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Submarine
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For other uses, see Submarine (disambiguation).
DSV Alvin in 1978, a year after first exploring hydrothermal vents.
German UC-1 class World War I submarine
Experimental sub with hydrofoils in Monterey Bay
A submarine is a watercraft capable of independent operation below water. It differs from a submersible that has only limited underwater capability. The term submarine most commonly refers to large manned autonomous vessels, however historically or more casually, submarine can also refer to medium sized or smaller vessels, (midget submarines, wet subs), Remotely Operated Vehicles or robots. The word submarine was originally an adjective meaning "under the sea", and so consequently other uses such as "submarine engineering" or "submarine cable" may not actually refer to submarines at all. Submarine was shortened from the term "submarine boat".
Submarines are referred to as "boats" for historical reasons because vessels deployed from a ship are referred to as boats. The first submarines were launched in such a manner. The English term U-Boat for a German submarine comes from the German word for submarine, U-Boot, itself an abbreviation for Unterseeboot ("undersea boat").
Although experimental submarines had been built before, submarine design took off during the 19th century. Submarines were first widely used in World War I, and feature in many large navies. Military usage ranges from attacking enemy ships or submarines, aircraft carrier protection, blockade running, ballistic missile submarines as part of a nuclear strike force, reconnaissance, conventional land attack (for example using a cruise missile), and covert insertion of special forces. Civilian uses for submarines include marine science, salvage, exploration and facility inspection/maintenance. Submarines can also be specialised to a function such as search and rescue, or undersea cable repair. Submarines are also used in tourism and for academic research.
Submarines have one of the largest ranges in capabilities of any vessel, ranging from small autonomous or one- or two-man vessels operating for a few hours, to vessels which can remain submerged for 6 months such as the Russian Typhoon class. Submarines can work at greater depths than are survivable or practical for human divers. Modern deep diving submarines are derived from the bathyscaphe, which in turn was an evolution of the diving bell.
Most large submarines comprise a cylindrical body with conical ends and a vertical structure, usually located amidships, which houses communications and sensing devices as well as periscopes. In modern submarines this structure is the "sail" in American usage ("fin" in European usage). A "conning tower" was a feature of earlier designs: a separate pressure hull above the main body of the boat that allowed the use of shorter periscopes. There is a propeller (or pump jet) at the rear and various hydrodynamic control fins as well as ballast tanks. Smaller, deep diving and specialty submarines may deviate significantly from this traditional layout.
[edit] Military usage
A model of Günther Prien's U-47, German WWII Type VII diesel-electric hunter
Prior to the development of the homing torpedo in World War II, the primary role of the diesel/electric submarine was anti-surface ship warfare, inserting and removing covert agents and military forces, and intelligence-gathering. Until that time they were generally not used against other submarines (although British developed a specialised anti-submarine submarine in World War I, the R class). The impact-detonated torpedoes of the era were difficult to use against a submarine because they ran a fixed course at a fixed depth and were relatively easy for the small submarines to avoid with three-dimensional maneuvers. Submarines were also used in limited roles for artillery support or raids, and rescuing aircrews during large-scale air attacks on islands, where the aircrewmen would be told of safe places to crash-land damaged aircraft so the submarine crew could rescue them.
With the development of the homing torpedo, better sonar systems, and nuclear propulsion, submarines also became able to effectively hunt each other as well as surface ships. The development of submarine-launched nuclear missiles and submarine-launched cruise missiles gave submarines a substantial and long-ranged ability to attack both land and sea targets with a variety of weapons ranging from cluster bombs to nuclear weapons.
Mine laying submarines were developed in the early part of the 20th century. The facility has been used in both World Wars. Such capabilities continue today.
The primary defensive power of a submarine lies in its ability to remain concealed in the depths of the ocean. Modern submarines are built with an emphasis on stealth. Advanced propeller designs, extensive sound-reducing insulation, and special machinery allow a submarine to be as quiet as ambient ocean noise, making them extremely difficult to detect. Such submarines can launch an attack on land targets, surface ships, and other submarines from seemingly nowhere, and require specialized equipment to find and attack in retaliation. Water is an excellent conductor of sound, and submarines have excellent sonars that can detect and track comparatively noisy surface ships from long distances. This allows an attacking sub, at its discretion, to quietly maneuver to and attack from the best possible position at the best possible time.
A concealed military submarine is a real threat and, because of its stealth, it can force an enemy navy to waste resources searching large areas of ocean and protecting all ships against possible attack, while in reality only threatening a small area. This advantage was vividly demonstrated in the 1982 Falklands War when the British SSN HMS Conqueror sank the Argentine cruiser General Belgrano. After the sinking the Argentine Navy realized that they were vulnerable to submarine attack, and that they had no defense from it. Thus the Argentinian surface fleet withdrew to port for the remainder of the war, though an Argentinian submarine remained at sea.
During World War II some military submarines were used as supply vessels for U-boats.
[edit] Anti-submarine net
One of the defenses against submarines is an antisubmarine net that blocks the passage, e.g. at the entrance of a harbor. It can sometimes be lowered to let friendly ships pass. See antisubmarine nets at Pearl Harbor or net laying ship.
[edit] Civil uses
Although the majority of the world's submarines are military ones, there are some civil submarines. They have a variety of uses, including tourism, exploration, oil and gas platform inspections and pipeline surveys.
A semi-civilian use was the adaption of U-boats for cargo transport during WWI and WWII.
[edit] Technology
[edit] Submersion and trimming
Control surfaces
HMS Astute is one of the most advanced nuclear submarines in the world.[1]
All surface ships, as well as surfaced submarines, are in a positively buoyant condition, weighing less than the volume of water they would displace if fully submerged. To submerge hydrostatically, a ship must have negative buoyancy, either by increasing its own weight or decreasing displacement of the water. To control their weight, submarines have ballast tanks, which can be filled with outside water or pressurized air.
For general submersion or surfacing, submarines use the forward and aft tanks, called Main Ballast Tanks or MBTs, which are filled with water to submerge, or filled with air to surface. Under submerged conditions, MBTs generally remain flooded, which simplifies their design, and on many submarines these tanks are a section of interhull space. For more precise and quick control of depth, submarines use smaller Depth Control Tanks or DCTs, also called hard tanks due to their ability to withstand higher pressure. The amount of water in depth control tanks can be controlled either to reflect changes in outside conditions or change depth. Depth control tanks can be located either near the submarine's center of gravity, or separated along the submarine body to prevent affecting trim.
