Torpedo tube

A torpedo tube is a cylinder shaped device for launching torpedoes.[1]

There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboard surface vessels. Deck-mounted torpedo launchers are usually designed for a specific type of torpedo, while submarine torpedo tubes are general-purpose launchers, and are often also capable of deploying mines and cruise missiles. Most modern launchers are standardised on a 12.75-inch (324 mm) diameter for light torpedoes (deck mounted aboard ship) or a 21-inch (533 mm) diameter for heavy torpedoes (underwater tubes), although other sizes of torpedo tube have been used: see Torpedo classes and diameters.

Torpedo tube on holland 1
The torpedo tube on HMS Holland 1

Submarine torpedo tube

A submarine torpedo tube is a more complex mechanism than a torpedo tube on a surface ship, because the tube has to accomplish the function of moving the torpedo from the normal atmospheric pressure within the submarine into the sea at the ambient pressure of the water around the submarine. Thus a submarine torpedo tube operates on the principle of an airlock.

Torpedo tube operation

Submarine torpedo tube
A simplified diagram of a submarine torpedo tube

The diagram on the right illustrates the operation of a submarine torpedo tube. The diagram is somewhat simplified but does show the working of a submarine torpedo launch.

A torpedo tube has a considerable number of interlocks for safety reasons. For example, an interlock prevents the breech door and muzzle door from opening at the same time.

The submarine torpedo launch sequence is, in simplified form:

Torpedo tube breech doors of USS Nautilus
Submarine torpedo tube breech doors of USS Nautilus in their closed position
MU90 Impact triple launcher onboard F221 Hessen, a modern Sachsen-class frigate of the German Navy
Torpdorohr eines Torpedoschnellbootes
Rear torpedo tube of a former German Jaguar class Schnellboot (MTB)
FS Redoutable torpilles
Torpedo tubes of the French SNLE Redoutable: French submarines use pistons to push the torpedo outside the tube, instead of blowing it out with compressed air.
  1. Open the breech door in the torpedo room. Load the torpedo into the tube.
  2. Hook up the wire-guide connection and the torpedo power cable.
  3. Shut and lock the breech door.
  4. Turn on power to the torpedo. A minimum amount of time is required for torpedo warmup. Fire control programs are uploaded to the torpedo.
  5. Flood the torpedo tube. This may be done manually or automatically, from sea or from tanks, depending on the class of submarine. The tube must be vented during this process to allow for complete filling and eliminate air pockets which could escape to the surface or cause damage when firing.
  6. Open the equalizing valve to equalize pressure in the tube with ambient sea pressure.
  7. Open the muzzle door. If the tube is set up for Impulse Mode the slide valve will open with the muzzle door. If Swim Out Mode is selected, the slide valve remains closed. The slide valve allows water from the ejection pump to enter the tube.
  8. When the launch command is given and all interlocks are satisfied, the water ram operates, thrusting a large volume of water into the tube at high pressure, which ejects the torpedo from the tube with considerable force. Modern torpedoes have a safety mechanism that prevents activation of the torpedo unless the torpedo senses the required amount of G-force.
  9. The power cable is severed at launch. However, if a guidance wire is used, it remains connected through a drum of wire in the tube. Torpedo propulsion systems vary but electric torpedoes swim out of the tube on their own and are of a smaller diameter. 21" weapons with fuel-burning engines usually start outside the tube.
  10. Once outside the tube the torpedo begins its run toward the target as programmed by the fire control system. Attack functions are programmed but with wire guided weapons, certain functions can be controlled from the ship.
  11. For wire-guided torpedoes, the muzzle door must remain open because the guidance wire is still connected to the inside of the breech door to receive commands from the submarine's fire-control system. A wire cutter on the inside of the breech door is activated to release the wire and its protective cable. These are drawn clear of the ship prior to shutting the muzzle door.
  12. The drain cycle is a reverse of the flood cycle. Water is returned to the ship's tanks and can be moved as necessary. The tube must be vented to completely drain the tube since it is usually by gravity.
  13. Open the breech door and remove the remnants of the torpedo power cable and the guidance wire basket. The tube must be wiped dry to prevent a buildup of slime. This process is called "diving the tube" and tradition dictates that "ye who shoots, dives".
  14. Shut and lock the breech door.

