A submarine (or sub) is a
Any vehicle used in or on water as well as underwater, including boats, ships, hovercraft and submarines, is a watercraft, also known as a water vessel or waterborne vessel. A watercraft usually has a propulsive capability (whether by sail, ...
capable of independent operation underwater. It differs from a
A submersible is a small watercraft designed to operate underwater. The term "submersible" is often used to differentiate from other underwater vessels known as submarines, in that a submarine is a fully self-sufficient craft, capable of ind ...
, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to
remotely operated vehicle
A remotely operated underwater vehicle (technically ROUV or just ROV) is a tethered underwater mobile device, commonly called ''underwater robot''.
This meaning is different from remote control vehicles operating on land or in the ...
robots "\n\n\n\n\nThe robots exclusion standard, also known as the robots exclusion protocol or simply robots.txt, is a standard used by websites to indicate to visiting web crawlers and other web robots which portions of the site they are allowed to visi ...
, as well as medium-sized or smaller vessels, such as the
A midget submarine (also called a mini submarine) is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to six or nine, with little or no on-board living accommodation. They normally work with mother ships, ...
A wet sub is a type of underwater vehicle, either a submarine or a submersible, that does not provide a dry environment for its occupants. It is also described as an underwater vehicle where occupants are exposed to ambient environment during oper ...
. Submarines are referred to as ''boats'' rather than ''ships'' irrespective of their size.
Although experimental submarines had been built earlier, submarine design took off during the 19th century, and they were adopted by several navies. They were first widely used during
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
(1914–1918), and are now used in many
A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake-borne, riverine, littoral, or ocean-borne combat operations and related functions. It include ...
, large and small. Military uses include attacking enemy surface
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguishe ...
s (merchant and military) or other submarines, and for
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows ...
protection, blockade running
Deterrence theory refers to the scholarship and practice of how threats or limited force by one party can convince another party to refrain from initiating some other course of action. The topic gained increased prominence as a military strategy ...
In military operations, reconnaissance or scouting is the exploration of an area by military forces to obtain information about enemy forces, terrain, and other activities.
Examples of reconnaissance include patrolling by troops ( skirmishe ...
, conventional land attack (for example, using a
A cruise missile is a guided missile used against terrestrial or naval targets that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhea ...
), and covert insertion of
Special forces and special operations forces (SOF) are military units trained to conduct special operations. NATO has defined special operations as "military activities conducted by specially designated, organized, selected, trained and equ ...
. Civilian uses include marine science
, exploration, and facility inspection and maintenance. Submarines can also be modified for specialized functions such as search-and-rescue missions and undersea cable
repair. They are also used in tourism and
Underwater archaeology is archaeology practiced underwater. As with all other branches of archaeology, it evolved from its roots in pre-history and in the classical era to include sites from the historical and industrial eras. Its acceptance has ...
. Modern deep-diving submarines derive from the
A bathyscaphe ( or ) is a free-diving self-propelled deep-sea submersible, consisting of a crew cabin similar to a bathysphere, but suspended below a float rather than from a surface cable, as in the classic bathysphere design.
The float is ...
, which evolved from the
A diving bell is a rigid chamber used to transport divers from the surface to depth and back in open water, usually for the purpose of performing underwater work. The most common types are the open-bottomed wet bell and the closed bell, which c ...
Most large submarines consist of a cylindrical body with hemispherical (or conical) ends and a vertical structure, usually located amidships, that houses communications and sensing devices as well as
A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.
In its simplest form, it consists of an outer case with ...
s. In modern submarines, this structure is the "
A sail is a tensile structure—which is made from fabric or other membrane materials—that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails m ...
" in American usage and "fin" in European usage. A "
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and gro ...
" was a feature of earlier designs: a separate pressure hull above the main body of the
A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats.
Small boats are typically found on in ...
that allowed the use of shorter periscopes. There is a propeller (or pump jet) at the rear, and various hydrodynamic control fins. Smaller, deep-diving, and specialty submarines may deviate significantly from this traditional design. Submarines dive and resurface by means of
Diving planes, also known as hydroplanes, are control surfaces found on a submarine which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when subm ...
s and changing the amount of water and air in
A ballast tank is a compartment within a boat, ship or other floating structure that holds water, which is used as ballast to provide hydrostatic stability for a vessel, to reduce or control buoyancy, as in a submarine, to correct trim or ...
s to affect their
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pr ...
Submarines encompass a wide range of types and capabilities. They include small autonomous examples using A-Navigation and one- or two-person subs that operate for a few hours, to vessels that can remain submerged for six months—such as the Russian , the biggest submarines ever built. Submarines can work at greater depths than are survivable or practical for human divers
The word ''submarine'' simply means 'underwater' or 'under-sea' (as in
A submarine canyon is a steep-sided valley cut into the seabed of the continental slope, sometimes extending well onto the continental shelf, having nearly vertical walls, and occasionally having canyon wall heights of up to 5 km, from ...
, submarine pipeline
) though as a noun it generally refers to a vessel that can travel underwater. The term is a contraction of ''submarine boat''. and occurs as such in several languages, e.g. French (), and Spanish (), although others retain the original term, such as Dutch (), German (), Swedish (), and Russian (: ), all of which mean 'submarine boat'. By naval tradition
, submarines are still usually referred to as ''boats'' rather than as ''ships'', regardless of their size.
Although referred to informally as ''boats'', U.S. submarines employ the designation USS ( United States Ship
) at the beginning of their names, such as . In the Royal Navy, the designation HMS can refer to "His Majesty's Ship" or "His Majesty's Submarine", though the latter is sometimes rendered "HMS/m"
[ For example, se]
Historic England (officially the Historic Buildings and Monuments Commission for England) is an executive non-departmental public body of the British Government sponsored by the Department for Digital, Culture, Media and Sport. It is tasked wit ...
and submarines are generally referred to as ''boats'' rather than ''ships''.
[The Submarine service page on the official website of the Royal Navy refers to "These powerful boat]
and in at a speech in Washington, Adm. Sir Philip Jones announced "that the name ''Dreadnought'' will return as lead boat and class name" for Dreadnought-class submarine, Britain’s latest ballistic missile submarinesbr>
Early human-powered submersibles
16th and 17th centuries
According to a report in ''Opusculum Jean Taisnier, Taisnieri'' published in 1562:
In 1578, the English mathematician William Bourne recorded in his book ''Inventions or Devises'' one of the first plans for an underwater navigation vehicle. A few years later the Scottish mathematician and theologian
John Napier of Merchiston (; 1 February 1550 – 4 April 1617), nicknamed Marvellous Merchiston, was a Scottish landowner known as a mathematician, physicist, and astronomer. He was the 8th Laird of Merchiston. His Latinized name was Ioan ... wrote in his ''Secret Inventions'' (1596) that "These inventions besides devises of sayling under water with divers, other devises and strategems for harming of the enemyes by the Grace of God and worke of expert Craftsmen I hope to perform." It's unclear whether he ever carried out his idea. [
Jerónimo de Ayanz y Beaumont (1553-1613) created detailed designs for two types of air-renovated submersible vehicles. They were equipped with oars, autonomous floating snorkels worked by inner pumps, portholes and gloves used for the crew to manipulate underwater objects. Ayanaz planned to use them for warfare, using them to approach enemy ships undetected and set up timed gunpowder charges on their hulls.
The first submersible of whose construction there exists reliable information was designed and built in 1620 by ] Cornelis Drebbel
Cornelis Jacobszoon Drebbel ( ) (1572 – 7 November 1633) was a Dutch engineer and inventor. He was the builder of the first operational submarine in 1620 and an innovator who contributed to the development of measurement and control systems, ..., a Dutchman in the service of James I of England
James VI and I (James Charles Stuart; 19 June 1566 – 27 March 1625) was King of Scotland as James VI from 24 July 1567 and King of England and Ireland as James I from the union of the Scottish and English crowns on 24 March 1603 until .... It was propelled by means of oars.
By the mid-18th century, over a dozen patents for submarines/submersible boats had been granted in England. In 1747, Nathaniel Symons patented and built the first known working example of the use of a ballast tank for submersion. His design used leather bags that could fill with water to submerge the craft. A mechanism was used to twist the water out of the bags and cause the boat to resurface. In 1749, the Gentlemen's Magazine reported that a similar design had initially been proposed by Giovanni Borelli in 1680. Further design improvement stagnated for over a century, until application of new technologies for propulsion and stability.
The first military submersible was (1775), a hand-powered acorn-shaped device designed by the American David Bushnell to accommodate a single person. It was the first verified submarine capable of independent underwater operation and movement, and the first to use screws
A screw and a bolt (see '' Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helical ridge, called a ''male thread'' (external thread). Screws and bolts are used to ... for propulsion.
In 1800, France built , a human-powered submarine designed by American
Robert Fulton (November 14, 1765 – February 24, 1815) was an American engineer and inventor who is widely credited with developing the world's first commercially successful steamboat, the (also known as ''Clermont''). In 1807, that steambo .... They gave up on the experiment in 1804, as did the British, when they reconsidered Fulton's submarine design.