When submerged, the water pressure on submarine's hull can reach 4 MPa for steel submarines and up to 10 MPa for titanium submarines like Komsomolets, while interior pressure remains unchanged. This difference results in hull compression, which decreases displacement. Water density also increases, as the salinity and pressure are higher, but this does not compensate for hull compression, so buoyancy decreases as depth increases. A submerged submarine is in an unstable equilibrium, having a tendency to either fall or float to the surface. Keeping a constant depth requires continual operation of either the depth control tanks or control surfaces.[2][verification needed][dubious ]
Submarines in a neutral buoyancy condition are not intrinsically trim-stable. To maintain desired trim, submarines use forward and aft trim tanks. Pumps can move water between these, changing weight distribution, creating a moment pointing the sub up or down. A similar system is sometimes used to maintain stability.
Sail of the French nuclear submarine Casabianca; note the diving planes, camouflaged masts, periscope, electronic warfare masts, door and windows.
The hydrostatic effect of variable ballast tanks is not the only way to control the submarine underwater. Hydrodynamic maneuvering is done by several surfaces, which can be moved to create hydrodynamic forces when a submarine moves at sufficient speed. The stern planes, located near the propeller and normally horizontal, serve the same purpose as the trim tanks, controlling the trim, and are commonly used, while other control surfaces may not be present on many submarines. The fairwater planes on the sail and/or bow planes on the main body, both also horizontal, are closer to the centre of gravity, and are used to control depth with less effect on the trim.
When a submarine performs an emergency surfacing, all depth and trim methods are used simultaneously, together with propelling the boat upwards. Such surfacing is very quick, so the sub may even partially jump out of the water, but it may inflict serious damage on submarine systems.
[edit] Submarine hull
Main article: Submarine hull
[edit] Overview
The
Modern submarines are cigar-shaped. This design, visible in early submarines (see below) is sometimes called a "teardrop hull". It reduces the hydrodynamic drag when submerged, but decreases the sea-keeping capabilities and increases drag while surfaced. Since the limitations of the propulsion systems of early submarines forced them to operate surfaced most of the time, their hull designs were a compromise. Because of the slow submerged speeds of those subs, usually well below 10 kt (18 km·h−1), the increased drag for underwater travel was acceptable. Late in World War II, when technology allowed faster and longer submerged operation and increased aircraft surveillance forced submarines to stay submerged, hull designs became teardrop shaped again to reduce drag and noise. On modern military submarines the outer hull is covered with a layer of sound-absorbing rubber, or anechoic plating, to reduce detection.
The occupied pressure hulls of deep diving submarines such as DSV Alvin are spherical instead of cylindrical. This allows a more even distribution of stress at the great depth. A titanium frame is usually affixed to the pressure hull, providing attachment for ballast and trim systems, scientific instrumentation, battery packs, syntactic flotation foam, and lighting.
A raised tower on top of a submarine accommodates the periscope and electronics masts, which can include radio, radar, electronic warfare, and other systems including the snorkel mast. In many early classes of submarines (see history), the Control Room, or "
"Bathtubs" are related to conning towers but are used on smaller submarines. The bathtub is a metal cylinder surrounding the hatch that prevents waves from breaking directly into the cabin. It is needed because surfaced submarines have limited freeboard, that is, they lie low in the water. Bathtubs help prevent swamping the vessel.
[edit] Single / double hull
U-995, Type VIIC/41 U-Boat of WWII, showing the typical combination of ship-like non-watertight outer hull with bulky strong hull below
Type XXI U-Boat, late WWII, with pressure hull almost fully enclosed inside the light hull
Modern submarines and submersibles, as well as the oldest ones, often have a single hull. Large submarines generally have an additional hull or hull sections outside. This external hull, which actually forms the shape of submarine, is called the outer hull (casing in the Royal Navy) or light hull, as it does not have to withstand a pressure difference. Inside the outer hull there is a strong hull, or pressure hull, which withstands sea pressure and has normal atmospheric pressure inside.
As early as World War I, it was realized that the optimal shape for withstanding pressure conflicted with the optimal shape for seakeeping and minimal drag, and construction difficulties further complicated the problem. This was solved either by a compromise shape, or by using two hulls; internal for holding pressure, and external for optimal shape. Until the end of World War II, most submarines had an additional partial cover on the top, bow and stern, built of thinner metal, which was flooded when submerged.
After World War II, approaches split. The
[edit] Pressure hull
The pressure hull is generally constructed of thick high strength steel with a complex structure and high strength reserve, and is separated with watertight bulkheads into several compartments. There are also examples of more than two hulls in a submarine, like the Typhoon class, which has two main pressure hulls and three smaller ones for control room, torpedoes and steering gear, with the missile launch system between the main hulls.
The dive depth cannot be increased easily. Simply making the hull thicker increases the weight and requires reduction of onboard equipment weight, ultimately resulting in a bathyscaph. This is acceptable for civilian research submersibles, but not military submarines.
WWI submarines had hulls of carbon steel, with a 100 meter maximum depth. During WW II, high-strength alloyed steel was introduced, allowing 200 meter depths. High-strength alloy steel remains the primary material for submarines today, with 250-400 meter depths, which cannot be exceeded on a military submarine without design compromises. To exceed that limit, a few submarines were built with titanium hulls. Titanium is almost as strong as steel, lighter, and is not ferromagnetic, important for stealth. Titanium submarines were built by the
Deep diving civilian submarines have used thick glass pressure hulls.
The task of building a pressure hull is very difficult, as it must withstand pressures up to that of its required diving depth. When the hull is perfectly round in cross-section, the pressure is evenly distributed, and causes only hull compression. If the shape is not perfect, the hull is bent, with several points heavily strained. Inevitable minor deviations are resisted by stiffener rings, but even a one inch (25 mm) deviation from roundness results in over 30 percent decrease of maximal hydrostatic load and consequently dive depth.[5] The hull must therefore be constructed with high precision. All hull parts must be welded without defects, and all joints are checked multiple times with different methods, contributing to the high cost of modern submarines. (For example, each Virginia-class attack submarine costs 2.6 billion dollars, over $200,000 per ton of displacement.)