Spare torpedoes are stored behind the tube in racks.

Speed is a desirable feature of a torpedo loading system, but safety is paramount. There are various manual and hydraulic handling systems for loading torpedoes into the tubes. Prior to the Ohio class, US SSBNs utilized manual block and tackle which took about 15 minutes to load a tube. SSNs prior to the Seawolf class used a hydraulic system that was much faster and safer in conditions where the ship needed to maneuver.

Lancement torpille L3 2
The French destroyer Kersaint prepares to launch a torpedo in 1970

The German Type 212 submarine uses a new development of the water ram expulsion system, which ejects the torpedo with water pressure to avoid acoustic detection.

See also


  1. ^ The New York Times

External links

British F-class submarine

The F class submarine was built for the Royal Navy as a coastal submarine based on the doubled hulled V class submarine (World War I) with very few minor improvements. The only important improvement was the addition of a stern torpedo tube. The F class were ordered as a successor to the E class submarine, but only three were built out of the ten ordered.

During World War I, the F class submarine was primarily used for coastal defence.

Only three of the class were built, the first F1 being built at Chatham. All three of the class survived the war and ended their service as training boats at Campbeltown. F1 and F3 were scrapped in 1920, F2 was sold in 1922.

German Type UE I submarine

The German Type UE I submarine was an ocean-going single-hull submarine with saddle tanks built by AG Vulkan in Hamburg and Kaiserliche Werft Danzig. The Type UE I was equipped with two six-cylinder Benz engines for 900 horsepower (670 kW) for a surface top speed of 9.6 knots (17.8 km/h; 11.0 mph) to 10.6 knots (19.6 km/h; 12.2 mph). Armed with a single torpedo tube forward and aft, plus one 8.8 cm (3.5 in) SK L/30 deck gun (U-72 received a 10.5 cm (4.1 in) SK L/45 gun in 1917), its main weapon were the 38 mines in two minelaying tubes. The boats were crewed by four officers and 28 men for a complement of 32.

Guangdong Fleet

The Guangdong Fleet (Chinese: 廣東水師) was the smallest of China's four regional fleets during the second half of the nineteenth century. The fleet played virtually no part in the Sino-French War (August 1884–April 1885), but several of its ships saw action in the Sino-Japanese War (1894–5).


HMS A1 was the Royal Navy's first British-designed submarine, and their first to suffer fatal casualties.

She was the lead ship of the first British A-class submarines and the only one to have a single bow torpedo tube. She was actually sunk twice: first in 1904 when she became the first submarine casualty, with the loss of all hands; however, she was recovered, but sank again in 1911, this time when she was unmanned. The wreck was discovered in 1989 and is now a protected wreck.

HMS Stygian

HMS Stygian (pennant number P249) was a S-class submarine of the British Royal Navy, and the only ship so far to bear the name. The boat is listed as being a member of the fourth group, although she had the external stern torpedo tube fitted as in the third group.

After an eventful career in the Pacific during the Second World War, she was sold to be broken up for scrap on 28 October 1949, and finally scrapped by Metal Industries of Ardgour in August 1950.

Italian cruiser Pietro Micca

Pietro Micca was the first torpedo cruiser built by the Italian Regia Marina, and one of the first vessels of the type to built by any navy. She was laid down in February 1875, launched in August 1876, and completed in July 1877. Armed with a single 16-inch (410 mm) torpedo tube, she proved to be unable to reach the projected speed of 17 knots (31 km/h; 20 mph), and so she did not see much active service. She remained in the Regia Marina's inventory until 1893, but spent most of her 16-year life in the reserve.

Long-Term Mine Reconnaissance System

The AN/BLQ-11 autonomous unmanned undersea vehicle (formerly the Long-Term Mine Reconnaissance System (LMRS)) is a torpedo tube-launched and tube-recovered underwater search and survey unmanned undersea vehicle (UUV) capable of performing autonomous minefield reconnaissance as much as 200 kilometers (120 mi) in advance of a host Los Angeles-, Seawolf-, or Virginia-class submarine.

LMRS is equipped with both forward-looking sonar and side-scan synthetic aperture sonar.

Boeing concluded the detailed design phase of the development project on 31 August 1999.

In January 2006, USS Scranton successfully demonstrated homing and docking of an LMRS UUV system during at-sea testing.

