Air-Independent Propulsion (AIP), is a term that encompasses technologies which allow a submarine to operate without the need to surface or use a snorkel to access atmospheric oxygen. The term usually excludes the use of nuclear power, and describes augmenting or replacing the diesel-electric propulsion system of non-nuclear vessels. Snorkel A snorkel (also spelled schnorkel or schnorchel) is a tube that allows a person, vehicle, or vessel to draw air while submerged under water. ... Layers of Atmosphere (NOAA) Earths atmosphere is a layer of gases surrounding the planet Earth and retained by the Earths gravity. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... A nuclear power station. ...

AIP is usually implemented as an auxiliary source. Most such systems generate electricity which in turn drives an electric motor for propulsion or recharging the boat's batteries. The submarine's electrical system is also used to provide "hotel services"—ventilation, lighting, heating etc—although this consumes a small amount of power compared to that required for propulsion. This article or section does not cite its references or sources. ...

A particular benefit of this approach is that it can be retrofitted into existing submarine hulls by inserting an additional hull section. AIP does not normally provide the endurance or power to replace the atmospheric dependent propulsion, but allows it to remain on station underwater for longer than a more conventionally propelled submarine could. A typical conventional power plant will provide 3 megawatts maximum, and an AIP source around a tenth of that. A nuclear submarine's propulsion plant is usually much greater than 20 megawatts. A hull is the body or frame of a ship or boat. ... In physics, power (symbol: P) is the amount of work done per unit of time. ... The megawatt (symbol: MW) is a unit for measuring power corresponding to one million (106) watts. ...

Internal oxygen supply

History

During the Second World War the German firm Walter experimented with submarines that used concentrated hydrogen peroxide as their source of oxygen underwater. These used steam turbines which used steam heated by burning diesel fuel in the hydrogen/oxygen atmosphere created by the decomposition of hydrogen peroxide by a potassium permanganate catalyst. Mushroom cloud from the nuclear explosion over Nagasaki rising 18 km into the air. ... Hellmuth Walter (August 26, 1900 – December 16, 1980) was a German engineer who pioneered research into rocket engines and gas turbines. ... Flash point Non-flammable. ... A rotor of a modern steam turbine, used in a power plant A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical work. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Potassium permanganate (KMnO4) is an inorganic chemical compound composed of potassium (K+) and permanganate (MnO4−) ions. ... A catalyst (Greek: καταλύτης, catalytēs) is a substance that accelerates the rate (speed) or ease of a chemical reaction (see also catalysis) without itself being changed at the end of the chemical reaction . ...

Several experimental boats were produced, and one, U-1407, which had been scuttled at the end of the war was salvaged and recommissioned into the Royal Navy as HMS Meteorite. The British built two improved models in the late 1950s, HMS Explorer, and HMS Excalibur. The Royal Navy of the United Kingdom is the senior service of the British armed services being the oldest of its three branches. ... The 1950s were a decade that spanned the years 1950 through 1959. ...

The Soviet Union also experimented with the technology. Hydrogen Peroxide was eventually abandoned since it was highly reactive when it came into contact with various metals, was volatile and submarines suffered from a high rate of consumption. Both countries abandoned it when the United States succeeded in developing a nuclear reactor small enough to be installed in a submarine. Core of a small nuclear reactor used for research. ...

It was retained for propelling torpedoes by the British and the Soviet Union, although hastily abandoned by the former following the HMS Sidon tragedy. Both this and the loss of the Russian Submarine Kursk were due to accidents involving hydrogen peroxide propelled torpedoes. A torpedo in Rail terminology refers to a small explosive device strapped to the top of the rail to alert an approaching train of immediate danger ahead. ... HMS Sidon was launched in September 1944, one of the third group of S-class submarines built by Cammell Laird & Co Limited, Birkenhead. ... K-141 Kursk (Russian in full: Атомная подводная лодка Курск [АПЛ Курск] - nuclear submarine Kursk) was a Project 949A Антей (Antey, Antaeus; also known by its NATO reporting name of Oscar-II class) nuclear cruise missile submarine named after the Russian city Kursk, where one of the biggest battles of World War II took place (Battle of...

