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...

's T class (or Triton class) of diesel-electric 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 was designed in the 1930s to replace the O

Odin class submarine

The Odin class submarine was a class of nine submarines developed and built for the Royal Navy in the 1920s. The prototype was followed by two ships originally ordered for the Royal Australian Navy, but transferred to the RN in 1931 because of the poor economic situation in Australia, and six...

, P

Parthian class submarine

The Parthian class submarine or P class was a class of six submarines built for the Royal Navy in the late 1920s. They were designed as long-range patrol submarines for the Far East. These ships were almost identical to the Odin class, the only difference being a different bow...

 and R

Rainbow class submarine

The Rainbow class submarine or R class was a class of four submarines built for the Royal Navy in the early 1930s. They were designed as long range patrol submarines for the Far East and were essentially repeats of the preceding Parthian class submarines with minor modifications...

 classes. Fifty-three members of the class were built just before and during the Second World War

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...

, where they played a major role in the Royal Navy's submarine operations. Four boats in service for the Royal Netherlands Navy

Royal Netherlands Navy

The Koninklijke Marine is the navy of the Netherlands. In the mid-17th century the Dutch Navy was the most powerful navy in the world and it played an active role in the wars of the Dutch Republic and later those of the Batavian Republic and the Kingdom of the Netherlands...

 were known as the Zwaardfisch class.

In the decade following the war, the oldest surviving boats were scrapped and the remainder converted to anti-submarine vessels to counter the perceived growing Soviet submarine threat

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...

. The Royal Navy disposed of its last operational boat in 1969, although it retained one permanently moored as a static training submarine until 1974. The last surviving boat, serving in the Israel Sea Corps, was scrapped in 1977.

Design and development

Design began in 1934 but was constrained by the 1930 London Naval Treaty

London Naval Treaty

The London Naval Treaty was an agreement between the United Kingdom, the Empire of Japan, France, Italy and the United States, signed on April 22, 1930, which regulated submarine warfare and limited naval shipbuilding. Ratifications were exchanged in London on October 27, 1930, and the treaty went...

 restricting the total British submarine fleet to 52,700 tons

Long ton

Long ton is the name for the unit called the "ton" in the avoirdupois or Imperial system of measurements, as used in the United Kingdom and several other Commonwealth countries. It has been mostly replaced by the tonne, and in the United States by the short ton...

, a maximum of 2,000 tons for any boat, and maximum armament of one 5.1 inch (130 mm) gun. The "Repeat P"s, as the design was originally called, were intended to be large and powerful enough to operate against 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...

 in the absence of other British

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...

 naval units. Britain was in a financial crisis and would have difficulty affording enough boats to meet their allowance.

It was expected from British work on ASDIC

Sonar

Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

 that the other nations would develop something similar. To that end a smaller vessel around 1,100 tons would avoid detection. In the face of expected enemy anti-submarine measures any attack would probably have to be made at long range without the aid of the periscope but on ASDIC. To counter the resultant inaccuracy a large salvo of at least eight torpedoes would be needed.

The eventual design had 10 forward-facing torpedo

Torpedo

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...

 tubes and a maximum diving depth of 300 ft (91 m). The design was finalised in 1935 and on June 24 the decision was made to drop the "Repeat P" designation and give all boats names starting with "T".
The forward firing armament was 6 internal bow torpedo tubes, two external tubes on the bow and two more external tubes amidships angled to fire forward. A single 4 inches (101.6 mm) deck gun was carried.

The ten-torpedo salvo was the largest ever fitted to an operational submarine. British operational planning at the time assumed that international treaties would prevent unrestricted submarine warfare, and that the main purpose of the submarine would be to attack enemy warships. In such a situation a commander may only have had one chance to attack, so a large salvo was essential. Placing six of the ten torpedo tubes within the pressure hull prevented the design from having the perfect cylindrical shape, like contemporary German designs, which were more lightly armed. This reduced the T-class pressure depth, but it was a conscious design compromise. T-class boats built later in the war reversed the two amidships tubes to fire astern, rather than forward.

