British 21-inch torpedo

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1956, the complex wire guidance system was transferred to the "Grog" program. This would be simplified, improved, and the first production units of the Mark 23 Grog were delivered in 1959. The Mark 23 was fitted with a 10,000 m (11,000 yd) outboard dispenser that contained a control wire to guide the weapon. Wire guidance was optional, with the control wire spool being a separate module which remained inside the launch tube. An operator onboard the submarine would listen to the torpedo's hydrophones, guiding the weapon past decoys and countermeasures. Entered service in 1966 although already obsolescent, considering the common speeds of nuclear-propelled submarines of the era. According to one report, the weapon did not become fully operational until 1971, and served until 1987, which is when all stocks of the Mark 24 Tigerfish were converted to Mod 2.

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single speed of 20 knots, and the E variant had a dual-speed mode of 15 knots and 24 knots, for target search and subsequent autonomously-switched attack run. In the E configuration, the torpedo was designed to have a total endurance of 20,000 yd (18,000 m) at the 15 knot speed, and 6,000 yd (5,500 m) upon switching to the 24 knot speed. A total of 75 units of the Mark 20E were produced, with trial samples being distributed to the

1118:-augmented propulsion was considered, but its implementation required too many alterations to be practical. The final version of what would have become Mark IX*** took up the extra space by enlarging the warhead to 930 lb (420 kg) of Torpex. None were in service by the end of the war in 1945, by which time the enlarged warhead became unnecessary. The Mark IX torpedo remained in service throughout the 1960s. 1086: 883: 902: 1542:. The warhead was removed and replaced with a sealed cargo capsule. Like other such vehicles of the type, the "Archimedes" could beach itself in a controlled manner, allowing frogmen or other clandestine agents to open the capsule and retrieve its contents. The vehicle could also be directly piloted by a frogman, with variable speeds, functioning as an underwater tug and 1240:

The weapon exploded inside the launch tube, simultaneously blowing out the bow caps as well as the rear hatch of the launch tube. A blast of debris and dense carbon dioxide were propelled into the submarine. Two officers and ten seamen were killed instantly, six from the initial blast and six more by asphyxiation from the ejected gases. One more victim, a doctor from the

1244:, subsequently perished in an effort to rescue the crew from the submarine. The submarine sank in shallow water due to flooding from the blown-open launch tube. Ultimately the accident caused enough damage to have the submarine taken permanently out of service. Following this accident, a second Mark 12 Fancy exploded at the Arrochar torpedo range in 1221:

was used, in an effort to adapt it to HTP propulsion. The "Ferry" was supposed to be a surface-running torpedo with a gyroscopically-guided search pattern. Prototypes of the weapon were ready in 1953, except for the pattern-running feature, which was then omitted and the weapon was redesignated as "Fancy". In 1954, several prototypes were issued to

1866:(AGC) circuit had been replaced by a silicon diode, following an instruction by RN stores that all germanium diodes had to be replaced by more modern silicon diodes. The silicon diode's different characteristics caused the AGC circuit to fail. Once the mistake was found, replacing the diode with the original type cured the problem. 1239:

in Portland Harbor, preparing to make way to Stage II trials of the "Fancy". Crewmen on the submarine were in the process of loading one of the prototype torpedoes into a launch tube, when the stop valve on the weapon was accidentally opened, triggering the release of reactant in its propulsion unit.

63:

The first British 21-inch torpedo came in two lengths, "Short" at 17 ft 10.5 in (5.45 m), and "Long" at 23 ft 1.25 in (7.04 m). The explosive charge was 200 lb (91 kg) of guncotton, increased later to 225 lb (102 kg). The torpedoes were first deployed

1880:

The Mark 24 Tigerfish was a high-speed, long-range, wire-guided torpedo originally developed under Project Ongar. The staff requirement for this weapon was written in 1959 and the weapon was expected to enter service in the mid-1960s, with an in-service target date of 1969. Initial production rounds

1605:

aircraft in an anti-submarine role, originally conceived in 1947. Development commenced in 1949, and a final design was selected in 1954, delivering functional prototypes with a speed of 30 knots. By this time several of the aircraft capable of carrying a 21-inch torpedo were in the process of being

1220:

during the Second World War. At first codenamed "Ferry", then "Fancy", the Mark 12 never moved past the prototype stage. The design was conceived in 1945, after the end of the war in Europe, with the arrival of technical documentation from Germany. For economical reasons, the Mark VIII torpedo body

