Torpedo
Overview
 
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.

The term torpedo was originally employed for a variety of devices, most of which would today be called mines
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

. From about 1900, "torpedo" has been used strictly to designate an underwater self-propelled missile.

While the battleship
Battleship
A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

 had evolved primarily around engagements between armoured ships with large-caliber guns
Naval artillery
Naval artillery, or naval riflery, is artillery mounted on a warship for use in naval warfare. Naval artillery has historically been used to engage either other ships, or targets on land; in the latter role it is currently termed naval gunfire fire support...

, the torpedo allowed torpedo boat
Torpedo boat
A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

s and other lighter surface ships, submersible
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s, and later, aircraft to destroy large armoured ships without the use of large guns, though sometimes at the risk of being hit by longer-range shellfire.

Today's torpedoes can be divided into lightweight and heavyweight classes; and into straight-running, autonomous homers, and wire-guided.
Encyclopedia
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.

The term torpedo was originally employed for a variety of devices, most of which would today be called mines
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

. From about 1900, "torpedo" has been used strictly to designate an underwater self-propelled missile.

While the battleship
Battleship
A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

 had evolved primarily around engagements between armoured ships with large-caliber guns
Naval artillery
Naval artillery, or naval riflery, is artillery mounted on a warship for use in naval warfare. Naval artillery has historically been used to engage either other ships, or targets on land; in the latter role it is currently termed naval gunfire fire support...

, the torpedo allowed torpedo boat
Torpedo boat
A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

s and other lighter surface ships, submersible
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s, and later, aircraft to destroy large armoured ships without the use of large guns, though sometimes at the risk of being hit by longer-range shellfire.

Today's torpedoes can be divided into lightweight and heavyweight classes; and into straight-running, autonomous homers, and wire-guided. They can be launched from a variety of platforms.

Etymology

The word torpedo comes from a genus of electric ray
Electric ray
The electric rays are a group of rays, flattened cartilaginous fish with enlarged pectoral fins, comprising the order Torpediniformes. They are known for being capable of producing an electric discharge, ranging from as little as 8 volts up to 220 volts depending on species, used to stun prey and...

s in the order Torpediniformes, which in turn comes from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 "torpere" (to be stiff or numb). In naval usage, the American Robert Fulton
Robert Fulton
Robert Fulton was an American engineer and inventor who is widely credited with developing the first commercially successful steamboat...

 introduced the name to refer to a towed gunpowder
Gunpowder
Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...

 charge used by his French submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

 Nautilus
Nautilus (1800 submarine)
Nautilus, first tested in 1800, is often considered the first practical submarine, though preceded by Cornelius Drebbel's of 1620.-Background:...

 to demonstrate that it could sink warship
Warship
A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way from merchant ships. As well as being armed, warships are designed to withstand damage and are usually faster and more maneuvrable than merchant ships...

s.

History

The concept of a torpedo existed many centuries before it was developed as a working device. The earliest description is found in the works of Syria
Syria
Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....

n engineer Hassan al-Rammah in 1275. He described various kinds of incendiary arrows and lances, and illustrated what has been supposed to be a torpedo, which al-Rammah called "the egg which moves itself and burns", with the text suggesting that it was intended to move on the surface of water. In a 2011 episode of Mythbusters
MythBusters
MythBusters is a science entertainment TV program created and produced by Beyond Television Productions for the Discovery Channel. The series is screened by numerous international broadcasters, including Discovery Channel Australia, Discovery Channel Latin America, Discovery Channel Canada, Quest...

, Jamie Hyneman
Jamie Hyneman
James Franklin "Jamie" Hyneman is an American special effects expert, best known for being the co-host of the television series MythBusters. He is also the owner of M5 Industries, the special effects workshop where MythBusters is filmed...

 and Adam Savage
Adam Savage
Adam Whitney Savage is an American industrial design and special effects designer/fabricator, actor, educator, and co-host of the Discovery Channel television series MythBusters. His model work has appeared in major films, including Star Wars: Episode II - Attack of the Clones and The Matrix...

 constructed a replica of al-Rammah's torpedo and after several tries, discovered it was indeed a plausible weapon.

Before the invention of the self-propelled torpedo the term was applied to any number of different types of explosive devices, generally having the property of being secret or hidden, including devices which today would include booby trap
Booby trap
A booby trap is a device designed to harm or surprise a person, unknowingly triggered by the presence or actions of the victim. As the word trap implies, they often have some form of bait designed to lure the victim towards it. However, in other cases the device is placed on busy roads or is...

s, land mine
Land mine
A land mine is usually a weight-triggered explosive device which is intended to damage a target—either human or inanimate—by means of a blast and/or fragment impact....

s and naval mine
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

s.

Early naval "torpedoes"

Although the term "torpedo" was not coined until 1800, the early submarine Turtle
Turtle (submarine)
The Turtle was the world's first submersible with a documented record of use in combat. It was built in Old Saybrook, Connecticut in 1775 by American Patriot David Bushnell as a means of attaching explosive charges to ships in a harbor...

 attacked using an explosive very similar in intent and function. Turtle dived under a British vessel to attach a bomb by means of an auger. The bomb was to be detonated by a timed fuse, probably a type of clockwork mechanism. In its only recorded attack, Turtle failed to attach its charge to the hull of HMS Eagle
HMS Eagle (1774)
HMS Eagle was a 64-gun third rate ship of the line of the Royal Navy, launched on 2 May 1774 at Rotherhithe.On 7 September 1776, the experimental American submarine Turtle, under the guidance of Army volunteer Sergeant Ezra Lee, attacked HMS Eagle, which was moored off what is today called Liberty...

.

The first usage of the term torpedo to refer to a naval explosive was by American inventor Robert Fulton
Robert Fulton
Robert Fulton was an American engineer and inventor who is widely credited with developing the first commercially successful steamboat...

. In 1800, Fulton launched his submarine, Nautilus, and demonstrated its method of attack using a floating explosive charge Fulton called a torpedo. The submarine would tow the torpedo, submerging beneath an enemy vessel and dragging the torpedo into contact with it. Fulton successfully destroyed demonstration targets in both France and Britain, but neither government was interested in purchasing the vessel and Fulton's experiments ceased in 1805.

During the American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

, the term torpedo was used for what is today called a contact mine, floating on or below the water surface using an air-filled demijohn
Carboy
A carboy is a rigid container with a typical capacity of 5 to 15 gallons . Carboys are primarily used for transporting fluids, often water or chemicals.They are also used for in-home fermentation of beverages, often wine.-Brewing:...

 or similar flotation device. (As self-propelled torpedoes were developed the tethered variety became known as stationary torpedoes and later mines.) Several types of naval "torpedo" were developed and deployed, most often by the Confederates, who faced a severe disadvantage in more traditional warfare methods.

In this period, "torpedoes" floated freely on the surface or were bottom-moored just below the surface. They were detonated when struck by a ship, or after a set time, but were unreliable. These could be as much a danger to Confederate as to Union
Union (American Civil War)
During the American Civil War, the Union was a name used to refer to the federal government of the United States, which was supported by the twenty free states and five border slave states. It was opposed by 11 southern slave states that had declared a secession to join together to form the...

 shipping, and were sometimes marked with flags that could be removed if Union attack was deemed imminent. Rivers mined with Confederate torpedoes were often cleared by Unionists placing captured Confederate soldiers with knowledge of the torpedoes' location in small boats ahead of the main fleet.

"Torpedoes" (mines) could also be detonated electrically by an operator on shore (as demonstrated also by Fulton), so friendly vessels or low-value enemy vessels could be ignored while waiting for the capital ships to sail over them. However, the Confederacy was plagued by a chronic shortage of materials including platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...

 and copper wire and acid for batteries, and the wires had a tendency to break. Electricity was a new technology, and the limitations of direct current
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

 for effective distance was poorly understood, so failures were also possible because of the decrease in voltage when the torpedoes were too far from the batteries. Former United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 Commander Matthew Maury
Matthew Fontaine Maury
Matthew Fontaine Maury , United States Navy was an American astronomer, historian, oceanographer, meteorologist, cartographer, author, geologist, and educator....

, who served as a commander in the Confederate Navy
Confederate States Navy
The Confederate States Navy was the naval branch of the Confederate States armed forces established by an act of the Confederate Congress on February 21, 1861. It was responsible for Confederate naval operations during the American Civil War...

, worked on the development of an underwater electrical mine.

David Farragut
David Farragut
David Glasgow Farragut was a flag officer of the United States Navy during the American Civil War. He was the first rear admiral, vice admiral, and admiral in the United States Navy. He is remembered in popular culture for his order at the Battle of Mobile Bay, usually paraphrased: "Damn the...

 encountered tethered and floating contact mines in 1864 at the American Civil War Battle of Mobile Bay
Battle of Mobile Bay
The Battle of Mobile Bay of August 5, 1864, was an engagement of the American Civil War in which a Federal fleet commanded by Rear Adm. David G. Farragut, assisted by a contingent of soldiers, attacked a smaller Confederate fleet led by Adm...

. After his leading ironclad, USS Tecumseh
USS Tecumseh (1863)
The first USS Tecumseh was an iron-hulled, single-turret monitor in the United States Navy during the American Civil War.Tecumseh was launched on 12 September 1863 at Jersey City, New Jersey, by Secor and Company,of New York City; and was commissioned at the New York Navy Yard on 19 April 1864,...

, was sunk by a tethered contact mine (torpedo), his vessels halted, afraid of hitting additional torpedoes. Inspiring his men to push forward, Farragut famously ordered, "Damn the torpedoes, full speed ahead!"

The first torpedo designed to attack a specific target was the spar torpedo
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 the end, so it would stick to wooden hulls...

, an explosive device mounted at the end of a spar up to 30 feet (9.1 m) long projecting forward underwater from the bow of the attacking vessel. When driven up against the enemy and detonated, a hole would be caused below the water line. Spar torpedoes were employed by the Confederate submarine H. L. Hunley
H. L. Hunley (submarine)
H. L. Hunley was a submarine of the Confederate States of America that played a small part in the American Civil War, but a large role in the history of naval warfare. The Hunley demonstrated both the advantages and the dangers of undersea warfare...