The lead boat, Triton

HMS Triton (N15)

HMS Triton was a submarine of the Royal Navy named for the son of Poseidon and Amphitrite, the personification of the roaring waters, was the lead ship of her class. Her keel was laid down on 28 August 1936 by Vickers Armstrong at Barrow-in-Furness. She was launched on 5 October 1937, and...

, was ordered on 5 March 1936 and ran her first-of-class trials in December 1938. Fifty-three T-class submarines were built before and during the war in three distinct groups, although there were minor differences between boats within the same group. The second and third groups had the fuel capacity increased on many boats to 230 tons, giving a range of 11000 nmi (20,372 km) at 10 knots (19.6 km/h)

Service history

T-class submarines fought in all theatres in the Second World War and suffered around 25 percent losses. They were particularly vulnerable in the Mediterranean, where their large size made them easily visible from the air in the clear waters, but they had much more success elsewhere.

After the war, all surviving Group One and Two boats were scrapped and the remainder fitted with snorts

Submarine snorkel

A submarine snorkel is a device which allows a submarine to operate submerged while still taking in air from above the surface. Navy personnel often refer to it as the snort.-History:...

.

In the late 1940s and 1950s, most were streamlined for quiet and higher-speed underwater operation against Soviet

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....

 submarines, in place of the anti-surface-ship role that they had been designed for. In January 1948, it was formally acknowledged that the main operational function of the British submarine fleet would now be to intercept Soviet submarines slipping out of their bases in Northern 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...

 to attack British and Allied merchant vessels. The following April, the Assistant Chief of Naval Staff, Rear-Admiral Geoffrey Oliver

Geoffrey Oliver

Admiral Sir Geoffrey Nigel Oliver GBE, KCB, DSO & Two Bars was a British Royal Navy officer during the Second World War.-Early career:...

, circulated a paper in which he proposed that British submarines take a more offensive role by attacking Soviet submarines off the Northern Russian coast and mining the waters in the area. With the dramatically reduced surface fleet following the end of the Second World War, he commented that this was one of the few methods the Royal Navy had for "getting to the enemy on his home ground."

Much of the work carried out on the submarines was underpinned by results of measurements made using Tradewind

HMS Tradewind

HMS Tradewind was a British submarine of the third group of the T class. She was built as P329 at Chatham, and launched on 11 December 1942...

, which had been modified in July 1945-September 1946 to become an acoustic trials submarine, with external tubes and guns removed, the bridge faired, the hull streamlined and some internal torpedo tubes blanked over.

Starting in 1948, eight newer all-welded boats underwent extensive "Super-T" conversion at Chatham Dockyard

Chatham Dockyard

Chatham Dockyard, located on the River Medway and of which two-thirds is in Gillingham and one third in Chatham, Kent, England, came into existence at the time when, following the Reformation, relations with the Catholic countries of Europe had worsened, leading to a requirement for additional...

. The modifications included the removal of deck guns and the replacement of the conning tower with a "sail", a smooth-surfaced and far more symmetrical and streamlined tower. An extra battery was installed, and a new section of hull inserted to accommodate an extra pair of motors and switchgear. This varied between 14 ft (4.3 m) in the earlier conversions and 17 ft 6 in (5.33 m) in the later ones. These changes allowed an underwater speed of 15 knots (28 km/h) or more and increased the endurance to around 32 hours at 3 knots (6 km/h). The first boats to undergo this modification were Taciturn

HMS Taciturn (P314)

HMS Taciturn was a British submarine of the third group of the T class. She was built as P314 by Vickers Armstrong, Barrow and Bellis and Morcom Ltd., and launched on 7 June 1944...

 in November 1948-March 1951, followed by Turpin

HMS Turpin (P354)

HMS Turpin was a group three T Class submarine of the Royal Navy which entered service in the last few months of World War II. So far she has been the only ship of the Royal Navy to be named Turpin...

 in June 1949-September 1951. The programme was completed with the conversion of Trump

HMS Trump (P333)

HMS Trump was a British submarine of the third group of the T class. She was built by Vickers Armstrong, Barrow, and launched on 25 March 1944. So far she has been the only ship of the Royal Navy to bear the name Trump. She spent the majority of her life attached to the 4th Submarine division...

 in February 1954-June 1956.