1473:

and shared elements of its design. The development program was elevated in scope and priority after the cancellation of the Mark 21 Pentane. Two variants were developed: the Mark 20S ("Submarine") for use by submarines, and a larger Mark 20E ("Escort") for use by surface ships. The S variant had a

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The Mark 20 was a passive-seeker battery-powered torpedo which was initially conceived in 1945, as a 21-inch development of the 18-inch "Dealer" project for a parachute-dropped ASW weapon, conceived in 1943. At the end of the Second World War the "Dealer" project was renamed "Dealer A" and became

1821:

A wire-guided version of the Mark 20 with a dual-speed mode, for target approach and attack run. Wire guidance had been worked on for the "Bidder" project from its inception, and the earliest prototypes of the "Grog" were available for testing in 1955. After the "Mackle" project was cancelled in

554:

Range and speed: 4,500 yd (4,100 m) at 44.5 kn (82.4 km/h), 6,000 yd (5,500 m) at 35 kn (65 km/h), 11,000 yd (10,000 m) at 29 kn (54 km/h), 15,000 yd (14,000 m) at 25 kn (46 km/h), 18,000 yd (16,000 m) at

1888:

The Mark 24 Tigerfish had a protracted development program, beginning with the initial two models, then studies to tackle its deficiencies, and finally a Marconi Consolidation Program (nicknamed "Get Well") undertaken in the late 1980s to convert existing units to the Mod 2 standard.

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was left as the sole operator and the project was cancelled in 1958 due to cost considerations and an assessment that the weapon lacked the speed to counter upcoming nuclear submarine designs. The seeker head development was transferred to Project Ongar, which would later become the

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The Mark IX was designed circa 1928 and first deployed in 1930. The design was considerably improved by 1939. The Mark IX was a larger and longer-range sibling to the Mark VIII, employing a very similar four-cylinder radial kerosene-air burner-cycle propulsion system. Used on the

1525:

gearing, and the earlier mechanical course and depth setting devices were replaced by electronic ones, receiving data from the launch console via an umbilical link. These improvements, together with new batteries common to the Mark 23, slightly increased torpedo endurance.

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prototype, with the primary function of an underwater tug. Supplementary batteries were added, increasing the vehicle's range. Ultimately the Mark 20 torpedo body would be selected for a similar vehicle, which went into series production.

1113:

in 1939. In 1943 it was decided to further improve the Mark IX** by lengthening it 12 inches (30.5 cm), and the weapon mass limit to 4,000 lb (1,800 kg), up to the capacity of torpedo tubes and ships under construction.

1546:. The prototype of the "Archimedes" was a larger Mark 23 torpedo, but the series-production version utilized a Mark 20 body. Captain John Moore was quoted as referring to the Mark 20 as "a useless device for its original task". 1533:

of the Royal Navy developed a variant of the Mark 20 which he dubbed "Archimedes". This was an underwater, submarine-launched, equipment delivery vehicle designed to support clandestine operations, particularly those of the

1513:, but as of 1963, this design consideration would also be eliminated. The final version of the Mark 20 Bidder was referred to as the Mark 20 Improved. The Mark 20 Improved entered service in 1971, originally developed by 1109:, and later destroyer classes. Also replaced the old Mark VII torpedo in some 8 in (200 mm) gun cruisers during the war. The principal version used during the Second World War was the Mark IX**, first issued to 2127: 1490:

helicopter was deemed more desirable. The deficient speed of the Mark 20 was also a motivating factor. As a result, the E variant project was eliminated, leaving only the S variant. This led to several of the

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Notes: Two warhead options were available, the IVa (400 lbs) and the IVb (500 lbs). Depth keeping was extremely unreliable at the 44.5-knot speed setting, prompting a suggestion to limit the top speed to 35

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Range and speed (surface vessel variant): 8,000 yd (7,300 m) at 35 kn (65 km/h), 10,000 yd (9,100 m) at 29 kn (54 km/h), 13,500 yd (12,300 m) at 25 kn

525:

Range and speed: 4,500 yd (4,100 m) at 44.5 kn (82.4 km/h), 15,000 yd (14,000 m) at 25 kn (46 km/h), 18,000 yd (16,000 m) at 21 kn (39 km/h)

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classes of frigates. As of 1958, the E variant was still not ready for service due to problems with its programming, and the prospect of a medium-range ASW torpedo being carried by the upcoming

1046:. This is the only sinking of a surface ship by a nuclear-powered submarine in wartime and the second (of three) sinkings of a surface ship by any submarine since the end of World War II. The 1631:(VSEL) as a private venture. The project was cancelled in 1956, but the wire guidance technology was transferred to the Mark 20 Bidder, contributing to the development of the Mark 23 Grog. 939:. The principal World War II version was the improved Mark VIII**, 3,732 being fired by September 1944 (56.4% of the total number). The torpedo was still in service with the 558:

Notes: Four speed settings and an improved gyro control gear. The Mark IV* was outfitted at the factory with either a 44.5-knot or a 35-knot high speed setting, but not both.