In 1850, Wilhelm Bauer
Wilhelm Bauer (23 December 1822 – 20 June 1875) was a German inventor and engineer who built several hand-powered submarines.
Wilhelm Bauer was born in Dillingen in the Kingdom of Bavaria. His father was a sergeant of a Bavarian ...'s Brandtaucher was built in Germany. It remains the oldest known surviving Submarine in the world.
In 1864, late in the American Civil War
The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by state ..., the Confederate navy's became the first military submarine to sink an enemy vessel, the Union sloop-of-war
In the 18th century and most of the 19th, a sloop-of-war in the Royal Navy was a warship with a single gun deck that carried up to eighteen guns. The rating system covered all vessels with 20 guns and above; thus, the term ''sloop-of-war'' en ... , using a gun-powder-filled keg on a spar as a torpedo charge. The ''Hunley'' also sank, as the explosion's shock waves killed its crew instantly, preventing them from pumping the bilge or propelling the submarine.
In 1866, was the first submarine to successfully dive, cruise underwater, and resurface under the crew's control. The design by German American
German Americans (german: Deutschamerikaner, ) are Americans who have full or partial German ancestry. With an estimated size of approximately 43 million in 2019, German Americans are the largest of the self-reported ancestry groups by the Unit ... Julius H. Kroehl (in German, ''Kröhl'') incorporated elements that are still used in modern submarines.
In 1866, was built at the Chilean government's request by Karl Flach, a German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ... engineer and immigrant. It was the fifth submarine built in the world and, along with a second submarine, was intended to defend the port of Valparaiso against attack by the Spanish Navy
The Spanish Navy or officially, the Armada, is the maritime branch of the Spanish Armed Forces and one of the oldest active naval forces in the world. The Spanish Navy was responsible for a number of major historic achievements in navigation, ... during the Chincha Islands War
The Chincha Islands War, also known as Spanish–South American War ( es, Guerra hispano-sudamericana), was a series of coastal and naval battles between Spain and its former colonies of Peru, Chile, Ecuador, and Bolivia from 1865 to 1879. The ....
Mechanically powered submarines
Submarines could not be put into widespread or routine service use by navies until suitable engines were developed. The era from 1863 to 1904 marked a pivotal time in submarine development, and several important technologies appeared. A number of nations built and used submarines. Diesel electric propulsion became the dominant power system and equipment such as the periscope became standardized. Countries conducted many experiments on effective tactics and weapons for submarines, which led to their large impact in
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ....
The first submarine not relying on human power for propulsion was the French (''Diver''), launched in 1863, which used compressed air at . Narcís Monturiol designed the first air-independent and
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combus ...-powered submarine, , which was launched in Barcelona
Barcelona ( , , ) is a city on the coast of northeastern Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within ci ..., Spain in 1864.
The submarine became a potentially viable weapon with the development of the Whitehead torpedo, designed in 1866 by British engineer Robert Whitehead
Robert Whitehead (3 January 1823 – 14 November 1905) was an English engineer who was most famous for developing the first effective self-propelled naval torpedo.
He was born in Bolton, England, the son of James Whitehead, ..., the first practical self-propelled or "locomotive" torpedo. The spar torpedo
A spar torpedo is a weapon consisting of a bomb placed at the end of a long pole, or spar, and attached to a boat. The weapon is used by running the end of the spar into the enemy ship. Spar torpedoes were often equipped with a barbed spear at ... that had been developed earlier by the Confederate States Navy
The Confederate States Navy (CSN) was the Navy, naval branch of the Confederate States Armed Forces, established by an act of the Confederate States Congress on February 21, 1861. It was responsible for Confederate naval operations during the Amer ... was considered to be impracticable, as it was believed to have sunk both its intended target, and probably ''H. L. Hunley'', the submarine that deployed it.
Irish may refer to:
* Someone or something of, from, or related to:
** Ireland, an island situated off the north-western coast of continental Europe
***Éire, Irish language name for the isle
** Northern Ireland, a constituent unit ... inventor John Philip Holland built a model submarine in 1876 and in 1878 demonstrated the Holland I prototype. This was followed by a number of unsuccessful designs. In 1896, he designed the Holland Type VI submarine, which used internal combustion engine power on the surface and electric battery power underwater. Launched on 17 May 1897 at Navy Lt. Lewis Nixon's Crescent Shipyard in , ''Holland VI'' was purchased by the United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnag ... on 11 April 1900, becoming the Navy's first commissioned submarine, christened .
Discussions between the English clergyman and inventor George Garrett and the Swedish industrialist Thorsten Nordenfelt led to the first practical steam-powered submarines, armed with torpedoes and ready for military use. The first was ''Nordenfelt I'', a 56-tonne, vessel similar to Garrett's ill-fated (1879), with a range of , armed with a single torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, s ..., in 1885.
A reliable means of propulsion for the submerged vessel was only made possible in the 1880s with the advent of the necessary electric battery technology. The first electrically powered boats were built by Isaac Peral y Caballero in Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, ... (who built ), Dupuy de Lôme (who built ) and Gustave Zédé (who built ''Sirène'') in France, and James Franklin Waddington (who built ''Porpoise'') in England. Peral's design featured torpedoes and other systems that later became standard in submarines.
Commissioned in June 1900, the French steam and electric employed the now typical double-hull design, with a pressure hull inside the outer shell. These 200-ton ships had a range of over 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.
The Royal Navy commissioned five s from Vickers
Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in ..., Barrow-in-Furness
Barrow-in-Furness is a port town in Cumbria, England. Historically in Lancashire, it was incorporated as a municipal borough in 1867 and merged with Dalton-in-Furness Urban District in 1974 to form the Borough of Barrow-in-Furness. In 2023 ..., under licence from the Holland Torpedo Boat Company from 1901 to 1903. Construction of the boats took longer than anticipated, with the first only ready for a diving trial at sea on 6 April 1902. Although the design had been purchased entirely from the US company, the actual design used was an untested improvement to the original Holland design using a new petrol engine.
These types of submarines were first used during the Russo-Japanese War
The Russo-Japanese War ( ja, 日露戦争, Nichiro sensō, Japanese-Russian War; russian: Ру́сско-япóнская войнá, Rússko-yapónskaya voyná) was fought between the Empire of Japan and the Russian Empire during 1904 and 1 ... of 1904–05. Due to the blockade at Port Arthur, the Russians sent their submarines to Vladivostok
Vladivostok ( rus, Владивосто́к, a=Владивосток.ogg, p=vɫədʲɪvɐˈstok) is the largest city and the administrative center of Primorsky Krai, Russia. The city is located around the Golden Horn Bay on the Sea of Japan, c ..., where by 1 January 1905 there were seven boats, enough to create the world's first "operational submarine fleet". The new submarine fleet began patrols on 14 February, usually lasting for about 24 hours each. The first confrontation with Japanese warships occurred on 29 April 1905 when the Russian submarine ''Som'' was fired upon by Japanese torpedo boats, but then withdrew.
World War I
Military submarines first made a significant impact in
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin .... Forces such as the U-boat
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare ro ...s of Germany saw action in the First Battle of the Atlantic
The Atlantic U-boat campaign of World War I (sometimes called the "First Battle of the Atlantic", in reference to the World War II campaign of that name) was the prolonged naval conflict between German submarines and the Allied navies in Atla ..., and were responsible for sinking , which was sunk as a result of unrestricted submarine warfare
Unrestricted submarine warfare is a type of naval warfare in which submarines sink merchant ships such as freighters and tankers without warning, as opposed to attacks per prize rules (also known as " cruiser rules") that call for warships to s ... and is often cited among the reasons for the entry of the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territor ... into the war.
At the outbreak of the war, Germany had only twenty submarines immediately available for combat, although these included vessels of the diesel-engined '' U-19'' class, which had a sufficient range of and speed of to allow them to operate effectively around the entire British coast., By contrast, the Royal Navy had a total of 74 submarines, though of mixed effectiveness. In August 1914, a flotilla of ten U-boats sailed from their base in Heligoland
Heligoland (; german: Helgoland, ; Heligolandic Frisian: , , Mooring Frisian: , da, Helgoland) is a small archipelago in the North Sea. A part of the German state of Schleswig-Holstein since 1890, the islands were historically possession ... to attack Royal Navy warships in the North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian ... in the first submarine war patrol in history.
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
The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. As the laying down of the keel is the initial step in the construction of a ship, in B ... to control rolling while surfaced, and a distinct bow. During World War I more than 5,000 Allied ships were sunk by U-boats.
The British responded to the German developments in submarine technology with the creation of the K-class submarines. However, these submarines were notoriously dangerous to operate due to their various design flaws and poor maneuverability.