The conversion was not entirely successful since the metacentric height

Metacentric height

The metacentric height is a measurement of the static stability of a floating body. It is calculated as the distance between the centre of gravity of a ship and its metacentre . A larger metacentric height implies greater stability against overturning...

 was reduced, making the boats roll heavily on the surface in rough weather. This was alleviated in 1953 in those conversions which had been completed by increasing the buoyancy by raising the capacity of a main ballast tank by 50 tons. This was done by merging it with an existing emergency oil fuel tank. For the four boats remaining to be converted, increase in buoyancy was achieved by lengthening the extra hull section to be inserted from 14 ft (4.3 m) to 17 ft 6 in (5.33 m). The effect was to lengthen the control room and strict instructions were issued that this space was not to be used for extra equipment otherwise the improved buoyancy would be affected.

In the meantime, in December 1950, approval was made for the streamlining of five riveted boats. This was a much less extensive process with the removal of deck guns, external torpedo tubes and the replacement of the conning tower with a "sail" and the batteries replaced with more modern versions providing a 23 percent increase in power. The work was much more straightforward than the conversion of the welded boats and was undertaken during normal refit. The first riveted boat to undergo this modification was Tireless

HMS Tireless (P327)

HMS Tireless , a Taciturn- or T-class submarine, was the first ship of the Royal Navy to bear that name. She was authorized under the 1941 War Emergency Program and her keel was laid down on 30 October 1941 at Portsmouth Dockyard...

 in 1951.

The last operational Royal Navy boat of the class was Tiptoe

HMS Tiptoe (P332)

HMS Tiptoe was a British submarine of the third group of the T class. She was built by Vickers Armstrong, Barrow, and launched on 25 February 1944. She was one of two submarines named by Winston Churchill, and so far has been the only ship of the Royal Navy to be named Tiptoe...

, which was decommissioned on 29 August 1969. The last T class boat in service with Royal Navy, albeit non-operationally, was Tabard

HMS Tabard (P342)

HMS Tabard was a British submarine of the third group of the T class. She was built by Scotts, Greenock, and launched on 21 November 1945. So far she has been the only boat of the Royal Navy to bear the name Tabard, after the item of clothing...

 which was permanently moored as a static training submarine at the HMS Dolphin shore-establishment from 1969 until 1974, when she was replaced by HMS Alliance

HMS Alliance (P417)

HMS Alliance is a Royal Navy A-class, Amphion class or Acheron class submarine, laid down towards the end of the Second World War and completed in 1947...

.

The last operational boat anywhere was the INS Dolphin, formerly HMS Truncheon

HMS Truncheon (P353)

HMS Truncheon was a group three T Class submarine of the Royal Navy which entered service in the last few months of World War II. So far she has been the only ship of the Royal Navy to be named Truncheon...

, one of three T-class boats (and two S-class ones) sold to the Israeli Navy - and which was decommissioned in 1977.

Another submarine sold to Israel, Totem

HMS Totem (P352)

HMS Totem was a group three T class submarine of the Royal Navy which entered service in the last few months of World War II. To-date, she is the only ship of the Royal Navy to have been named Totem....

 renamed INS Dakar

INS Dakar

INS Dakar was the former modified British T-class submarine of the Royal Navy. In 1965, she was purchased by Israel as part of a group of three T-class submarines. She was commissioned into the Israeli Sea Corps in November 1967 and underwent sea and diving trials in Scotland. Dakar departed for...

, was lost in the Mediterranean in 1969 while on passage from Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

 to Haifa

Haifa

Haifa is the largest city in northern Israel, and the third-largest city in the country, with a population of over 268,000. Another 300,000 people live in towns directly adjacent to the city including the cities of the Krayot, as well as, Tirat Carmel, Daliyat al-Karmel and Nesher...

 - a tragedy still remembered in Israel decades later. Although the wreck was discovered in 1999, the cause of the accident remains uncertain.