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provided to the UK during the early part of the Second World War. The running speed was reduced from 45 kn (83 km/h) (over 3,000 yards) for better reliability.

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The Mark IV torpedo was the principal British torpedo of World War I. Designed 1912, initially available 1915, adopted for service 1916. Used by destroyers,

1025:

with four Mark VIII** torpedoes. This remains the only historically acknowledged intentional sinking of one submarine by another while both were submerged.

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Electric battery-powered torpedo with a 710 lb (322 kg) TNT warhead. It entered service during the Second World War and was used by destroyers.

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Range and speed (submarine variant): 6,000 yd (5,500 m) at 40 kn (74 km/h), 9,500 yd (8,700 m) at 30 kn (56 km/h)

30:

Torpedoes of 21-inch caliber were the largest torpedoes in common use in the RN. They were used by surface ships and submarines; aircraft used smaller

874:

The power came from the use of oxygen-enriched air, though torpedo stocks were converted to run on normal air at the start of the Second World War.

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classes) never being fitted with torpedo tubes or having them removed. As of 1959, the only destroyer class projected to carry the Mark 20 was the

3022: 307: 1248:, Scotland. As a consequence of these accidents, and the perceived hazardous nature of HTP propulsion, the program was cancelled in 1959. 1180:

Range and speed: 11,000 yd (10,000 m) at 41 kn (76 km/h), 15,000 yd (14,000 m) at 35 kn (65 km/h)

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Range and speed: 11,000 yd (10,000 m) at 36 kn (67 km/h), 14,000 yd (13,000 m) at 30 kn (56 km/h)

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Range and speed: 5,000 yd (4,600 m) at 45.6 kn (84.5 km/h), 7,000 yd (6,400 m) at 41 kn (76 km/h)

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Range and speed: 10,500 yd (9,600 m) at 36 kn (67 km/h), 13,500 yd (12,300 m) at 30 kn (56 km/h)

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Range and speed: 12,000 yd (11,000 m) at 16 kn (30 km/h), 1,000 yd (910 m) at 27 kn (50 km/h)

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The Mark II, chiefly used by destroyers, entered service in 1914. Apart from some older British ships, it was used with the old US (

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Range and speed: 7,500 yd (6,900 m) at 16 kn (30 km/h), 1,000 yd (910 m) at 27 kn (50 km/h)

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further branched out into the 21-inch "Bidder" and 18-inch "Dealer B" projects. Thus, the Mark 20 was developed alongside the

863:

The Mark VII was issued for use on the British heavy cruisers, i.e. cruisers with 8-inch guns. Designed in the mid-1920s the

1885:, the first Tigerfish (Mod 0) entered deployment in 1983. All variants of the Tigerfish were removed from service in 2004. 1628: 1514: 1851:

During 1973, all of the RN torpedoes had to be taken out of service as the control system was failing at extreme range.

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were delivered in 1974, and a production order was made in 1977. Affected by the budgetary constraints of the

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Notes: Retrofitted older torpedoes in service during the Second World War. Issued to older warships and

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The Royal Navy, 1930-2000; excerpt, The Royal Navy and the Challenge of the Fast Submarine, 1944-1954

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The Royal Navy, 1930-2000; excerpt, The Royal Navy and the Challenge of the Fast Submarine, 1944-1954

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of the Royal Navy experimented with a sample of the torpedo body. Royal Navy engineers aboard the

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design torpedo. It was used from 1927 on all submarines, beginning with the later versions of the

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After months of investigation, it was discovered that the fault lay in the Guidance Unit made by

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The Mark 20 was the only torpedo in service which could fit the short stern launch tubes of the

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From 1939, used by submarines, motor torpedo boats and destroyers from other navies such as the

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A Mark IX torpedo undergoing maintenance while loaded in a destroyer's triple tube mounting.

1920:

Much more capable than Tigerfish. Deployed from 1992, and replacing all Tigerfish by 2004.

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class would relegate the stern launch tubes for storing beer, retiring the Mark 20 sooner.

