Upholder class — first Royal Navy diesel submarines to be completed of the ‘albacore’ teardrop hull shape. Of 2,400 tons surface displacement and designed for the ASW role, they could also embark Sub-Harpoon anti-ship missiles. Four were built and the class had a top underwater speed of 18 knots. Soon after completion of the first, HMS Upholder in 1988, as a cost-savings measure the decision was made to dispose of all the hulls once they were completed. All were sold to the Royal Canadian Navy in the late 1990s.
Explorer and Excalibur — two 800 tons surface displacement experimental unarmed submarines completed in the late 1950s and propelled by steam turbines fuelled by High Test Peroxide (HTP). Reached 26 knots dived but HTP proved very volatile and this type of propulsion was eclipsed by the advent of nuclear power at sea in submarines. Both were disposed of in the early 1960s.
HMS Dreadnought — prototype completed in 1963 of 3,500 tons surface displacement and capable of 30 knots dived. Design based upon the USN Skipjack class and was powered by a Westinghouse reactor and machinery. Noisy and not a very capable ASW platform, it was withdrawn from service in 1980.
Valiant class — all-British design but nuclear reactor was based upon the US S5W plant. Had significant noise reduction features and prime role was ASW with secondary role of anti-ship. Maximum speed 26 knots dived. Class of five built between 1966 and 1971. Latterly armed with the Sub-Harpoon missile and Tigerfish dual role torpedo. All withdrawn from service by 1992.
Swiftsure class — second-generation attack submarines; quieter, faster and deeper diving than Valiant class. Prime role was ASW but Tigerfish/Spearfish dual-role torpedoes and Sub-Harpoon missiles gave them a good anti-ship capability. Six were built between 1973 and 1981 and all withdrawn from service by 2010.
Trafalgar class — improved Swiftsure class with slightly bigger hull and similar performance. Fitted with improved sonar systems. Seven were completed between 1982 and 1991. Armed with Spearfish torpedoes and Sub-Harpoon anti-ship missiles; in the late 1990s the latter were replaced with Tomahawk missiles which provide a thousand-mile-plus range land-attack capability
Astute class — class of seven planned to replace the Trafalgar class, first HMS Astute commissioned in 2010. At 7,500 tons surface displacement, this class of SSN is significantly larger than previous classes and has much greater weapon capacity, carrying the Spearfish torpedo and Tomahawk missile.
Resolution class — armed with sixteen Polaris intercontinental ballistic missiles, four of this class were completed between 1967 and 1970 and constituted the UK’s independent nuclear deterrent between 1969 and the mid 1990s.
Vanguard class — armed with up to sixteen Trident D5 intercontinental ballistic missiles, the four vessels of this class were completed between 1993 and 2001. Of 14,500 tons surface displacement, the first deployed on patrol in 1994.
Fleet boats — large numbers built in the Second World War (300-plus hulls), many of which were streamlined and converted to the ASW role post-war. Considerable numbers were modernised under the Greater Underwater Propulsion Programme (GUPPY) which gave them much greater underwater endurance and burst speeds of 15 knots dived. Many were sold to overseas navies, but this class had been disposed of in the USN by the early 1970s.
Barbel class — the last diesel submarines built for the USN, a class of three completed in 1959/60. Of ‘teardrop’ hull construction, these submarines had a dived burst speed exceeding 20 knots.
Nautilus — the world’s first nuclear-powered submarine, commissioned in 1955. Of 3,500 tons surface displacement, had a maximum dived speed of 25 knots. Both ASW and anti-ship capable. Decommissioned from active service in 1980.
Skipjack class — completed between 1959 and 1960, six of a class. First nuclear submarines of ‘albacore’ hull form and single propeller. Fitted with the S5W reactor. Capable of 30 knots dived. Last of class paid off in 1986. Primarily had an ASW role and were armed with Mark 37 and Mark 48 torpedoes.
Thresher class — fourteen submarines completed between 1960 and 1967, of 3,700 tons surface displacement. Prime role was ASW and in addition to being armed with Mark 37 and Mark 48 torpedoes, embarked the Sub-Roc stand-off missile fitted with a nuclear depth-bomb.
Tullibee — one of a type, small ASW SSN of 2,200 tons surface displacement but limited to a maximum dived speed of 16 knots.
Sturgeon class (‘637’ class) — the workhorse of the US Submarine Fleet in the 1970s and 1980s, thirty-seven of this class were completed between 1967 and 1975. They had a prime role of ASW. Similar in size, performance and armament to the Thresher class; for the anti-ship role, in addition to the Mark 48 torpedo they embarked either Sub-Harpoon or Tomahawk ship-attack missiles. Possessed an excellent under-ice capability.
Los Angeles class (‘688’ class) — designed to achieve a speed well in excess of 30 knots dived, these are large — 6,500-ton surface displacement — SSNs fitted with the powerful S6G reactor. Sixty-two of these vessels were completed between 1976 and 1996. Prime role is ASW but later versions were armed with vertical launch tubes for Tomahawk land-attack missiles. Armed with the dual-role Mark 48 Adcap torpedo. Earlier vessels of the class started decommissioning in the 1990s.
George Washington class — five of this class were completed between 1959 and 1961 using the basic Skipjack-class hull configuration and S5W power plant. Of 6,000 tons surface displacement. Fitted with sixteen intercontinental ballistic missile tubes and the Polaris missile system. Class phased out in the 1980s.
Ethan Allen and Lafayette class — thirty-six of this all-SSBN designed class were built between 1961 and 1967. Similar to George Washington class, were fitted with sixteen missile tubes and in the 1980s were outfitted with the Trident C4 weapon system which replaced Polaris. Were all decommissioned by the 1990s.
Ohio class — eighteen of these 18,500-ton submarines were completed between 1981 and 1997. Armed with up to twenty-four Trident D5 missiles, four of these vessels have been decommissioned as SSBNs and converted to undertake a land-attack missile (Tomahawk) role.