Sea Denial & Undersea Warfare

Ayanz produced detailed designs for two types of submersible fitted with oars, floating snorkels driven by inner pumps, portholes and manipulation gloves. He intended them to approach enemy ships undetected and attach timed gunpowder charges, an early articulation of the submarine's stealth attack role.

The English mathematician William Bourne set down an early written design for a vessel able to navigate beneath the surface. It is among the earliest documented conceptions of submarine operation, predating any construction.

The Scottish mathematician and theologian described intentions to build craft capable of underwater travel for harming enemies. It is unclear whether he ever attempted to build them, but the writing shows early interest in submarine warfare.

The Dutchman, in the service of James I of England, constructed the earliest submersible whose construction is reliably documented. It established that a manned craft could operate beneath the water surface.

Symons used leather bags that filled with water to submerge the craft, with a mechanism to twist the water out and resurface. Ballast control remains the fundamental principle by which submarines dive and surface.

The hand-powered acorn-shaped craft accommodated a single person and was the first verified submarine capable of independent underwater operation and movement. It was also the first to use screws for propulsion.

France constructed Nautilus to a design by the American Robert Fulton. The experiment was abandoned in 1804, as was British interest in the design.

Brandtaucher remains the oldest known surviving submarine in the world. It marked German entry into submarine experimentation in the mid-19th century.

Plongeur used compressed air at 1,200 kPa for propulsion. It opened the era of mechanically powered submarines, running from 1863 to 1904, during which diesel-electric propulsion and the periscope became standard.

Hunley sank the Union sloop-of-war USS Housatonic using a gunpowder-filled keg on a spar as a torpedo charge during the American Civil War. Hunley itself was lost in the attack, but the action proved submarines could destroy warships.

Launched at Barcelona, Ictíneo II used a chemical solution of zinc, manganese dioxide and potassium chlorate to generate heat for a steam engine while supplying oxygen to the crew. It was the first application of anaerobic propulsion, a concept not revisited until 1940.

The German American designer's craft demonstrated full controlled underwater operation. Its design incorporated elements still used in modern submarines.

The fifth submarine built in the world was constructed by a German engineer and immigrant at Chile's request. Together with a second boat it was intended to defend Valparaíso against the Spanish Navy during the Chincha Islands War.

The British engineer's invention made the submarine feasible as a weapon, replacing the impracticable spar torpedo used by the Confederate States Navy. The torpedo allowed the submarine to make the leap from novelty to weapon of war.

The Irish inventor built a model submarine in 1876 and demonstrated the Holland I prototype two years later. A series of unsuccessful designs followed before his breakthrough Type VI.

Advances in electric battery technology finally made reliable submerged propulsion possible. Isaac Peral in Spain, Dupuy de Lôme and Gustave Zédé in France and James Franklin Waddington in England each built electric boats; Peral's featured torpedoes and other systems that became standard.

The 56-tonne, 19.5-metre vessel had a range of 240 kilometres and carried a single torpedo, following Garrett's ill-fated Resurgam of 1879. It was the first submarine armed with torpedoes and ready for military use.

Built to a Swedish design and operated by the Ottoman navy in the Bosphorus, the submarine's submerged torpedo launch was a genuine world first, though the Ottoman submarine programme did not continue long enough to translate the achievement into a lasting fleet.

The design used internal combustion engine power on the surface and electric battery power underwater, the configuration that defined submarines for half a century. Holland VI was launched on 17 May 1897 at Crescent Shipyard in Elizabeth, New Jersey.

The steam and electric Narval introduced the now typical double-hull layout, with a pressure hull inside an outer shell. These 200-ton boats had a submerged range of over 160 km.

Submarines were adapted to lay naval mines covertly in enemy waters. This extended the submarine's role beyond torpedo attack.

Some submarines began replacing conventional propellers with pump-jets. The change reduced radiated noise and improved stealth.

The US Navy purchased Holland VI on 11 April 1900 and christened it USS Holland, its first commissioned submarine. Designed by the Irish-American engineer John Philip Holland, the boat combined a petrol engine for surface running with an electric motor for underwater propulsion, a hybrid arrangement that became the standard submarine design for the next half-century, and its design became the template licensed to other navies.

Britain acquired its first submarines from Vickers at Barrow-in-Furness under licence from the Holland Torpedo Boat Company. The boats used an untested improvement on the original Holland design with a new 180 horsepower petrol engine; the first was ready for a sea diving trial on 6 April 1902.

Aigrette replaced the gasoline engine with a diesel, greatly improving safety and range. Seventy-six such submarines were completed before 1914.

During the Russo-Japanese War the Russians sent submarines to Vladivostok, where seven boats were gathered by 1 January 1905. Patrols began on 14 February and the first confrontation with Japanese warships came on 29 April 1905, marking the first combat use of mechanically powered submarines.

Hajen was among the pioneers of an alternative propulsion solution. Like other early Swedish designs it was small, under 200 tonnes, and confined to littoral operation; diesel-electric transmission was reintroduced when Sweden resumed submarine design in the mid-1930s.