Group One boats

These fifteen pre-war submarines were ordered under the Programmes of 1935 (Triton

HMS Triton (N15)

HMS Triton was a submarine of the Royal Navy named for the son of Poseidon and Amphitrite, the personification of the roaring waters, was the lead ship of her class. Her keel was laid down on 28 August 1936 by Vickers Armstrong at Barrow-in-Furness. She was launched on 5 October 1937, and...

), 1936 (next four), 1937 (next seven) and 1938 (last three). The boats originally had a bulbous bow covering the two forward external torpedo tubes, which quickly produced complaints that they reduced surface speed in rough weather. These external tubes were therefore removed from Triumph during repairs after she was damaged by a 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...

 and Thetis during the extensive repairs following her sinking and subsequent salvage. Only six survived the war, less than half.

• Triton
  HMS Triton (N15)
  HMS Triton was a submarine of the Royal Navy named for the son of Poseidon and Amphitrite, the personification of the roaring waters, was the lead ship of her class. Her keel was laid down on 28 August 1936 by Vickers Armstrong at Barrow-in-Furness. She was launched on 5 October 1937, and...
  
   (sunk in the Adriatic on 18 December 1940)
• Thetis
  HMS Thetis (N25)
  HMS Thetis was a Group 1 T-class submarine of the Royal Navy which served under two names. Under her first identity, HMS Thetis, she commenced sea trials on 4 March 1939. She sank during trials on 1 June 1939 with the loss of 99 lives...
  
   (sank during trials, was salvaged and recommissioned as Thunderbolt; sunk by the Italian corvette Cicogna off Messina Strait on 14 March 1942)
• Tribune
  HMS Tribune (N76)
  HMS Tribune was a British T class submarine built by Scotts, Greenock. She was laid down on 3 March 1937 and was commissioned on 17 October 1939. HMS Tribune was part of the first group of T class submarines.-Career:...
  
  
• Trident
  HMS Trident (N52)
  HMS Trident was a British T class submarine built by Cammell Laird, Birkenhead. She was laid down on 12 January 1937 and was commissioned on 1 October 1939...
  
  
• Triumph
  HMS Triumph (N18)
  HMS Triumph was a T-class submarine of the Royal Navy. She was laid down by Vickers at Barrow-in-Furness and launched in September 1938.-Career:...
  
   (lost, probably to Italian mines, on 14 January 1942)
• Taku
  HMS Taku (N38)
  HMS Taku was a British T class submarine built by Cammell Laird, Birkenhead. She was laid down on 18 November 1937 and was commissioned on 3 October 1940.-Career:...
  
  
• Tarpon
  HMS Tarpon (N17)
  HMS Tarpon was a T-class submarine of the Royal Navy. She was laid down by Scotts, Greenock and launched in October 1939.-Career:Tarpon had a tragically short career, serving in the North Sea....
  
   (probably sunk by German minesweeper M-6 on 14 April 1940)
• Thistle
  HMS Thistle (N24)
  HMS Thistle was a T-class submarine of the Royal Navy. She was laid down by Vickers Armstrong, Barrow and launched in October 1939.-Career:Thistle had a short wartime career with the Royal Navy....
  
   (torpedoed by U-4 on 10 April 1940)
• Tigris
  HMS Tigris (N63)
  HMS Tigris was a T-class submarine of the Royal Navy. She was laid down at Chatham Dockyard and launched in October 1939.-Career:Tigris had a relatively active career, serving in the North Sea and the Mediterranean.-Home waters:...
  
   (probably sunk by German ship UJ-2210 on 27 February 1943)
• Triad
  HMS Triad (N53)
  HMS Triad was a T-class submarine of the Royal Navy. She was laid down by Vickers Armstrong, Barrow and launched in May 1939. So far she has been the only ship of the Royal Navy to bear the name Triad.-Career:...
  
   (sunk by gunfire from the Italian submarine Enrico Toti in the Gulf of Taranto
  Gulf of Taranto
  The Gulf of Taranto is a gulf of the Ionian Sea, in southern Italy.The Gulf of Taranto is almost square, 140 km long and wide, and is delimited by the capes Santa Maria di Leuca and Colonna...
  
   on 15 October 1940)
• Truant
  HMS Truant (N68)
  HMS Truant was a T-class submarine of the Royal Navy. She was laid down by Vickers Armstrong, Barrow and launched on the 5 May 1939.-Career:...
  
