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| Porpoise-class submarine (1956) | |
|---|---|
| Name | Porpoise-class submarine (1956) |
| Type | Attack submarine |
| Service | 1956–1979 |
| Length | 290 ft (88 m) |
| Beam | 28 ft (8.5 m) |
| Draught | 17 ft (5.2 m) |
| Displacement | 1,565 t surfaced, 2,030 t submerged |
| Propulsion | Diesel-electric |
| Speed | 12 kn surfaced, 16 kn submerged |
| Armament | 8 × 21 in torpedo tubes |
| Complement | 68 |
Porpoise-class submarine (1956) was a post‑World War II diesel‑electric attack submarine class built for the Royal Navy and intended to replace wartime designs like the T-class submarine (1938) and U-class submarine (1937). Commissioned during the Cold War era, the class incorporated lessons from Operation Source and advances highlighted in studies by the Admiralty and Royal Navy Submarine Service. The design influenced subsequent classes including the Oberon-class submarine and contributed to NATO undersea doctrine influenced by the North Atlantic Treaty Organization.
Design work began in the early 1950s under direction from the Admiralty and the Ministry of Defence (United Kingdom), with design teams at Vickers-Armstrongs and Cammell Laird incorporating acoustic research from Admiralty Research Establishment facilities at Haslar and Portsmouth. Influences included captured German Type XXI experiences studied at the Berlin Conference (1945) and postwar tactical reviews such as the Defence White Paper 1957. Naval architects sought quieter hull forms informed by experiments conducted at the Admiralty Experimental Station, Haslar and by research from the National Physical Laboratory (United Kingdom), aiming to reduce cavitation and machinery noise encountered during encounters with Soviet Navy diesel submarines like the Whiskey-class submarine.
The class emphasized improved battery capacity and snorkel systems developed after trials with HMS Seraph (P214) and HMS Totem (P352), and hydrodynamic refinements from model testing at the Ship Model Basin, Haslar. Machinery layout borrowed from Vickers-Armstrongs practice, while sonar and fire‑control systems integrated equipment supplied by ASDIC contractors and manufacturers linked to Marconi Company research. Political imperatives from the Suez Crisis and rising tensions with the Soviet Union accelerated approval and funding via parliamentary committees including the Estimates Committee.
The Porpoise class measured approximately 88 metres in length with a beam near 8.5 metres and displaced roughly 1,565 tonnes surfaced and 2,030 tonnes submerged. Propulsion combined twin diesel engines coupled to generators charging large lead‑acid battery banks, driving an electric motor connected to a single shaft—arrangements refined after trials on HMS Artemis (P414) analogues. Maximum submerged speed was about 16 knots with a surfaced cruise near 12 knots; typical endurance was dictated by battery capacity and snorkel use, enabling extended submerged transits beyond the capabilities of earlier T-class submarine (1938) boats.
Sensorfit included passive and active sonar suites influenced by Type 177 sonar development and periscopes developed by Barr & Stroud, with torpedo armament comprising eight 21‑inch tubes compatible with G7 and Mark 8 family weapons. Crew complement typically numbered around 68 officers and ratings drawn from the Royal Naval Reserve and the Royal Navy Submarine Service. Acoustic signature reductions were aided by machinery isolation and hull form shaping informed by studies at the National Physical Laboratory (United Kingdom).
Construction was split among shipyards including Vickers-Armstrongs, Cammell Laird, Chatham Dockyard, and Barrow-in-Furness facilities. Keel‑laying began mid‑1950s with launches and commissions spanning 1956–1958; names reflected marine fauna following Royal Navy traditions. In service the class undertook trials, training and patrol duties under commands reporting to Commander Submarine Flotilla and operating from home bases such as HMNB Clyde and HMNB Devonport.
Throughout the 1960s and 1970s units participated in NATO exercises including Exercise Mainbrace and Operation Spring Train cooperations, conducting anti‑submarine warfare (ASW) training with ships from the United States Navy, Royal Canadian Navy, and French Navy. Some boats underwent mid‑life refits at Rosyth Dockyard with upgraded sonar and fire‑control systems supplied by contractors tied to Marconi Company and BAE Systems predecessor firms. Decommissionings began in the late 1960s and continued into the 1970s as nuclear submarines like HMS Dreadnought (S101) and Vanguard-class submarine altered Royal Navy force composition.
Operationally the Porpoise class served as anti‑surface and anti‑submarine platforms conducting patrols in the North Atlantic Treaty Organization theatre, North Atlantic convoy routes, and the Mediterranean Sea, including deployments to Gibraltar and exercises off Scapa Flow. Deployments supported intelligence collection during Cold War incidents such as monitoring Northern Fleet (Soviet Union) movements and shadowing Soviet Navy surface task groups near the Barents Sea. The submarines also conducted training support for carrier groups including HMS Ark Royal (R09) and provided platforms for torpedo and sonar trials in concert with establishments like the Submarine Command Course.
Although no major subclass split occurred, individual boats received varied refits: battery upgrades, snorkel improvements, sonar enhancements derived from Type 2001 sonar research, and hull treatments to reduce acoustic signature influenced by Admiralty Research Establishment programmes. Proposals for diesel‑electric air‑independent propulsion (AIP) conversions were examined by the Ministry of Defence (United Kingdom) and private firms but not implemented. Some boats served as testbeds for towed array sonar experiments later used on Oberon-class submarine and Swiftsure-class submarine developments.
No complete Porpoise‑class boat survives as a public museum ship; elements such as periscopes and control‑room fittings were preserved by institutions including the National Museum of the Royal Navy and maritime museums at Portsmouth and Greenock. The class influenced later designs—hydrodynamic lessons fed into the Oberon-class submarine and acoustic treatment practices informed Royal Navy Submarine Service doctrine and NATO ASW tactics. Historians at the Imperial War Museum and researchers from the National Maritime Museum recognize the Porpoise class as a pivotal transition between wartime designs and the advent of nuclear propulsion epitomized by HMS Dreadnought (S101).
Category:Submarine classes of the Royal Navy Category:Cold War submarines of the United Kingdom