[edit] Propulsion
HMCS Windsor, a Victoria-class diesel-electric hunter-killer submarine
German Type 212 submarine with AIP propulsion of the German Navy in dock at HDW/Kiel
German Type XXI submarines, also known as "Elektroboote", were the first submarines designed to operate entirely submerged
Originally, submarines were human propelled. The first mechanically driven submarine was the 1863 French Plongeur, which used compressed air for propulsion. Anaerobic propulsion was first employed by the Spanish Ictineo II in 1864. Ictineo's engine used a peroxide compound to generate heat for steam propulsion, while also providing oxygen for the crew. The system was not employed again until 1940 when the German Navy tested a hydrogen peroxide-based system employing the same principles, the Walter turbine, on the experimental V-80 submarine and later on the naval U-791 and type XVII submarines.[6]
Until the advent of nuclear marine propulsion, most 20th century submarines used batteries for running underwater and gasoline (petrol) or diesel engines on the surface, and for battery recharging. Early submarines used gasoline, but this quickly gave way to kerosene (paraffin), then diesel, because of reduced flammability. Diesel-electric became the standard means of propulsion. The diesel or gasoline engine and the electric motor, separated by clutches, were initially on the same shaft driving the propeller. This allowed the engine to drive the electric motor as a generator to recharge the batteries and also propel the submarine. The clutch between the motor and the engine would be disengaged when the submarine dove, so that the motor could drive the propeller. The motor could have multiple armatures on the shaft, which could be electrically coupled in series for slow speed and in parallel for high speed. (These connections were called "group down" and "group up", respectively.)
The principle was modified in some designs in the 1930s, particularly those of the U.S. Navy and the British U class submarines. The engine was not connected to the motor/propeller drive shaft, but drove a separate generator to drive the motors on the surface while recharging the batteries. This diesel-electric propulsion allowed greater flexibility. For example, the submarine could travel slowly with the engines at full power to recharge the batteries quickly, reducing time on the surface, or use its snorkel. It was then possible to insulate the noisy diesel engines from the pressure hull, making the submarine quieter.
Other power sources were tested. Oil-fired steam turbines powered the British "K" class submarines, built during the first World War (and later), to give them the surface speed to keep up with battle fleet. The "K" class subs were not very successful, however. German Type XXI submarines were designed to carry hydrogen peroxide for long-term, fast air-independent propulsion, but were ultimately built with very large batteries instead.
At the end of the Second World War, the British and Russians experimented with hydrogen peroxide/kerosene (paraffin) engines which could be used surfaced and submerged. The results were not encouraging; although the Russians deployed a class of submarines with this engine type (codenamed Quebec by NATO), they were considered unsuccessful. Today several navies use air-independent propulsion. Notably Sweden uses Stirling technology on the Gotland class and Södermanland class submarines. The
Steam power was resurrected in the 1950s with a nuclear-powered steam turbine driving a generator. By eliminating the need for atmospheric oxygen, the length of time that a modern submarine could remain submerged was limited only by its food stores, as breathing air was recycled and fresh water distilled from seawater. Nuclear-powered submarines have a relatively small battery and diesel engine/generator powerplant for emergency use if the reactors must be shut down.
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy and the Royal Navy operate only nuclear submarines,[7] which is explained by the need for distant operations. Other major operators rely on a mix of nuclear submarines for strategic purposes and diesel-electric submarines for defense. Most fleets have no nuclear submarines, due to the limited availability of nuclear power and submarine technology. Diesel-electric submarines have a stealth advantage over their nuclear counterparts. Nuclear submarines generate noise from coolant pumps and turbo-machinery needed to operate the reactor, even at low power levels. A conventional submarine operating on batteries is almost completely silent, the only noise coming from the shaft bearings and flow noise around the hull, all of which stops when the sub hovers in mid water to listen. Commercial submarines usually rely only on batteries, since they never operate independently of a mother ship.
Toward the end of the 20th century, some submarines, such as the British Vanguard class, began to be fitted with pump-jet propulsors instead of propellers. Although these are heavier, more expensive, and less efficient than a propeller, they are significantly quieter, giving an important tactical advantage.
The magnetohydrodynamic drive, or "caterpillar drive", which has no moving parts, was portrayed as a submarine propulsion system in the movie The Hunt for Red October, which portrayed it as a virtually silent system.
Although experimental surface ships have used this system, speeds have been below expectations. In addition, the drive system can induce bubble formation, compromising stealth, and the low efficiency requires high powered reactors. These factors make it unlikely for military usage.
[edit] Armament
A sequence of photos showing the decommissioned Australian warship HMAS Torrens sinking after being used as a target for a submarine-launched torpedo.
The forward torpedo tubes on HMS Ocelot
The success of the submarine is inextricably linked to the development of the torpedo, invented by Robert Whitehead in 1866. His invention is essentially the same now as it was 100 years ago. Only with self propelled torpedoes could the submarine make the leap from novelty to a weapon of war. Until the perfection of the guided torpedo, multiple "straight running" torpedoes were required to attack a target. With at most 20 to 25 torpedoes stored onboard, the number of attacks was limited. To increase combat endurance most WWI submarines functioned as submersible gunboats, using their deck guns against unarmed targets, and diving to escape and engage enemy warships. The importance of guns encouraged the development of the unsuccessful Submarine Cruiser such as the French Surcouf and the Royal Navy's X1 and M class submarines. With the arrival of ASW aircraft, guns became more for defence than attack. A more practical method of increasing combat endurance was the external torpedo tube, loaded only in port.
The ability of submarines to approach enemy harbors covertly led to their use as minelayers. Minelaying submarines of WWI and WWII were specially built for that purpose. Modern submarine-laid mines, such as the British Mark 6 Sea Urchin, are designed to be deployed by a submarine's torpedo tubes.
After WWII, both the
The strategic mission of the SSM-N-8 and the P-5 were taken up by submarine-launched ballistic missile beginning with the US Navy's Polaris missile, and subsequently the Poseidon and Trident missiles.
