British Porpoise class submarine
Encyclopedia

The Porpoise class was an eight-boat class
Ship class
A ship class is a group of ships of a similar design. This is distinct from a ship-type, which might reflect a similarity of tonnage or intended use. For example, the is a nuclear aircraft carrier of the Nimitz class....

 of diesel-electric
Diesel-electric
Diesel-electric transmission or diesel-electric powertrain is used by a number of vehicle and ship types for providing locomotion.A diesel-electric transmission system includes a diesel engine connected to an electrical generator, creating electricity that powers electric traction motors...

 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 operated 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...

. This class was originally designated patrol submarines, then attack. They were the first conventional British submarines to be built after the end 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...

. Their design was, in many ways, influenced by the German WWII-era Type XXI U-boats.

Design

The Porpoise class were larger but shorter than their T-class
British T class submarine
The Royal Navy's T class of diesel-electric submarines was designed in the 1930s to replace the O, P and R classes. Fifty-three members of the class were built just before and during the Second World War, where they played a major role in the Royal Navy's submarine operations...

 predecessors and used a much improved steel known as UXW. This, and improved design and construction techniques allowed much deeper diving. It was found in tests that the unusually long engine room was liable to collapse, so there were extra large frames in this section, which proved to be something of an operational inconvenience.

Designed with a top speed of 18 knots (9.8 m/s), the boats were capable of 17 knots (9.3 m/s), or 16 knots (8.7 m/s) once fitted with silenced propellers. However, quieter running was felt to be a positive trade off for the reduced speed. The Porpoise class were exceptionally quiet underwater, more so than their NATO counterparts and far more so than the Soviet Whiskeys
Whiskey class submarine
Whiskey-class submarines are a class of naval submarines that the Soviet Union built in the early Cold War period.-Design:...

. This was in part due to careful attention to detail in the mounting of machinery, and advances made in propeller design to prevent cavitation
Cavitation
Cavitation is the formation and then immediate implosion of cavities in a liquidi.e. small liquid-free zones that are the consequence of forces acting upon the liquid...

. Initially, the silenced propellers actually set up a distinctive resonant "singing", and it was said that Rorqual was once identified leaving the River Clyde
River Clyde
The River Clyde is a major river in Scotland. It is the ninth longest river in the United Kingdom, and the third longest in Scotland. Flowing through the major city of Glasgow, it was an important river for shipbuilding and trade in the British Empire....

 from a listening station from Long Island
Long Island
Long Island is an island located in the southeast part of the U.S. state of New York, just east of Manhattan. Stretching northeast into the Atlantic Ocean, Long Island contains four counties, two of which are boroughs of New York City , and two of which are mainly suburban...

. However, grooves were cut into the propellers and injected with a damping filler which cured the problem; Rorqual was later able to surface undetected off the Statue of Liberty
Statue of Liberty
The Statue of Liberty is a colossal neoclassical sculpture on Liberty Island in New York Harbor, designed by Frédéric Bartholdi and dedicated on October 28, 1886...

. The silent running
Silent running (submarine)
Silent running is a stealth mode of operation for naval submarines. The aim is to evade discovery by passive sonar by eliminating superfluous noise: nonessential systems are shut down, the crew is urged to rest and refrain from making any unnecessary sound, and speed is greatly reduced to minimize...

 abilities made their sonar equipment particularly effective.

Each submarine's armament consisted of eight 21 in (533.4 mm) torpedo tubes; six in the bow, and two in the stern. Initially, up to 30 Mark 8 or Mark 23 torpedoes were carried, although these were replaced in the 1970s by 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...

 torpedo. The class were also the first since the World War I-era R-class
British R class submarine
The R-class submarines were a class of 12 small British diesel-electric submarines built for the Royal Navy during World War I, and were forerunners of the modern hunter-killer submarines, in that they were designed specifically to attack and sink enemy submarines, their battery capacity and hull...

 to not carry a deck gun.

The Porpoises were far more capable than previous submarine classes in operating for prolonged periods, thanks to much improved air recirculation and cleaning systems. The class also performed excellently in clandestine operations, such as surveillance and inserting special forces.

The first Porpoise-class boats were launched in 1958 during the ever increasing threat of the Soviet Union's submarine fleet. The Porpoise class boats were all decommissioned by the 1980s. The Oberon-class
Oberon class submarine
The Oberon class was a 27-boat class of British-built diesel-electric submarines based on the successful British Porpoise-class submarine....

 submarines, which were almost identical to the Porpoises, and the first of which was commissioned in 1961, survived their predecessor only a little longer, all being decommissioned in the early 1990s.

Boats in the class

Name Launched Fate
25 April 1956, built by the Vickers
Vickers Shipbuilding and Engineering Ltd
In 1994 VSEL was subject to two takeover proposals, one from GEC and another from British Aerospace . VSEL was willing to participate in a merger with a larger company to reduce its exposure to cycles in warship production, particularly following the "Options for Change" defence review after the...

 at Barrow-in-Furness
Barrow-in-Furness
Barrow-in-Furness is an industrial town and seaport which forms about half the territory of the wider Borough of Barrow-in-Furness in the county of Cumbria, England. It lies north of Liverpool, northwest of Manchester and southwest from the county town of Carlisle...

Sunk as a target in 1985.
5 December 1956, built by Vickers at Barrow-in-Furness Broken up 1977
25 October 1957. Built by Vickers at Barrow-in-Furness Sunk as a target on 3 August 1983
30 May 1957. Built by Cammell Laird
Cammell Laird
Cammell Laird, one of the most famous names in British shipbuilding during the nineteenth and twentieth centuries, came about following the merger of Laird, Son & Co. of Birkenhead and Johnson Cammell & Co. of Sheffield at the turn of the twentieth century.- Founding of the business :The Company...

 at Birkenhead
Birkenhead
Birkenhead is a town within the Metropolitan Borough of Wirral in Merseyside, England. It is on the Wirral Peninsula, along the west bank of the River Mersey, opposite the city of Liverpool...

.
Sunk as a target in 1980
21 July 1959. Built by Cammell Laird at Birkenhead. Broken up in 1988
11 December 1957 Built by Scotts
Scotts Shipbuilding and Engineering Company
Scotts Shipbuilding and Engineering Company Limited, often referred to simply as Scotts, was a Scottish shipbuilding company based in Greenock on the River Clyde.- History :...

 at 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...

Broken up in 1980
31 December 1959. Built by Cammell Laird at Birkenhead. Sold in 1987; scrapped 1990
22 September 1959 Built by Scotts at Greenock Sold in 1987; scrapped 1991

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK