck for the German Navy, the Kriegsmarine . The Kriegsmarine first viewed the snorkel as a means to take fresh air into the boats but saw no need to run the diesel engines under water. However, by 1943 more U-boats were being lost, so the snorkel was retrofitted to

288-724: A name with Captain Nemo 's fictional submarine Nautilus in Jules Verne 's 1870 novel Twenty Thousand Leagues Under the Seas , the first demonstrably practical submarine Nautilus , and another USS  Nautilus  (SS-168) that served with distinction in World War II ). The Westinghouse Corporation was assigned to build its reactor. After the submarine was completed at the Electric Boat Company , First Lady Mamie Eisenhower broke

336-455: A per unit energy delivered basis. Compressed air is used for many purposes, including: Compressor rooms must be designed with ventilation systems to remove waste heat produced by the compressors. When air at atmospheric pressure is compressed, it contains much more water vapor than the high-pressure air can hold. Relative humidity is governed by the properties of water and is not affected by air pressure. After compressed air cools, then

384-952: A system of pipes installed for municipal distribution of compressed air to power machines and to operate generators for lighting. Early air compressors were steam-driven, but in certain locations a trompe could directly obtain compressed air from the force of falling water. Air for breathing may be stored at high pressure and gradually released when needed, as in scuba diving , or produced continuously to meet requirements, as in surface-supplied diving . Air for breathing must be free of oil and other contaminants; carbon monoxide, for example, in trace volumetric fractions that might not be dangerous at normal atmospheric pressure may have deadly effects when breathing pressurized air due to proportionally higher partial pressure . Air compressors, filters, and supply systems intended for breathing air are not generally also used for pneumatic tools or other purposes, as air quality requirements differ. Workers constructing

432-400: Is a hazard when diving. For diving much beyond 30 metres (100 ft), it is less safe to use air alone and special breathing mixes containing helium are often used. In industry, compressed air is so widely used that it is often regarded as the fourth utility, after electricity, natural gas and water. However, compressed air is more expensive than the other three utilities when evaluated on

480-523: Is commonly used for improved traction and reduced vibration. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers , drills , wrenches , and others, as well as to atomize paint, to operate air cylinders for automation, and can also be used to propel vehicles. Brakes applied by compressed air made large railway trains safer and more efficient to operate. Compressed air brakes are also found on large highway vehicles. Compressed air

528-424: Is mitigated with the use of high-vacuum cut-off sensors that shut down the submerged boat's engines when any sudden pressure drop is detected. Likewise, modern snorkels have a fail-safe design. An electrical circuit controls a compressed air system that holds a "head valve" open against the pull of a powerful spring. When waves wash over exposed contacts, the control circuit breaks, venting the compressed air, causing

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576-452: Is observable by thermal imaging systems, e.g., FLIR . Another problem is that the reactor is always running, creating steam noise, which can be heard on sonar , and the reactor pump (used to circulate reactor coolant), also creates noise, as opposed to a conventional submarine, which can move about on almost silent electric motors. The useful lifetime of a nuclear submarine is estimated to be approximately 25 to 30 years, after this period

624-533: Is to produce compressed air—amounting to 80 terawatt hours consumption per year. Industrial use of piped compressed air for power transmission was developed in the mid-19th century; unlike steam , compressed air could be piped for long distances without losing pressure due to condensation. An early major application of compressed air was in the drilling of the Mont Cenis Tunnel in Italy and France in 1861, where

672-426: Is used as a breathing gas by underwater divers . It may be carried by the diver in a high-pressure diving cylinder , or supplied from the surface at lower pressure through an air line or diver's umbilical . Similar arrangements are used in breathing apparatus used by firefighters, mine rescue workers and industrial workers in hazardous atmospheres. In Europe, 10 percent of all industrial electricity consumption

720-597: The S1W and iterations of designs have operated without incident since USS Nautilus (SSN-571) launched in 1954. The idea for a nuclear-powered submarine was first proposed in the United States Navy by the Naval Research Laboratory 's physicist Ross Gunn in 1939. The Royal Navy began researching designs for nuclear propulsion plants in 1946. Construction of the world's first nuclear-powered submarine