World War II
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ..., Germany used submarines to devastating effect in the Battle of the Atlantic
The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allied naval blocka ..., where it attempted to cut Britain's supply routes by sinking more merchant ship
A merchant ship, merchant vessel, trading vessel, or merchantman is a watercraft that transports cargo or carries passengers for hire. This is in contrast to pleasure craft, which are used for personal recreation, and naval ships, which are ...s than Britain could replace. These merchant ships were vital to supply Britain's population with food, industry with raw material, and armed forces with fuel and armaments. Although the U-boats had been updated in the interwar years, the major innovation was improved communications, encrypted using the Enigma cipher machine. This allowed for mass-attack naval tactics (''Rudeltaktik'', commonly known as " wolfpack"), but was also ultimately the U-boats' downfall. By the end of the war, almost 3,000 Allied ships (175 warships, 2,825 merchantmen) had been sunk by U-boats. Although successful early in the war, Germany's U-boat fleet suffered heavy casualties, losing 793 U-boats and about 28,000 submariners out of 41,000, a casualty rate of about 70%.
The Imperial Japanese Navy
The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrend ... operated the most varied fleet of submarines of any navy, including '' Kaiten
were crewed torpedoes and suicide craft, used by the Imperial Japanese Navy in the final stages of World War II.
In recognition of the unfavorable progress of the war, towards the end of 1943 the Japanese high command considered s ...'' crewed torpedoes, midget submarines ( and es), medium-range submarines, purpose-built supply submarines and long-range fleet submarines. They also had submarines with the highest submerged speeds during World War II (s) and submarines that could carry multiple aircraft (s). They were also equipped with one of the most advanced torpedoes of the conflict, the oxygen-propelled Type 95. Nevertheless, despite their technical prowess, Japan chose to use its submarines for fleet warfare, and consequently were relatively unsuccessful, as warships were fast, maneuverable and well-defended compared to merchant ships.
The submarine force was the most effective anti-ship weapon in the American arsenal. Submarines, though only about 2 percent of the U.S. Navy, destroyed over 30 percent of the Japanese Navy, including 8 aircraft carriers, 1 battleship and 11 cruisers. US submarines also destroyed over 60 percent of the Japanese merchant fleet, crippling Japan's ability to supply its military forces and industrial war effort. Allied submarines in the Pacific War destroyed more Japanese shipping than all other weapons combined. This feat was considerably aided by the Imperial Japanese Navy's failure to provide adequate escort forces for the nation's merchant fleet.
During World War II, 314 submarines served in the US Navy, of which nearly 260 were deployed to the Pacific. [O'Kane, p. 333] When the Japanese attacked Hawaii in December 1941, 111 boats were in commission; 203 submarines from the , , and es were commissioned during the war. During the war, 52 US submarines were lost to all causes, with 48 directly due to hostilities. US submarines sank 1,560 enemy vessels, a total tonnage of 5.3 million tons (55% of the total sunk). [Blair, p. 878]
The Royal Navy Submarine Service was used primarily in the classic Axis blockade
A blockade is the act of actively preventing a country or region from receiving or sending out food, supplies, weapons, or communications, and sometimes people, by military force.
A blockade differs from an embargo or sanction, which are .... Its major operating areas were around Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and ..., in the Mediterranean
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ... (against the Axis supply routes to North Africa
North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...), and in the Far East. In that war, British submarines sank 2 million tons of enemy shipping and 57 major warships, the latter including 35 submarines. Among these is the only documented instance of a submarine sinking another submarine while both were submerged. This occurred when engaged
An engagement or betrothal is the period of time between the declaration of acceptance of a marriage proposal and the marriage itself (which is typically but not always commenced with a wedding). During this period, a couple is said to be ''fi ... ; the ''Venturer'' crew manually computed a successful firing solution against a three-dimensionally maneuvering target using techniques which became the basis of modern torpedo computer targeting systems. Seventy-four British submarines were lost, the majority, forty-two, in the Mediterranean.
Cold-War military models
The first launch of a
A cruise missile is a guided missile used against terrestrial or naval targets that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhea ... ( SSM-N-8 Regulus) from a submarine occurred in July 1953, from the deck of , a World War II fleet boat modified to carry the missile with a nuclear warhead
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both b .... ''Tunny'' and its sister boat, , were the United States' first nuclear deterrent patrol submarines. In the 1950s, nuclear power
Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produ ... partially replaced diesel–electric propulsion. Equipment was also developed to extract oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements a ... from sea water. These two innovations gave submarines the ability to remain submerged for weeks or months. Most of the naval submarines built since that time in the US, the Soviet Union/ Russian Federation
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ..., Britain, and France have been powered by nuclear reactors
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat fr ....
In 1959–1960, the first ballistic missile submarine
A ballistic missile submarine is a submarine capable of deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads. The United States Navy's hull classification symbols for ballistic missile submarines are SSB and SSBN – ...s were put into service by both the United States () and the Soviet Union () as part of the Cold War
The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term ''cold war'' is used because the ... nuclear deterrent
Nuclear strategy involves the development of doctrines and strategies for the production and use of nuclear weapons.
As a sub-branch of military strategy, nuclear strategy attempts to match nuclear weapons as means to political ends. In addit ... strategy.
During the Cold War, the US and the Soviet Union maintained large submarine fleets that engaged in cat-and-mouse games. The Soviet Union lost at least four submarines during this period: was lost in 1968 (a part of which the CIA retrieved from the ocean floor with the Howard Hughes
Howard Robard Hughes Jr. (December 24, 1905 – April 5, 1976) was an American business magnate, record-setting pilot, engineer, film producer, and philanthropist, known during his lifetime as one of the most influential and richest people in t ...-designed ship ''Glomar Explorer''), in 1970, in 1986, and in 1989 (which held a depth record among military submarines—). Many other Soviet subs, such as (the first Soviet nuclear submarine, and the first Soviet sub to reach the North Pole) were badly damaged by fire or radiation leaks. The US lost two nuclear submarines during this time: due to equipment failure during a test dive while at its operational limit, and due to unknown causes.
During India's intervention in the Bangladesh Liberation War
The Bangladesh Liberation War ( bn, মুক্তিযুদ্ধ, , also known as the Bangladesh War of Independence, or simply the Liberation War in Bangladesh) was a revolution and armed conflict sparked by the rise of the Bengali n ..., the Pakistan Navy
ur, ہمارے لیے اللّٰہ کافی ہے اور وہ بہترین کارساز ہے۔ English: Allah is Sufficient for us - and what an excellent (reliable) Trustee (of affairs) is He!('' Qur'an, 3:173'')
, type ...'s sank the Indian frigate . This was the first sinking by a submarine since World War II. During the same war, , a ''Tench''-class submarine on loan to Pakistan from the US, was sunk by the Indian Navy
The Indian Navy is the maritime branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of Naval Staff, a four-star admiral, commands the navy. As a blue-water navy, it operates s .... It was the first submarine combat loss since World War II. In 1982 during the Falklands War
The Falklands War ( es, link=no, Guerra de las Malvinas) was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British dependent territories in the South Atlantic: the Falkland Islands and its territorial ..., the Argentine cruiser was sunk by the British submarine , the first sinking by a nuclear-powered submarine in war. Some weeks later, on 16 June, during the Lebanon War, an unnamed Israeli submarine torpedoed and sank the Lebanese coaster ''Transit'', which was carrying 56 Palestinian refugees to Cyprus
Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is g ..., in the belief that the vessel was evacuating anti-Israeli militias. The ship was hit by two torpedoes, managed to run aground but eventually sank. There were 25 dead, including her captain. The Israeli Navy
The Israeli Navy ( he, חיל הים הישראלי, ''Ḥeil HaYam HaYisraeli'' (English: The Israeli Sea Corps); ar, البحرية الإسرائيلية) is the naval warfare service arm of the Israel Defense Forces, operating primarily in ... disclosed the incident in November 2018.
Before and during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ..., the primary role of the submarine was anti-surface ship warfare. Submarines would attack either on the surface using deck guns, or submerged using torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, s ...es. They were particularly effective in sinking Allied transatlantic shipping in both World Wars, and in disrupting Japanese supply routes and naval operations in the Pacific in World War II.
Mine-laying submarines were developed in the early part of the 20th century. The facility was used in both World Wars. Submarines were also used for inserting and removing covert agents and military forces in special operations
Special operations (S.O.) are military activities conducted, according to NATO, by "specially designated, organized, selected, trained, and equipped forces using unconventional techniques and modes of employment". Special operations may include ..., for intelligence gathering, and to rescue aircrew during air attacks on islands, where the airmen would be told of safe places to crash-land so the submarines could rescue them. Submarines could carry cargo through hostile waters or act as supply vessels for other submarines.
Submarines could usually locate and attack other submarines only on the surface, although managed to sink with a four torpedo spread while both were submerged. The British developed a specialized anti-submarine submarine in WWI, the R class. After WWII, with the development of the homing torpedo, better sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on ... systems, and nuclear propulsion
Nuclear propulsion includes a wide variety of propulsion methods that use some form of nuclear reaction as their primary power source. The idea of using nuclear material for propulsion dates back to the beginning of the 20th century. In 1903 it was ..., submarines also became able to hunt each other effectively.
The development of submarine-launched ballistic missile
A submarine-launched ballistic missile (SLBM) is a ballistic missile capable of being launched from submarines. Modern variants usually deliver multiple independently targetable reentry vehicles (MIRVs), each of which carries a nuclear warhea ... and submarine-launched cruise missile
A cruise missile is a guided missile used against terrestrial or naval targets that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhea ...s gave submarines a substantial and long-ranged ability to attack both land and sea targets with a variety of weapons ranging from cluster bomb
A cluster munition is a form of air-dropped or ground-launched explosive weapon that releases or ejects smaller submunitions. Commonly, this is a cluster bomb that ejects explosive bomblets that are designed to kill personnel and destroy vehic ...s to nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both b ...s.