Closed cycle diesel engines

This technology uses a submarine diesel engine which can be operated conventionally on the surface, but which can also be provided with oxidant, usually stored as liquid oxygen, when submerged. Since the metal of an engine will burn in pure oxygen, the oxygen is usually diluted with recycled exhaust gases. As there are no exhaust gases to use when the engine is started, initially argon is used. The diesel engine is a type of internal combustion engine; more specifically, it is a compression ignition engine, in which the fuel is ignited by being suddenly exposed to the high temperature and pressure of a compressed gas, rather than by a separate source of ignition, such as a spark... An oxidizing agent is a substance that oxidizes another substance in electrochemistry or redox chemical reactions in general. ... Liquid oxygen (also LOx, LOX or Lox in the aerospace industry) is the liquid form of oxygen. ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Atomic mass 39. ...

The Soviet Union invested heavily in this technology, developing the small 650 ton Quebec-class submarine of which thirty examples were built between 1953 and 1956. These had three diesel engines—two conventional ones and one closed cycle engine which used liquid oxygen. They had a poor safety record, for instance the M-256 was lost following an explosion and fire. They were sometimes sarcastically nicknamed cigarette lighters. The last was scrapped in the early 1970s. The Quebec-class submarine was the NATO reporting name of the Soviet Project 615 submarine class, a small coastal attack submarine of the late 1950s. ... 1953 (MCMLIII) was a common year starting on Thursday (link is to a full 1953 calendar). ... 1956 (MCMLVI) was a leap year starting on Sunday of the Gregorian calendar. ... M-256 was a Project 615 (also known by the NATO reporting name of Quebec-class) short-range attack diesel submarine of the Soviet Navy. ... The 1970s decade refers to the years from 1970 to 1979, inclusive. ...

The German Type 205 submarine U1 was fitted with an experimental 3000 horsepower (2.2 MW) unit. The Type 205 was a class of diesel-electric German hunter-killer submarines. ...

Closed cycle steam turbines

The French (Module d'Energie Sous-Marine Autonome) system is being offered by the French shipyard DCN. Currently a Mesma Section is retrofitted to an Agosta 90 B of the Pakistan Navy. It is essentially a modified version of their nuclear propulsion system with heat being generated by ethanol and compressed oxygen. Ethanol, also known as ethyl alcohol or grain alcohol, is a flammable, colorless chemical compound, one of the alcohols that is most often found in alcoholic beverages. ...

Stirling cycle engines

The Swedish shipbuilder Kockums has constructed four submarines for the Swedish Navy which are fitted with auxiliary Stirling engine which burn liquid oxygen and diesel fuel driving 75 kilowatt generators for either propulsion or charging batteries. The AIP endurance of the 1,500 ton boats is around 14 days at five knots (9 km/h). Kockums in Malmö, 1970 Foto: Pål-Nils Nilsson. ... The Swedish Naval Ensign Coat of arms of the Swedish Navy The Swedish Navy (Swedish: Marinen) is the naval branch of the Swedish Armed Forces. ... A Stirling engine and generator set with 55 kW electrical output, for combined heat and power applications. ...

Fuel cells

Siemens has developed a 30-50 kilowatt unit, and nine of these are incorporated into Howaldtswerke Deutsche Werft AG's 1,830t submarine U31, lead ship for the Type 212A class. The other boats of this class and HDW's AIP equipped export submarines (Type 209 mod and Type 214) use two 120 kW modules, also from Siemens [1]. Siemens AG (FWB:SIE, NYSE: SI) is the worlds largest electronics company. ... Howaldtswerke is a German shipyard founded 1838 in Kiel. ... A tonne (also called metric ton) is a non-SI unit of mass, accepted for use with SI, defined as: 1 tonne = 103 kg (= 106 g). ... Typ 212 Typ 212 The German Type 212 is an advanced design of non-nuclear submarine developed by Howaldtswerke-Deutsche Werft AG (HDW). ... The German Type 209 diesel-electric submarine was the most popular export-sales submarine in the world from the late 1960s into the first years of the 21st century. ... The Type 214 is a diesel-electric submarine developed by Howaldtswerke-Deutsche Werft GmbH (HDW). ...