More than 5,000 Allied ships were sunk by U-boats during the First World War, the first conflict in which submarines made a significant strategic impact. The sinking of RMS Lusitania is often cited among the reasons for United States entry into the war.

A flotilla of ten U-boats sailed to attack Royal Navy warships in the North Sea. Germany began the war with twenty combat submarines including the diesel U-19 class, with 5,000 miles of range, against the Royal Navy's 74 boats of mixed effectiveness.

The sinking, which killed a large number of civilians including American passengers, turned public opinion in neutral countries against unrestricted submarine warfare and became one of the events that drew the United States toward entering the First World War.

The proposal was tried in the S-class submarines S-3, S-6 and S-7 before entering production with the Porpoise class of the 1930s. Apart from Sweden and the US, few navies made much use of diesel-electric transmission before 1945.

Germany attempted to cut Britain's supply routes by sinking merchant ships faster than they could be replaced, coordinating mass attacks by radio encrypted with the Enigma machine. Rudeltaktik ceased to be effective once the U-boat Enigma was cracked; almost 3,000 Allied ships were sunk, while 793 U-boats and around 28,000 of 41,000 submariners were lost.

WWI submarines used carbon steel hulls limited to about 100 metres depth; alloyed steel introduced during the Second World War allowed 200-metre depths. High-strength alloy steel remains the primary hull material today, permitting 250 to 400 metres.

The experimental air-independent system was later fitted to U-791 and the type XVII submarines. It was further developed for the British Explorer-class, completed in 1958.

Though only about 2 percent of the US Navy, submarines destroyed over 30 percent of the Japanese Navy and sank 1,560 vessels totalling 5.3 million tons. Allied submarines in the Pacific destroyed more Japanese shipping than all other weapons combined, aided by Japan's failure to provide adequate convoy escorts.

Improved sonar, long-range aircraft, escort carriers and the breaking of German naval codes let Allied convoys sink U-boats faster than German shipyards could replace them, ending the most sustained submarine campaign in history and securing the Atlantic supply line to Britain.

Venturer engaged and sank U-864 with a four-torpedo spread while both boats were submerged. Her crew manually computed the firing solution against a three-dimensionally manoeuvring target, using techniques that became the basis of modern torpedo computer targeting systems.

Nuclear power partially replaced diesel-electric propulsion while new equipment extracted oxygen from sea water. Together these innovations let submarines stay submerged for weeks or months, and most naval submarines built since in the US, USSR, UK and France have been nuclear-powered.

The review reflected concern within the US Navy's own shipbuilding programme, which has struggled to meet its production targets, over whether transferring boats to Australia in the early 2030s would leave American attack submarine numbers too thin.

The common design, built by TKMS for both the German and Norwegian navies, combines air-independent propulsion with reduced acoustic and magnetic signatures, and construction of the first boats continued at the Kiel shipyard through the year.

The programme, splitting construction between Chinese and Pakistani yards, aims to significantly expand the navy's underwater fleet and offset India's growing submarine force, with successive boats launched or floated out as the programme progressed through the mid-2020s.

Kim Jong Un repeated public calls for a nuclear-powered attack submarine as part of a wider naval buildup, and satellite imagery of shipyard activity suggested continuing construction work, though the programme's progress remained difficult to verify from outside the country.

Work continued at HMAS Stirling in Western Australia to prepare for the rotational presence of US and UK submarines planned later in the decade, alongside a growing number of Australian personnel training in American and British submarine crews.

Washington agreed in principle to share the technology needed for Seoul to move from conventional diesel-electric boats to nuclear propulsion, a shift South Korea had sought for years, though the arrangement's technical and regulatory detail remained to be worked out.

The second Arihant-class boat gives the navy a spare hull for deterrent patrols, reducing the gap in coverage whenever one submarine is in maintenance, and marks a step toward India's goal of a permanently available submarine-launched deterrent.

The decision, made after a competition against Swedish and German bidders, will replace the Dutch navy's ageing Walrus-class boats with four new submarines built to a French design, deepening defence-industrial ties between the two countries.

Satellite imagery reviewed by foreign officials indicated the boat went down alongside its dock before entering service, an incident China did not publicly acknowledge, though analysts read it as a setback for the navy's newest attack submarine construction.

The navy continued to add to its newest class of nuclear-powered strategic submarines, which form the sea-based leg of Russia's nuclear deterrent, even as sanctions and wartime spending pressured the wider shipbuilding industry.

The agreement marked only the second time the United States had shared naval nuclear propulsion technology with another country, after a 1958 arrangement with Britain, and set in motion a decades-long programme to build and eventually transfer submarines to Australia.

The craft could hold a crew of five and cost around $2 million. It illustrated the spread of submersible technology to non-state actors.

Announced on 8 December 2011, the ban was to end from 2013. In May 2014 three women became the Royal Navy's first female submariners.

