Type system of the Royal Navy
The Type system is a classification system used by the British Royal Navy to classify surface escorts by function. The system evolved in the early 1950s, when the Royal Navy was experimenting with building single-purpose escort vessels with specific roles in light of experience gained in World War II. The original numbering scheme was:
Type 1X were Anti-Submarine frigates.
Type 3X were General-Purpose frigates
Type 4X were Anti-Aircraft frigates.
Type 6X were Aircraft-Direction frigates.
Type 8X were multi-role ships. An Admiralty Fleet Order defined these ships as "destroyers" if they could achieve "fleet speed" or as "sloops" if they could not.
Types 11-30, anti-submarine frigates
Type 11 : Diesel powered anti-submarine frigate based on hull of Type 41 / 61. Not built.Type 12 Whitby-class : Steam powered, high-speed "first-rate" anti-submarine frigate.Type 12M Rothesay-class : Modified Type 12 design.Type 12I Leander : Improved Type 12, general purpose frigate. Also produced as the,, and for other naviesType 14 Blackwood : Steam powered, high-speed, "second-rate" anti-submarine frigate. Type 15 : High-speed anti submarine frigate, produced by full conversion of wartime built destroyers of the R-, T-, U- and V- and W and Z-classes.Type 16 : High-speed anti submarine frigate, produced by a limited conversion of wartime T-class, O- and P-class destroyers.Type 17 : "Third-rate" anti-submarine frigate, analogous to wartime corvettes. Design abandoned in 1953 and not built.Type 18 : High-speed anti submarine frigate, intermediate conversion of wartime destroyer hulls of the N-, S-, T and Z- classes. Design abandoned in 1953 and not built.- Type 19 : Very high speed gas turbine powered anti-submarine frigate. Design abandoned in 1965. Not built.Type 21 Amazon-class: General purpose, gas-turbine powered commercially designed frigate. Type 22 Broadsword-class : Large, gas-turbine powered, anti-submarine frigates. Type 23 Duke-class : Gas-turbine and diesel powered, anti-submarine frigates. Smaller and less expensive than the Type 22, with similar capabilities. 16 built.Type 24 : Cheap frigate design intended for export. In RN service would have served as a towed array ASW ship. Not built.Type 25 : More capable development of the Type 24, designed to have almost the capability of a Type 22 but at only three-quarters of the cost. Much of the thinking, including the diesel-electric machinery, went into the Type 23. Not built.Type 26 : "Global Combat Ship" : First announced in March 2010, and formerly known as the Future Surface Combatant. Initial orders placed in February 2014.