  
• Tuna
  HMS Tuna (N94)
  HMS Tuna was a T-class submarine of the Royal Navy. She was laid down by Scotts, Greenock and launched on the 10 May 1940. She was equipped with German built engines, and spent her service career in World War II in western European waters, in both the North Sea and off the western coast of France...
  
  
• Talisman
  HMS Talisman (N78)
  HMS Talisman was a T-class submarine of the Royal Navy. She was laid down by Cammell Laird & Co Limited, Birkenhead and launched on the 29 January 1940.-Career:...
  
   (lost, probably to Italian mines, on 17 September 1942)
• Tetrarch
  HMS Tetrarch (N77)
  HMS Tetrarch was a T-class submarine of the Royal Navy. She was laid down by Vickers Armstrong, Barrow and launched in November 1939.-Career:...
  
  , the only boat completed with mine laying equipment (lost, probably to Italian mines, on 2 November 1941)
• Torbay
  HMS Torbay (N79)
  was a T-class submarine of the Royal Navy. She was laid down at Chatham Dockyard and launched on 9 April 1940.Torbay had an active and successful career, serving mainly in the Mediterranean, although she also served in the Pacific Far East at the end of the war.Altogether she sank 17 merchant...
  
  

Group Two boats

These seven vessels were all ordered under the 1939 War Emergency Programme. The first, Thrasher, was launched on 5 November 1940. The external bow torpedo tubes were moved seven feet aft to help with sea keeping. The two external forward-angled tubes just forward of conning tower were repositioned aft of it and angled backwards to fire astern, and a stern external torpedo tube was also fitted. This gave a total of eight forward-facing tubes and three rear-facing ones. All Group Two boats were sent to the Mediterranean, only Thrasher and Trusty returned.

• Tempest
  HMS Tempest (N86)
  HMS Tempest was a T-class submarine of the Royal Navy. She was laid down by Cammell Laird & Co Limited, Birkenhead and launched in June 1941.-Career:Tempest had a short-lived career, serving in the Mediterranean....
  
   (sunk by the Italian Spica class torpedo boat
  Spica class torpedo boat
  The Spica-class were a class of torpedo boats of the Regia Marina during World War II. These ships were built as a result of a clause in the Washington Naval Treaty, which stated that ships with a tonnage of less than 600 tons could be built in unlimited numbers...
  
   Circe on 13 February 1942)
• Thorn
  HMS Thorn (N11)
  HMS Thorn was a T-class submarine of the Royal Navy. She was laid down by Cammell Laird & Co Limited, Birkenhead and launched in March 1941.-Career:Thorn had a short-lived career, serving in the Mediterranean....
  
   (sunk by the Italian Orsa class torpedo boat
  Orsa class torpedo boat
  The Orsa class were a group of large torpedo boats or destroyer escorts built for the Italian Navy in the late 1930s. They were an enlarged version of the , with more endurance and a greater depth charge load but less powerful machinery and a lighter gun armament. The surviving pair were rebuilt as...
  
   Pegaso on 6 August 1942)
• Thrasher
  HMS Thrasher (N37)
  HMS Thrasher was a T-class submarine of the Royal Navy. She was laid down by Cammell Laird & Co Limited, Birkenhead, launched in November 1940, and had an active career in the Mediterranean and Pacific Far East.-Mediterranean:...
  
  
• Traveller
  HMS Traveller (N48)
  HMS Traveller was a T-class submarine of the Royal Navy. She was laid down by Scotts, Greenock and launched in August 1941.-Career:Traveller spent most of her career serving in the Mediterranean...
  
   (lost, probably to Italian mines, on 12 December 1942)
• Trooper
  HMS Trooper (N91)
  HMS Trooper was a T-class submarine of the Royal Navy. She was laid down by Scotts, Greenock and launched in March 1942.-Career:Trooper spent most of her short career serving in the Mediterranean. She sank the Italian tanker Rosario, the Italian merchant Forli, a sailing vessel and the Italian...
  