 (and were successful in sinking the USS Housatonic
USS Housatonic (1861)
The first USS Housatonic was a screw sloop-of-war of the United States Navy, named for the Housatonic River of New England which rises in Berkshire County, Massachusetts, and flows southward into Connecticut before emptying into Long Island Sound a little east of Bridgeport, Connecticut...

), as well as by David
CSS David
CSS David was a Civil War-era torpedo boat built as a private venture by T. Stoney at Charleston, South Carolina in 1863, and put under the control of the Confederate States Navy. The cigar-shaped boat carried a 60- or 70-pound explosive charge on the end of a spar projecting forward from her bow...

-class torpedo boats, among others. However, these torpedoes were apt to cause as much harm to their users as to their targets.

Bombs and booby traps

During the US Civil War, the term "torpedo" was also used to refer to various types of bombs and boobytraps. Confederate General Gabriel J. Rains
Gabriel J. Rains
Gabriel James Rains was a career United States Army officer and a brigadier general in the Confederate States Army during the American Civil War.-Early life:...

 deployed "sub-terra shells" or "land torpedoes", artillery
Artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...

 shells
Shell (projectile)
A shell is a payload-carrying projectile, which, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot . Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used...

 with pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...

 fuses
Fuse (explosives)
In an explosive, pyrotechnic device or military munition, a fuse is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately...

 buried in the road by retreating Confederate forces to delay their pursuers. These were the forerunners of modern land mines. Union generals publicly deplored this conduct.

Confederate secret agent John Maxwell used a clockwork mechanism to detonate a large "horological torpedo" (time bomb) on August 9, 1864. The bomb was hidden in a box marked "candles" and placed aboard a barge containing Union ammunition (20,000–30,000 artillery shells and 75,000 small arms
Small arms
Small arms is a term of art used by armed forces to denote infantry weapons an individual soldier may carry. The description is usually limited to revolvers, pistols, submachine guns, carbines, assault rifles, battle rifles, multiple barrel firearms, sniper rifles, squad automatic weapons, light...

 rounds) moored at City Point, Virginia
City Point, Virginia
City Point was a town in Prince George County, Virginia that was annexed by the independent city of Hopewell in 1923. It served as headquarters of the Union Army during the Siege of Petersburg during the American Civil War.- History :...

, on the James River
James River (Virginia)
The James River is a river in the U.S. state of Virginia. It is long, extending to if one includes the Jackson River, the longer of its two source tributaries. The James River drains a catchment comprising . The watershed includes about 4% open water and an area with a population of 2.5 million...

. The explosion caused more than US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

2 million in damage and killed at least 43 people.

The coal torpedo
Coal torpedo
The coal torpedo was a hollow iron casting filled with explosives and covered in coal dust, deployed by the Confederate Secret Service during the American Civil War, and intended for doing harm to Union steam transportation. When shoveled into the firebox amongst the coal, the resulting explosion...

 was a bomb shaped like a lump of coal, to be hidden in coal piles used for fueling Union naval vessels. The bomb would be shoveled into the firebox along with the real coal, causing a Boiler explosion
Boiler explosion
A boiler explosion is a catastrophic failure of a boiler. As seen today, boiler explosions are of two kinds. One kind is over-pressure in the pressure parts of the steam and water sides. The second kind is explosion in the furnace. Boiler explosions of pressure parts are particularly associated...

. Although the North referred to the device as the coal torpedo in newspaper articles, the Confederates referred to it as a "coal shell".

Self-propelled torpedoes

From the 1870s onwards, the word torpedo was increasingly used only to describe self-propelled projectiles that traveled under or on water. By the turn of the 20th century, the term no longer included mines and booby-traps as the navies of the world added submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s, torpedo boat
Torpedo boat
A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

s and torpedo boat destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s to their fleets.
The first working prototype of the modern self-propelled torpedo was created by a commission placed by Giovanni Luppis
Giovanni Luppis
Giovanni Biagio Luppis von Rammer was an officer of the Austrian Navy who had the idea of the first self-propelled torpedo.-Early years:...

 , an Austrian naval officer
Austro-Hungarian Navy
The Austro-Hungarian Navy was the naval force of Austria-Hungary. Its official name in German was Kaiserliche und Königliche Kriegsmarine , abbreviated as k.u.k. Kriegsmarine....

 from Fiume (now called Rijeka
Rijeka
Rijeka is the principal seaport and the third largest city in Croatia . It is located on Kvarner Bay, an inlet of the Adriatic Sea and has a population of 128,735 inhabitants...

), a port city of the Austro-Hungarian Monarchy (modern Croatia
Croatia
Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

), and Robert Whitehead
Robert Whitehead
Robert Whitehead was an English engineer. He developed the first effective self-propelled naval torpedo. His company, located in the Austrian naval centre in Fiume, was the world leader in torpedo development and production up to the First World War.- Early life:He was born the son of a...

, an English
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 engineer who was the manager of a town factory. In 1864, Luppis presented Whitehead with the plans of the salvacoste (coastsaver), a floating weapon driven by ropes from the land, and made a contract with him in order to perfect the invention.

Whitehead was unable to improve the machine substantially, since the clockwork motor, attached ropes, and surface attack mode all contributed to a slow and cumbersome weapon. However, he kept considering the problem after the contract had finished, and eventually developed a tubular device, designed to run underwater on its own, and powered by compressed air. The result was a submarine weapon, the Minenschiff (mine ship), the first self-propelled torpedo, officially presented to the Austrian Imperial Naval commission on December 21, 1866.

Maintaining proper depth was a major problem in the early days but Whitehead introduced his "secret" in 1868 which overcame this. It was a mechanism consisting of a hydrostatic valve and pendulum that caused the torpedo's hydroplanes to be adjusted so as to maintain a preset depth.

After the Austrian government decided to invest in the invention, Whitehead started the first torpedo factory in Fiume. In 1870, he improved the devices to travel up to approximately 1000 yards at a speed of up to 6 kn (11.8 km/h), and by 1881 the factory was exporting torpedoes to ten other countries. The torpedo was powered by compressed air and had an explosive charge of gun-cotton. Whitehead went on to develop more efficient devices, demonstrating torpedoes capable of 18 knots in 1876, 24 knots in 1886, and, finally, 30 knots in 1890.

Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 representatives visited Fiume for a demonstration in late 1869, and in 1870 a batch of torpedoes was ordered. In 1871, the British Admiralty
Admiralty
The Admiralty was formerly the authority in the Kingdom of England, and later in the United Kingdom, responsible for the command of the Royal Navy...

 paid Whitehead £
Pound sterling
The pound sterling , commonly called the pound, is the official currency of the United Kingdom, its Crown Dependencies and the British Overseas Territories of South Georgia and the South Sandwich Islands, British Antarctic Territory and Tristan da Cunha. It is subdivided into 100 pence...

15,000 for certain of his developments and production started at the Royal Laboratories in Woolwich the following year. In 1893, RN torpedo production was transferred to the Royal Gun Factory. The British later established a Torpedo Experimental Establishment at HMS Vernon
HMS Vernon
Two ships and a training establishment of the Royal Navy have borne the name HMS Vernon, possibly after Admiral Edward Vernon:*HMS Vernon was a 14-gun armed ship listed between 1781 and 1782....

 and a production facility at the Royal Naval Torpedo Factory, Greenock
Greenock
Greenock is a town and administrative centre in the Inverclyde council area in United Kingdom, and a former burgh within the historic county of Renfrewshire, located in the west central Lowlands of Scotland...

 in 1910. These are now closed.

Whitehead opened a new factory near Portland Harbour
Portland Harbour
Portland Harbour is located beside the Isle of Portland, off Dorset, on the south coast of England. It is one of the largest man-made harbours in the world. Grid reference: .-History:...

, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 in 1890, which continued making torpedoes until the end of the Second World War. Because orders from the RN were not as large as expected, torpedoes were mostly exported. A series of devices was produced at Fiume, with diameters from 14 in (35.6 cm) upward. The largest Whitehead torpedo was 18 in (46 cm) in diameter and 19 ft (5.8 m) long, made of polished steel or phosphor-bronze, with a 200 pounds (90.7 kg) gun-cotton warhead. It was propelled by a three-cylinder Brotherhood engine, using compressed air at around 1300 psi (9 MPa) and driving two propellers, and was designed to self-regulate its course and depth as far as possible. By 1881, nearly 1500 torpedoes had been produced. Whitehead also opened a factory at St Tropez in 1890 which exported torpedoes to Brazil, Holland, Turkey and Greece.

Whitehead faced competition from the American Lieutenant Commander
Lieutenant Commander
Lieutenant Commander is a commissioned officer rank in many navies. The rank is superior to a lieutenant and subordinate to a commander...

 John A. Howell
John Adams Howell
John Adams Howell was a Rear Admiral of the United States Navy, who served during the Civil War and the Spanish–American War. He was also a noted inventor.-Biography:Howell was born in Bath, New York, on 16 March 1840...

, whose own design
Howell torpedo
The Howell Automobile Torpedo was the first self-propelled torpedo in United States Navy service.It was conceived by LCdr. John A. Howell , USN, in 1870, using a 60 kg flywheel spun at very high speed to store energy and drive propellers...

, driven by flywheel
Flywheel
A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a significant moment of inertia, and thus resist changes in rotational speed. The amount of energy stored in a flywheel is proportional to the square of its rotational speed...

, was simpler and cheaper. It was produced from 1885 to 1895, and it ran straight, leaving no wake. A Torpedo Test Station had been set up in Rhode Island in 1870, and an automobile torpedo produced in 1871 was unsuccessful. The Lay torpedoes were also largely unsuccessful as were various privately invented types. The Howell torpedo was the only USN model until Whitehead torpedoes produced by Bliss and Williams (later E W Bliss and Co) entered service in 1894. Five varieties were produced, all 18 in (45.7 cm) diameter. An improved version, the Bliss-Leavitt, with a turbine engine was later produced, some with a larger diameter. Various versions were used in both World War I and World War II.

