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 30 kn and four funnels, although the funnel spacings differed between ships. All "30 knotter" vessels with four funnels were classified by the Admiralty as the B class in 1913 to provide some system to the naming of HM destroyers. At the same time all "30 knotter" vessels with three funnels were classified by the Admiralty as the C-class destroyer (1913) and those with two funnels became the D-class destroyer (1913). Fourteen vessels were built by Laird Brothers at Birkenhead (in 1903 to become part of Cammell Laird, Birkenhead), seven by Palmers Shipbuilding and Iron Company at Hebburn-on-Tyne, and one each by Armstrong Whitworth at Walker-on-Tyne, William Doxford and Sons at Sunderland, and J & G Thomson (later to become John Brown and Company) at Clydebank. All vessels had a distinctive "turtleback" forecastle that was intended to clear water from the bow, but actually tended to dig the bow into anything of a sea, resulting in a very wet conning position. They generally displaced around 350 tons, one third more than the preceding A-class destroyer (1913), giving an increase in speed of 3 kn over the "27 knotters". Length was around 210 ft. All were powered by triple expansion steam engines and had coal-fired water-tube boilers. However, Albacore, Arab, Bonetta, Cobra and Express were builder's specials, and had steam turbines fitted in addition to, or in lieu of, the reciprocating engines, giving 6000 SHP to 9000 SHP for 26.75 to 31 kn. Armament was one QF 12-pounder gun on a raised platform at the rear of the forecastle, five QF 6-pounder guns (two sited abreast the conning tower, two sited between the funnels and one on the quarterdeck) and 2 single torpedo tubes for 18-inch (450 mm) torpedoes. The last two Palmers boats, built in 1908, were replacements for the River-class destroyer Gala and the C-class Tiger that had collided and sunk that year. They were generally similar to the River (or E-class) design, but were grouped with the B class as they possessed four funnels and were similarly armed, and made 27 kn on turbines.

Ships