The Royal Navy's Type classification system

After the Second World War, the Royal Navy adopted a system that classified surface escorts by function:

• Type 1X (and later Type 2X) were Anti-Submarine Frigates
• Type 4X were Anti-Aircraft Frigates (this later evolved into the "Destroyer" Type series)
• Type 6X were Aircraft-Direction Frigates
• Type 8X were Multi-Role Destroyers

The following is a list of the surface escort Types:

• Type 11: Diesel powered anti-submarine frigates based on hull of Type 41/61 frigates. NOT BUILT
• Type 12: Whitby-class: Steam powered, high-speed first-rate anti-submarine frigates.
• Type 12M: Rothesay-class: Modified version of the original Type 12 design.
• Type 12I: Leander-class: An improved Type 12, general purpose frigate; a very successful design which was used by the Royal Navy, the Royal Australian Navy, the Royal New Zealand Navy; the Indian Navy, the Royal Netherlands Navy, the Chilean Navy, and the Indonesian Navy (ex-Netherlands).
• Type 14: Blackwood-class: Steam powered, high-speed, second-rate anti-submarine frigates.
• Type 15: High-speed anti submarine frigates; these were full conversions of wartime destroyers from R, T, U, V, W, and Z class.
• Type 16: High-speed anti submarine frigates; these were limited conversions of wartime destroyers from the O, P, and T classes.
• Type 17: A third-rate anti-submarine frigates, similar in concept to the wartime corvettes. NOT BUILT
• Type 18: High-speed anti-submarine frigates; these were an intermediate conversion of wartime destroyers of the N, S, T, and Z classes. NOT BUILT
• Type 19: Very high-speed gas-turbine powered anti-submarine frigates. NOT BUILT
• Type 21: Amazon-class: Commercially-designed gas-turbine powered general purpose frigates.
• Type 22: Broadsword-class: Large, gas-turbine powered, anti-submarine frigates.
• Type 23: Duke-class: Gas-turbine and diesel powered, anti-submarine frigates.
• Type 24: A cheap frigate design intended for export. NOT BUILT
• Type 25: A more capable development of the Type 24 design. NOT BUILT
• Type 26: Formerly known as the Future Surface Combat Ship, it is now called the Global Combat Ship. (Eight are projected to be built, with the first coming into service in the mid 2020s.)
• Type 31: A proposed lighter, cheaper, general purpose frigate to supplement the Type 26. (Five are projected to be built, with the first coming into service in the mid 2020s.)
• Type 41: Leopard-class: Diesel-powered anti-aircraft frigate; it shared its hull design with the Type 61 frigate.
• Type 42(i): High-speed coastal escort; also known as the East Coast frigate. NOT BUILT
• Type 42(ii): Sheffield-class: Gas-turbine powered, fleet area-defence anti-aircraft destroyer.
• Type 43: Large gas-turbine powered, fleet area-defence anti-aircraft destroyer. NOT BUILT
• Type 44: A smaller version of the Type 43 intended as a cheaper alternative. NOT BUILT
• Type 45: Daring-class: Fleet area-defence anti-aircraft destroyer.
• Type 61: Salisbury-class: Diesel powered aircraft-direction frigate; it shared its hull design with the Type 41 frigate.
• Type 62: M-class: High-speed aircraft-direction frigate; full conversion of wartime destroyers of the M-class. NOT BUILT
• Type 81: Tribal-class: Steam/gas-turbine powered, general purpose frigates; intended for ‘showing the flag’ in areas that were former British colonies or that had been part of the UK ‘sphere of influence’.
• Type 82: Bristol-class: Large steam/gas-turbine powered fleet anti-aircraft and anti-submarine destroyers.

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The proposed Black Swan-class ‘sloop-of-war’ – some of whose projected roles would normally be performed by a light frigate – has not yet been given a Type classification.