Senior officials including the Secretary of the Navy had begun work on implementation in 2009. The first class of female submarine officers graduated from the Submarine Officer Basic Course in 2011, with assignments to fleet SSBNs and SSGNs beginning late that year.

The Type 212 carried nine 34 kW or two 120 kW fuel cells for air-independent propulsion. Fuel cells represented the newest generation of AIP for conventional submarines.

Sweden supplemented diesel-electric transmission with AIP provided by Stirling engines. This allowed conventional submarines much longer submerged endurance without nuclear power.

Norway opened submarine service to women, followed by Denmark in 1988, Sweden in 1989, Australia in 1998, Spain in 1999, Germany in 2001 and Canada in 2002. In 1995 Solveig Krey of the Royal Norwegian Navy became the first female officer to command a military submarine, HNoMS Kobben.

On 16 June 1982, during the Lebanon War, an unnamed Israeli submarine sank the vessel carrying 56 Palestinian refugees to Cyprus, believing it was evacuating militias. Twenty-five people died; the Israeli Navy disclosed the incident in November 2018.

During the Falklands War the British nuclear-powered submarine torpedoed the Argentine cruiser. The action demonstrated the decisive effect nuclear attack submarines could have on surface fleet movements.

Titanium alloys allowed a major increase in depth, with test depth limited to 1,000 metres, making Komsomolets the deepest-diving combat submarine. Other systems had to be redesigned to cope, and continuous operation at such depths would stress many submarine systems.

The Soviet Union was notably late in adopting diesel-electric transmission for its conventional submarines. Its introduction came decades after Sweden and the US.

The boat gave China an independent nuclear submarine capability developed largely without direct Soviet assistance after the Sino-Soviet split, laying the industrial and technical foundation the navy built on for its later generations of attack and missile submarines.

During the Indo-Pakistani War, Hangor destroyed the frigate, ending a 26-year gap in submarine kills. In the same war Ghazi, a Tench-class boat on loan from the US, was sunk by the Indian Navy in the first submarine combat loss since 1945.

The mission used submarine sensors for large-scale seabed survey beneath the Arctic. It illustrated the scientific and intelligence value of under-ice submarine operations.

K-129 was lost in 1968, part of it later retrieved by the CIA using the Glomar Explorer, followed by K-8 in 1970, K-219 in 1986 and Komsomolets in 1989. The US lost USS Thresher and USS Scorpion during the same period, underlining the hazards of deep submarine operations.

The lead boat of the Sjöormen class was launched in 1967, before Albacore had finished her test runs. The German and Italian navies later adopted the x-stern with the Type 212, and by the early 2020s the configuration was becoming dominant.

The Soviet-built Foxtrot-class boat made India the first South Asian navy to operate submarines, beginning a submarine arm that would later expand to include nuclear-powered boats and give India an independent deterrent capability.

The vessel opened commercial passenger operation beneath the water. By 1997 there were 45 tourist submarines operating around the world.

The November-class boat brought Soviet nuclear submarines to the pole, following the earlier American voyages. HMS Dreadnought reached the North Pole in 1971.

Seadragon completed a submerged transit of the Northwest Passage in the same year USS Sargo travelled 900 miles under ice over the shallow Bering-Chukchi shelf. These voyages extended submarine reach across the Arctic basin.

Albacore was a unique experimental boat that established the American teardrop or Albacore hull form used by modern submarines. She also first tried the x-stern configuration in practice in the early 1960s.

On 23 January 1960 the bathyscaphe carried Jacques Piccard and Lieutenant Don Walsh to the deepest part of the Mariana Trench, with onboard systems indicating 11,521 metres, later revised to around 10,916 metres. The dive was part of Project Nekton, for which Trieste had departed San Diego on 5 October 1959.

The submarine's extended patrol, armed with missiles that could be launched while submerged, began the practice of keeping a nuclear-armed submarine continuously at sea and hidden, a form of deterrent that land-based missiles and bomber aircraft could not match.

On 17 March 1959 Skate broke through the polar ice to surface at the pole. It demonstrated a capability essential for Arctic submarine operations and missile launch.

The US George Washington class and Soviet Golf class entered service as part of the Cold War nuclear deterrent strategy. This gave submarines a central role in strategic deterrence.

On 3 August 1958 USS Nautilus, using an inertial navigation system, navigated beneath the polar ice cap to become the first vessel to reach the North Pole submerged, having already reached 87 degrees north near Spitsbergen in 1957. The transit demonstrated that nuclear power freed a submarine from the need to surface for air, opening the Arctic ice cap as an operating area and a potential corridor between the Atlantic and Pacific for submarines of both Cold War superpowers.

A nuclear reactor let the boat stay submerged for weeks rather than hours, ending the diesel-electric submarine's need to surface regularly to recharge batteries and run its engines, and setting the design pattern followed by every major navy's attack and missile submarines since.

An SSM-N-8 Regulus with a nuclear warhead was fired from the deck of the modified World War II fleet boat. Tunny and its sister Barbero became the United States' first nuclear deterrent patrol submarines.