Whitehead purchased rights to the gyroscope
Gyroscope
A gyroscope is a device for measuring or maintaining orientation, based on the principles of angular momentum. In essence, a mechanical gyroscope is a spinning wheel or disk whose axle is free to take any orientation...

 of Ludwig Obry in 1888 but it was not sufficiently accurate, so in 1890 he purchased a better design (ironically from Howell) to improve control of his designs, which came to be called the "Devil's Device". The firm of L. Schwartzkopf in Germany also produced torpedoes and exported them to Russia, Japan and Spain. In 1885, Britain ordered a batch of 50 as torpedo production at home and at Fiume could not meet demand.

On 16 January 1878, the Turkish
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

 steamer Intibah became the first vessel to be sunk by self-propelled torpedoes, launched from torpedo boats operating from the tender Velikiy Knyaz Konstantin
Russian tender Velikiy Knyaz Konstantin
Veliky Knyaz Konstantin was the name of a torpedo boat tender of the Russian Navy named after the Grand Duke Konstantin of Russia, and which served in the Russo-Turkish War of 1877-78...

 under the command of Stepan Osipovich Makarov during the Russo-Turkish War of 1877-78. In another early use of the torpedo, Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

an frigate Blanco Encalada
Chilean frigate Blanco Encalada (1875)
Blanco Encalada was an armored frigate built by Earle's Shipbuilding Co. in England for the Chilean Navy in 1875. She was nicknamed El Blanco...

 was sunk on April 23, 1891 by a torpedo from the gunboat Almirante Lynch
Almirante Lynch
The Almirante Lynch was a destroyer in service with the Chilean Navy through World War I and World War II. She was named after Admiral Patricio Lynch, Chilean sailor, hero of the War of the Pacific....

, during the Chilean Civil War
Chilean Civil War
The Chilean Civil War of 1891 was an armed conflict between forces supporting Congress and forces supporting the sitting President, José Manuel Balmaceda. The war saw a confrontation between the Chilean Army and the Chilean Navy, which had sided with the president and the congress, respectively...

.

By this time the torpedo boat
Torpedo boat
A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

, the first of which had been built at the shipyards of Sir John Thornycroft
John Isaac Thornycroft
Sir John Isaac Thornycroft was a British shipbuilder, the founder of the Thornycroft shipbuilding company and member of the Thornycroft family.-Biography:He was born in 1843 to Mary Francis and Thomas Thornycroft....

 in 1877, had gained recognition for its effectiveness, and the first torpedo boat destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s (later simply destroyers) were built to counter it. Torpedoes were also used to equip gunboat
Gunboat
A gunboat is a naval watercraft designed for the express purpose of carrying one or more guns to bombard coastal targets, as opposed to those military craft designed for naval warfare, or for ferrying troops or supplies.-History:...

s of around 1,000 tons, these becoming torpedo gunboat
Torpedo gunboat
In late 19th-century naval terminology, torpedo gunboats or, in north European usage, torpedo cruisers, were a form of gunboat armed with torpedoes and designed for hunting and destroying smaller torpedo boats...

s.

Originally, torpedoes were designed to be straight running, though this was not always the case in practice. Around 1897, Nikola Tesla
Nikola Tesla
Nikola Tesla was a Serbian-American inventor, mechanical engineer, and electrical engineer...

 patented a remote control
Remote control
A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...

led boat and later demonstrated the feasibility of radio-guided torpedoes to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 military.

Twentieth Century and the Russo-Japanese War 1904-1905

Several western sources reported that the Qing dynasty
Qing Dynasty
The Qing Dynasty was the last dynasty of China, ruling from 1644 to 1912 with a brief, abortive restoration in 1917. It was preceded by the Ming Dynasty and followed by the Republic of China....

 Imperial Chinese military under the direction of Li Hongzhang
Li Hongzhang
Li Hongzhang or Li Hung-chang , Marquis Suyi of the First Class , GCVO, was a leading statesman of the late Qing Empire...

 acquired "Electric torpedoes", which were deployed in numerous waterways along with fortresses and numerous other modern military weapons acquired by China. At the Tientsin Arsenal in 1876, the Chinese developed the capacity to manufacture these "electric torpedoes" on their own. A form of Chinese art, the Nianhua, depict such torpedoes being used against Russian ships during the Boxer Rebellion
Boxer Rebellion
The Boxer Rebellion, also called the Boxer Uprising by some historians or the Righteous Harmony Society Movement in northern China, was a proto-nationalist movement by the "Righteous Harmony Society" , or "Righteous Fists of Harmony" or "Society of Righteous and Harmonious Fists" , in China between...

, whether they were actually used in battle against them was undocumented and unknown.

The Russo-Japanese War
Russo-Japanese War
The Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...

 (1904–1905) was the first great war of the 20th century. It was the first practical and mass deployment of man's newly built steel battleship
Battleship
A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

s, cruiser
Cruiser
A cruiser is a type of warship. The term has been in use for several hundreds of years, and has had different meanings throughout this period...

s, his fledgling destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s and submarines, and the torpedo boat
Torpedo boat
A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

. During the course of the war the Imperial Russian and Imperial Japanese navies would launch nearly 300 torpedoes at each other, all of them of the "self propelled automotive" type. The deployment of these new under water missiles resulted in only 1 battleship, but 2 armored cruisers and 2 destroyers being sunk in action; with the remainder of the 80 some odd warships being sunk by the more conventional methods of gunfire, mines, and scuttling.

On 27 May 1905, during the battle of Tsushima
Battle of Tsushima
The Battle of Tsushima , commonly known as the “Sea of Japan Naval Battle” in Japan and the “Battle of Tsushima Strait”, was the major naval battle fought between Russia and Japan during the Russo-Japanese War...

, Admiral Rozhestvensky's flagship
Flagship
A flagship is a vessel used by the commanding officer of a group of naval ships, reflecting the custom of its commander, characteristically a flag officer, flying a distinguishing flag...

, the battleship Knyaz Suvorov, had been gunned to a wreck by Admiral Togo
Togo Heihachiro
Fleet Admiral Marquis was a Fleet Admiral in the Imperial Japanese Navy and one of Japan's greatest naval heroes. He was termed by Western journalists as "the Nelson of the East".-Early life:...

's 12 inch gunned battleline. With the Russians sunk and scattering, Togo prepared for pursuit, and while doing so ordered his torpedo boat destroyers (TBDs) (mostly referred to as just destroyers in most written accounts) to finish off the Russian battleship. The Knyaz Suvorov was set upon by 17 torpedo firing warships, 10 of which were TBDs and 4 torpedo boats. 21 torpedoes were launched at the pre-dreadnought
Pre-dreadnought
Pre-dreadnought battleship is the general term for all of the types of sea-going battleships built between the mid-1890s and 1905. Pre-dreadnoughts replaced the ironclad warships of the 1870s and 1880s...

, and 3 struck home, one fired from the destroyer IJN Murasame and two from torpedo boats #72 and #75. The flagship slipped under the waves shortly thereafter, taking over 900 men with her to the bottom.
The end of the war fuelled new theories, and the idea of dropping lightweight torpedoes from aircraft was conceived in the early 1910s by Bradley A. Fiske, an officer in the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

. Awarded a patent in 1912,
Fiske worked out the mechanics of carrying and releasing the aerial torpedo
Aerial torpedo
The aerial torpedo, airborne torpedo or air-dropped torpedo is a naval weapon, the torpedo, designed to be dropped into water from an aircraft after which it propels itself to the target. First used in World War I, air-dropped torpedoes were used extensively in World War II, and remain in limited...

 from a bomber
Bomber
A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...

, and defined tactics that included a night-time approach so that the target ship would be less able to defend itself. Fiske determined that the notional torpedo bomber
Torpedo bomber
A torpedo bomber is a bomber aircraft designed primarily to attack ships with aerial torpedoes which could also carry out conventional bombings. Torpedo bombers existed almost exclusively prior to and during World War II when they were an important element in many famous battles, notably the...

 should descend rapidly in a sharp spiral to evade enemy guns, then when about 10 to 20 ft (3 to 6.1 ) above the water the aircraft would straighten its flight long enough to line up with the torpedo's intended path. The aircraft would release the torpedo at a distance of 1500 yard from the target. Fiske reported in 1915 that, using this method, enemy fleets could be attacked within their own harbors if there were enough room for the torpedo track.

World War I

Torpedoes were widely used in the First World War, both against shipping and against submarines. Germany and its allies disrupted the supply lines to Britain largely by use of submarine torpedoes (though submarines also extensively used guns). Britain and its allies also used torpedoes throughout the war. U-boats themselves were often targeted, twenty being sunk by torpedo. Two Royal Italian Navy torpedo boat
MAS (boat)
Motoscafo Armato Silurante , commonly abbreviated as MAS was a class of fast torpedo armed vessel used by the Regia Marina during World War I and World War II...

s scored a success against an Austrian-Hungarian squadron
Squadron (naval)
A squadron, or naval squadron, is a unit of 3-4 major warships, transport ships, submarines, or sometimes small craft that may be part of a larger task force or a fleet...

, sinking the battleship Szent István
SMS Szent István
SMS Szent István was a dreadnought , the only one built in the Hungarian part of Austria-Hungary. The Ganz & Company's Danubius yard in Hungarian-owned Fiume was awarded the contract to build the battleship in return for the Hungarian government agreeing to the 1910 and 1911 naval budgets...

 with two torpedoes.

Initially the Japanese Navy purchased Whitehead or Schwartzkopf torpedoes but by 1917 they were conducting experiments with pure oxygen instead of compressed air. Because of explosions they abandoned the experiments but resumed them in 1926 and by 1933 had a working torpedo. They also used conventional wet-heater torpedoes.

World War II

In the inter-war years, tight budgets caused nearly all navies to skimp on testing their torpedoes. As a result, only the Japanese had fully tested torpedoes (in particular the Type 93
Type 93 torpedo
The Type 93 was a -diameter torpedo of the Imperial Japanese Navy , launched from surface ships. It is commonly referred to as the Long Lance by most modern English-language naval historians, a nickname given it after the war by Samuel E. Morison, the chief historian of the U.S...

, nicknamed Long Lance postwar by historian Samuel E. Morison) at the start of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. The lack of reliability caused major problems for the American Submarine Force in the early years of the American involvement in World War II, primarily in the Pacific Theater
Pacific War
The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...

.