768-567: The VIIC and IXC classes and designed into the new XXI and XXIII types. The first Kriegsmarine boat to be fitted with a snorkel was U-58 , which experimented with the equipment in the Baltic Sea during the summer of 1943. Operational use began in early 1944, and by June 1944 about half of the boats stationed in the French bases had snorkels fitted. On Type VII U-boats the snorkel folded forward and

816-474: The propeller shaft or rely on the reactor heat to produce steam that drives steam turbines ( cf. nuclear marine propulsion ). Reactors used in submarines typically use highly enriched fuel (often greater than 20%) to enable them to deliver a large amount of power from a smaller reactor and operate longer between refuelings – which are difficult due to the reactor's position within the submarine's pressure hull. The nuclear reactor also supplies power to

864-523: The traditional bottle of champagne on Nautilus ' bow, and the submarine was commissioned USS  Nautilus  (SSN-571) , on 30 September 1954. On 17 January 1955, she departed Groton, Connecticut , to begin sea trials . The submarine was 320 feet (98 m) long and cost about $ 55 million. Recognizing the utility of such vessels, the British Admiralty formed plans to build nuclear-powered submarines. The Soviet Union soon followed

912-574: The Admiralty Research Station, HMS Vulcan , at Dounreay , developed a completely new British nuclear propulsion system. In 1960, the UK's second nuclear-powered submarine was ordered from Vickers Armstrong and, fitted with Rolls-Royce's PWR1 nuclear plant, HMS  Valiant was the first all-British nuclear submarine. Further technology transfers from the United States made Rolls-Royce entirely self-sufficient in reactor design in exchange for

960-938: The Golfs. The first Soviet SSBN with 16 missiles was the Project 667A (Yankee class) , the first of which entered service in 1967, by which time the US had commissioned 41 SSBNs, nicknamed the " 41 for Freedom ". At the height of the Cold War , approximately five to ten nuclear submarines were being commissioned from each of the four Soviet submarine yards ( Sevmash in Severodvinsk , Admiralteyskiye Verfi in St.Petersburg, Krasnoye Sormovo in Nizhny Novgorod , and Amurskiy Zavod in Komsomolsk-on-Amur ). From

1008-525: The United Kingdom, all former and current nuclear submarines of the British Royal Navy (with the exception of three: HMS  Conqueror , HMS  Renown and HMS  Revenge ) have been constructed in Barrow-in-Furness (at BAE Systems Submarine Solutions or its predecessor VSEL ) where construction of nuclear submarines continues. Conqueror is the only nuclear-powered submarine in

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1056-604: The United States in developing nuclear-powered submarines in the 1950s. Stimulated by the U.S. development of Nautilus , Soviets began work on nuclear propulsion reactors in the early 1950s at the Institute of Physics and Power Engineering , in Obninsk , under Anatoliy P. Alexandrov, later to become head of the Kurchatov Institute . In 1956, the first Soviet propulsion reactor designed by his team began operational testing. Meanwhile,

1104-619: The company received a British patent for the design, no further use was made of it—the British Admiralty did not accept it for use in the Royal Navy . In November 1926 Capt. Pericle Ferretti of the technical corps of the Italian Navy ran tests with a ventilation pipe installed on the submarine H 3 . The tests were largely successful, and a similar system was designed for the Sirena class, but

1152-517: The disease on projects such as the Brooklyn Bridge and the Eads Bridge and it was not until the 1890s that it was understood that workers had to decompress slowly, to prevent the formation of dangerous bubbles in tissues. Air under moderately high pressure, such as is used when diving below about 20 metres (70 ft), has an increasing narcotic effect on the nervous system. Nitrogen narcosis

1200-716: The early months of the Battle of the Atlantic in World War II, British ships using the radar set Model 271 were able to detect the periscope of a submerged submarine at a distance of 800 m (0.50 mi) during tests in 1940. Nuclear submarine A nuclear submarine is a submarine powered by a nuclear reactor , but not necessarily nuclear-armed . Nuclear submarines have considerable performance advantages over "conventional" (typically diesel-electric ) submarines. Nuclear propulsion , being completely independent of air, frees