After the success of Howaldtswerke Deutsche Werft AG's with regards to its export activities several builders have answered the potential by a development of own fuel-cell auxiliary units for submarines but until today no other shipyard has a contract for a submarine equipped with this technology. Howaldtswerke is a German shipyard founded 1838 in Kiel. ...

Nuclear power

Nuclear reactors have been used for 50 years to power submarines, the first being USS Nautilus. Five countries; the USA, France, the United Kingdom, Russia and the Peoples Republic of China are the only countries known to operate nuclear powered submarines. These five countries also happen to have permanent seats on the United Nations Security Council and are the only countries allowed to possess nuclear-powered weapons according to the Nuclear Non-Proliferation Treaty. India has leased nuclear powered submarines from Russia in the past and plans to acquire two used Akula class submarines from Russia to gain experience and build their own class in future. Brazil is also known to research nuclear propulsion for submarine use. However Air Independent Propulsion is a term normally used in the context of improving the performance of conventionally propelled submarines. For other ships named Nautilus, see USS Nautilus and Ships named Nautilus USS Nautilus (SSN-571) was the worlds first operational nuclear-powered submarine and the first vessel to complete a submerged transit across the North Pole. ... The United Nations Security Council is the most powerful organ of the United Nations (UN). ... Nuclear Non-Proliferation Treaty Opened for signature July 1, 1968 in New York Entered into force March 5, 1970 Conditions for entry into force Ratification by the United Kingdom, the Soviet Union, the United States, and 40 other signatory states. ... Akula class submarine underway in the Baltic Sea // Overview Project 971 Щука-Б (Shchuka-B, Shchuka meaning pike, NATO reporting name Akula), is a nuclear-powered attack submarine (SSN) first deployed by the Soviet Navy in 1986. ...

There have nevertheless been suggestions for a reactor as an auxiliary power supply, which does fall into the normal definition of AIP. For example, there has been a proposal to use a small 200 kilowatt reactor as an auxiliary power source (styled a "nuclear battery") to improve the under-ice capability of Canadian submarines. A radioisotope thermoelectric generator (RTG) is a simple electrical generator which obtains its power from radioactive decay. ...

Nuclear marine propulsion is propulsion of a Merchant ship powered by a nuclear reactor. ...

Production Non-Nuclear AIP Submarines

As of 2006, three nations offer non-nuclear AIP submarines for export: 2006 is a common year starting on Sunday of the Gregorian calendar. ...

• the French Scorpène-class submarine (MESMA)
• the German Type 209-1400mod (Fuel cell)
• the German Type 214 (Fuel cell)
• the Russian Project 1650 Амур

Sweden is going to sell its remaining two Västergötland class submarines to the Republic of Singapore Navy after they have been refitted with Stirling AIP systems like the Södermanland class submarines. Scorpène class submarines are a class of diesel-electric attack submarine jointly developed by the French company DCN and the Spanish company Navantia. ... The German Type 209 diesel-electric submarine was the most popular export-sales submarine in the world from the late 1960s into the first years of the 21st century. ... The Type 214 is a diesel-electric submarine developed by Howaldtswerke-Deutsche Werft GmbH (HDW). ... The A-17 Västergötland class of diesel-electric submarines was introduced in 1987 by the Swedish Navy. ... The Republic of Singapore Navy (RSN, Malay: Angkatan Laut Republik Singapura, Simplified Chinese: 新加坡海军部队) is the navy of the Singapore Armed Forces (SAF). ... The Swedish Södermanland class of diesel-electric submarines consist of the HMS Södermanland and HMS Östergötland. ...

Also several shipbuilders offer AIP upgrades for existing submarines:

• German Nordseewerke (Closed-cycle diesel)
• Sweden Kockums (Stirling)

Nordseewerke GmbH is a German shipyard in Emden, now part of ThyssenKrupp Marine Systeme. ... Kockums in Malmö, 1970 Foto: Pål-Nils Nilsson. ...

References

• Underseas Warfare article
• Seapower article
• Air Independent Propulsion
• Auxilary nuclear reactor for Canadian submarines
• Air-independent Propulsion @ Nordseewerke, closed cycle diesel system