All classes of ship, including submarines, and aircraft were armed with torpedoes. Naval strategy at the time was to use torpedoes, launched from submarines or warships, against enemy warships in a fleet action on the high seas. Targeting unarmed enemy merchant shipping was prohibited by rules of war
Laws of war
The law of war is a body of law concerning acceptable justifications to engage in war and the limits to acceptable wartime conduct...

. (In the event, merchantmen were armed and acted as de facto naval auxiliaries, rendering the distinction irrelevant.) There was concern torpedoes would be ineffective against warships' heavy armor; an answer to this was to detonate torpedoes underneath a ship, badly damaging its keel
Keel
In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...

 and the other structural members in the hull, commonly called "breaking its back". This was demonstrated by magnetic influence mines in World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. The torpedo would be set to run at a depth just beneath the ship, relying on a magnetic exploder to activate at the appropriate time. Germany, Britain and the U.S. independently devised ways to do this; German and American torpedoes, however, suffered problems with their depth-keeping mechanisms, coupled with faults in magnetic pistol
Magnetic pistol
Magnetic pistol is the term for the device on a torpedo or naval mine that detects its target by its magnetic field, and triggers the fuse for detonation...

s shared by all designs.

Inadequate testing had failed to reveal the effect of the Earth's magnetic field on ships and exploder mechanisms, which resulted in premature detonation. The Kriegsmarine
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...

and Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 promptly identified and eliminated the problems. In the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

, there was an extended wrangle over the problems plaguing the Mark 14 torpedo
Mark 14 torpedo
The Mark 14 torpedo was the United States Navy's standard submarine-launched anti-ship torpedo of World War II.This weapon was plagued with many problems which crippled its performance early in the war, and was supplemented by the Mark 18 electric torpedo in the last 2 years of the war...

 (and its Mark 6 exploder). Cursory trials had allowed bad designs to enter service. Both the Navy Bureau of Ordnance
Bureau of Ordnance
The Bureau of Ordnance was the U.S. Navy's organization responsible for the procurement, storage, and deployment of all naval ordnance, between the years 1862 and 1959.-History:...

 and the United States Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....

 were too busy protecting their own interests to correct the errors, and fully functioning torpedoes only became available to the USN 21 months into the Pacific War.

British submarines used torpedoes to interdict the Axis supply shipping to North Africa, while Fleet Air Arm
Fleet Air Arm
The Fleet Air Arm is the branch of the British Royal Navy responsible for the operation of naval aircraft. The Fleet Air Arm currently operates the AgustaWestland Merlin, Westland Sea King and Westland Lynx helicopters...

 Swordfish
Fairey Swordfish
The Fairey Swordfish was a torpedo bomber built by the Fairey Aviation Company and used by the Fleet Air Arm of the Royal Navy during the Second World War...

 sank three Italian battleships at Taranto
Battle of Taranto
The naval Battle of Taranto took place on the night of 11–12 November 1940 during the Second World War. The Royal Navy launched the first all-aircraft ship-to-ship naval attack in history, flying a small number of obsolescent biplane torpedo bombers from an aircraft carrier in the Mediterranean Sea...

 by torpedo and (after a mistaken, but abortive, attack on Sheffield
HMS Sheffield (C24)
HMS Sheffield was one of the Southampton sub class of the Town-class cruisers of the Royal Navy during the Second World War. She took part in actions against several major German warships. Unlike most Royal Navy ships of her time, her fittings were constructed from stainless steel instead of the...

) scored one crucial hit in the hunt for the German battleship Bismarck
German battleship Bismarck
Bismarck was the first of two s built for the German Kriegsmarine during World War II. Named after Chancellor Otto von Bismarck, the primary force behind the German unification in 1871, the ship was laid down at the Blohm & Voss shipyard in Hamburg in July 1936 and launched nearly three years later...

. Large tonnages of merchant shipping were sunk by submarines with torpedoes in both the Battle of the Atlantic and the Pacific War.

Torpedo boats such as the American PT boat
PT boat
PT Boats were a variety of motor torpedo boat , a small, fast vessel used by the United States Navy in World War II to attack larger surface ships. The PT boat squadrons were nicknamed "the mosquito fleet". The Japanese called them "Devil Boats".The original pre–World War I torpedo boats were...

s enabled relatively small but fast craft to carry enough firepower, in theory, to destroy a larger ship, though this rarely occurred in practice. Destroyers of all navies were also armed with torpedoes to attack larger ships. In the Battle off Samar
Battle off Samar
The Battle off Samar was the centermost action of the Battle of Leyte Gulf, one of the largest naval battles in history, which took place in the Philippine Sea off Samar Island, in the Philippines on 25 October 1944...

, destroyer-mounted torpedoes of the American task force "Taffy 3" showed effectiveness at defeating armor. Damage and confusion caused by torpedo attacks were instrumental in beating back a superior Japanese force of battleships and cruisers.

Post–World War II

Because of improved submarine strength and speed, torpedoes had to be given improved warheads and better motors. During the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 torpedoes were an important asset with the advent of nuclear powered submarines, which did not have to surface often, particularly those carrying strategic nuclear missiles.

In postwar times, the navies of Pakistan, the United Kingdom and Croatia made torpedo hits against hostile navy ships. The sinkings of INS Khukri and ARA General Belgrano
ARA General Belgrano
The ARA General Belgrano was an Argentine Navy light cruiser in service from 1951 until 1982. Formerly the , she saw action in the Pacific theater of World War II before being sold to Argentina. After almost 31 years of service, she was sunk during the Falklands War by the Royal Navy submarine ...

 caused a combined death toll of approximately 500. The Croatian Navy crippled the Yugoslav patrol boat PČ-176 Mukos with a torpedo launched from an improvised device during the battle of the Dalmatian channels
Battle of the Dalmatian channels
The Battle of the Dalmatian channels was a three-day long confrontation between two task forces of the Yugoslav War Navy and coastal defenses of the Croatian Navy along Šolta island, the port of Split, and the islands of Brač, Hvar and Korčula, which took place from 14 to 16 November 1991...

 in November 1991. 46 personnel of the South Korean Navy died in the ROKS Cheonan sinking
ROKS Cheonan sinking
The ROKS Cheonan sinking occurred on 26 March 2010, when the Cheonan, a South Korean Navy ship carrying 104 personnel, sank off the country's west coast near Baengnyeong Island in the Yellow Sea, killing 46 seamen...

; the subsequent investigation concluded that the warship had been sunk by a North Korean torpedo fired by a midget submarine. Another incident involving the use of torpedoes took place when Israeli Navy units attacked by mistake the technical research ship USS Liberty
USS Liberty incident
The USS Liberty incident was an attack on a United States Navy technical research ship, , by Israeli Air Force jet fighter aircraft and Israeli Navy torpedo boats, on June 8, 1967, during the Six-Day War. The combined air and sea attack killed 34 crew members , wounded 170 crew members, and...

 during the 1967 Six Day War.

During the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...

 the United States Navy successfully attacked a dam with air-launched torpedoes.

Energy sources

Compressed air

This first successful self-propelled Whitehead torpedo of 1866 used compressed air
Pneumatics
Pneumatics is a branch of technology, which deals with the study and application of use of pressurized gas to effect mechanical motion.Pneumatic systems are extensively used in industry, where factories are commonly plumbed with compressed air or compressed inert gases...

 as its energy source. The air was stored at pressures of up to 2.55 MPa (369.8 psi) and fed to a piston engine which turned a single propeller
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...

 at about 100 rpm
Revolutions per minute
Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...

. It was able to travel about 180 metre at an average speed of 6.5 knots (12.7 km/h). The speed and range of later models was improved by increasing the pressure of the stored air. In 1906 Whitehead built torpedoes which could cover nearly 1000 metre at an average speed of 35 knots (68.6 km/h).

At higher pressures the cooling experienced by the air as it expanded in the engine caused icing problems (see adiabatic cooling). This drawback was remedied by heating the air with seawater before it was fed to the engine, which increased engine performance further, because the air expanded even more after heating. This was the principle used by the Brotherhood engine.

Heated torpedoes

This led to the idea of injecting a liquid fuel, like kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...

, into the air and igniting it. In this manner the air is heated up more and expands even further, and the burned propellant adds more gas to drive the engine. Construction of such heated torpedoes started circa 1904 by Whitehead's company.

Wet-heater

A further improvement was the use of water to cool the combustion chamber
Combustion chamber
A combustion chamber is the part of an engine in which fuel is burned.-Internal combustion engine:The hot gases produced by the combustion occupy a far greater volume than the original fuel, thus creating an increase in pressure within the limited volume of the chamber...

. This not only solved heating problems so more fuel could be burnt but also allowed additional power to be generated by feeding the resulting steam into the engine together with the combustion
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...

 products. Torpedoes with such a propulsion system became known as wet heaters, while heated torpedoes without steam generation were retrospectively called dry heaters. A simpler system was introduced by the British Royal Gun factory in 1908. Most torpedoes used in World War I and World War II were wet-heaters.

Compressed oxygen

The amount of fuel that can be burnt by a torpedo engine is limited by the amount of oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

 it can carry. Since compressed air contains only about 21%
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...

 oxygen, engineers in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 developed the Type 93
Type 93 torpedo
The Type 93 was a -diameter torpedo of the Imperial Japanese Navy , launched from surface ships. It is commonly referred to as the Long Lance by most modern English-language naval historians, a nickname given it after the war by Samuel E. Morison, the chief historian of the U.S...

 (nicknamed Long Lance postwar) for destroyers and cruisers in the 1930s. It used pure compressed oxygen instead of compressed air and had unmatched performance in World War II. However, oxygen systems posed a serious danger to any ship that came under attack while still carrying such torpedoes; Japan lost several cruisers partly due to catastrophic secondary explosions of Type 93s. During the war, Germany experimented with hydrogen peroxide
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...

 for the same purpose.