1248-404: The effective disposal of nuclear submarines is costly, in 2004 it was estimated to cost around 4 billion dollars. Generally there are two options when it comes to decommissioning nuclear submarines. The first option is to defuel the nuclear reactor and remove the material and components that contain radioactivity, after which the hull section containing the nuclear reactor will then be cut out of

1296-408: The engines to rapidly draw air from within the boat itself. The sudden reduction in pressure would cause the crew to experience extreme pain in their ears, occasionally causing ruptured eardrums. Atmospheric pressure would then hold the ballcock valve firmly shut, forcing the boat to shut down its diesel engines and surface. The engineering problem still exists in modern submarines; however, the effect

1344-469: The foundations of bridges or other structures may be working in a pressurized enclosure called a caisson , where water is prevented from entering the open bottom of the enclosure by filling it with air under pressure. It was known as early as the 17th century that workers in diving bells experienced shortness of breath and risked asphyxia, relieved by the release of fresh air into the bell. Such workers also experienced pain and other symptoms when returning to

1392-430: The head valve to slam shut. The valve is immediately reopened by compressed air when the contacts are again clear of the water. As snorkels were designed to draw in and vent gases, a submarine's diesel exhaust could be seen on the surface up to a distance of about 4.5 km (2.8 mi). Also, "periscope feather" (the wave created by the snorkel or periscope moving through the water) can be spotted in calm seas. During

1440-504: The late 1950s through the end of 1997, the Soviet Union, and later Russia, built a total of 245 nuclear submarines, more than all other nations combined. Today, six countries deploy some form of nuclear-powered strategic submarines: the United States, Russia, the United Kingdom, France, China, and India. Several other countries including Brazil and Australia have ongoing projects in various phases to build nuclear-powered submarines. In

1488-565: The most advanced conventional submarine can remain submerged for only a few days at slow speed, and only a few hours at top speed, though recent advances in air-independent propulsion have somewhat ameliorated this disadvantage. The high cost of nuclear technology means that relatively few of the world's military powers have fielded nuclear submarines. Radiation incidents have occurred within the Soviet submarines, including serious nuclear and radiation accidents , but American naval reactors starting with

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1536-481: The most serious nuclear and radiation accidents by death toll in the world have involved nuclear submarine mishaps. To date, all of these were units of the former Soviet Union . Reactor accidents that resulted in core damage and release of radioactivity from nuclear-powered submarines include: Compressed air Compressed air is air kept under a pressure that is greater than atmospheric pressure . Compressed air in vehicle tyres and shock absorbers

1584-718: The sea floor. This last option has been considered by some navies and countries in the past. However, while sea disposal is cheaper than land disposal the uncertainty regarding regulations and international law, such as the London Dumping Convention and the Law of the Sea Convention , has stopped them from proceeding with this option. Under development Under development Under development Under development Under development Under development Under development Plans to purchase Under development Some of

1632-425: The submarine and transported to a disposal site for low-level radioactive waste and get buried according to waste procedures. The second option is to defuel the nuclear reactor, disassemble the submarine propulsion plant, install vents in the nonreactor compartments and fill the reactor compartment. After sealing the submarine it can then be towed to a designated deep-sea disposal site, be flooded and settle intact on

1680-473: The submarine from the need to surface frequently, as is necessary for conventional submarines. The large amount of power generated by a nuclear reactor allows nuclear submarines to operate at high speed for long periods, and the long interval between refuelings grants a virtually unlimited range, making the only limits on voyage times being factors such as the need to restock food or other consumables. The limited energy stored in electric batteries means that even

1728-414: The submarine will face fatigue and corrosion of components, obsolescence and escalating operating costs. The decommissioning of these submarines is a long process; some are held in reserve or mothballed for some time and eventually scrapped, others are disposed of immediately. Countries operating nuclear submarines have different strategies when it comes to decommissioning nuclear submarines. Nonetheless,

1776-544: The submarine's other subsystems, such as for maintenance of air quality, fresh water production by distilling salt water from the ocean, temperature regulation, etc. All naval nuclear reactors currently in use are operated with diesel generators as a backup power system. These engines are able to provide emergency electrical power for reactor decay heat removal, as well as enough electric power to supply an emergency propulsion mechanism. Submarines may carry nuclear fuel for up to 30 years of operation. The only resource that limits