   (lost, probably to German mines, on 14 October 1943)
• Trusty
  HMS Trusty (N45)
  HMS Trusty was a T-class submarine of the Royal Navy. She was laid down by Vickers Armstrong, Barrow and launched in March 1941.-Career:Trusty served in the Mediterranean and in the Pacific Far East...
  
  
• Turbulent
  HMS Turbulent (N98)
  HMS Turbulent was a T-class submarine of the Royal Navy. She was laid down by Vickers Armstrong, Barrow and launched in May 1942.-Career:Turbulent spent most of her career serving in the Mediterranean...
  
   (sunk by Italian torpedo boats on 12 March 1943)

Turbulent sank over 90,000 tons of enemy shipping. She was depth charged on over 250 occasions by enemy forces hunting her.

Group Three boats

Wartime austerity meant that they lacked many refinements such as jackstaffs and guardrails, and had only one anchor. Much of the internal pipework was steel rather than copper. The first Group Three boat was P311, launched on 10 June 1942. Welding gradually replaced riveting and some boats were completely welded, which gave them an improved rated maximum diving depth of 350 ft (107 m).

• Nine submarines were ordered under the 1940 Programme.
• P311
  HMS P311
  HMS P311 was a T-class submarine of the Royal Navy, the only boat of her class never to be given a name. She was to have received the name Tutankhamen but was lost before this was formally done. P311 was a Group 3 T-class boat built by Vickers-Armstrong at Barrow-in-Furness and commissioned on 5...
  
   (lost, probably to Italian mines, before her name Tutankhamen was formally assigned)
• Trespasser
  HMS Trespasser (P312)
  HMS Trespasser was a British submarine of the third group of the T class. She was built as P312 by Vickers Armstrong, Barrow, and launched on 29 May 1942...
  
  
• Taurus
  HMS Taurus (P399)
  HMS Taurus was a Second World War British T class submarine, built by Vickers Armstrong, Barrow.-As HMS Taurus:The submarine was laid down on the 30th of September 1941, and launched on 27 June 1942. She served in the Mediterranean and the Pacific Far East during the Second World War...
  
   (To the Royal Netherlands Navy as Dolfijn)
• Tactician
  HMS Tactician (P314)
  HMS Tactician was a British submarine of the third group of the T class. She was built as P314 by Vickers Armstrong, Barrow, and launched on 29 July 1942.-Service:...
  
  
• Truculent
  HMS Truculent (P315)
  HMS Truculent was a British submarine of the third group of the T class. She was built as P315 by Vickers Armstrong, Barrow, and launched on 12 September 1942.-Service:...
  
   (sunk in collision on 12 January 1950)
• Templar
  HMS Templar (P316)
  HMS Templar was a British submarine of the third group of the T class. She was built as P316 by Vickers Armstrong, Barrow, and launched on 26 October 1942...
  
  
• Tally-Ho
  HMS Tally-Ho (P317)
  HMS Tally-Ho was a British submarine of the third group of the T class. She was built as P317 by Vickers Armstrong, Barrow, and John Brown & Company, Clydebank, and launched on 23 December 1942. So far she has been the only ship of the Royal Navy to bear the name Tally-Ho, probably after Tally-ho,...
  
  
• Tantalus
  HMS Tantalus (P318)
  HMS Tantalus was a British submarine of the third group of the T class. She was built as P318 by Vickers Armstrong, Barrow, and launched on 24 February 1943. So far she has been the only ship of the Royal Navy to bear the name Tantalus, after the mythological Tantalus, son of...
  
  
• Tantivy
  HMS Tantivy (P319)
  HMS Tantivy was a British submarine of the third group of the T class. She was built as P319 by Vickers Armstrong, Barrow, and John Brown & Company, Clydebank, and launched on 6 April 1943...
  
  

• Seventeen submarines were ordered under the 1941 Programme.
• Telemachus
  HMS Telemachus (P321)
  HMS Telemachus was a British submarine of the third group of the T class. She was built as P321 by Vickers Armstrong, Barrow, and launched on 19 June 1943.-Service:...
  