Mark 27 torpedo

The Mark 27 torpedo was the first of the United States Navy 19-inch (48-cm) submarine-launched torpedoes. This electrically-propelled torpedo was 125 inches (3.175 m) long and weighed 1174 pounds (534 kg). The torpedo employed a passive acoustic guidance system and was intended for both submarine and surface targets. Nicknamed "Cutie" by submarine crews, the Mark 27 entered service in 1943 as a defensive weapon. The torpedo was classified as obsolete in the 1960s.The Mark 27 was essentially a Mark 24 mine which had been modified for submarine launching in a 21-inch submerged torpedo tube by the addition of 1" wood guide studs mounted on the torpedo's outer shell.

Mark 32 Surface Vessel Torpedo Tubes

The Mark 32 Surface Vessel Torpedo Tubes (Mk 32 SVTT) system is a torpedo launching system designed for the United States Navy. The Mark 32 has been the standard anti-submarine torpedo launching system aboard United States Navy surface vessels since its introduction in 1960, and is in use aboard the warships of several other navies.Most versions (referred to as modifications or mods) are triple-tube sets that can be rotated or trained to face a target. The exception is the Mod 9 sets, which only have two tubes and are fixed in position. The Mark 32 can fire 12.75-inch (324 mm) torpedoes of the Mark 44, Mark 46, Mark 50 (from the Mod 17 tubes onwards), and Mark 54 designs, and can be modified to use other torpedoes (such as the MU90 Impact aboard Royal Australian Navy frigates, or Royal Navy units using Sting Ray torpedoes). The tubes are designed to be fired remotely, but manual firing controls are fitted as a backup to all but the Spruance-class destroyer's Mod 15 sets, as all aspects of the tubes' operation are controlled remotely. The launch is powered by compressed air in a rear flask, which also doubles as each tube's breech, and the torpedoes are fire-and-forget weapons.The launcher can be made from fibreglass, or with a fibreglass liner encased in metal. The tubes were designed to be weatherproof and capable of storing torpedoes for long periods, but this is only practical with regular maintenance. Each triple-tube set weighs around 2,230 pounds (1,010 kg) unloaded, with variations between mods.

Oriani-class destroyer

The Oriani class (also known as the Poeti class), were a group of four destroyers built for the Italian Navy in the late 1930s. They were a repeat of the Maestrale-class destroyers, but had increased machinery power and a different anti-aircraft armament. The increase in power, however, disappointed in that there was only a marginal speed improvement. The obsolete 40 mm/39 pom-pom anti-aircraft guns were finally discontinued, being replaced by extra 13.2 mm (0.52 in) machine guns; otherwise armament was unchanged. Significant upgrades were made to the weapons systems of the two ships that survived Matapan, similar to those made to the Maestrales. One torpedo tube mounting was replaced by two 37 mm (1.5 in)/54 guns; 20 mm (0.79 in) cannon, a 120 mm star-shell gun and depth charge throwers were also installed. Before the end of the war, one ship, Oriani had German Seetakt radar and an additional 20 mm cannon.

RPK-2 Vyuga

The RPK-2 Vyuga (Russian: РПК-2 Вьюга, blizzard; NATO reporting name: SS-N-15 Starfish), also designated as 81R, is a Soviet submarine-launched, nuclear-armed anti-submarine missile system, launched exclusively through 533mm torpedo tubes. The system was designed in Sverdlovsk, Russian SFSR in the 1960s.

Analogous to the now retired Subroc missile carried by US Navy submarines, it is designed to be fired from a 533 mm (21 in) torpedo tube. It is boosted by a choice of mechanisms depending on model before clearing the water, firing a solid fuel rocket and delivering its payload up to 45 km (28 mi) away. The payload ranges from a simple depth charge to a 200 kt thermonuclear warhead.

RPK-6 Vodopad/RPK-7 Veter

RPK-6 Vodopad (Russian: РПК-6 Водопад, "waterfall") is a Soviet 533 mm anti-submarine missile deployed operationally since 1981.RPK-7 Veter (Russian: РПК-7 Ветер, "wind") is a 650 mm version, deployed operationally since 1984.Both missiles are given the same United States Navy designation SS-N-16 and NATO designation Stallion.Both missiles are torpedo-tube launched, with a solid-fuel rocket engine to power them above the surface. Both missiles are dual-role; they can be armed with either a 400 mm anti-submarine torpedo or a nuclear depth charge.The Veter's increased range of approximately 100 kilometers was an impressive boost over its predecessor the SS-N-15 Starfish, which could only reach half the distance.

