Concern about the higher speeds of foreign boats had prompted to Admiralty to order new destroyers capable of 30kn, rather than the 27kn requirement which had been standard. The boats were not able to make this speed in bad weather, where they were usually wet and uncomfortable with cramped crew quarters, but they proved their toughness in serving through World War I, despite being twenty years old. Thanks to their watertight bulkheads, their thin plating and light structure they were able to take a great deal of damage and remain afloat, although their plates buckled easily, affecting their handling.
The ships were fitted with Normand boilers which generated around 6300hp. They were armed with the standard 12-pounder gun and two torpedo tubes and carried a complement of 63 officers and ratings.
In 1913 the Ernest class, along with all other surviving "30 knotter" vessels with 4 funnels, were classified by the Admiralty as the B-class to provide some system to the naming of HM destroyers (at the same time, the 3-funnelled, "30 knotters" became the C-class and the 2-funnelled ships the D-class).