The Amphion class (also known as the "A" class) of diesel-electric submarines were ordered by the Admiralty in 1943. 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 featured an effective air conditioning system 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 and 16 of them actually commissioned. The remaining two hulls were used for crush testing before being scrapped.

The Amphion class was one of only two new British designs produced during World War II - the other being the X-craft 4-man submarines. Wartime experience had shown that submarines had to operate at greater distances from the United Kingdom - in the Fast East and Mediterranean for example; and with larger patrol areas than had been forseen, and consequently the A class was slightly larger and had greater range and habitability than the T class.

It was also designed for quicker construction - the hull was entirely welded and could be fabricated in sections. These techniques were new for the British although already standard practice for German U-boat construction. This meant that they took an average of 8 months from keel laying to launching, compared with around 15 months for the T class.

However, only two of the boats were completed before the end of the war — Amphion was launched in August 1944, followed by Astute in January 1945 and neither saw enemy action.

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.

In response to the start of the cold war in the early 1950s, their role changed from being anti-shipping warships to targetting Soviet submarines. This required the upper decks and conning towers to be streamlined and deck guns removed to make them faster and quieter underwater, and the sonar greatly improved.

The Amphion class served the Royal Navy for almost three decades, and was gradually replaced with the Porpoise and Oberon classes. The last operational Amphion-class boat, Andrew , was decommissioned in 1974.

1 General Characteristics

Contents

1 Built at Vickers-Armstrong, Barrow-in-Furness 2 Built at Cammell Laird, Birkenhead 3 Built at Scotts of Greenock 4 Built at HM Dockyard, Chatham

Built at Vickers-Armstrong, Barrow-in-Furness

• Amphion (P439/S43) (laid down as Anchorite but name changed before launch)
• Astute (P447)
• Auriga (P419)
• Aurochs (P426)
• Alcide (P415)
• Alderney (P416/S66)
• Alliance (P417/S67) (now at HM Submarine Museum, Gosport)
• Ambush (P418)
• Anchorite (P422) (originally laid down as Amphion but name changed before launch)
• Andrew (P423)

Built at Cammell Laird, Birkenhead

• Affray (P421) (the last British submarine lost at sea)
• Aeneas (P427)
• Alaric (P441)

Built at Scotts of Greenock

• Artemis (P449/S49)
• Artful (P456)

Built at HM Dockyard, Chatham

• Acheron (P411)

In 1945, orders were canceled for Andromache, Answer, Antagonist, Antaeus, Anzac, Aphrodite, Approach, Arcadian, Argent, Argosy, and Atlantis from Barrow-in-Furness, and Abalord, Acasta, Ace, Achates, Adept, Admirable, Adversary, Agate, Aggressor, Agile, Aladdin, Alcestis, Asgard, Asperity, Assurance, Astarte, Austere, Awake, and Aztec from other yards.

General Characteristics

• Displacement: 1385 tons surfaced, 1620 tons submerged
• Length: 280.5 feet
• Beam: 22.3 feet
• Draught: 16.8 feet
• Operating Depth: 500 feet
• Shafts: 2
• Speed: 18.5 knots surfaced, 8 knots submerged
• Endurance:
  • 10,500 miles at 11 knots surfaced
  • 16 miles at 8 knots submerged
  • 90 miles at 3 knots submerged
• Armament
  • Torpedoes: six 21-inch bow tubes (2 external, one-shot, later removed), four 21-inch stern tubes (2 external, one-shot, later removed), 16 torpedoes or 26 mines carried internally
  • Guns: one four-inch gun, one 20mm Oerlikon anti-aircraft cannon, three .303-caliber machine guns
• Complement: 61 officers and men