[edit] Sensors
A submarine will have a variety of sensors determined by its missions. Modern military submarines rely almost entirely on a suite of passive and active sonars to find their prey. Active sonar relies on an audible "ping" to generate echoes to reveal objects around the submarine. Active systems are rarely used, as doing so reveals the sub's presence. Passive sonar is a set of sensitive hydrophones set into the hull or trailed in a towed array, generally several hundred feet long. The towed array is the mainstay of NATO submarine detection systems, as it reduces the flow noise heard by operators.
Submarines also carry radar equipment for detection of surface ships and aircraft. Sub captains are more likely to use radar detection gear rather than active radar to detect targets, as radar can be detected far beyond its own return range, revealing the submarine. Periscopes are rarely used, except for position fixes and to verify a contact's identity.
Civilian submarines, such as the DSV Alvin or the Russian Mir submersibles, rely on small active sonar sets and viewing ports to navigate. Sunlight does not penetrate below about 300 feet (91 m) underwater, so high intensity lights are used to illuminate the viewing area.
[edit] Navigation
Early submarines had few navigation aids, but modern subs have a variety of navigation systems. Modern military submarines use an inertial guidance system for navigation while submerged, but drift error unavoidably builds up over time. To counter this, the Global Positioning System will occasionally be used to obtain an accurate position. The periscope - a retractable tube with prisms allowing a view to the surface - is only used occasionally in modern submarines, since the range of visibility is short. The Virginia-class submarines and Astute Class submarines have "photonics masts" rather than hull-penetrating optical periscopes. These masts must still be hoisted above the surface, and employ electronic sensors for visible light, infrared, laser range-finding, and electromagnetic surveillance.
[edit] Communication
Main article: Communication with submarines
Military submarines have several systems for communicating with distant command centers or other ships. One is VLF radio, which can reach a submarine either on the surface or submerged up to a fairly shallow depth, usually less than 250 feet (76 m). ELF frequencies can reach a submarine at much greater depths, but have a very low bandwidth and are generally used to call a submerged sub to a shallower depth where VLF signals can reach. A submarine also has the option of floating a long, buoyant wire to a shallower depth, allowing VLF transmissions to be made by a deeply submerged boat.
By extending a radio mast, a submarine can also use a "burst transmission" technique. A burst transmission takes only a fraction of a second, minimizing a submarine's risk of detection.
To communicate with other submarines, a system known as Gertrude is used. Gertrude is basically a sonar telephone. Voice communication from one submarine is transmitted by low power speakers into the water, where it is detected by passive sonars on the receiving submarine. The range of this system is probably very short, and using it radiates sound into the water, which can be heard by the enemy.
Civilian submarines can use similar, albeit less powerful systems to communicate with support ships or other submersibles in the area.
[edit] Command and control
All submarines need facilities to control their motion. Military submarines also need facilities to operate their sensors and weapons.
[edit] Crew
A typical nuclear submarine has a crew of over 80. Non-nuclear boats typically have fewer than half as many. The conditions on a submarine can be difficult because crewmembers must work in isolation for long periods of time, without family contact. Submarines normally maintain radio silence to avoid detection. Operating a submarine is dangerous, even in peacetime, and submarines have been lost in accidents.
[edit] Women as part of crew
Norway opened up every function in the armed forces to women in 1985, making the Royal Norwegian Navy the first navy to allow female crewmen. The Royal Danish Navy conducted trials with mixed gender crews in 1985 and 1987, making no alterations to the sub, and allowed for female submariners in 1988.[8] Sweden followed after in 1989.[9] The Royal Australian Navy (RAN) began to allow female personnel in 1998 and thereafter Canadian Navy in 2002. Germany, Spain and Portugal also allow for females on all military functions, including submarines.[8]
In 1995, Solveig Krey of the Royal Norwegian Navy became the first female officer to assume command on a submarine, the HNoMS Kobben.[10]
The usual reasons for barring women is primness, given the lack of privacy and "hot bunking" or "hot racking", a common practice on submarines where three sailors share two bunks on a rotating basis to save space. The US Navy argues it would cost $300,000 per bunk to permit women to serve on submarines versus $4,000 per bunk to allow women to serve on aircraft carriers. However, this calculation is based on the assumption of semi segregation of the female crew, possibly to the extent of structural redesign of the vessel.[11]
The US Navy, which permits women to serve on almost every other ship in the fleet, only allows three exceptions for women being on board military submarines: (1) Female civilian technicians for a few days at most; (2) Women midshipmen on an overnight during summer training for both Navy ROTC and Naval Academy; (3) Family members for one-day dependent cruises.[12]
[edit] Life support systems
With nuclear power, submarines can remain submerged for months at a time. Diesel submarines must periodically resurface or snorkel to recharge their batteries. Most modern military submarines generate breathing oxygen by electrolysis of water. Atmosphere control equipment includes a CO2 scrubber, which uses an amine absorbent to remove the gas from air and diffuse it into waste pumped overboard. A machine that uses a catalyst to convert carbon monoxide into carbon dioxide (removed by the CO2 scrubber) and bonds hydrogen produced from the ship's storage battery with oxygen in the atmosphere to produce water, is also used. An atmosphere monitoring system samples the air from different areas of the ship for nitrogen, oxygen, hydrogen, R12 and R114 refrigerant, carbon dioxide, carbon monoxide, and others. Poisonous gases are removed, and oxygen is replenished by use of an oxygen bank located in a main ballast tank. Some heavier submarines have two oxygen bleed stations (forward and aft). The oxygen in the air is sometimes kept a few percent less than atmospheric concentration to reduce fire danger.
Fresh water is produced by either an evaporator or a reverse osmosis unit. It is used for showers, sinks, cooking and cleaning. Seawater is used to flush toilets, and the resulting "black water" is stored in a sanitary tank until it is blown overboard using pressurised air or pumped overboard by using a special sanitary pump. The method for blowing sanitaries overboard is difficult to operate, and the German Type VIIC boat U-1206 was lost with casualties because of a mistake with the toilet. Water from showers and sinks is stored separately in "gray water" tanks, which are pumped overboard using the drain pump.
Trash on modern large submarines is usually disposed of using a tube called a Trash Disposal Unit (TDU), where it is compacted into a galvanised steel can. At the bottom of the TDU is a large ball valve. An ice plug is set on top of the ball valve to protect it, the cans atop the ice plug. The top breech door is shut, and the TDU is flooded and equalised with sea pressure, the ball valve is opened and the cans fall out assisted by scrap iron weights in the cans.
