British Porpoise class submarine
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.jpg) HMS Rorqual |
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| Class overview | |
|---|---|
| In commission: | 1956–1988 |
| Completed: | 8 |
| General characteristics | |
| Displacement: | 2,080 tons surfaced 2,450 tons submerged |
| Length: | 290 ft (88 m) |
| Beam: | 26 ft 7 in (8.1 m) |
| Draught: | 18 ft (5.5 m) |
| Propulsion: | 2 × Admiralty Standard range diesel generators, 1,650 hp (1.230 MW) 2 × English Electric main motors, 12,000 hp (8.95 MW) 2 shafts |
| Speed: | 12 kn (22 km/h) surfaced 17 kn (31 km/h)submerged |
| Range: | 9,000 nmi (17,000 km) at 12 kn (22 km/h) |
| Complement: | 71 |
| Armament: | 8 × 21 in (530 mm) torpedo tubes, 6 bow, 2 stern 30 × Mk8 or Mk23 torpedoes, later the Mark 24 Tigerfish |
The Porpoise class was an eight-boat class of diesel-electric submarines of the Royal Navy. 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. Their design was, in many ways, influenced by the German WWII-era Type XXI U-boats, which were the first "true" submarines, rather than submersibles.
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[edit] Design
The Porpoises were larger but shorter than their T-class predecessors and used a much improved steel known as UXW.[1] 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.[1]
Designed for 18 knots, they made 17 knots, which, with the use of silenced propellers, dropped to 16 knots. 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.[1] This was in part due to careful attention to detail in the mounting of machinery, and advanced made in propeller design to prevent cavitation. Initially, the silenced propellers actually set up a distinctive resonant "singing", and it was said that Rorqual was once identified leaving the River Clyde from a listening station from Long Island! 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.[1] The silent running abilities made their sonar equipment particularly efficient.
They 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 class were also the first to not have a gun on deck, a decision that would be carried in all subsequent submarine classes in the RN.
The first Porpoise-class boats were launched in 1958 during the ever increasing threat of the Soviet Union's submarine fleet. The weaponry of the Porpoise-class was updated in 1970 to operate the Mark 24 Tigerfish torpedo. The Porpoise-class were all decommissioned by the 1980s. The Oberon-class 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.
[edit] Ships of the class
| Name | Launched | Fate |
|---|---|---|
| HMS Finwhale (S05) | 21 July 1959 | broken up in 1988 |
| HMS Cachalot (S06) | 11 December 1957 | broken up in 1980 |
| HMS Narwhal (S03) | 25 October 1957. Built by the Vickers shipyard in Barrow-in-Furness | sunk as a target on 3 August 1983 |
| HMS Porpoise (S01) | 25 April 1956, built in Barrow | sunk as a target in 1985. |
| HMS Sealion (S07) | 22 February 1959. Build by Cammell Laird at Birkenhead. | sold in 1987 |
| HMS Grampus (S04) | 1957. Build by Cammell Laird at Birkenhead. | sunk as a target in 1980 |
| HMS Walrus (S08) | 22 February 1959 | sold in 1987 |
| HMS Rorqual (S02) | 1956, built in Barrow | broken up 1977 |
[edit] See also
- The Grampus class of six submarines that served in World War II is sometimes called the Porpoise class.