The primary defense of a submarine lies in its ability to remain concealed in the depths of the ocean. Early submarines could be detected by the sound they made. Water is an excellent conductor of sound (much better than air), and submarines can detect and track comparatively noisy surface ships from long distances. Modern submarines are built with an emphasis on stealth. Advanced propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ... designs, extensive sound-reducing insulation, and special machinery help a submarine remain as quiet as ambient ocean noise, making them difficult to detect. It takes specialized technology to find and attack modern submarines.
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on ... uses the reflection of sound emitted from the search equipment to detect submarines. It has been used since WWII by surface ships, submarines and aircraft (via dropped buoys and helicopter "dipping" arrays), but it reveals the emitter's position, and is susceptible to counter-measures.
A concealed military submarine is a real threat, and because of its stealth, can force an enemy navy to waste resources searching large areas of ocean and protecting ships against attack. This advantage was vividly demonstrated in the 1982 Falklands War
The Falklands War ( es, link=no, Guerra de las Malvinas) was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British dependent territories in the South Atlantic: the Falkland Islands and its territorial ... when the British nuclear-powered submarine sank the Argentine cruiser . After the sinking the Argentine Navy recognized that they had no effective defense against submarine attack, and the Argentine surface fleet withdrew to port for the remainder of the war, though an Argentine submarine remained at sea.
Although the majority of the world's submarines are military, there are some civilian submarines, which are used for tourism, exploration, oil and gas platform inspections, and pipeline surveys. Some are also used in illegal activities.
The Submarine Voyage ride opened at
Disneyland is a theme park in Anaheim, California. Opened in 1955, it was the first theme park opened by The Walt Disney Company and the only one designed and constructed under the direct supervision of Walt Disney. Disney initially envisio ... in 1959, but although it ran under water it was not a true submarine, as it ran on tracks and was open to the atmosphere. The first tourist submarine was , which went into service in 1964 at Expo64. By 1997 there were 45 tourist submarines operating around the world. Submarines with a crush depth in the range of are operated in several areas worldwide, typically with bottom depths around , with a carrying capacity of 50 to 100 passengers.
In a typical operation a surface vessel carries passengers to an offshore operating area and loads them into the submarine. The submarine then visits underwater points of interest such as natural or artificial reef structures. To surface safely without danger of collision the location of the submarine is marked with an air release and movement to the surface is coordinated by an observer in a support craft.
A recent development is the deployment of so-called narco-submarines by South American drug smugglers to evade law enforcement detection. Although they occasionally deploy true submarines, most are self-propelled semi-submersibles, where a portion of the craft remains above water at all times. In September 2011, Colombian authorities seized a 16-meter-long submersible that could hold a crew of 5, costing about $2 million. The vessel belonged to FARC
The Revolutionary Armed Forces of Colombia – People's Army ( es, link=no, Fuerzas Armadas Revolucionarias de ColombiaEjército del Pueblo, FARC–EP or FARC) is a Marxist–Leninist guerrilla group involved in the continuing Colombian conf ... rebels and had the capacity to carry at least 7 tonnes of drugs.
File:PX-8 Mésoscaphe - Swiss Submarine (15722856966).jpg, Model of the Mésoscaphe ''Auguste Piccard''
File:AtlantisSubInterior3497.JPG, Interior of the tourist submarine ''Atlantis'' whilst submerged
File:AtlantisVIISubmarineClip3494.jpg, Tourist submarine ''Atlantis''
* 1903 – Simon Lake submarine ''Protector'' surfaced through ice off
Newport, Rhode Island
Newport is an American seaside city on Aquidneck Island in Newport County, Rhode Island. It is located in Narragansett Bay, approximately southeast of Providence, south of Fall River, Massachusetts, south of Boston, and northeast of New .... [McLaren, Alfred S., CAPT USN "Under the Ice in Submarines" ''United States Naval Institute Proceedings'' July 1981, pp. 105–9]
* 1930 – operated under ice near Spitsbergen
Spitsbergen (; formerly known as West Spitsbergen; Norwegian: ''Vest Spitsbergen'' or ''Vestspitsbergen'' , also sometimes spelled Spitzbergen) is the largest and the only permanently populated island of the Svalbard archipelago in northern Nor ....
* 1937 – Soviet submarine ''Krasnogvardeyets'' operated under ice in the Denmark Strait
The Denmark Strait () or Greenland Strait ( , 'Greenland Sound') is an oceanic strait between Greenland to its northwest and Iceland to its southeast. The Norwegian island of Jan Mayen lies northeast of the strait.
The strait conne ....
* 1941–45 – German U-boats operated under ice from the Barents Sea
The Barents Sea ( , also ; no, Barentshavet, ; russian: Баренцево море, Barentsevo More) is a marginal sea of the Arctic Ocean, located off the northern coasts of Norway and Russia and divided between Norwegian and Russian terri ... to the Laptev Sea
The Laptev Sea ( rus, мо́ре Ла́птевых, r=more Laptevykh; sah, Лаптевтар байҕаллара, translit=Laptevtar baỹğallara) is a marginal sea of the Arctic Ocean. It is located between the northern coast of Siberia, t ....
* 1946 – used upward-beamed fathometer in Operation Nanook in the Davis Strait
Davis Strait is a northern arm of the Atlantic Ocean that lies north of the Labrador Sea. It lies between mid-western Greenland and Baffin Island in Nunavut, Canada. To the north is Baffin Bay. The strait was named for the English explorer John ....
* 1946–47 – used under-ice sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on ... in Operation High Jump in the Antarctic.
* 1947 – used upward-beamed echo sounder under pack ice in the Chukchi Sea.
* 1948 – developed techniques for making vertical ascents and descents through polynya
A polynya () is an area of open water surrounded by sea ice. It is now used as a geographical term for an area of unfrozen seawater within otherwise contiguous pack ice or fast ice. It is a loanword from the Russian полынья (), which r ...s in the Chukchi Sea.
* 1952 – used an expanded upward-beamed sounder array in the Beaufort Sea
The Beaufort Sea (; french: Mer de Beaufort, Iñupiaq: ''Taġiuq'') is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, and west of Canada's Arctic islands. The sea is named after Sir ....
* 1957 – reached 87 degrees north near Spitsbergen.
* 3 August 1958 – ''Nautilus'' used an inertial navigation system
An inertial navigation system (INS) is a navigation device that uses motion sensors (accelerometers), rotation sensors (gyroscopes) and a computer to continuously calculate by dead reckoning the position, the orientation, and the velocity (direc ... to reach the North Pole.
* 17 March 1959 – surfaced through the ice at the north pole.
* 1960 – transited under ice over the shallow ( deep) Bering-Chukchi shelf.
* 1960 – transited the Northwest Passage
The Northwest Passage (NWP) is the sea route between the Atlantic and Pacific oceans through the Arctic Ocean, along the northern coast of North America via waterways through the Canadian Arctic Archipelago. The eastern route along the Arc ... under ice.
* 1962 – Soviet reached the north pole.
* 1970 – carried out an extensive undersea mapping survey of the Siberian continental shelf.
* 1971 – reached the North Pole.
* conducted three Polar Exercises: 1976 (with US actor Charlton Heston
Charlton Heston (born John Charles Carter; October 4, 1923April 5, 2008) was an American actor and political activist.
As a Hollywood star, he appeared in almost 100 films over the course of 60 years. He played Moses in the epic film '' The Ten ... aboard); 1984 joint operations with ; and 1990 joint exercises with .
* 6 May 1986 – , and meet and surface together at the Geographic North Pole
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface. It is called the True North Pole to distinguish from the Mag .... First three-submarine surfacing at the Pole.
* 19 May 1987 – joined and at the North Pole.
* March 2007 – participated in the Joint US Navy/ Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against ... Ice Exercise 2007 (ICEX-2007) in the Arctic Ocean with the .
* March 2009 – took part in Ice Exercise 2009 to test submarine operability and war-fighting capability in Arctic conditions.
Buoyancy and trim
All surface ships, as well as surfaced submarines, are in a positively
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pr ... 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 its displacement of water. To control their displacement and weight, submarines have ballast tank
A ballast tank is a compartment within a boat, ship or other floating structure that holds water, which is used as ballast to provide hydrostatic stability for a vessel, to reduce or control buoyancy, as in a submarine, to correct trim or ...s, which can hold varying amounts of water and air.
For general submersion or surfacing, submarines use the main ballast tanks (MBTs), which are ambient pressure tanks, filled with water to submerge, or with air to surface. While submerged, MBTs generally remain flooded, which simplifies their design, and on many submarines these tanks are a section of the space between the light hull and the pressure hull. For more precise control of depth, submarines use smaller depth control tanks (DCTs)—also called hard tanks (due to their ability to withstand higher pressure), or trim tanks. These are variable buoyancy pressure vessels, a type of buoyancy control device. The amount of water in depth control tanks can be adjusted to hydrostatically change depth or to maintain a constant depth as outside conditions (mainly water density) change. Depth control tanks may be located either near the submarine's center of gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force m ..., to minimise the effect on trim, or separated along the length of the hull so they can also be used to adjust static trim by transfer of water between them.
