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HMS Alliance at Gosport submarine museum
|Builders:||Vickers Armstrong, Barrow-in-Furness
Cammell Laird, Birkenhead
Scotts of Greenock
HM Dockyard, Chatham
|Succeeded by:||Explorer class|
|In service:||1945 - 1974|
|Completed:||46 planned, 16 commissioned|
|Displacement:||1,385 tons surfaced, 1,620 tons submerged|
|Length:||280.5 ft (85.50 m)|
|Beam:||22.3 ft (6.80 m)|
|Draught:||16.8 ft (5.12 m)|
|Speed:||18.5 knots (34.3 km/h) surfaced
8 knots (10 km/h) submerged
|Range:||10,500 nautical miles (19,400 km) at 11 knots (19,400 km at 20 km/h) surfaced
16 nautical miles at 8 knots (30 km at 10 km/h) submerged
90 nautical miles at 3 knots (170 km at 6 km/h) submerged
|Test depth:||500 ft (150 m)|
|Complement:||61 officers and men|
|Armament:||six 21 inch (530 mm) bow torpedo tubes (2 external, one-shot, later removed)
four 21 inch (530 mm) stern torpedo tubes (2 external, one-shot, later removed)
16 torpedoes or 26 mines carried internally
one four-inch gun, one Oerlikon 20 mm gun, three .303-caliber machine guns
The Amphion class (also known as the "A" class and Acheron class) of diesel-electric submarines were ordered by the British Admiralty in 1943, upon the realisation that the new Pacific theatre of war following the attack on Pearl Harbor needed a new type of submarine. They were originally designed to replace the S-class and T-class submarines, which were too slow and unable to dive deep enough to be suited to Pacific waters during World War II. They were an enlargement of the T class, arranged for fast, simple construction and to utilize much of the materials and equipment set aside for the T boats. They had a high, flared bow for excellent sea performance and had effective air conditioning, essential for Far East submarine operations. They were operated by a crew of between 60 and 68.
Originally, 46 submarines were ordered, but only 18 were launched (10 by Vickers-Armstrong in Barrow-in-Furness) and 16 commissioned, the other 2 hulls being used for crush testing. The class was designed for quick construction, using an entirely welded hull which could be fabricated in sections, a technique new to Britain but standard for German U-boats. Each submarine took about 8 months from keel-laying to launching, compared with around 15 months for the earlier T class, but only two of the boats were completed before the end of the war: Amphion, launched in August 1944, and Astute in January 1945; neither saw action.
The Amphion class was one of only two new British submarine designs produced during World War II, the other being the X-craft 4-man submarines. Wartime experience had shown that submarines had to operate further from the United Kingdom and with larger patrol areas than had been foreseen—in the Far East and Mediterranean for example—so the faster and slightly larger A class was designed to have a longer range than the T class, and accommodation suitable for longer missions.
After World War II various modifications were made to these Overseas Patrol Submarines, as they were known. A snort mast based on the schnorkel used by U-boats during the war, a radar which could be used from periscope depth, and a night periscope were added to the A- and surviving T-class submarines.
In response to the start of the cold war in the early 1950s their target changed from surface ships to Soviet submarines. In January 1948 the primary operational function of the British submarine fleet was announced to be interception of Soviet submarines slipping out of their bases in Northern Russia, potentially to attack British and Allied merchant vessels. The following April Assistant Chief of Naval Staff Rear-Admiral Geoffrey Oliver circulated a paper in which he proposed that British submarines take a more offensive role, attacking Soviet submarines off the Northern Russian coast and mining the waters in the area. With the dramatically reduced surface fleet, he commented that this was one of the few methods the Royal Navy had for "getting to the enemy on his home ground".
The A- and T-classes were refitted for their new role between 1955 and 1960 with a complete rebuild of the forward and after hull section, lengthening and streamlining of the upper decks and conning towers, removal of deck guns to improve underwater speed and noise, removal of external torpedo tubes, and greatly improved sonar. When Affray was lost in 1951 all the Amphion class were briefly confined to port pending investigation into her loss.
The Amphion class served the Royal Navy for almost three decades as the backbone of the Royal Naval Submarine Service, and was gradually replaced with the Porpoise and Oberon patrol classes that began to be phased in 1958. The last operational Amphion-class boat, Andrew, was decommissioned in 1974.
Built at Vickers-Armstrong, Barrow-in-Furness 
- Amphion (P439/S43) (laid down as Anchorite but name changed before launch)
- Astute (P447)
- Auriga (P419/S69)
- Aurochs (P426)
- Alcide (P415/S65)
- Alderney (P416/S66)
- Alliance (P417/S67) (now at Royal Navy Submarine Museum, Gosport)
- Ambush (P418)
- Anchorite (P422) (originally laid down as Amphion but name changed before launch)
- Andrew (P423/S63)
Built at Cammell Laird, Birkenhead 
Built at Scotts Shipbuilding and Engineering Company of Greenock 
Built at HM Dockyard, Chatham 
Built at HM Dockyard, Plymouth 
These were the two vessels which were launched but not completed.
Cancelled orders 
In 1945, besides the two vessels at Devonport, the following twenty-seven orders were cancelled:
Scotts of Greenock
See also 
Media related to Amphion class submarines at Wikimedia Commons
Notes and references