  
• Talent (P322)
  HMS Talent (P322)
  HNLMS Zwaardvisch was the lead ship of the Royal Netherlands Navy's , which was based on the British T class. The submarine was originally ordered as HMS Talent and built by Vickers Armstrong, Barrow, and John Brown & Company, Clydebank...
  
   (to the Royal Netherlands Navy
  Royal Netherlands Navy
  The Koninklijke Marine is the navy of the Netherlands. In the mid-17th century the Dutch Navy was the most powerful navy in the world and it played an active role in the wars of the Dutch Republic and later those of the Batavian Republic and the Kingdom of the Netherlands...
  
   as Zwaardvisch)
• Terrapin
  HMS Terrapin (P323)
  HMS Terrapin was a British submarine of the third group of the T class. She was built as P323 by Vickers Armstrong, Barrow and Bellis and Morcom Ltd, and launched on 31 August 1943...
  
  
• Thorough
  HMS Thorough (P324)
  HMS Thorough was a British submarine of the third group of the T class. She was built as P324 by Vickers Armstrong, Barrow, and launched on 30 October 1943...
  
  
• Thule
  HMS Thule (P325)
  HMS Thule was a British submarine of the third group of the T class. She was built as P325 at Devonport Dockyard, and launched on 22 October 1942...
  
  
• Tudor
  HMS Tudor (P326)
  HMS Tudor was a British submarine of the third group of the T class. She was built as P326 at Devonport Dockyard, and launched on 23 September 1942...
  
  
• Tireless
  HMS Tireless (P327)
  HMS Tireless , a Taciturn- or T-class submarine, was the first ship of the Royal Navy to bear that name. She was authorized under the 1941 War Emergency Program and her keel was laid down on 30 October 1941 at Portsmouth Dockyard...
  
  
• Token
  HMS Token (P328)
  HMS Token was a British submarine of the third group of the T class. She was built as P328 at Portsmouth Dockyard, and launched on 19 March 1943...
  
  
• Tradewind
  HMS Tradewind
  HMS Tradewind was a British submarine of the third group of the T class. She was built as P329 at Chatham, and launched on 11 December 1942...
  
  
• Trenchant
  HMS Trenchant (P331)
  HMS Trenchant was a British T class submarine of the Second World War.On completion she was given over to the crew of HMS Thrasher whose submarine was due for a refit.-Service:...
  
  
• Tiptoe
  HMS Tiptoe (P332)
  HMS Tiptoe was a British submarine of the third group of the T class. She was built by Vickers Armstrong, Barrow, and launched on 25 February 1944. She was one of two submarines named by Winston Churchill, and so far has been the only ship of the Royal Navy to be named Tiptoe...
  
  
• Trump
  HMS Trump (P333)
  HMS Trump was a British submarine of the third group of the T class. She was built by Vickers Armstrong, Barrow, and launched on 25 March 1944. So far she has been the only ship of the Royal Navy to bear the name Trump. She spent the majority of her life attached to the 4th Submarine division...
  
  
• Taciturn
  HMS Taciturn (P314)
  HMS Taciturn was a British submarine of the third group of the T class. She was built as P314 by Vickers Armstrong, Barrow and Bellis and Morcom Ltd., and launched on 7 June 1944...
  
  
• Tapir
  HMS Tapir (P335)
  HMS Tapir was a Second World War British T class submarine, built by Vickers-Armstrong in Barrow-in-Furness. So far she has been the only ship of the Royal Navy to bear the name Tapir, after the animal.-As HMS Tapir:...
  
   (to the Royal Netherlands Navy as Zeehond (2))
• Tarn
  HMS Tarn (P336)
  HNLMS Tijgerhaai was a of the Royal Netherlands Navy during and after World War II. She was originally ordered as HMS Tarn , a British T-class submarine, built by Vickers Armstrong, Barrow, but never saw service under that name...
  
   (to the Royal Netherlands Navy as Tijgerhaai)
• Talent (P337)
  HMS Talent (P337)
  HMS Talent was a British submarine of the third group of the T class. She was built as P337 by Vickers Armstrong, Barrow, and launched on 13 February 1945...
  
  
• Teredo
  HMS Teredo (P338)
  HMS Teredo was a British submarine of the third group of the T class. She was built as P338 at Vickers Armstrong, Barrow, and John Brown & Company, Clydebank, and launched on 27 April 1945...
  