SMS Vulkan

SMS Vulkan was a U-boat salvage tug in the Kaiserliche Marine laid down in 1907 and commissioned 1908. The ship displaced 1595 tons and had a top speed of 12 knots.

The famous U-boat ace Max Valentiner served as salvage officer on Vulkan in early 1911. On 17 January 1911, he and the crew saved all 30 men from U-3 by getting them out of the torpedo tube after it sank near Kiel harbour in Heikendorfer Bay because of an unclosed valve in the ventilation shaft. Amongst the saved crew was Otto Weddigen, the later commander of U-9 and Paul Clarrendorf, the commander of U-boot-Abnahme-Kommando in Kiel which enlisted u-boat crews.

Vulkan is also famous for salvaging two U-boats, U-30 on 27 August 1915 and UC-45 on 17 September 1917.

Vulkan was taken out of service 11 November 1918 and surrendered to the British forces together with the bigger salvage tug, SMS Cyclop. Being pulled to Harwich it was sunk 6 April 1919 in position 54°54′N 06°18′E.

Somers-class destroyer

The Somers-class destroyer was a class of five 1850-ton United States Navy destroyers based on the Porter class. They were answers to the large destroyers that the Japanese navy was building at the time, and were initially intended to be flotilla leaders. They were laid down 1935-1936 and commissioned 1937-1939. They were built to round out the thirteen destroyers of 1,850 tons standard displacement allowed by the tonnage limits of the London Naval Treaty, and were originally intended to be repeat Porters. However, new high-pressure, high-temperature boilers became available, allowing the use of a single stack. This combined with weight savings (including elimination of reload torpedoes) allowed an increase from two quadruple centerline torpedo tube mounts to three. However, the Somers class were still over-weight and top-heavy. This was the first US destroyer class to use 600 psi (4,100 kPa) steam superheated to 850 °F (454 °C), which became standard for US warships built in the late 1930s and World War II.Like the Porters, they were originally built with eight 5-inch (127 mm)/38 caliber guns in four single purpose (surface action only) twin mounts. Anti-aircraft (AA) protection was initially provided by two quadruple 1.1-inch (28 mm) machine cannon mounts and two .50-caliber machine guns. The 1.1-inch mounts were intended to compensate for the 5-inch guns' lack of AA capability; in the 1930s this was thought to be sufficient. As with the Porters, the Somers' main armament was reduced to six guns (and replaced with dual-purpose mounts totaling five guns in Davis and Jouett) during World War II, with the anti-aircraft armament replaced by 40 mm Bofors and 20 mm Oerlikon guns and the torpedo armament reduced to eight tubes. In two ships (Davis and Jouett) the torpedo armament was eliminated to maximize the number of 40 mm guns.All of the class served in World War II, initially on Neutrality Patrols in the Atlantic and Caribbean. In early 1942 Warrington and Sampson were transferred to the Southeast Pacific Area, where they primarily escorted convoys between the Panama Canal and the Society Islands. In mid-1943 these two were transferred to the Southwest Pacific Area and operated near New Guinea and in the Solomon Islands; the others operated off Brazil and in the Caribbean and South Atlantic. In May 1944 all were transferred to the North Atlantic to support the invasion of Normandy, which Somers, Davis, and Jouett were directly involved in. Somers and Jouett supported the invasion of southern France in August. Warrington foundered in a hurricane in the Bahamas in September 1944. The others escorted convoys for the remainder of the war, and were scrapped by 1947.