When submerged, the water pressure on a submarine's hull can reach for steel submarines and up to for titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corros ... submarines like , while interior pressure remains relatively unchanged. This difference results in hull compression, which decreases displacement. Water density also marginally increases with depth, as the salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equa ... and pressure are higher. This change in density incompletely compensates for hull compression, so buoyancy decreases as depth increases. A submerged submarine is in an unstable equilibrium, having a tendency to either sink or float to the surface. Keeping a constant depth requires continual operation of either the depth control tanks or control surfaces.
Submarines in a neutral buoyancy condition are not intrinsically trim-stable. To maintain desired longitudinal trim, submarines use forward and aft trim tanks. Pumps move water between the tanks, changing weight distribution and pitching the sub up or down. A similar system may be used to maintain transverse trim.
The hydrostatic effect of variable ballast tanks is not the only way to control the submarine underwater. Hydrodynamic maneuvering is done by several control surfaces, collectively known as
Diving planes, also known as hydroplanes, are control surfaces found on a submarine which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when subm ...s or hydroplanes, which can be moved to create hydrodynamic forces when a submarine moves longitudinally at sufficient speed. In the classic cruciform stern configuration, the horizontal stern planes serve the same purpose as the trim tanks, controlling the trim. Most submarines additionally have forward horizontal planes, normally placed on the bow until the 1960s but often on the sail on later designs, where they are closer to the center of gravity and can control depth with less effect on the trim.
An obvious way to configure the control surfaces at the stern of a submarine is to use vertical planes to control yaw and horizontal planes to control pitch, which gives them the shape of a cross when seen from astern of the vessel. In this configuration, which long remained the dominant one, the horizontal planes are used to control the trim and depth and the vertical planes to control sideways maneuvers, like the rudder of a surface ship.
Alternatively, the rear control surfaces can be combined into what has become known as an x-stern or an x-rudder. Although less intuitive, such a configuration has turned out to have several advantages over the traditional cruciform arrangement. First, it improves maneuverability, horizontally as well as vertically. Second, the control surfaces are less likely to get damaged when landing on, or departing from, the seabed as well as when mooring and unmooring alongside. Finally, it is safer in that one of the two diagonal lines can counteract the other with respect to vertical as well as horizontal motion if one of them accidentally gets stuck.
The x-stern was first tried in practice in the early 1960s on the USS ''Albacore'', an experimental submarine of the US Navy. While the arrangement was found to be advantageous, it was nevertheless not used on US production submarines that followed due to the fact that it requires the use of a computer to manipulate the control surfaces to the desired effect. Instead, the first to use an x-stern in standard operations was the Swedish Navy with its ''Sjöormen'' class, the lead submarine of which was launched in 1967, before the ''Albacore'' had even finished her test runs. Since it turned out to work very well in practice, all subsequent classes of Swedish submarines ( ''Näcken'', ''Västergötland'', ''Gotland'', and ''Blekinge'' class) have or will come with an x-rudder.
The Kockums shipyard responsible for the design of the x-stern on Swedish submarines eventually exported it to Australia with the ''Collins'' class as well as to Japan with the ''Sōryū'' class. With the introduction of the type 212, the German and Italian Navies came to feature it as well. The US Navy with its ''Columbia'' class, the British Navy with its Dreadnought-class submarine, ''Dreadnought'' class, and the French Navy with its Barracuda-class submarine (France), ''Barracuda'' class are all about to join the x-stern family. Hence, as judged by the situation in the early 2020s, the x-stern is about to become the dominant technology.
When a submarine performs an emergency surfacing, all depth and trim control 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, potentially damaging submarine systems.
Modern submarines are cigar-shaped. This design, also used in very early submarines, is sometimes called a "teardrop hull". It reduces hydrodynamic drag (physics), drag when the sub is 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 knot (unit), kt (18 km/h), 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. was a unique research submarine that pioneered the American version of the teardrop hull form (sometimes referred to as an "Albacore hull") of modern submarines. On modern military submarines the outer hull is covered with a layer of sound-absorbing rubber, or anechoic tile, anechoic plating, to reduce detection.
The occupied pressure hulls of deep-diving submarines such as are spherical instead of cylindrical. This allows a more even distribution of stress and efficient use of materials to withstand external pressure as it gives the most internal volume for structural weight and is the most efficient shape to avoid buckling instability in compression. A frame is usually affixed to the outside of the pressure hull, providing attachment for ballast and trim systems, scientific instrumentation, battery packs, syntactic foam, syntactic flotation foam, and lighting.
A raised tower on top of a standard submarine accommodates the
A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.
In its simplest form, it consists of an outer case with ... and electronics masts, which can include radio, radar, electronic warfare, and other systems. It might also include a snorkel mast. In many early classes of submarines (see history), the control room, or "conn", was located inside this tower, which was known as the " conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and gro ...". Since then, the conn has been located within the hull of the submarine, and the tower is now called the Sail (submarine), "sail" or "fin". The conn is distinct from the "bridge", a small open platform in the top of the sail, used for observation during surface operation.
"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 (nautical), freeboard, that is, they lie low in the water. Bathtubs help prevent swamping the vessel.
Single and double hulls
Modern submarines and submersibles usually have, as did the earliest models, 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 (submarine), 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 at the surface, and construction difficulties further complicated the problem. This was solved either by a compromise shape, or by using two layered hulls: the internal strength hull for withstanding pressure, and an external fairing for hydrodynamic shape. Until the end of World War II, most submarines had an additional partial casing on the top, bow and stern, built of thinner metal, which was flooded when submerged. Germany went further with the Type XXI, a general predecessor of modern submarines, in which the pressure hull was fully enclosed inside the light hull, but optimized for submerged navigation, unlike earlier designs that were optimized for surface operation.
After World War II, approaches split. The Soviet Union changed its designs, basing them on German developments. All post-World War II heavy Soviet and Russian submarines are built with a double hull structure. American and most other Western submarines switched to a primarily single-hull approach. They still have light hull sections in the bow and stern, which house main ballast tanks and provide a hydrodynamically optimized shape, but the main cylindrical hull section has only a single plating layer. Double hulls are being considered for future submarines in the United States to improve payload capacity, stealth and range.
The pressure hull is generally constructed of thick high-strength steel with a complex structure and high strength reserve, and is separated by watertight bulkhead (partition), bulkheads into several Compartmentalization (fire protection), compartments. There are also examples of more than two hulls in a submarine, like the , 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, all surrounded and supported by the outer light hydrodynamic hull. When submerged the pressure hull provides most of the buoyancy for the whole vessel.
The Submarine depth ratings, dive depth cannot be increased easily. Simply making the hull thicker increases the structural weight and requires reduction of onboard equipment weight, and increasing the diameter requires a proportional increase in thickness for the same material and architecture, ultimately resulting in a pressure hull that does not have sufficient buoyancy to support its own weight, as in a
A bathyscaphe ( or ) is a free-diving self-propelled deep-sea submersible, consisting of a crew cabin similar to a bathysphere, but suspended below a float rather than from a surface cable, as in the classic bathysphere design.
The float is .... This is acceptable for civilian research submersibles, but not military submarines, which need to carry a large equipment, crew, and weapons load to fulfill their function. Construction materials with greater specific strength and specific modulus are needed.
WWI submarines had hulls of carbon steel, with a maximum depth. During WWII, high-strength alloyed steel was introduced, allowing depths. High-strength alloy steel remains the primary material for submarines today, with depths, which cannot be exceeded on a military submarine without design compromises. To exceed that limit, a few submarines were built with titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corros ... hulls. Titanium alloys can be stronger than steel, lighter, and most importantly, have higher immersed specific strength and specific modulus. Titanium is also not ferromagnetism, ferromagnetic, important for stealth. Titanium submarines were built by the Soviet Union, which developed specialized high-strength alloys. It has produced several types of titanium submarines. Titanium alloys allow a major increase in depth, but other systems must be redesigned to cope, so test depth was limited to for the , the deepest-diving combat submarine. An may have successfully operated at , though continuous operation at such depths would produce excessive stress on many submarine systems. Titanium does not flex as readily as steel, and may become brittle after many dive cycles. Despite its benefits, the high cost of titanium construction led to the abandonment of titanium submarine construction as the Cold War ended. Deep-diving civilian submarines have used thick Poly(methyl methacrylate), acrylic pressure hulls. Although the specific strength and specific modulus of acrylic are not very high, the density is only 1.18g/cm3, so it is only very slightly denser than water, and the buoyancy penalty of increased thickness is correspondingly low.