[edit] History of submarines
Main article: History of submarines
[edit] Early history of submarines and the first submersibles
The first submersible with reliable information on its construction was built in 1620 by Cornelius Jacobszoon Drebbel, a Dutchman in the service of James I of England. It was created to the standards of the design outlined by English mathematician William Bourne. It was propelled by means of oars. The precise nature of the submarine type is a matter of some controversy; some claim that it was merely a bell towed by a boat. Two improved types were tested in the Thames between 1620 and 1624. In 2002 a two-man version of Bourne's design was built for the BBC TV programme Building the Impossible by Mark Edwards, and successfully rowed under water at Dorney Lake, Eton.
Though the first submersible vehicles were tools for exploring under water, it did not take long for inventors to recognize their military potential. The strategic advantages of submarines were set out by Bishop John Wilkins of Chester,
- Tis private: a man may thus go to any coast in the world invisibly, without discovery or prevented in his journey.
- Tis safe, from the uncertainty of Tides, and the violence of Tempests, which do never move the sea above five or six paces deep. From Pirates and Robbers which do so infest other voyages; from ice and great frost, which do so much endanger the passages towards the Poles.
- It may be of great advantages against a Navy of enemies, who by this may be undermined in the water and blown up.
- It may be of special use for the relief of any place besieged by water, to convey unto them invisible supplies; and so likewise for the surprisal of any place that is accessible by water.
- It may be of unspeakable benefit for submarine experiments.
[edit] The first military submarines
The first military submarine was Turtle (1775), a hand-powered egg-shaped device designed by the American David Bushnell to accommodate a single man. It was the first verified submarine capable of independent underwater operation and movement, and the first to use screws for propulsion. During the American Revolutionary War, Turtle (operated by Sgt. Ezra Lee, Continental Army) tried and failed to sink the British warship HMS Eagle, flagship of the blockaders in New York harbor on September 7, 1776.
The Nautilus (1800)
In 1800,
During the War of 1812, in 1814, Silas Halsey lost his life while using a submarine in an unsuccessful attack on a British warship stationed in New London harbor.
In 1851, a Bavarian artillery corporal, Wilhelm Bauer, took a submarine designed by him called the Brandtaucher (incendiary-diver) to sea in Kiel
[edit] Submarines in the American Civil War
The 1862 Alligator, first submarine of the US Navy, was developed in conjunction with the French
During the American Civil War, the
The Confederate States of America fielded several man-powered submarines. The first Confederate submarine was the 30-foot (9 m) long Pioneer which sank a target schooner using a towed mine during tests on Lake Pontchartrain, but was not used in combat. It was scuttled after
The Confederate submarine H. L. Hunley (named for one of its financiers, Horace Lawson Hunley) was intended for attacking the North's ships, which were blockading the South's seaports. The submarine had a long pole with an explosive charge in the bow, called a spar torpedo. The sub had to approach an enemy vessel, attach an explosive, move away, and then detonate it. The sub was extremely hazardous to operate, and had no air supply other than what was contained inside the main compartment. On two occasions, the sub sank; on the first occasion half the crew died and on the second, the entire eight-man crew (including Hunley himself) drowned. On February 18, 1864 Hunley sank USS Housatonic off
[edit] South America
The first submarine in South America was the Hipopotamo, tested in Ecuador on September 18, 1837. It was built by Jose Rodriguez Lavandera, who successfully crossed the Guayas River in Guayaquil accompanied by Jose Quevedo. Rodriguez Lavandera enrolled in the Navy in 1823, becoming a Lieutenant by 1830. The Hipopotamo crossed the Guayas on two more occasions, but it was then abandoned because of lack of funding and interest from the government.
The submarine Flach was commissioned in 1865 by the Chilean government during the war of Chile and Peru against Spain (1864-1866). It was built by the German engineer Karl Flach. The submarine sank during tests in Valparaiso bay on May 3, 1866, with the entire eleven-man crew.
[edit] Mechanically-powered submarines (late 19th century)
Plongeur, the first submarine to rely on mechanical power for propulsion
The first submarine not relying on human power for propulsion was the French Plongeur, launched in 1863, and using compressed air at 180 psi (1241 kPa).[13]
The first combustion-powered submarine was Ictineo II, designed in
A replica of Monturiol's wooden Ictineo II stands near Barcelona harbor.
In 1870, the French writer Jules Verne published the science fiction classic 20,000 Leagues under the Sea, which concerns the adventures of a maverick inventor in Nautilus, a submarine more advanced than any at the time. The story inspired inventors to build more advanced submarines.
In 1879, the Peruvian government, during the War of the Pacific, commissioned and built the fully operational submarine Toro Submarino. It never saw military action before being scuttled after the defeat of that country in the war to prevent its capture by the enemy.
The first submarine to be mass-produced was human-powered. It was the submarine of the Polish inventor Stefan Drzewiecki—50 units were built in 1881 for the Russian government. In 1884 the same inventor built an electric-powered submarine.
The Nordenfelt-designed Ottoman submarine Abdülhamid (1886) was the first submarine in the world to fire a torpedo while submerged.[14] It and its sister ship, Abdülmecid (1887), were built in pieces by Des Vignes (Chertsey) and Vickers (Sheffield) in England, and were assembled at the Taşkızak Naval Shipyard in Istanbul, Turkey.
Discussions between the English clergyman and inventor George Garrett and the industrially and commercially adept Swede Thorsten Nordenfelt led to a series of steam-powered submarines. The first was the Nordenfelt I, a 56 tonne, 19.5 metre (64 ft) vessel similar to Garret's ill-fated Resurgam (1879), with a range of 240 kilometres (150 mi, 130 nm), armed with a single torpedo, in 1885. Like Resurgam, Nordenfelt I operated on the surface by steam, then shut down its engine to dive. While submerged the submarine released pressure generated when the engine was running on the surface to provide propulsion for some distance underwater. Greece, fearful of the return of the Ottomans, purchased it. Nordenfelt then built Nordenfelt II (Abdülhamid) in 1886 and Nordenfelt III (Abdülmecid) in 1887, a pair of 30 metre (100 ft) submarines with twin torpedo tubes, for the Ottoman navy. Abdülhamid became the first submarine in history to fire a torpedo submerged.[15] Nordenfelt's efforts culminated in 1887 with Nordenfelt IV which had twin motors and twin torpedoes. It was sold to the Russians, but proved unstable, ran aground, and was scrapped.