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and over 200 test runs were carried out until a catastrophic accident. On 16 June 1955,

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12,000 yd (11,000 m) (Mark 20S), 14,000 yd (13,000 m) (Mark 20I)

2965: 2012: 1974: 1229: 545:

Length: 22 ft 2.5 in (6.769 m) to 22 ft 5 in (6.83 m)

516:

Length: 22 ft 2.5 in (6.769 m) to 22 ft 5 in (6.83 m)

59:, in 1910. These destroyers would become the primary users of the Mark I torpedoes. 2995: 288:

design, it could run for 4,500 yd (4,100 m) at 45 knots (83 km/h).

3115: 3088: 3083: 3078: 2899: 2708: 2658: 2433: 2401: 2311: 1793:

12,000 yd (11,000 m) low-speed, 8,900 yd (8,100 m) high-speed

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The Mark II*, an improved Mark II, was used by battleships and battlecruisers. A

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Preston, Antony (1981). "From Fancy to Stingray, British Torpedoes Since 1945".

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submarines. It remained in the submarine service until 1988, which is when the

3130: 2827: 2808: 2598: 2528: 2248: 1844: 1602: 1567: 1487: 1043: 714: 3068: 1115: 477:, and other surface ships equipped with 21-inch torpedo tubes, such as the 474: 1905:

Mark 24 Mod 3 Tigerfish (simplified inexpensive version, paper study only)

1589:

A project for an autonomous active sonar ASW torpedo to be carried by the

978:

Range and speed: 5,000 yd (4,600 m) at 40 kn (74 km/h)

1803:

20 kn (37 km/h) low-speed, 28 kn (52 km/h) high-speed

887: 3000: 2377: 2348: 1833: 940: 484: 285: 24: 1245: 488: 487:. In the Second World War they were carried as auxiliary armament on 121: 96: 71: 492: 3032: 2207:"World War II Torpedoes of the United Kingdom/Britain – NavWeaps" 2105:"World War II Torpedoes of the United Kingdom/Britain – NavWeaps" 1535: 1518: 1492: 1085: 20: 2691:"United Kingdom Aerospace and Weapons Projects - Guided Weapons" 1899:

Mark 24(N) Tigerfish (nuclear payload variant, paper study only)

1093:

in Overloon, Netherlands. The Mark IX is the first from the top.

1002:

The Mark VIII** was used in two particularly notable incidents:

919:

The Mark VIII was designed circa 1925 and was the first British

882: 2792:. Journal of the Royal Navy Scientific Service. p. 99-100. 1270: 1175: 993: 989: 901: 542:

Weight: Approximately 3,100–3,200 lb (1,400–1,500 kg)

513:

Weight: Approximately 3,100–3,200 lb (1,400–1,500 kg)

2300:. Journal of the Royal Navy Scientific Service. p. 98-99. 1627:

A wire-guided version of the Mark 20 separately developed by

1051: 74:

throughout most of their service during the First World War.

2843:

Vanguard to Trident; British Naval Policy Since World War II

2824:

The Silent Deep: The Royal Navy Submarine Service Since 1945

2805:

The Silent Deep: The Royal Navy Submarine Service Since 1945

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The Silent Deep: The Royal Navy Submarine Service Since 1945

2525:

The Silent Deep: The Royal Navy Submarine Service Since 1945

2245:

The Silent Deep: The Royal Navy Submarine Service Since 1945

2232:. Journal of the Royal Navy Scientific Service. p. 100. 1655:

A Mark 23 torpedo repainted as an advertisement in front of

2991:

Post-WWII Whitehead Torpedo and Engineering Works Torpedoes

2647:. Journal of the Royal Navy Scientific Service. p. 99. 2285:. Journal of the Royal Navy Scientific Service. p. 91. 2264:"Post-World War II Torpedoes of the United Kingdom/Britain" 1798: 1577:

was forced to return to Portsmouth to have it removed, the

1517:

as an export version. It featured weight reductions to its

1445: 852: 688: 462: 262: 2013:"Pre-World War II Torpedoes of the United Kingdom/Britain" 1975:"Pre-World War II Torpedoes of the United Kingdom/Britain" 1843:) modified the torpedo body to his specifications, into a 594:

equipped with 21-inch launch tubes, as well as submarines.

548:

Explosive charge: 400 or 500 lb (180 or 230 kg)

519:

Explosive charge: 400 or 500 lb (180 or 230 kg)

1825:

During the trials phase of the Mark 23, in 1965, Captain

1610:, which de-emphasized the role of aircraft carriers, the 1570:, when an armed Mark 20 became stuck inside its tube and 1275:

Range and speed: Unknown, above 40 kn (74 km/h)

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