Wire driven

The Brennan torpedo
Brennan Torpedo
The Brennan torpedo was a torpedo patented by Irish born Australian inventor Louis Brennan in 1877. It was powered by two contra-rotating propellors that were spun by rapidly pulling out wires from drums wound inside the torpedo...

 had two wires wound around drums inside it. Shore-based steam winch
Winch
A winch is a mechanical device that is used to pull in or let out or otherwise adjust the "tension" of a rope or wire rope . In its simplest form it consists of a spool and attached hand crank. In larger forms, winches stand at the heart of machines as diverse as tow trucks, steam shovels and...

es pulled the wires, which spun the drums and drove the propellers. An operator controlled the relative speeds of the winches, providing guidance. Such systems were used for coastal defence
Coastal defence and fortification
Coastal defence , Coastal defense and Coastal fortification are measures taken to provide protection against attack by military and naval forces at or near the shoreline...

 of the British homeland and colonies from 1887 to 1903 and were purchased by, and under the control of, the Army as opposed to the Navy. Speed was about 25 knots (49 km/h) for over 2,400 m.

Flywheel

The Howell torpedo
Howell torpedo
The Howell Automobile Torpedo was the first self-propelled torpedo in United States Navy service.It was conceived by LCdr. John A. Howell , USN, in 1870, using a 60 kg flywheel spun at very high speed to store energy and drive propellers...

 used by the US Navy in the late 19th century featured a heavy flywheel
Flywheel
A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a significant moment of inertia, and thus resist changes in rotational speed. The amount of energy stored in a flywheel is proportional to the square of its rotational speed...

 which had to be spun up before launch. It was able to travel about 400 yards (365.8 m) at 25 knots (49 km/h). The Howell had the advantage of not leaving a trail of bubbles behind it, unlike compressed air torpedoes. This gave the target vessel less chance to detect and evade the torpedo, and avoided giving away the attacker's position. Additionally, it ran at a constant depth, unlike Whitehead models.

Electric batteries

Electric propulsion systems avoided tell-tale bubbles. John Ericsson
John Ericsson
John Ericsson was a Swedish-American inventor and mechanical engineer, as was his brother Nils Ericson. He was born at Långbanshyttan in Värmland, Sweden, but primarily came to be active in England and the United States...

 invented an electrically propelled torpedo in 1873; it was powered by a cable from an external power source, as batteries
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...

 of the time had insufficient capacity. The Sims-Edison torpedo was similarly powered. The Nordfelt torpedo was also electrically powered and was steered by impulses down a trailing wire.

Germany introduced its first battery-powered torpedo shortly before World War II, the G7e. It was slower and had shorter range than the conventional G7a, but was wakeless and much cheaper. Its lead-acid rechargeable battery
Rechargeable battery
A rechargeable battery or storage battery is a group of one or more electrochemical cells. They are known as secondary cells because their electrochemical reactions are electrically reversible. Rechargeable batteries come in many different shapes and sizes, ranging anything from a button cell to...

 was sensitive to shock, required frequent maintenance before use, and required preheating for best performance. The experimental G7ep, an enhancement of the G7e, used primary cell
Primary cell
A primary cell is any kind of battery in which the electrochemical reaction is not reversible, rendering the cell non-rechargeable. A common example of a primary cell is the disposable battery. Unlike a secondary cell, the reaction cannot be reversed by running a current into the cell; the chemical...

s.

The United States had an electric design, the Mark 18
Mark 18 torpedo
The Mark 18 torpedo was an electric torpedo used by the US Navy during World War II.The Mark 18 was built in competition to the Bureau of Ordnance electric torpedoes, which had been in development at the Newport Torpedo Station , Newport, Rhode Island, since the 1920s, in particular the Mark II,...

, largely copied from the German torpedo (although with improved batteries), as well as FIDO, an air-dropped acoustic homing torpedo for anti-submarine use.

Modern electric torpedoes such as the Mark 24 Tigerfish
Mark 24 Tigerfish
The Mk 24 Tigerfish torpedo was a heavyweight acoustic homing torpedo used by the Royal Navy for several years. The early Mod0 and Mod1 variants were unreliable and unsuccessful, and were issued to the RN even though they failed Fleet Weapon Acceptance...

 or DM2 series commonly use silver oxide batteries
Silver-oxide battery
A silver oxide battery , not to be confused with a similar but different silver–zinc battery, which is a secondary cell, is a primary cell with relatively very high energy/weight ratio. They are costly due to the high price of silver...

 which need no maintenance, allowing torpedoes to be stored for years without losing performance.

Rockets

A number of experimental rocket-propelled torpedoes were tried soon after Whitehead's invention but they were not successful. Rocket propulsion has been implemented successfully by the Soviet Union and has been recently revived in Russian and German torpedoes as it is especially suitable for supercavitating devices.

Modern drive systems

Modern torpedoes utilize a variety of drive mechanisms, including gas turbines (the British Spearfish
Spearfish torpedo
The Spearfish torpedo is the heavy torpedo used by the submarines of the Royal Navy. It can be guided by wire or by autonomous active or passive sonar, and provides both anti-submarine warfare and anti-surface ship warfare capability.It replaces the unreliable Tigerfish torpedo, which was...

), monopropellant
Monopropellant
Monopropellants are propellants composed of chemicals or mixtures of chemicals which can be stored in a single container with some degree of safety. While stable under defined storage conditions, they react very rapidly under certain other conditions to produce a large volume of energetic gases...

s, and sulphur hexafluoride gas sprayed over a block of solid lithium
Lithium
Lithium is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly...

.

Propulsion

The first of Whitehead's torpedoes had a single propeller and needed a large vane to stop it turning in a circle. Not long afterward the idea of contra-rotating propellers was introduced (at Woolwich), to avoid the need for the vane. The three-bladed propeller came in 1893 and the four-bladed one in 1897. To minimise noise, today's torpedoes often use pump-jet
Pump-jet
A pump-jet, hydrojet, or water jet, is a marine system that creates a jet of water for propulsion. The mechanical arrangement may be a ducted propeller with nozzle, or a centrifugal pump and nozzle...

s.

Some torpedoes, such as the Russian VA-111 Shkval
VA-111 Shkval
The VA-111 Shkval torpedo and its descendants are supercavitating torpedoes developed by the Soviet Union. They are capable of speeds in excess of 200 knots .-Design and capabilities:...

, the Iranian Hoot
Hoot (missile)
Hoot is an Iranian supercavitation torpedo that travels at approximately 360 km/h, several times faster than a conventional torpedo. It was test-fired successfully from a surface ship against a dummy submarine during the Iranian military exercise "Great Prophet" ) on 2 April 2006 and 3 April...

 and the German Unterwasserlaufkörper/ Barracuda, use supercavitation
Supercavitation
Supercavitation is the use of cavitation effects to create a bubble of gas inside a liquid large enough to encompass an object traveling through the liquid, greatly reducing the skin friction drag on the object and enabling achievement of very high speeds...

 to increase their speed to over 200 knots (392 km/h); the maximum speed of torpedoes which do not use supercavitation, such as the American Mark 48
Mark 48 torpedo
The Mark 48 and its improved ADCAP variant are heavyweight submarine-launched torpedoes. They were designed to sink fast, deep-diving nuclear-powered submarines and high-performance surface ships.-History:...

 and British Spearfish
Spearfish torpedo
The Spearfish torpedo is the heavy torpedo used by the submarines of the Royal Navy. It can be guided by wire or by autonomous active or passive sonar, and provides both anti-submarine warfare and anti-surface ship warfare capability.It replaces the unreliable Tigerfish torpedo, which was...

, is well under 100 kn (121.8 mph; 196 km/h), although figures are not always supplied.

Guidance

Torpedoes may be aimed at the target and fired unguided, similarly to an artillery shell, or they may be guided onto the target. They may be guided automatically towards the direction in which the target is detected by some procedure, e.g. sound it produces (homing), or by the operator, typically via commands sent over a signal-carrying cable (wire guidance).

Unguided

The Victorian era Brennan
Brennan Torpedo
The Brennan torpedo was a torpedo patented by Irish born Australian inventor Louis Brennan in 1877. It was powered by two contra-rotating propellors that were spun by rapidly pulling out wires from drums wound inside the torpedo...

 could be steered onto its target by varying the relative speeds of its propulsion cables. However, the Brennan required a substantial infrastructure and was not suitable for shipboard use. Therefore, for the first part of its history, the torpedo was guided only in the sense that its course could be regulated so as to achieve an intended impact depth (because of the sine wave running path of the Whitehead, this was a hit or miss proposition, even when everything worked correctly) and, through gyroscopes, a straight course. With such torpedoes the method of attack in small torpedo boats, Torpedo bomber
Torpedo bomber
A torpedo bomber is a bomber aircraft designed primarily to attack ships with aerial torpedoes which could also carry out conventional bombings. Torpedo bombers existed almost exclusively prior to and during World War II when they were an important element in many famous battles, notably the...

s and small submarines was to steer a predictable collision course abeam to the target and release the torpedo at the last minute, then peeling away, all the time subject to defensive fire.

In larger ships and submarines, fire control calculators gave a wider engagement envelope. Originally, plotting tables (in large ships), combined with specialised slide rule
Slide rule
The slide rule, also known colloquially as a slipstick, is a mechanical analog computer. The slide rule is used primarily for multiplication and division, and also for functions such as roots, logarithms and trigonometry, but is not normally used for addition or subtraction.Slide rules come in a...

s (known in U.S. service as the "banjo" and "Is/Was"), reconciled the speed, distance, and course of a target with the firing ship's speed and course, together with the performance of its torpedoes, to provide a firing solution. By the Second World War, all sides had developed automatic electro-mechanical calculators, exemplified by the U.S. Navy's Torpedo Data Computer
Torpedo Data Computer
The Torpedo Data Computer was an early electromechanical analog computer used for torpedo fire-control on American submarines during World War II . Britain, Germany, and Japan also developed automated torpedo fire control equipment, but none were as advanced as US Navy's TDC...

. Submarine commanders were still expected to be able to calculate a firing solution by hand as a backup against mechanical failure, and because many submarines existing at the start of the war were not equipped with a TDC; most could keep the "picture" in their heads and do much of the calculations (simple trigonometry) mentally, from extensive training.

Against high value targets and multiple targets, submarines would launch a spread of torpedoes, to increase the probability of success. Similarly, squadrons of torpedo boats and torpedo bombers would attack together creating a "fan" of torpedoes across the target's course. Faced with such an attack, the prudent thing for a target to do was to turn 90 degrees to its original course and steam away from the torpedoes and the firer, allowing the relatively short range torpedoes to use up their fuel. An alternative was to "comb the tracks", turning 90 degrees towards the torpedoes. The intention of such a tactic was still to minimise the size of target offered to the torpedoes, but at the same time be able to aggressively engage the firer. This was the tactic advocated by critics of Jellicoe's actions at Jutland, his caution at turning away from the torpedoes being seen as the reason the Germans escaped.

