The B class as designated in 1913 was a heterogeneous group of torpedo boat destroyers (TBDs) built for the Royal Navy in the late 1890s. They were constructed to the individual designs of their builders to meet Admiralty specifications, the uniting feature being a specified top speed of and 4 funnels, although the funnel spacings differed between ships. All "30 knotter" vessels with 4 funnels were classified by the Admiralty as the B class in 1913 to provide some system to the naming of HM destroyers.