Hull of Peral submarine at Cartagena, Spain
On September 8, 1888, an electrically powered vessel built by the Spanish engineer and sailor Isaac Peral for the Spanish Navy was launched. It had two torpedoes, new air systems, and a hull shape, propeller, and cruciform external controls anticipating much later designs. Its underwater speed was ten knots (19 km/h). In June 1890 Peral's submarine launched a torpedo while submerged. Its ability to fire torpedoes under water while maintaining full propulsive power and control has led some to call it the first U-boat. After many successful dives the project was scrapped because of the difficulties of recharging at sea and the short range of battery-powered vessels.
Shortly after, the French Gymnote was launched on September 24, 1888. The electrically-powered Gymnote, another fully functional military submarine, completed 2,000 dives successfully.
Many more designs were built at this time by various inventors, but submarines were not to become effective weapons until the 20th century.
[edit] Late 19th century to World War I
USS Plunger, launched in 1902
The turn of the 19th century marked a pivotal time in the development of submarines, with a number of important technologies making their debut, as well as the widespread adoption and fielding of submarines by a number of nations. Diesel electric propulsion would become the dominant power system and equipment such as the periscope would become standardized. Large numbers of experiments were done by countries on effective tactics and weapons for submarines, all of which would culminate in them making a large impact on the coming World War I.
In 1896, the Irish-American inventor John Philip Holland designed submarines that, for the first time, made use of internal combustion engine power on the surface and electric battery power for submerged operations. The Holland VI was launched on May 17, 1897 at Navy Lt. Lewis Nixon's Crescent Shipyard of
A proto-type version of the A-class submarines (
Many "civilized" countries became interested in
The 1900 French submarine Narval
Commissioned in June 1900, the French steam and electric submarine Narval introduced the classic double-hull design, with a pressure hull inside the outer light hull. These 200-ton ships had a range of over 100 miles (160 km) on the surface, and over 10 miles (16 km) underwater. The French submarine Aigrette in 1904 further improved the concept by using a diesel rather than a gasoline engine for surface power. Large numbers of these submarines were built, with seventy-six completed before 1914.
[edit] Submarines during World War I
The German submarine U-9, which sank three British cruisers in a few minutes in September 1914
Military submarines first made a significant impact in World War I. Forces such as the U-boats of Germany saw action in the First Battle of the Atlantic, and were responsible for the sinking of Lusitania, which was sunk as a result of unrestricted submarine warfare and among the reasons for the entry of the United States into the war.
The U-boats' ability to function as practical war machines relied on new tactics, their numbers, and submarine technologies such as combination diesel-electric power system developed in the preceding years. More submersibles than true submarines, U-boats operated primarily on the surface using regular engines, submerging occasionally to attack under battery power. They were roughly triangular in cross-section, with a distinct keel to control rolling while surfaced, and a distinct bow.
[edit] Interwar developments
Various new submarine designs were developed during the interwar years. Among the most notorious ones were submarine aircraft carriers, equipped with a waterproof hangar and steam catapult to launch and recover one or more small seaplanes. The submarine and its plane could then act as a reconnaissance unit ahead of the fleet, an essential role at a time when radar still did not exist. The first example was the British HMS M2, followed by the French Surcouf, and numerous aircraft-carrying submarines in the Imperial Japanese Navy.
[edit] Submarines during World War II
[edit] Germany
Main article: U-boat
U-47 returns to port after sinking HMS Royal Oak in October 1939. The battlecruiser Scharnhorst is seen in the background.
After putting to sea, U-boats operated mostly on their own, trying to find convoys in areas assigned to them by the High Command. If a convoy was found, the submarine did not attack immediately, but shadowed the convoy to allow other submarines in the area to find the convoy. These were then grouped into a larger striking force to attack the convoy simultaneously, preferably at night while surfaced.
From September 1939 to the beginning of 1943, the Ubootwaffe ("U-boat force") scored unprecedented success with these tactics, but were too few to have any decisive success. By the spring of 1943, German U-boat construction was at full capacity, but this was more than nullified by increased numbers of convoy escorts, aircraft, as well as technical advances like radar and sonar. Huff-Duff and Ultra allowed the Allies to route convoys around wolf packs when they detected them from their radio transmissions. The results were devastating: from March to July of that year, over 130 U-boats were lost, 41 in May alone. Concurrent Allied losses dropped dramatically, from 750,000 tons in March to only 188,000 in July. Although the Second battle of the Atlantic would continue to the last day of the war, the U-boat arm was unable to stem the tide of men and material, paving the way for Operation Torch, Operation Husky, and ultimately, D-Day. Winston Churchill wrote that the U-boat "peril" was the only thing that ever gave him cause to doubt the Allies' eventual victory.
[edit] Japan
Main article: Imperial Japanese Navy submarines
The Imperial Japanese Navy's I-400 class submarine, the largest submarine type of WWII
The Japanese Imperial Navy started their submarine service with five
Nevertheless, despite their technical prowess, Japanese submarines were relatively unsuccessful. They were often used in offensive roles against warships, which were fast, maneuverable and well-defended compared to merchant ships. In 1942, Japanese submarines sank two aircraft carriers among other warships, but were not able to sustain these results afterwards. By the end of the war, submarines were instead often used to transport supplies to island garrisons.
[edit] United States
The
Whereas
During World War II, 314 submarines served in the United States Navy. On December 7, 1941, 111 boats were in commission; 203 submarines from the Gato, Balao, and Tench classes were commissioned during the war. During hostilities, 48[17] boats and 3,294[18] men were lost, the highest percentage killed in action of any
[edit] United Kingdom
The Royal Navy Submarine Service was primarily used to enforce the classic British blockade role. It therefore chiefly operated in inshore waters and tended to only surface by night.[citation needed]
Its major operating areas were around Norway, the Mediterranean (against the Axis supply routes to North Africa), and in the
In the war British submarines sank 2 million tons of enemy shipping and 57 major warships, the latter including 35 submarines. Amongst these is the only instance ever of a submarine sinking another submarine while both were submerged. This occurred when HMS Venturer engaged the U864; the Venturer crew manually computed a successful firing solution against a three-dimensionally manoeveuring target using techniques which became the basis of modern torpedo computer targeting systems. Seventy-four British submarines were lost, half probably to naval mines.[19]
[edit] The snorkel
The diesel engines on HMS Ocelot charged the batteries located beneath the decking.