The use of multiple torpedoes to engage single targets depletes torpedo supplies and greatly reduces a submarine's combat endurance
Combat endurance
Combat endurance is the time for which a military system can remain in combat before having to withdraw due to depleted resources. The definition is not precise; for example the combat endurance of an aircraft, without qualification, is usually the time the aircraft can remain at an altitude...

. Endurance can be improved by ensuring a target can be effectively engaged by a single torpedo, which gave rise to the guided torpedo.

Radio and Wire guidance

Though Lupis' original design had been rope guided, torpedoes were not wire-guided until the 1960s.

During the First World War the U.S. Navy evaluated a radio controlled torpedo launched from a surface ship called the Hammond Torpedo. A later version tested in the 1930s was claimed to have an effective range of 6 miles.

Modern torpedoes use an umbilical wire, which nowadays allows the computer processing power of the submarine or ship to be used. Torpedoes such as the U.S. Mark 48
Mark 48 torpedo
The Mark 48 and its improved ADCAP variant are heavyweight submarine-launched torpedoes. They were designed to sink fast, deep-diving nuclear-powered submarines and high-performance surface ships.-History:...

 can operate in a variety of modes, increasing tactical flexibility.

Homing

Homing "fire and forget" torpedoes can use passive or active guidance, or a combination of both. Passive acoustic torpedo
Acoustic torpedo
An acoustic torpedo is a torpedo that aims itself by listening for characteristic sounds of its target or by searching for it using sonar. Acoustic torpedoes are usually designed for medium-range use, and often fired from a submarine....

es home in on emissions from a target. Active acoustic torpedoes home in on the reflection of a signal, or "ping", from the torpedo or its parent vehicle; this has the disadvantage of giving away the presence of the torpedo. In semi-active mode, a torpedo can be fired to the last known position or calculated position of a target, which is then acoustically illuminated ("pinged") once the torpedo is within attack range.

Later in the Second World War torpedoes were given acoustic (homing) guidance system
Guidance system
A guidance system is a device or group of devices used to navigate a ship, aircraft, missile, rocket, satellite, or other craft. Typically, this refers to a system that navigates without direct or continuous human control...

s, originally by the Germans in the G7es torpedo
G7es torpedo
The G7es or Zaunkönig T-5 was a torpedo employed by German U-boats during World War II. It was known as the GNAT to the British.- Description :...

. Pattern-following and wake homing torpedoes were also developed. Acoustic homing formed the basis for torpedo guidance after the Second World War.

The homing systems for torpedoes are generally acoustic, though there have been other target sensor types used. A ship's acoustic signature
Acoustic signature
Acoustic signature is used to describe a combination of acoustic emissions of ships and submarines.-Contributing factors:The acoustic signature is made up of a number of individual elements...

 is not the only emission a torpedo can home in on: to engage U.S. supercarrier
Supercarrier
Supercarrier is an unofficial descriptive term for the largest type of aircraft carrier, usually displacing over 70,000 long tons.Supercarrier is an unofficial descriptive term for the largest type of aircraft carrier, usually displacing over 70,000 long tons.Supercarrier is an unofficial...

s, the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 developed the 53-65
53-65 torpedo
The 53-65 torpedo family are Russian made, wake-homing torpedoes designed to destroy surface ships. The 53-65 became operational in 1965, while the 53-65K and 53-65M both became operational in 1969. The 53-65KE is an exported version...

 wake
Wake
A wake is the region of recirculating flow immediately behind a moving or stationary solid body, caused by the flow of surrounding fluid around the body.-Fluid dynamics:...

-homing torpedo.

Warhead and fuzing

The warhead
Warhead
The term warhead refers to the explosive material and detonator that is delivered by a missile, rocket, or torpedo.- Etymology :During the early development of naval torpedoes, they could be equipped with an inert payload that was intended for use during training, test firing and exercises. This...

 is generally some form of aluminised
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

 explosive, because the sustained explosive pulse produced by the powdered aluminium is particularly destructive against underwater targets. Torpex
Torpex
Torpex is a secondary explosive 50% more powerful than TNT by mass. Torpex is composed of 42% RDX, 40% TNT and 18% powdered aluminium. It was used in the Second World War from late 1942. The name is short for Torpedo Explosive', having been originally developed for use in torpedoes...

 was popular until the 1950s, but has been superseded by PBX compositions. Nuclear warheads for torpedoes have also been developed, e.g. the Mark 45 torpedo
Mark 45 torpedo
The Mark 45 anti-submarine torpedo was a submarine-launched wire-guided nuclear torpedo designed by the United States Navy for use against high-speed, deep-diving, enemy submarines...

. In lightweight antisubmarine torpedoes designed to penetrate submarine hulls, a shaped charge
Shaped charge
A shaped charge is an explosive charge shaped to focus the effect of the explosive's energy. Various types are used to cut and form metal, to initiate nuclear weapons, to penetrate armor, and in the oil and gas industry...

 can be used. Detonation
Detonation
Detonation involves a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations are observed in both conventional solid and liquid explosives, as well as in reactive gases...

 can be triggered by direct contact with the target or by a proximity fuze
Proximity fuze
A proximity fuze is a fuze that is designed to detonate an explosive device automatically when the distance to target becomes smaller than a predetermined value or when the target passes through a given plane...

 incorporating sonar and/or magnetic sensors.

Control surfaces and hydrodynamics

Control surfaces are essential for a torpedo to maintain its course and depth. A homing torpedo also needs to be able to out-manoeuvre a target. Good hydrodynamics are needed for it to attain high speed efficiently and also to give long range since the torpedo has limited stored energy.

Launch platforms and launchers

Torpedoes may be launched from submarines, surface ships, helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s and fixed-wing aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

, unmanned naval mine
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

s and naval fortresses. They are also used in conjunction with other weapons; for example the Mark 46
Mark 46
The designation Mark 46 can refer to:* Mark 46 machine gun, lighter weight version of the M249 machine gun* Mk 46 nuclear bomb* Mark 46 torpedo...

 torpedo used by the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 becomes the warhead section of the ASROC
ASROC
ASROC is an all-weather, all sea-conditions anti-submarine missile system. Developed by the United States Navy in the 1950s, it was deployed in the 1960s, updated in the 1990s, and eventually installed on over 200 USN surface ships, specifically cruisers, destroyers, and frigates...

 (Anti-Submarine ROCket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

) and the CAPTOR mine
CAPTOR mine
The CAPTOR is the United States Navy's primary anti-submarine naval mine. This deep-water mine is laid by ship, aircraft or submarine, and is anchored to the ocean floor. When its sonar detects a hostile submarine, the CAPTOR launches a Mark 46 torpedo.The name CAPTOR is short for enCAPsulated...

 (CAPsulated TORpedo) is a submerged sensor platform which releases a torpedo when a hostile contact is detected.

Ship

Originally, Whitehead torpedoes were intended for launch underwater and the firm was upset when they found out the British were launching them above water, as they considered their torpedoes too delicate for this. However, the torpedoes survived. The launch tubes could be fitted in a ship's bow, which weakened it for ramming, or on the broadside; this introduced problems because of water flow twisting the torpedo, so guide rails and sleeves were used to prevent it. The torpedoes were originally ejected from the tubes by compressed air but later slow burning gunpowder was used. Torpedo boats originally used a frame that dropped the torpedo into the sea. Royal Navy Coastal Motor Boats of World War I used a rear-facing trough and a cordite
Cordite
Cordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Like gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance...

 ram to push the torpedoes into the water tail-first; they then had to move rapidly out of the way to avoid being hit by their own torpedo.

Developed in the run up to Second World War, multiple-tube mounts (up to quintuple in some ships) for 21" to 24" torpedoes in rotating turntable mounts appeared. Destroyers could be found with two or three of these mounts with between five and twelve tubes in total. The Japanese went one better, covering their tube mounts with splinter protection and adding reloading gear (both unlike any other navy in the world), making them true turrets and increasing the broadside without adding tubes and top hamper (as the quadruple and quintuple mounts did). Considering their Type 93
Type 93 torpedo
The Type 93 was a -diameter torpedo of the Imperial Japanese Navy , launched from surface ships. It is commonly referred to as the Long Lance by most modern English-language naval historians, a nickname given it after the war by Samuel E. Morison, the chief historian of the U.S...

s very effective weapons, the IJN equipped their cruisers with torpedoes. The Germans also equipped their capital ships with torpedoes.

Smaller vessels such as PT boats carried their torpedoes in fixed deck mounted tubes using compressed air. These were either aligned to fire forward or at an offset angle from the centerline.

Later, lightweight mounts for 12.75" homing torpedoes were developed for anti-submarine use consisting of triple launch tubes used on the decks of ships. These were the 1960 Mk 32 torpedo launcher in the USA and part of STWS (Shipborne Torpedo Weapon System) in the UK. Later a below-decks launcher was used by the RN. This basic launch system continues to be used today with improved torpedoes and fire control systems.

Submarines

Modern submarines use either swim out systems or a pulse of water to discharge the torpedo from the tube, both of which have the advantage of being significantly quieter than previous systems, helping avoid detection of the firing from passive sonar. Earlier designs used a pulse of compressed air or a hydraulic ram.

Originally, torpedo tubes were fitted to both the bow and stern of submarines. Modern submarine bows are usually occupied by a large sonar array, necessitating torpedoes launched from midships tubes angled outward, while stern tubes have largely disappeared. The first French and Russian submarines carried their torpedoes externally in Drzewiecki
Stefan Drzewiecki
Stefan Drzewiecki was a Polish scientist, journalist, engineer, constructor and inventor, working in Russia and France....

 drop collars. These were cheaper than tubes, but less reliable. Both Britain and America experimented with external tubes in World War II. External tubes offered a cheap and easy way of increasing torpedo capacity without radical redesign, something neither had time or resources to do prior to, or early in, the war. America's use was mainly limited to earlier Porpoise
United States Porpoise class submarine
The Porpoise class were submarines built for the United States Navy in the late 1930s, and incorporated a number of modern features that would make them the basis for subsequent classes such as the Salmon, Tambor, Gato, Balao, and Tench classes...

