British Porpoise class submarine

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.

Design

The "Porpoises" were larger but shorter than their T-class predecessors and used a much improved steel known as UXW."Rebuilding the Royal Navy : Warship Design Since 1945", D. K. Brown and George Moore, Chatham Publishing, 2003, pp.114-115] 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 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. This was in part due to careful attention to detail in the mounting of machinery, and advances made in propeller design to prevent cavitation. Initially, the silenced propellers actually set up a distinctive resonant "singing", and it was said that "HMS 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; "HMS Rorqual" was later able to surface undetected off the Statue of Liberty. The silent running abilities made their sonar equipment particularly effective.

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 since the R-class of 1917 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 boats 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.

hips of the class

ee also

* The "Grampus" class of six submarines that served in World War II is sometimes called the "Porpoise" class.

References

External links

* [http://www.battleships-cruisers.co.uk/porpoise_class1.htm#HMS%20Rorqual Battleships-Cruisers.co.uk's page of photographs of "Porpoise" Class submarines]
* [http://www.submariners.co.uk/Boats/Barrowbuilt/Postwar/index.htm Submariners Association -- Post-war Submarines]