1824-469: The surface, as the pressure was relieved. Denis Papin suggested in 1691 that the working time in a diving bell could be extended if fresh air from the surface was continually forced under pressure into the bell. By the 19th century, caissons were regularly used in civil construction, but workers experienced serious, sometimes fatal, symptoms on returning to the surface, a syndrome called caisson disease or decompression sickness . Many workers were killed by

1872-418: The time underwater is the food supply for the crew and maintenance of the vessel. The stealth technology weakness of nuclear submarines is the need to cool the reactor even when the submarine is not moving; about 70% of the reactor output heat is dissipated into the sea water. This leaves a "thermal wake", a plume of warm water of lower density which ascends to the sea surface and creates a "thermal scar" that

1920-427: The tube. The Gruppenhorchgerät (the boat's hydrophone array ) was useless while running diesel engines submerged. However, the most dramatic effect caused by the use of snorkels was their ability to create partial vacuums within the submarine. Early snorkels had automatic ballcock valves fitted (to prevent seawater from waves being sucked into the diesel engines) that could slam shut in rough weather, forcing

1968-437: The vaporized water turns to liquefied water. Cooling the air as it leaves the compressor will take most of the moisture out before it gets into the piping. Aftercooler, storage tanks, etc. can help the compressed air cool to 104 °F; two-thirds of the water then turns to liquid. Management of the excessive moisture is a requirement of a compressed air distribution system. System designers must ensure that piping maintains

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2016-485: The war progressed, submarines (notably, the German U-boats in the Battle of the Atlantic ) were forced to spend more time underwater, running on electric motors that gave speeds of only a few knots and very limited range. An early submarine snorkel was designed by James Richardson, an Assistant Manager at Scotts Shipbuilding and Engineering Company , Greenock, Scotland as early as 1916, during World War I . Although

2064-418: The world ever to have engaged an enemy ship with torpedoes, sinking the cruiser ARA  General Belgrano with two Mark 8 torpedoes during the 1982 Falklands War . The main difference between conventional submarines and nuclear submarines is the power generation system. Nuclear submarines employ nuclear reactors for this task. They either generate electricity that powers electric motors connected to

2112-469: Was USS  George Washington with 16 Polaris A-1 missiles, which conducted the first SSBN deterrent patrol November 1960 – January 1961. The Soviets already had several SSBs of the Project 629 (Golf class) and were only a year behind the US with their first SSBN, ill-fated K-19 of Project 658 (Hotel class), commissioned in November 1960. However, this class carried the same three-missile armament as

2160-490: Was eventually scrapped; subsequent snorkel systems were not based on Ferretti's design. The Royal Netherlands Navy had been experimenting as early as 1938 with a simple pipe system on the submarines O-19 and O-20 that enabled diesel propulsion at periscope depth , while also charging the batteries. The system was designed by the Dutchman Jan Jacob Wichers. The Dutch O-21 class were equipped with such

2208-503: Was fitted with an American S5W reactor , provided to Britain under the 1958 US-UK Mutual Defence Agreement . The hull and combat systems of Dreadnought were of British design and construction, although the hull form and construction practices were influenced by access to American designs. During Dreadnought ' s construction, Rolls-Royce , in collaboration with the United Kingdom Atomic Energy Authority at

2256-630: Was made possible by the successful development of a nuclear propulsion plant by a group of scientists and engineers in the United States at the Naval Reactors Branch of the Bureau of Ships and the Atomic Energy Commission . In July 1951, the U.S. Congress authorized construction of the first nuclear-powered submarine, Nautilus , under the leadership of Captain Hyman G. Rickover , USN (sharing

2304-509: Was stored in a recess on the port side of the hull, while on the IX Types the recess was on the starboard side. The XXI and XXIII types both had telescopic masts that rose vertically through the conning tower close to the periscope. Although snorkels allowed submarines to use their diesel engines while submerged, their use had limitations and problems. U-boats with their snorkels raised were limited to six knots to avoid damaging or breaking

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