  

• Fourteen submarines were ordered under the 1942 Programme, but only five were completed.
• Tabard
  HMS Tabard (P342)
  HMS Tabard was a British submarine of the third group of the T class. She was built by Scotts, Greenock, and launched on 21 November 1945. So far she has been the only boat of the Royal Navy to bear the name Tabard, after the item of clothing...
  
  
• Totem
  HMS Totem (P352)
  HMS Totem was a group three T class submarine of the Royal Navy which entered service in the last few months of World War II. To-date, she is the only ship of the Royal Navy to have been named Totem....
  
   (lost in accident on passage to Israel as INS Dakar
  INS Dakar
  INS Dakar was the former modified British T-class submarine of the Royal Navy. In 1965, she was purchased by Israel as part of a group of three T-class submarines. She was commissioned into the Israeli Sea Corps in November 1967 and underwent sea and diving trials in Scotland. Dakar departed for...
  
  )
• Truncheon
  HMS Truncheon (P353)
  HMS Truncheon was a group three T Class submarine of the Royal Navy which entered service in the last few months of World War II. So far she has been the only ship of the Royal Navy to be named Truncheon...
  
   (later the Israeli INS Dolphin)
• Turpin
  HMS Turpin (P354)
  HMS Turpin was a group three T Class submarine of the Royal Navy which entered service in the last few months of World War II. So far she has been the only ship of the Royal Navy to be named Turpin...
  
   (later the Israeli INS Leviathan)
• Thermopylae
  HMS Thermopylae (P355)
  HMS Thermopylae was a T-class submarine of the United Kingdom's Royal Navy laid down on 26 October 1943 at Chatham Dockyard, and launched on 27 June 1945. So far she has been the only ship of the Royal Navy to bear the name Thermopylae, after the Battle of Thermopylae.Commissioned after the end...
  
  

The other nine were ordered but cancelled on October 29, 1945 following the end of hostilities:

• Thor
  HMS Thor (P349)
  HMS Thor was a Royal Navy Group Three T-class submarine laid down at Portsmouth Dockyard on 5 April 1943 and launched on 18 April 1944....
  
   (launched 18 April 1944 but not completed)
• Tiara
  HMS Tiara (P351)
  HMS Tiara was a Royal Navy Group Three T-class submarine laid down at Portsmouth Dockyard on 8 April 1943 and launched on 18 April 1944. However the war ended before she was completed and she arrived at Dover Industries for scrapping in June 1947 . Her sister vessel Thor was launched on the same...
  
   (also launched on 18 April 1944 but not completed)
• Theban (P341)
• Talent (P343)
• Threat (P344)
• also four unnamed submarines (P345, P346, P347 and P348).

Transfers to Royal Netherlands Navy

• Tijgerhaai (ex-Tarn
  HMS Tarn (P336)
  HNLMS Tijgerhaai was a of the Royal Netherlands Navy during and after World War II. She was originally ordered as HMS Tarn , a British T-class submarine, built by Vickers Armstrong, Barrow, but never saw service under that name...
  
  )
• Zwaardvisch (ex-Talent
  HMS Talent (P322)
  HNLMS Zwaardvisch was the lead ship of the Royal Netherlands Navy's , which was based on the British T class. The submarine was originally ordered as HMS Talent and built by Vickers Armstrong, Barrow, and John Brown & Company, Clydebank...
  
  )
• Zeehond (2) (ex-Tapir
  HMS Tapir (P335)
  HMS Tapir was a Second World War British T class submarine, built by Vickers-Armstrong in Barrow-in-Furness. So far she has been the only ship of the Royal Navy to bear the name Tapir, after the animal.-As HMS Tapir:...
  
  )
• Dolfijn (ex-Taurus
  HMS Taurus (P399)
  HMS Taurus was a Second World War British T class submarine, built by Vickers Armstrong, Barrow.-As HMS Taurus:The submarine was laid down on the 30th of September 1941, and launched on 27 June 1942. She served in the Mediterranean and the Pacific Far East during the Second World War...
  
  )