The deepest deep-submergence vehicle (DSV) to date is Bathyscaphe Trieste, ''Trieste''. On 5 October 1959, ''Trieste'' departed San Diego for Guam aboard the freighter ''Santa Maria'' to participate in ''Project Nekton'', a series of very deep dives in the Mariana Trench. On 23 January 1960, ''Trieste'' reached the ocean floor in the Challenger Deep (the deepest southern part of the Mariana Trench), carrying Jacques Piccard (son of Auguste) and Lieutenant Don Walsh, USN. This was the first time a vessel, crewed or uncrewed, had reached the deepest point in the Earth's oceans. The onboard systems indicated a depth of , although this was later revised to and more accurate measurements made in 1995 have found the Challenger Deep slightly shallower, at .
Building a pressure hull is difficult, as it must withstand pressures at 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 deflects more in some places and buckling instabity is the usual failure mode. 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. 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 attack submarine costs US$2.6 1000000000 (number), billion, over US$200,000 per long ton, ton of displacement.)
The first submarines were propelled by humans. The first mechanically driven submarine was the 1863 French , which used compressed air for propulsion. Anaerobic propulsion was first employed by the Spanish ''Ictineo II'' in 1864, which used a solution of zinc, manganese dioxide, and potassium chlorate to generate sufficient heat to power a steam engine, while also providing
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements a ... for the crew. A similar system was not employed again until 1940 when the German Navy tested a hydrogen peroxide-based system, the Hellmuth Walter, Walter turbine, on the experimental V-80 submarine and later on the naval and German Type XVII submarine, type XVII submarines; the system was further developed for the British , completed in 1958.
Until the advent of nuclear marine propulsion, most 20th-century submarines used electric motors and batteries for running underwater and Internal combustion engine, combustion engines on the surface, and for battery recharging. Early submarines used gasoline (petrol) engines but this quickly gave way to kerosene (paraffin) and then Diesel fuel, diesel engines because of reduced flammability and, with diesel, improved fuel-efficiency and thus also greater range. A combination of diesel and electric propulsion became the norm.
Initially, the combustion engine and the electric motor were in most cases connected to the same shaft so that both could directly drive the propeller. The combustion engine was placed at the front end of the stern section with the electric motor behind it followed by the propeller shaft. The engine was connected to the motor by a clutch and the motor in turn connected to the propeller shaft by another clutch.
With only the rear clutch engaged, the electric motor could drive the propeller, as required for fully submerged operation. With both clutches engaged, the combustion engine could drive the propeller, as was possible when operating on the surface or, at a later stage, when snorkeling. The electric motor would in this case serve as a generator to charge the batteries or, if no charging was needed, be allowed to rotate freely. With only the front clutch engaged, the combustion engine could drive the electric motor as a generator for charging the batteries without simultaneously forcing the propeller to move.
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).
While most early submarines used a direct mechanical connection between the combustion engine and the propeller, an alternative solution was considered as well as implemented at a very early stage. That solution consists in first converting the work of the combustion engine into electric energy via a dedicated generator. This energy is then used to drive the propeller via the electric motor and, to the extent required, for charging the batteries. In this configuration, the electric motor is thus responsible for driving the propeller at all times, regardless of whether air is available so that the combustion engine can also be used or not.
Among the pioneers of this alternative solution was the very first submarine of the Swedish Navy, :sv:HMS Hajen (1904), HMS ''Hajen'' (later renamed ''Ub no 1''), launched in 1904. While its design was generally inspired by the first submarine commissioned by the US Navy, USS Holland (SS-1), USS ''Holland'', it deviated from the latter in at least three significant ways: by adding a periscope, by replacing the gasoline engine by a semidiesel engine (a hot-bulb engine primarily meant to be fueled by kerosene, later replaced by a true diesel engine) and by severing the mechanical link between the combustion engine and the propeller by instead letting the former drive a dedicated generator. By so doing, it took three significant steps toward what was eventually to become the dominant technology for conventional (i.e., non-nuclear) submarines.
In the following years, the Swedish Navy added another seven submarines in three different classes (:sv:2:a klass ubåt, ''2nd'' class, :sv:Laxen-klass, ''Laxen'' class, and :sv:Braxen-klass, ''Braxen'' class) using the same propulsion technology but fitted with true diesel engines rather than semidiesels from the outset. Since by that time, the technology was usually based on the diesel engine rather than some other type of combustion engine, it eventually came to be known as diesel–electric transmission.
Like many other early submarines, those initially designed in Sweden were quite small (less than 200 tonnes) and thus confined to littoral operation. When the Swedish Navy wanted to add larger vessels, capable of operating further from the shore, their designs were purchased from companies abroad that already had the required experience: first Italian (Fiat S.p.A., Fiat-Cesare Laurenti (engineer), Laurenti) and later German (AG Weser, A.G. Weser and NV Ingenieurskantoor voor Scheepsbouw, IvS). As a side-effect, the diesel–electric transmission was temporarily abandoned.
However, diesel–electric transmission was immediately reintroduced when Sweden began designing its own submarines again in the mid 1930s. From that point onwards, it has been consistently used for all new classes of Swedish submarines, albeit supplemented by Air-independent propulsion, air-independent propulsion (AIP) as provided by Stirling engines beginning with HSwMS Näcken (Näk), HMS ''Näcken'' in 1988.
Another early adopter of diesel–electric transmission was the United States Navy, US Navy, whose Bureau of Engineering proposed its use in 1928. It was subsequently tried in the United States S-class submarine, S-class submarines , , and before being put into production with the United States Porpoise-class submarine, ''Porpoise'' class of the 1930s. From that point onwards, it continued to be used on most US conventional submarines.
Apart from the British British U-class submarine, U-class and some submarines of the Imperial Japanese Navy that used separate diesel generators for low speed running, few navies other than those of Sweden and the US made much use of diesel–electric transmission before 1945. After World War II, by contrast, it gradually became the dominant mode of propulsion for conventional submarines. However, its adoption was not always swift. Notably, the Soviet Navy did not introduce diesel–electric transmission on its conventional submarines until 1980 with its Kilo-class submarine, ''Paltus'' class.
If diesel–electric transmission had only brought advantages and no disadvantages in comparison with a system that mechanically connects the diesel engine to the propeller, it would undoubtedly have become dominant much earlier. The disadvantages include the following:
* It entails a loss of fuel-efficiency as well as power by converting the output of the diesel engine into electricity. While both generators and electric motors are known to be very efficient, their efficiency nevertheless falls short of 100 percent.
* It requires an additional component in the form of a dedicated generator. Since the electric motor is always used to drive the propeller it can no longer step in to take on generator service as well.
* It does not allow the diesel engine and the electrical motor to join forces by simultaneously driving the propeller mechanically for maximum speed when the submarine is surfaced or snorkeling. This may, however, be of little practical importance inasmuch as the option it prevents is one that would leave the submarine at a risk of having to dive with its batteries at least partly depleted.
The reason why diesel–electric transmission has become the dominant alternative in spite of these disadvantages is of course that it also comes with many advantages and that, on balance, these have eventually been found to be more important. The advantages include the following:
* It reduces external noise by severing the direct and rigid mechanical link between the relatively noisy diesel engine(s) on the one hand and the propeller shaft(s) and hull on the other. With Stealth ship, stealth being of paramount importance to submarines, this is a very significant advantage.
* It increases the Crash dive, readiness to dive, which is of course of vital importance for a submarine. The only thing required from a propulsion point of view is to shut down the diesel(s).
* It makes the speed of the diesel engine(s) temporarily independent of the speed of the submarine. This in turn often makes it possible to run the diesel(s) at close to optimal speed from a fuel-efficiency as well as durability point of view. It also makes it possible to reduce the time spent surfaced or snorkeling by running the diesel(s) at maximum speed without affecting the speed of the submarine itself.
* It eliminates the clutches otherwise required to connect the diesel engine, the electric motor, and the propeller shaft. This in turn saves space, increases reliability and reduces maintenance costs.
* It increases flexibility with regard to how the driveline components are configured, positioned, and maintained. For example, the diesel no longer has to be aligned with the electric motor and propeller shaft, two diesels can be used to power a single propeller (or vice versa), and one diesel can be turned off for maintenance as long as a second is available to provide the required amount of electricity.
* It facilitates the integration of additional primary sources of energy, beside the diesel engine(s), such as various kinds of Air-independent propulsion, air-independent power (AIP) systems. With one or more electric motors always driving the propeller(s), such systems can easily be introduced as yet another source of electric energy in addition to the diesel engine(s) and the batteries.
During World War II the Germans experimented with the idea of the ''schnorchel'' (snorkel) from captured Dutch submarines but did not see the need for them until rather late in the war. The ''schnorchel'' is a retractable pipe that supplies air to the diesel engines while submerged at periscope depth, allowing the boat to cruise and recharge its batteries while maintaining a degree of stealth.
Especially as first implemented however, it turned out to be far from a perfect solution. There were problems with the device's valve sticking shut or closing as it dunked in rough weather. Since the system used the entire pressure hull as a buffer, the diesels would instantaneously suck huge volumes of air from the boat's compartments, and the crew often suffered painful ear injuries. Speed was limited to , lest the device snap from stress. The ''schnorchel'' also created noise that made the boat easier to detect with sonar, yet more difficult for the on-board sonar to detect signals from other vessels. Finally, allied radar eventually became sufficiently advanced that the ''schnorchel'' mast could be detected beyond visual range.