The larger search periscope, and the smaller, less detectable attack periscope on HMS Ocelot
Diesel-electric submarines need air to run their diesel engines, and so carried very large batteries for submerged operation. The need to recharge the batteries from the diesel engines limited the endurance of the submarine while submerged and required it to surface regularly for extended periods, during which it was especially vulnerable to detection and attack. The snorkel, a prewar Dutch invention, was used to allow German submarines to run their diesel engines whilst running just under the surface, drawing air through a tube from the surface.
The German Navy also experimented with engines that would use hydrogen peroxide to allow diesel fuel to be used while submerged, but technical difficulties were great. The Allies experimented with a variety of detection systems, including chemical sensors to "smell" the exhaust of submarines.
Cold-war diesel-electric submarines, such as the Oberon class, used batteries to power their electric motors in order to run silently. They recharged the batteries using the diesel engines without ever surfacing.
[edit] Modern submarines
In the 1950s, nuclear power partially replaced diesel-electric propulsion. Equipment was also developed to extract oxygen from sea water. These two innovations gave submarines the ability to remain submerged for weeks or months, and enabled previously impossible voyages such as USS Nautilus' crossing of the North pole beneath the Arctic ice cap in 1958 [20]and the USS Triton's submerged circumnavigation of the world in 1960.[21] Most of the naval submarines built since that time in the
In 1959–1960, the first ballistic missile submarines were put into service by both the United States (George Washington class) and the Soviet Union (Hotel class) as part of the Cold War nuclear deterrent strategy.
While the greater endurance and performance from nuclear reactors makes nuclear submarines better for long-distance missions or the protection of a carrier battle-force they have the technical limitation in stealthiness as the reactor always have to be chilled with the inherent noise it brings from pumps. Conventional diesel-electric submarines have continued to be produced by both nuclear and non-nuclear powers as they lack this limitation, except when required to run the diesel engine to recharge the ship’s battery. Technological advances in sound damping, noise isolation, and cancellation have substantially eroded this advantage.[clarify] Though far less capable regarding speed and weapons payload, conventional submarines are also cheaper to build. The introduction of air-independent propulsion boats, conventional diesel-electric submarines with some kind of auxiliary air-independent electricity generator, have led to increased sales of such types of submarines.
During the Cold War, the
During the Indo-Pakistani War of 1971, the Pakistan Navy's Hangor sank the Indian frigate INS Khukri. This was the first submarine kill since World War II, and the only one until the
More recently,
[edit] Polar Operations
- 1903 - Simon Lake submarine Protector surfaced through ice off Newport, Rhode Island.[22]
- 1930 - USS O-12 (SS-73) operated under ice near Spitsbergen.[22]
- 1937 - Soviet submarine Krasnogvardeyets operated under ice in the Denmark Strait.[22]
- 1941-45 - German U-boats operated under ice from the Barents Sea to the Laptev Sea.[22]
- 1946 - USS Atule (SS-403) used upward-beamed fathometer in Operation Nanook in the Davis Strait.[22]
- 1946-47 - USS Sennet (SS-408) used under-ice SONAR in Operation High Jump in the Antarctic.[22]
- 1947 - USS Boarfish (SS-327) used upward-beamed echo sounder under pack ice in the Chukchi Sea.[22]
- 1948 - USS Carp (SS-338) developed techniques for making vertical ascents and descents through polynyas in the
- 1952 - USS Redfish (SS-395) used an expanded upward-beamed sounder array in the Beaufort Sea.[22]
- 1957 - USS Nautilus (SSN-571) reached 87 degrees north near
- 3 August 1958 - Nautilus used an inertial navigation system to reach the north pole.[22]
- 17 March 1959 - USS Skate (SSN-578) surfaced through the ice at the north pole.[22]
- 1960 - USS Sargo (SSN-583) transited 900 miles under ice over the shallow (125 to 180 feet deep) Bering-Chukchi shelf.[22]
- 1960 - USS Seadragon (SSN-584) transited the Northwest Passage under ice.[22]
- 1962 - Soviet November class submarine Leninskiy Komsomol reached the north pole.[22]
- 1971 - HMS Dreadnought (S101) reached the north pole.[22]
[edit] Submarines in popular culture
[edit] Fiction books
For more fictional submarines, see the category of Fictional submarines.
As early as 1666, English writer Margaret Cavendish wrote Blazing World - one of the earliest science fiction books - which included the depiction of a naval war fought by submarines, towed by "fish-men".
The most famous fictional submarine is probably Nautilus, which belongs to Captain Nemo in Jules Verne's Twenty Thousand Leagues Under the Sea. Many other ships were named Nautilus; however, Verne named the submarine after Robert Fulton's real-life submarine Nautilus, and the name has been associated with fighting ships of the United SUGM-27 Polaris
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Polaris A-3 on launch pad in
The Polaris missile was a submarine-launched, two-stage solid-fuel nuclear-armed ballistic missile (SLBM) built during the Cold War by Lockheed for the United States Navy. It was designed to be used as part of the US Navy's contribution to the
Following the Polaris Sales Agreement in 1963 Polaris missiles were also carried on
Polaris was replaced in the US Navy by Poseidon, beginning in 1972. In the 1980s both were replaced by Trident I.
Contents[hide] |
[edit] History and development
Polaris replaced an earlier plan to create a submarine-based missile force based on a huge surfaced submarine carrying four Jupiter missiles, which would be carried and launched horizontally. This Navy Jupiter missile is not to be confused with the U.S. Army (later USAF) Jupiter IRBM. At Edward Teller's prompting [1], the Navy's Jupiter plans were abandoned in favor of the much smaller, solid-propellant Polaris.