-, Salmon
Salmon class submarine
The United States Navy Salmon-class submarines were an important developmental step in the design of the "Fleet Submarine" concept during the 1930's...

-, and Sargo
Sargo class submarine
The Sargo-class submarines were the first US submarines to be sent into action after the Japanese attack on Pearl Harbor, starting war patrols the day after the attack...

-class boats. Until the widespread introduction of the Gato class, common American submarines only carried 4 forward and either 2 or 4 Stern tubes, something many American submarine officers felt provided them with inadequate firepower. This problem was compounded by the notorious unreliability of the Mark 14 torpedo
Mark 14 torpedo
The Mark 14 torpedo was the United States Navy's standard submarine-launched anti-ship torpedo of World War II.This weapon was plagued with many problems which crippled its performance early in the war, and was supplemented by the Mark 18 electric torpedo in the last 2 years of the war...

.

Late in World War II, the U.S. adopted a 16 in (40.6 cm) homing torpedo (known as "Cutie"
Mark 27 torpedo
The Mark 27 torpedo was the first of the United States Navy 19-inch submarine-launched torpedoes. This electrically propelled torpedo was 125 inches long and weighed 1174 pounds . The torpedo employed a passive acoustic guidance system and was intended for both submarine and surface targets...

) for use against escorts. It was basically a modified Mark 24 Mine with wooden rails to allow firing from a 21 in (53.3 cm) torpedo tube.

Air launch

Aerial torpedo
Aerial torpedo
The aerial torpedo, airborne torpedo or air-dropped torpedo is a naval weapon, the torpedo, designed to be dropped into water from an aircraft after which it propels itself to the target. First used in World War I, air-dropped torpedoes were used extensively in World War II, and remain in limited...

es may be carried by fixed-wing aircraft, helicopters or missiles. They are launched from the first two at prescribed speeds and altitudes, dropped from bomb-bays or underwing hardpoint
Hardpoint
A hardpoint, or weapon station, is any part of an airframe designed to carry an external load. This includes a point on the wing or fuselage of military aircraft where external ordnance, countermeasures, gun pods, targeting pods or drop tanks can be mounted.-Rail launchers:Large missiles and...

s.

Torpedo handling equipment

Although lightweight torpedoes are fairly easily handled, the transport and handling of heavyweight ones is difficult, especially in the small space of a submarine. After the Second World War, some Type XXI submarines were obtained from Germany by the United States and Britain. One of the main novel developments seen was a mechanical handling system for torpedoes. Such systems were widely adopted as a result of this discovery.

Torpedo classes and diameters

Torpedoes are launched several ways:
  • From a torpedo tube
    Torpedo tube
    A torpedo tube is a device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units installed aboard surface vessels...

     mounted either in a trainable deck mount (common in destroyer
    Destroyer
    In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

    s), or fixed above or below the waterline of a surface vessel (as in cruiser
    Cruiser
    A cruiser is a type of warship. The term has been in use for several hundreds of years, and has had different meanings throughout this period...

    s, battleship
    Battleship
    A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

    s, and armed merchant cruisers) or submarine
    Submarine
    A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

    .
  • Early submarines, and some torpedo boat
    Torpedo boat
    A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

    s (such as the U.S. World War II PT boat
    PT boat
    PT Boats were a variety of motor torpedo boat , a small, fast vessel used by the United States Navy in World War II to attack larger surface ships. The PT boat squadrons were nicknamed "the mosquito fleet". The Japanese called them "Devil Boats".The original pre–World War I torpedo boats were...

    s, which used the Mark 13
    Mark 13 torpedo
    The Bliss-Leavitt Mark 13 torpedo was the U.S. Navy's most common aerial torpedo of World War II. It was designed with unusually squat dimensions for its type: diameter was and length . In the water, the Mark 13 could reach a speed of for up to . The Mark 13 ran slower than the Mark 14 torpedo...

     aircraft torpedo) used deck-mounted "drop collars", which simply relied on gravity.
  • From shackles aboard low-flying aircraft
    Torpedo bomber
    A torpedo bomber is a bomber aircraft designed primarily to attack ships with aerial torpedoes which could also carry out conventional bombings. Torpedo bombers existed almost exclusively prior to and during World War II when they were an important element in many famous battles, notably the...

     or helicopter
    Helicopter
    A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

    s.
  • As the final stage of a compound rocket
    Rocket
    A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

     or ramjet
    Ramjet
    A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of airbreathing jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill...

     powered munition (sometimes called an assisted torpedo).


Many navies have two weights of torpedoes:
  • A light torpedo used primarily as a close attack weapon, particularly by aircraft.
  • A heavy torpedo used primarily as a standoff weapon, particularly by submerged submarines.


In the case of deck or tube launched torpedoes, the diameter of the torpedo is obviously a key factor in determining the suitability of a particular torpedo to a tube or launcher, similar to the caliber
Caliber
In guns including firearms, caliber or calibre is the approximate internal diameter of the barrel in relation to the diameter of the projectile used in it....

 of the gun. The size is not quite as critical as for a gun, but diameter has become the most common way of classifying torpedoes.

Length, weight, and other factors also contribute to compatibility. In the case of aircraft launched torpedoes, the key factors are weight, provision of suitable attachment points, and launch speed. Assisted torpedoes are the most recent development in torpedo design, and are normally engineered as an integrated package. Versions for aircraft and assisted launching have sometimes been based on deck or tube launched versions, and there has been at least one case of a submarine torpedo tube being designed to fire an aircraft torpedo.

As in all munition design, there is a compromise between standardisation, which simplifies manufacture and logistics
Logistics
Logistics is the management of the flow of goods between the point of origin and the point of destination in order to meet the requirements of customers or corporations. Logistics involves the integration of information, transportation, inventory, warehousing, material handling, and packaging, and...

, and specialisation, which may make the weapon significantly more effective. Small improvements in either logistics or effectiveness can translate into enormous operational advantages.
Some common torpedo diameters (using the most common designation, metric or inch, and listed in increasing order of size):
  • 12.75 inch (approximately 324 mm) is the most common size for light torpedoes.
  • 15 inch torpedoes were mounted on Russia
    Russia
    Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

    n torpedo boat destroyers (TBDs) during the Russo-Japanese War
    Russo-Japanese War
    The Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...

     in 1904-1905. After the war, the Imperial Russian Navy
    Imperial Russian Navy
    The Imperial Russian Navy refers to the Tsarist fleets prior to the February Revolution.-First Romanovs:Under Tsar Mikhail Feodorovich, construction of the first three-masted ship, actually built within Russia, was completed in 1636. It was built in Balakhna by Danish shipbuilders from Holstein...

     re-armed their TBDs with 18" torpedoes.
  • 406 mm (16 inch) was the size of the earliest specialised Soviet ASW
    Anti-submarine warfare
    Anti-submarine warfare is a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines....

     torpedoes. 16 inches (406 mm) torpedo tubes were fitted to Soviet Hotel
    Hotel class submarine
    The Hotel class is the general NATO classification for a type of nuclear-powered ballistic missile submarine that was originally put into service by the Soviet Union around 1959. The Soviet designation is Project 658.-Design:...

    , Echo
    Echo class submarine
    The Echo class submarines were nuclear cruise missile submarines of the Soviet Navy built during the 1960s. Their Soviet designation was Project 659 class for the first five vessels, and Project 675 for the following twenty-nine...

     and early Delta
    Delta class submarine
    The Delta class is a class of submarines which formed the backbone of the Soviet and Russian strategic submarine fleet since its introduction in 1973...

     class submarines, often in addition to 21 inches (533.4 mm) tubes.
  • 450 mm (17.7 inch) was the standard size for light torpedoes of the Imperial Japanese Navy
    Imperial Japanese Navy
    The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

    . It was also widely used by Italian Navy (Regia Marina) during World War II; it was the common size of the torpedo used by torpedo bomber. This size is sometimes referred to as 18 inches (457.2 mm).
  • 483 mm (19 inch) was the size for the first U.S. homing torpedo, the Mark 24
    Mark 24 FIDO Torpedo
    The Mark 24 Mine was a US air-dropped passive acoustic homing anti-submarine torpedo used during the Second World War against German and Japanese submarines. It entered service in March 1943 and continued in service with the US Navy until 1948...

    , also known as Fido.
  • 533 mm (21 inch) is the most common size for heavy torpedoes, including:
    • Allied torpedoes of World War II
      World War II
      World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

    • Imperial Japanese Navy
      Imperial Japanese Navy
      The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

       submarine-fired torpedoes
    • Torpedoes of the Kriegsmarine
      Kriegsmarine
      The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...

    • NATO torpedoes
    • Some Soviet and Russia
      Russia
      Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

      n torpedoes, including the current ASW models
  • 550 mm (approximately 21.7 inches) was the standard size for French Navy
    French Navy
    The French Navy, officially the Marine nationale and often called La Royale is the maritime arm of the French military. It includes a full range of fighting vessels, from patrol boats to a nuclear powered aircraft carrier and 10 nuclear-powered submarines, four of which are capable of launching...

     torpedoes until France joined NATO and switched to 533 mm
  • 610 mm (24 inch) torpedoes, the infamous World War II Type 93
    Type 93 torpedo
    The Type 93 was a -diameter torpedo of the Imperial Japanese Navy , launched from surface ships. It is commonly referred to as the Long Lance by most modern English-language naval historians, a nickname given it after the war by Samuel E. Morison, the chief historian of the U.S...

     'Long Lance', were used by Imperial Japanese Navy destroyers and cruisers, and as the basis for some Kaiten
    Kaiten
    The Kaiten were manned torpedos and suicide craft, they were used by the Imperial Japanese Navy in the final stages of World War II.-History:...

    .
  • 650 mm (approximately 25.6 inches) is the largest torpedo diameter used by the Russian navy, such as the Type 65
    Type 65 torpedo
    The Type 65 is a torpedo manufactured in the Soviet Union/Russia. It was developed to counter the US Navy's aircraft carrier battle groups as well as to be used against large merchant targets such as supertankers...