While the snorkel renders a submarine far less detectable, it is thus not perfect. In clear weather, diesel exhausts can be seen on the surface to a distance of about three miles, while "periscope feather" (the wave created by the snorkel or periscope moving through the water) is visible from far off in calm sea conditions. Modern radar is also capable of detecting a snorkel in calm sea conditions.
The problem of the diesels causing a vacuum in the submarine when the head valve is submerged still exists in later model diesel submarines but is mitigated by high-vacuum cut-off sensors that shut down the engines when the vacuum in the ship reaches a pre-set point. Modern snorkel induction masts have a fail-safe design using compressed air, controlled by a simple electrical circuit, to hold the "head valve" open against the pull of a powerful spring. Seawater washing over the mast shorts out exposed electrodes on top, breaking the control, and shutting the "head valve" while it is submerged. US submarines did not adopt the use of snorkels until after WWII.
During World War II, German Type XXI submarines (also known as "''Elektroboote''") were the first submarines designed to operate submerged for extended periods. Initially they were 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 War, the United Kingdom, British and Soviets experimented with hydrogen peroxide/kerosene (paraffin) engines that could run surfaced and submerged. The results were not encouraging. Though the Soviet Union deployed a class of submarines with this engine type (codenamed by NATO), they were considered unsuccessful.
The United States also used hydrogen peroxide in an experimental
A midget submarine (also called a mini submarine) is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to six or nine, with little or no on-board living accommodation. They normally work with mother ships, ..., USS X-1, X-1. It was originally powered by a hydrogen peroxide/diesel engine and battery system until an explosion of her hydrogen peroxide supply on 20 May 1957. X-1 was later converted to use diesel–electric drive.
Today several navies use air-independent propulsion. Notably Sweden uses Stirling engine, Stirling technology on the and s. The Stirling engine is heated by burning diesel fuel with liquid oxygen from cryogenic tanks. A newer development in air-independent propulsion is hydrogen fuel cells, first used on the German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ... Type 212 submarine, with nine 34 kW or two 120 kW cells. Fuel cells are also used in the new Spanish Navy, Spanish s although with the fuel stored as ethanol and then converted into hydrogen before use.
One new technology that is being introduced starting with the Japanese Navy's eleventh Sōryū-class submarine, ''Sōryū''-class submarine (JS ''Ōryū'') is a more modern battery, the lithium-ion battery. These batteries have about double the electric storage of traditional batteries, and by changing out the lead-acid batteries in their normal storage areas plus filling up the large hull space normally devoted to Air-independent propulsion, AIP engine and fuel tanks with many tons of lithium-ion batteries, modern submarines can actually return to a "pure" diesel–electric configuration yet have the added underwater range and power normally associated with AIP equipped submarines.
Steam power was resurrected in the 1950s with a nuclear-powered steam turbine driving a generator. By eliminating the need for atmospheric oxygen, the time that a submarine could remain submerged was limited only by its food stores, as breathing air was recycled and fresh water Distillation, distilled from seawater. More importantly, a nuclear submarine has unlimited range at top speed. This allows it to travel from its operating base to the combat zone in a much shorter time and makes it a far more difficult target for most anti-submarine weapons. 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, French Navy, and the British
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against ... operate only nuclear submarines, 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. Some nuclear submarines such as the American can operate with their reactor coolant pumps secured, making them quieter than electric subs. A conventional submarine operating on batteries is almost completely silent, the only noise coming from the shaft bearings, propeller, and flow noise around the hull, all of which stops when the sub hovers in mid-water to listen, leaving only the noise from crew activity. Commercial submarines usually rely only on batteries, since they operate in conjunction with a mother ship.
Several nuclear and radiation accidents by death toll, serious nuclear and radiation accidents have involved nuclear submarine mishaps. [ The reactor accident in 1961 resulted in 8 deaths and more than 30 other people were over-exposed to radiation.] [Strengthening the Safety of Radiation Sources] The reactor accident in 1968 resulted in 9 fatalities and 83 other injuries.
The accident in 1985 resulted in 10 fatalities and 49 other radiation injuries.
Oil-fired steam turbines powered the British K-class submarines, built during
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ... and later, to give them the surface speed to keep up with the battle fleet. The K-class subs were not very successful, however.
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. Though these are heavier, more expensive, and less efficient than a propeller, they are significantly quieter, providing an important tactical advantage.
The success of the submarine is inextricably linked to the development of the
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, s ..., invented by Robert Whitehead
Robert Whitehead (3 January 1823 – 14 November 1905) was an English engineer who was most famous for developing the first effective self-propelled naval torpedo.
He was born in Bolton, England, the son of James Whitehead, ... in 1866. His invention is essentially the same now as it was 140 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 Acoustic torpedo, guided torpedo, multiple "straight-running" torpedoes were required to attack a target. With at most 20 to 25 torpedoes stored on board, the number of attacks was limited. To increase combat endurance most World War I 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 cruiser submarine, Submarine Cruiser such as the French and the Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against ...'s and British M-class submarine, M-class submarines. With the arrival of anti-submarine warfare (ASW) aircraft, guns became more for defense 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 harbours covertly led to their use as minelayers. Minelaying submarines of World War I and World War II were specially built for that purpose. Modern submarine-laid Naval mine, mines, such as the British Mark 5 Stonefish (mine), Stonefish and Mark 6 Sea Urchin, can be deployed from a submarine's torpedo tubes.
After World War II, both the US and the USSR experimented with submarine-launched cruise missile
A cruise missile is a guided missile used against terrestrial or naval targets that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhea ...s such as the SSM-N-8 Regulus and P-5 Pyatyorka. Such missiles required the submarine to surface to fire its missiles. They were the forerunners of modern submarine-launched cruise missiles, which can be fired from the torpedo tubes of submerged submarines, for example, the US BGM-109 Tomahawk and Russian RPK-2 Viyuga and versions of surface-to-surface anti-ship missiles such as the Exocet and Boeing Harpoon, Harpoon, encapsulated for submarine launch. Ballistic missiles can also be fired from a submarine's torpedo tubes, for example, missiles such as the anti-submarine SUBROC. With internal volume as limited as ever and the desire to carry heavier warloads, the idea of the external launch tube was revived, usually for encapsulated missiles, with such tubes being placed between the internal pressure and outer streamlined hulls.
The strategic mission of the SSM-N-8 and the P-5 was taken up by submarine-launched ballistic missile
A submarine-launched ballistic missile (SLBM) is a ballistic missile capable of being launched from submarines. Modern variants usually deliver multiple independently targetable reentry vehicles (MIRVs), each of which carries a nuclear warhea ... beginning with the US Navy's UGM-27 Polaris, Polaris missile, and subsequently the UGM-73 Poseidon, Poseidon and Trident (missile), Trident missiles.
Germany is working on the torpedo tube-launched short-range IDAS (missile), IDAS missile, which can be used against ASW helicopters, as well as surface ships and coastal targets.
A submarine can have a variety of sensors, depending on its missions. Modern military submarines rely almost entirely on a suite of passive and active
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on ...s to locate targets. 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, normally trailing several hundred feet behind the sub. The towed array is the mainstay of NATO submarine detection systems, as it reduces the flow noise heard by operators. Hull mounted sonar is employed in addition to the towed array, as the towed array can't work in shallow depth and during maneuvering. In addition, sonar has a blind spot "through" the submarine, so a system on both the front and back works to eliminate that problem. As the towed array trails behind and below the submarine, it also allows the submarine to have a system both above and below the thermocline at the proper depth; sound passing through the thermocline is distorted resulting in a lower detection range.
Submarines also carry radar equipment to detect surface ships and aircraft. Submarine captains are more likely to use radar detection gear 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 or the MIR (submersible), Russian ''Mir'' submersibles, rely on small active sonar sets and viewing ports to navigate. The human eye cannot detect sunlight below about underwater, so high intensity lights are used to illuminate the viewing area.
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 over time. To counter this, the crew occasionally uses the Global Positioning System to obtain an accurate position. The
A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.
In its simplest form, it consists of an outer case with ...—a retractable tube with a prism (optics), prism system that provides a view of the surface—is only used occasionally in modern submarines, since the visibility range is short. The and s use photonics masts rather than hull-penetrating optical periscopes. These masts must still be deployed above the surface, and use electronic sensors for visible light, infrared, laser range-finding, and electromagnetic surveillance. One benefit to hoisting the mast above the surface is that while the mast is above the water the entire sub is still below the water and is much harder to detect visually or by radar.
Military submarines use several systems to communicate with distant command centers or other ships. One is VLF (very low frequency) radio, which can reach a submarine either on the surface or submerged to a fairly shallow depth, usually less than . Extremely low frequency, ELF (extremely low frequency) can reach a submarine at greater depths, but has a very low bandwidth and is 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 antenna to a shallower depth, allowing VLF transmissions 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 underwater telephone, 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.