Originally, the Navy favored cruise missile systems in a strategic role as deployed on the earlier USS Greyback, but a major drawback of these early cruise missile launch systems (and the Jupiter proposals) was the need to surface, and remain surfaced for some time, to launch. Subs were very vulnerable to attack during launch, and a fully or partially fueled missile on deck was a serious hazard. Rough weather was another major drawback for these designs, but rough sea conditions did not unduly affect Polaris launches.
It quickly became apparent solid-fueled ballistic missiles had advantages over cruise missiles in range and accuracy, and unlike both Jupiter and cruise, were able to be launched from a submerged submarine, improving submarine survivability.
The prime contractor for all three versions of Polaris was Lockheed, now Lockheed Martin.
The Polaris program started development in 1956. The USS George Washington, the first
[edit] Polaris A-1
Polaris A-1 on launch pad in
The first version, the Polaris A-1, had a range of 1000 nautical miles (1853 km) and a single Mk 1 re-entry vehicle, carrying a single W-47-Y1 600 kT nuclear warhead, with an inertial guidance system which provided a CEP of 1800m (6000ft). The two-stage solid propellant missile had a length of 28.5 ft (8.69 m), a body diameter of 54 in (1.37 m) and a launch weight of 28,800 lbs (13,090 kg).
A test launch from a submarine on July 20, 1960, was the first underwater guided-missile launch (apart from German experiments during World War 2). USS George Washington was the first fleet ballistic missile submarine (SSBN in
Work on its W47 nuclear warhead began in 1957 at the facility now called the Lawrence Livermore National Laboratory by a team headed by Edward Teller and Harold Brown[2]. The Navy accepted delivery of the first 16 warheads in July 1960. On May 6, 1962, a Polaris missile with a live W47 warhead was tested in Operation Dominic in the Pacific Ocean, the only
The two stages were both steered by thrust vectoring. Inertial navigation guided the missile to about a 900 m (3,000 foot) CEP, insufficient for use against hardened targets. They were mostly useful for attacking dispersed military surface targets (airfields or radar sites), clearing a pathway for heavy bombers, although in the general public perception Polaris was a strategic second-strike retaliatory weapon.
[edit] Strategic role
The Polaris A-1 missile served as a strategic asset. The missile was developed to complement the limited number of medium-range systems deployed throughout
[edit] Later versions
The later versions (the A-2, A-3, and B-3) were larger, weighed more, and had longer ranges than the A-1. The range increase was most important: The A-2 range was 1,500 nautical miles (2,779 km), the A-3 2,500 nautical miles (4,631 km), and the B-3 2,000 nautical miles (3,705 km). The A-3 featured multiple re-entry vehicles (MRVs) which spread the warheads about a common target, and the B-3 was to have penetration aids to counter Soviet Anti-Ballistic Missile defenses. The B-3 missile evolved into the C-3 Poseidon missile, which abandoned the decoy concept in favor of using the C3's greater throw-weight for larger numbers (10-14) of new hardened high-re-entry-speed reentry vehicles that could overwhelm Soviet defences by sheer weight of numbers, and its high speed after re-entry. The abandoned decoy system for the B-3 (Antelope) was known to the
[edit] British Polaris
British Polaris, Imperial War Museum, London
The British became interested in Polaris after the cancellations of the Blue Streak and Skybolt missiles in the 1960s. Under the Nassau agreement that emerged from the 1962 Nassau Conference between Harold Macmillan and John F. Kennedy, the United States would supply Britain with Polaris missiles, launch tubes, ReBs and the fire control system.
British Polaris submarines were the Resolution-class ballistic missile submarines. Although one boat of the four was always in refit, recent declassifications of archived files disclose that the Royal Navy deployed four boatloads of RVs and warheads plus spare warheads for Polaris A3T, retaining a limited ability to arm and put to sea the boat that was in refit. When replaced by Chevaline, the deployed RVs/warheads reduced to three boatloads.
The original U.S. Navy Polaris had not been designed to penetrate ABM defenses, but the British had to ensure that their small Polaris force operating alone and often with only one submarine on station, could penetrate the ABM screen around
For the origins of the British Polaris program, see Peter Nailor, The Nassau Connection (1988).
[edit] Chevaline
Main article: Chevaline
The UK Polaris was subsequently updated with an 'Improved-Front-End' (
The result was a programme called Chevaline that reduced the number of new super-hardened warheads and ReBs to two, and added multiple decoys, chaff, and other defensive countermeasures. Its genesis was in part, a similar program in the
The Chevaline project was kept secret by four successive British governments, and its existence was only revealed in 1980 by Margaret Thatcher's then defence minister Francis Pym, partly because cost over-runs of the project which had almost quadrupled the original estimate given when the project was finally approved in January 1975. The system became operational in mid-1982 on HMS Renown and the last British SSBN submarine was equipped with it in mid-1987.[3]
Although planning for a successor-system to Chevaline began in 1969, the British rationale for pursuing the expensive Chevaline program was part-based on the expected lifetime of the submarine hulls. When the decision was taken in January 1975, to opt for Chevaline, the hulls were less than ten years old, with an expected life of thirty years. The improvements to Polaris extended the missile life to almost match the life of the submarines, while meeting the essential requirement of the British military planners; that Chevaline could penetrate the
The 'unimproved' British Polaris A3T carried three 200kt warheads[4] designated ET.317 in U.S. Mk-2 RVs, comprised of a primary known as Jennie and a thermonuclear secondary known as Reggie.[5] The integrated upgraded Polaris and Chevaline system was known as A3TK and carried two warheads in upgraded British-designed RVs. These warheads used the new Harriet primary[6] with the Reggie thermonuclear secondary re-used from the ET.317 warhead,[7] and their nuclear yield increased to 225kt.[8] This system was deployed from 1982 to 1996, when it was gradually replaced by Trident D5.
[edit] Replacement
The British upgraded to the Trident missile after much political wrangling within the Callaghan Labour government over the cost and necessity. The outgoing Prime Minister James Callaghan made his government's papers on Trident available to Margaret Thatcher's incoming Conservative government who took the decision to acquire Trident C4.
A subsequent decision to upgrade to the larger, longer-ranged Trident D5 was probably taken to ensure that there was commonality between the United States Navy and the Royal Navy; which was especially important when they were to use common repair and maintenance facilities at King's
Polaris remained in
[edit] Italy
tates Navy since 1803.
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