Spanish submarine Peral

Peral was one of the first electric battery-powered submarines, built by the Spanish engineer and sailor Isaac Peral for the Spanish Navy. The first fully capable military submarine, and the first electric battery-powered submarine, she was launched 8 September 1888. She had one torpedo tube (and two torpedoes) and an air regeneration system. Her hull shape, propeller, periscope, torpedo launcher and cruciform external controls anticipated later designs. Her underwater speed was 3 kn (5.6 km/h; 3.5 mph). With fully charged batteries, she was the fastest submarine yet built, with underwater performance levels (except for range) that matched those of First World War U-boats for a very short period, before her batteries began to drain. For example, the SM U-9, a pre-war German U-boat built in 1908, had an underwater speed of 8.1kn, and an underwater range of 150 km (81 nmi) at 5.8kn, before having to resurface to recharge her batteries. Although advanced in many ways, Peral lacked a means of charging batteries while underway, such as an internal combustion engine, thus had a very limited endurance and range. In June 1890, Peral's submarine launched a torpedo while submerged. It was also the first submarine to incorporate a fully reliable underwater navigation system. However, conservatives in the Spanish naval hierarchy terminated the project despite two years of successful tests. Her operational abilities have led some to call her the first U-boat.Peral was withdrawn from service in 1890 and is now preserved at the Cartagena Naval Museum.

Type 95 torpedo

The Type 95 torpedo was a torpedo of the Imperial Japanese Navy.

It was based on the Type 93 torpedo (Long Lance) but mod 1 had a smaller 405 kg (893 lb) and mod 2 had a larger 550 kg (1,210 lb) warhead, shorter range and a smaller diameter. It was intended to be fired from a standard 533 mm (21.0 in) torpedo tube of a submerged submarine.

Its range was (for the mod 1) 9,000 m (9,800 yd) at 49–51 kn (91–94 km/h), or 12,000 m (13,000 yd) at 45–47 kn (83–87 km/h),

which was about three times the range of the American Mark 14 at the same speed.

The Type 95 was the fastest torpedo in common use by any navy at the time. Its warhead size was the largest of any submarine torpedo, and second only to the Type 93 used by Japanese surface ships. Its engine was a kerosene-oxygen wet-heater rather than the compressed air used by most torpedo types at the time.

USS Lancetfish (SS-296)

USS Lancetfish (SS-296), a Balao-class submarine, was the only ship of the United States Navy to be named for the lancetfish (Alepisaurus ferox), a large voracious, deep sea fish having long lancetlike teeth and a high long dorsal fin.

Her keel was laid down on 30 September 1942 by Cramp Shipbuilding Company of Philadelphia. She was launched on 15 August 1943 sponsored by Miss Beatrice P. Barker, towed to Boston Navy Yard 19 May 1944 for completion, and commissioned 12 February 1945 with Commander Ellis Burton Orr in command.

While tied up alongside Pier 8, Lancetfish flooded through an aft torpedo tube and sank 15 March 1945. She was raised eight days later and decommissioned 24 March. Assigned to the Atlantic Reserve Fleet in uncompleted condition, she was transferred to the First Naval District 27 February 1947 and was assigned to the New London Group 9 December 1952. She was struck from the Naval Vessel Register on 9 June 1958 and sold for scrap for $57,189 on 20 August 1959 having never gone to sea on patrol, to Yale Waste Co., Boston, Mass.

Although Lancetfish was commissioned at the time of her sinking, she never saw active service, and she is not counted among the 52 American submarines lost during World War II.

USS Sennet (SS-408)

USS Sennet (SS-408) was a Balao-class submarine, a ship of the United States Navy named for the sennet, a barracuda.

Sennet was laid down on 8 March 1944 by the Portsmouth Navy Yard in Kittery, Maine, launched on 6 June 1944, sponsored by Mrs. Roscoe W. Downs, and commissioned on 22 August 1944, Commander George E. Porter in command.

Sennet was fitted out by 18 September. She held training exercises and torpedo-tube testing off the coast of Connecticut and Rhode Island until 22 October. The submarine then tested mines and torpedoes for the Mine Warfare Test Station, Solomons Island, Md. On 11 November, Sennet proceeded to the operations area off Balboa, C. Z. and conducted further training exercises. The submarine departed Balboa on 29 November for Pearl Harbor and arrived there on 16 December 1944.

Sennet's topside armament was increased to two 5-inch (130 mm) guns, two 40 millimeter guns, and three .50 caliber machine guns before departing Pearl Harbor for her first war patrol on 5 January 1945.

Vauquelin-class destroyer

The Vauquelin-class large destroyers (contre-torpilleurs) of the French Navy were laid down in 1930 and commissioned in 1931. They were very similar to the previous Aigle class, the only differences being a single extra torpedo tube and the ability to carry naval mines. The class saw action in World War II.


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