Life support systems
With nuclear reactor, nuclear power or air-independent propulsion, submarines can remain submerged for months at a time. Conventional diesel submarines must periodically resurface or run on Submarine snorkel, snorkel to recharge their batteries. Most modern military submarines generate breathing
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements a ... by electrolysis of fresh water (using a device called an "Elektron (ISS)#Elektron, Electrolytic Oxygen Generator"). Emergency oxygen can be produced by burning sodium chlorate candles. Atmosphere control equipment includes a Carbon dioxide scrubber, which uses a spray of Amine gas treating , monoethanolamine (MEA) absorbent to remove the gas from the air, after which the MEA is heated in a boiler to release the CO2 which is then pumped overboard. Emergency scrubbing can also be done with lithium hydroxide, which is consumable. A machine that uses a catalyst to convert carbon monoxide into carbon dioxide (removed by the 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, Dichlorodifluoromethane, R-12 and 1,2-Dichlorotetrafluoroethane, R-114 refrigerants, carbon dioxide, carbon monoxide, and other gases. 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 risk.
Fresh water is produced by either an evaporator or a reverse osmosis unit. The primary use for fresh water is to provide feedwater for the reactor and steam propulsion plants. It is also available for showers, sinks, cooking and cleaning once propulsion plant needs have been met. Seawater is used to flush toilets, and the resulting Blackwater (waste), "blackwater" is stored in a sanitary tank until it is blown overboard using pressurized air or pumped overboard by using a special sanitary pump. The blackwater-discharge system requires skill to operate, and isolation valves must be closed before discharge. The German Type VII submarine, Type VIIC boat was lost with casualties because of human error while using this system. Water from showers and sinks is stored separately in "greywater, grey water" tanks and discharged overboard using drain pumps.
Trash on modern large submarines is usually disposed of using a tube called a Trash Disposal Unit (TDU), where it is compacted into a galvanized 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 equalized with sea pressure, the ball valve is opened and the cans fall out assisted by scrap iron weights in the cans. The TDU is also flushed with seawater to ensure it is completely empty and the ball valve is clear before closing the valve.
A typical nuclear submarine has a crew of over 80; conventional boats typically have fewer than 40. The conditions on a submarine can be difficult because crew members must work in isolation for long periods of time, without family contact, and in cramped conditions. Submarines normally maintain radio silence to avoid detection. Operating a submarine is dangerous, even in peacetime, and many submarines have been lost in accidents.
Most navies prohibited women from serving on submarines, even after they had been permitted to serve on surface warships. The Royal Norwegian Navy became the first navy to allow women on its submarine crews in 1985. The Royal Danish Navy allowed female submariners in 1988.
Others followed suit including the Swedish Navy (1989), the Royal Australian Navy (1998), the Spanish Navy
The Spanish Navy or officially, the Armada, is the maritime branch of the Spanish Armed Forces and one of the oldest active naval forces in the world. The Spanish Navy was responsible for a number of major historic achievements in navigation, ... (1999), the German Navy (2001) and the Royal Canadian Navy, Canadian Navy (2002). In 1995, Solveig Krey of the Royal Norwegian Navy became the first female officer to assume command on a military submarine, Kobben-class submarine, HNoMS ''Kobben''.
On 8 December 2011, British Secretary of State for Defence, Defence Secretary Philip Hammond announced that the United Kingdom, UK's ban on women in submarines was to be lifted from 2013. Previously there were fears that women were more at risk from a build-up of carbon dioxide in the submarine. But a study showed no medical reason to exclude women, though pregnant women would still be excluded. Similar dangers to the pregnant woman and her fetus barred women from submarine service in Sweden in 1983, when all other positions were made available for them in the Swedish Navy. Today, pregnant women are still not allowed to serve on submarines in Sweden. However, the policymakers thought that it was discriminatory with a general ban and demanded that women should be tried on their individual merits and have their suitability evaluated and compared to other candidates. Further, they noted that a woman complying with such high demands is unlikely to become pregnant. In May 2014, three women became the RN's first female submariners.
Women have served on US Navy surface ships since 1993, and , began serving on submarines for the first time. Until presently, the Navy allowed only three exceptions to women being on board military submarines: female civilian technicians for a few days at most, women midshipman, midshipmen on an overnight during summer training for Navy ROTC and United States Naval Academy, Naval Academy, and family members for one-day dependent cruises. In 2009, senior officials, including then-Secretary of the Navy Ray Mabus, Joint Chief of Staff Admiral Michael Mullen, and Chief of Naval Operations Admiral Gary Roughead, began the process of finding a way to implement women on submarines. The US Navy rescinded its "no women on subs" policy in 2010.
Both the US and British navies operate nuclear-powered submarines that deploy for periods of six months or longer. Other navies that permit women to serve on submarines operate conventionally powered submarines, which deploy for much shorter periods—usually only for a few months. Prior to the change by the US, no nation using nuclear submarines permitted women to serve on board.
In 2011, the first class of female submarine officers graduated from Naval Submarine School's Submarine Officer Basic Course (SOBC) at the Naval Submarine Base New London. Additionally, more senior ranking and experienced female supply officers from the surface warfare specialty attended SOBC as well, proceeding to fleet Ballistic Missile (SSBN) and Guided Missile (SSGN) submarines along with the new female submarine line officers beginning in late 2011. By late 2011, several women were assigned to the ''Ohio''-class ballistic missile submarine . On 15 October 2013, the US Navy announced that two of the smaller ''Virginia''-class attack submarines, and , would have female crew-members by January 2015.
In 2020, Japan's national naval submarine academy accepted its first female candidate.
Abandoning the vessel
In an emergency, submarines can transmit a signal to other ships. The crew can use escape sets such as the Submarine Escape Immersion Equipment to abandon the submarine via an escape trunk, which is a small airlock compartment that provides a route for crew to escape from a downed submarine at ambient pressure in small groups, while minimising the amount of water admitted to the submarine.
The crew can avoid lung injury from over-expansion of air in the lungs due to the pressure change known as Barotrauma#Pulmonary barotrauma, pulmonary barotrauma by maintaining an open airway and exhaling during the ascent. Following escape from a pressurized submarine, in which the air pressure is higher than atmospheric due to water ingress or other reasons, the crew is at risk of developing decompression sickness on return to surface pressure.
An alternative escape means is via a deep-submergence rescue vehicle that can dock onto the disabled submarine, establish a seal around the escape hatch, and transfer personnel at the same pressure as the interior of the submarine. If the submarine has been pressurised the survivors can lock into a decompression chamber on the submarine rescue ship and transfer under pressure for safe surface decompression.
* Autonomous underwater vehicle
* Coastal submarine
* Columbia-class submarine
* Depth charge
* :Fictional submarines, Fictional submarines
* Flying submarine
* List of ships sunk by submarines by death toll
* List of submarine actions
* List of submarine classes
* List of submarine museums
* List of submarines of World War II
* List of specifications of submarines of World War II
* List of sunken nuclear submarines
* Merchant submarine
* Nuclear navy
* Semi-submersible naval vessel
* Submarine films
* Submarine power cable
* Submarine simulator, a computer game genre
* Unmanned underwater vehicle
* List of submarine operators
* Australia – Collins-class submarine
* Bangladesh- List of active ships of the Bangladesh Navy, Submarines of the Bangladesh Navy
* Britain – List of submarines of the Royal Navy, List of submarine classes of the Royal Navy
* China – Submarines of the People's Liberation Army Navy
* France – Submarine forces (France), Submarines in the French Navy, List of submarines of France, List of submarines of the French Navy, List of submarines of France, List of French submarine classes and types
* Germany – List of U-boats of Germany
* India – Submarines of the Indian Navy
* Israel – Dolphin-class submarine
* Japan – Imperial Japanese Navy submarines,
* The Netherlands – List of submarines of the Netherlands
* Pakistan –
* Romania – Romanian submarines of World War II
* Russia – List of Soviet and Russian submarine classes, Future of the Russian Navy#Submarines, Future Russian submarines
* Soviet Union –
* Spain – List of submarines of the Spanish Navy
* Singapore –
* Turkey – List of submarines of the Turkish Navy
* United States – Submarines in the United States Navy, Submarines in the US Navy, List of submarines of the United States Navy, List of submarines of the US Navy, List of United States submarine classes, List of US submarine classes, Naval Submarine Medical Research Laboratory
* ''Histoire des sous-marins: des origines à nos jours'' by Jean-Marie Mathey and Alexandre Sheldon-Duplaix. (Boulogne-Billancourt: ETAI, 2002).
* Redford, Duncan. ''The Submarine: A Cultural History From the Great War to Nuclear Combat'' (I.B. Tauris, 2010) 322 pages; focus on British naval and civilian understandings of submarine warfare, including novels and film.
Submarines before 1914
1900/Russo-Japanese War 1904–1905
World War II
* ''Hide and seek: the untold story of
The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term ''cold war'' is used because the ... espionage at sea'', by Peter Huchthausen and Alexandre Sheldon-Duplaix. (Hoboken, NJ: J. Wiley & Sons, 2008, )
* – ''Submarine boat''
''The Fleet Type Submarine Online''
US Navy submarine training manuals, 1944–1946
* American Society of Safety Engineers. Journal of Professional Safety. ''Submarine Accidents: A 60-Year Statistical Assessment''. C. Tingle. September 2009. pp. 31–39
Ordering full article