    . Adaptors are used to fire 533 mm (21 inch) models from 650 mm tubes.


Even larger sizes of torpedo tube
Torpedo tube
A torpedo tube is a device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units installed aboard surface vessels...

, including 660 mm (26 inches), 762 mm (30 inches), and 916 mm (about 36 inches), have been installed on some nuclear submarines. These tubes are designed to be capable of firing large diameter munitions such as cruise missile
Cruise missile
A cruise missile is a guided missile that carries an explosive payload and is propelled, usually by a jet engine, towards a land-based or sea-based target. Cruise missiles are designed to deliver a large warhead over long distances with high accuracy...

s, as well as the standard 21 inch heavy torpedo.

Torpedoes used by various navies

German Navy

Modern German Navy
German Navy
The German Navy is the navy of Germany and is part of the unified Bundeswehr .The German Navy traces its roots back to the Imperial Fleet of the revolutionary era of 1848 – 52 and more directly to the Prussian Navy, which later evolved into the Northern German Federal Navy...

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  • DM2A4 heavyweight torpedo
    DM2A4
    DM2A4 Seehecht is the latest heavyweight torpedo developed by Atlas Elektronik for the German Navy, as a further update of DM2 torpedo which was released in 1976...

  • DM2A3 heavyweight torpedo
  • MU 90 lightweight impact torpedo
    MU90 Impact
    The MU90/IMPACT is an advanced lightweight anti-submarine torpedo used by navies of Germany, France, Italy, Denmark, Australia and Poland. It is designed to compete with and outperform the US-built Mark 46 in the anti-submarine role, and is also available in a special MU90 Hard Kill version for...

  • Mark 46 torpedo
    Mark 46 torpedo
    Designed to attack high-performance submarines, the Mark 46 torpedo is the backbone of the U.S. Navy's lightweight ASW torpedo inventory, and is the current NATO standard. These aerial torpedoes, such as the Mark 46 Mod 5, are expected to remain in service until the year 2015...

  • Barracuda (supercavitating torpedo)


The torpedoes used by the World War II Kriegsmarine
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...

 included:
  • G7a
    G7a torpedo
    The G7a or G7a/T1 was the standard issue Kriegsmarine torpedo during the early years of World War II.- Design :The torpedo was 53.3cm in diameter, 7.163 m in length, and with a warhead of 280 kg of Hexanite, and was standard issue for all U-boats of the war.The torpedo was of a straight-running...

     (T1)
  • G7e
    G7e torpedo
    The G7e or more appropriately the G7e/T2, G7e/T3, and G7e/T4 Falke torpedoes were, with the exception of the T4 model, the standard torpedoes for Germany during World War II...

     (T2)
  • G7e/T4 (Falke)
  • G7es
    G7es torpedo
    The G7es or Zaunkönig T-5 was a torpedo employed by German U-boats during World War II. It was known as the GNAT to the British.- Description :...

     (Zaunkönig)
  • T11
    T11 torpedo
    The T11 was a torpedo developed for German U-boats during World War II. The torpedo was electric and had an effective range of 5,700 meters at a speed of 24 knots . This torpedo employed acoustic, passive homing to find its target after a straight run of 400 meters. This evolution of the G7es...


Imperial Japanese Navy

The torpedoes used by the Imperial Japanese Navy
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 (World War II) included:
  • Type 91 torpedo
    Type 91 torpedo
    The Type 91 was an aerial torpedo of the Imperial Japanese Navy which was designed to be launched from an aircraft. It was used in the naval battles of carrier task forces in World War II.The Type 91 aerial torpedo rev.2 won the admiration of the world...

  • Type 92 torpedo
    Type 92 torpedo
    The Type 92 torpedo was a submarine-launched torpedo used by the Imperial Japanese Navy during World War II. It was in length and 21 inches in diameter. This type of torpedo was battery powered. It could deliver a 660 pound warhead at 30 knots to a target 7 kilometers away....

  • Type 93 torpedo
    Type 93 torpedo
    The Type 93 was a -diameter torpedo of the Imperial Japanese Navy , launched from surface ships. It is commonly referred to as the Long Lance by most modern English-language naval historians, a nickname given it after the war by Samuel E. Morison, the chief historian of the U.S...

     (Long Lance)
  • Type 95 torpedo
    Type 95 torpedo
    The Type 95 torpedo was a torpedo of the Imperial Japanese Navy.It was based on the formidable Type 93 torpedo but had a smaller warhead, shorter range and a smaller diameter...

  • Type 97 torpedo
    Type 97 torpedo
    The Type 97 was a diameter torpedo used by the Imperial Japanese Navy during World War II. Intended for use with Japan's Ko-hyoteki class midget submarines, the torpedo was based on the Type 93 "Long Lance" used by larger Japanese submarines, but redesigned to meet the smaller physical dimensions...

  • Kaiten
    Kaiten
    The Kaiten were manned torpedos and suicide craft, they were used by the Imperial Japanese Navy in the final stages of World War II.-History:...


Japan Maritime Self-Defense Force

Modern Japan Maritime Self-Defense Force
Japan Maritime Self-Defense Force
The , or JMSDF, is the naval branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. It was formed following the dissolution of the Imperial Japanese Navy after World War II....

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  • Type 72 torpedo
  • Type 73 Light Weight torpedo
  • Type 80 torpedo (G-RX1)
  • Type 89 torpedo (G-RX2)
    Type 89 torpedo
    The Type 89 torpedo is a Japanese submarine-launched homing torpedo produced by Mitsubishi heavy industries. It was developed in the early 1980s, and is similar in capabilities to the U.S. Mark 48 ADCAP torpedo. It entered service in the 1990s and is currently carried aboard the Harushio, Oyashio...

  • Type 97 Light Weight Torpedo (G-RX4)

Indian Navy

  • Advanced Experimental Torpedo (lightweight torpedo)
  • Varunastra (heavyweight torpedo)
  • Thakshak (heavy weight torpedo)

Royal Navy

The torpedoes used by the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 include:
  • Spearfish torpedo
    Spearfish torpedo
    The Spearfish torpedo is the heavy torpedo used by the submarines of the Royal Navy. It can be guided by wire or by autonomous active or passive sonar, and provides both anti-submarine warfare and anti-surface ship warfare capability.It replaces the unreliable Tigerfish torpedo, which was...

  • Stingray torpedo
  • Tigerfish
    Mark 24 Tigerfish
    The Mk 24 Tigerfish torpedo was a heavyweight acoustic homing torpedo used by the Royal Navy for several years. The early Mod0 and Mod1 variants were unreliable and unsuccessful, and were issued to the RN even though they failed Fleet Weapon Acceptance...

  • Mark 8, designed in 1925, last used in action in 1982

Russian Navy

Torpedoes used by the Russian Navy include:
  • Type 53 torpedo
    Type 53 torpedo
    Type 53 is the common name for a family of 53 cm torpedoes manufactured in Russia, starting with the 53-27 torpedo and continuing to the modern UGST....

  • Type 65 torpedo
    Type 65 torpedo
    The Type 65 is a torpedo manufactured in the Soviet Union/Russia. It was developed to counter the US Navy's aircraft carrier battle groups as well as to be used against large merchant targets such as supertankers...

  • APR-3E torpedo
    APR-3E torpedo
    The APR-3E airborne light ASW acoustic homing torpedo is designed by Russian Tactical Missiles Corporation JSC to engage current and future submarines in at depth from the surface down to 800 metres at speed of up to 43+ kts, and it is a replacement for earlier APR-2 light antisubmarine acoustic...

  • VA-111 Shkval torpedo

U.S. Navy

The major torpedoes in the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 inventory are:
  • the Mark 46 lightweight
    Mark 46 torpedo
    Designed to attack high-performance submarines, the Mark 46 torpedo is the backbone of the U.S. Navy's lightweight ASW torpedo inventory, and is the current NATO standard. These aerial torpedoes, such as the Mark 46 Mod 5, are expected to remain in service until the year 2015...

  • the Mark 48 heavyweight torpedo
    Mark 48 torpedo
    The Mark 48 and its improved ADCAP variant are heavyweight submarine-launched torpedoes. They were designed to sink fast, deep-diving nuclear-powered submarines and high-performance surface ships.-History:...

  • the Mark 50 advanced lightweight
    Mark 50 torpedo
    The Mark 50 torpedo is a U.S. Navy advanced lightweight torpedo for use against fast, deep-diving submarines. The Mk-50 can be launched from all anti-submarine aircraft and from torpedo tubes aboard surface combatant ships. The Mk-50 was intended to replace the Mk-46 as the fleet's lightweight...

  • the Mark 54 Lightweight Hybrid Torpedo
    Mark 54 LHT
    The Mark 54 Lightweight Hybrid Torpedo is a standard 12.75 inch antisubmarine warfare torpedo used by the United States Navy.- Development :...

  • the Mark 60 Encapsulated Torpedo (CAPTOR)
    CAPTOR mine
    The CAPTOR is the United States Navy's primary anti-submarine naval mine. This deep-water mine is laid by ship, aircraft or submarine, and is anchored to the ocean floor. When its sonar detects a hostile submarine, the CAPTOR launches a Mark 46 torpedo.The name CAPTOR is short for enCAPsulated...

A moored anti-submarine mine that releases a torpedo as its warhead

See also

  • List of torpedoes
  • Missile guidance
    Missile guidance
    Missile guidance refers to a variety of methods of guiding a missile or a guided bomb to its intended target. The missile's target accuracy is a critical factor for its effectiveness...

  • Human torpedo
    Human torpedo
    Human torpedoes or manned torpedoes are a type of rideable submarine used as secret naval weapons in World War II. The basic design is still in use today; they are a type of diver propulsion vehicle....

  • Bangalore Torpedo
    Bangalore torpedo
    A Bangalore torpedo is an explosive charge placed on the end of a long, extendible tube. It is used by combat engineers to clear obstacles that would otherwise require them to approach directly, possibly under fire...

  • Autonomous Underwater Vehicle
    Autonomous Underwater Vehicle
    An autonomous underwater vehicle is a robot which travels underwater without requiring input from an operator. AUVs constitute part of a larger group of undersea systems known as unmanned underwater vehicles, a classification that includes non-autonomous remotely operated underwater vehicles...


External links

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