were a length of , a speed of , a dual purpose main armament and an open bridge. The United States Navy had been looking into the feasibility of such a vessel since 1939, and Captain E. L. Cochrane of the US Navy's Bureau of Ships – who, during his visit to the United Kingdom in 1940, had looked at Royal Navy corvettes and s – had come up with a design for such a vessel. This design anticipated a need for large numbers of this type of vessel, and had sought to remove the major production bottleneck for such vessels: the double helical reduction gearing required for the steam turbine machinery of destroyers. The production of reduction gears could not be easily increased, as the precision machinery required for their construction alone took over a year to produce. Therefore, a readily-available and proven layout of diesel-electric machinery, also used on submarines, was adopted. When the United Kingdom made its request, Admiral Stark of the US Navy decided to put these plans into motion and recommended that the British order be approved. Gibbs and Cox, the marine architects charged with creating working plans, had to make several alterations to the production methods and to Captain Cochrane's original design, most notably dropping another production bottleneck – the 5-inch/38-caliber gun – and replacing it with the 3-inch/50-caliber gun, which allowed adding a superfiring third gun (at the "B" position, forward); also, the original design specified eight engines for but other priority programs forced the use of only four with a consequent shortening of the hull and reduction of the ship's maximum speed by an estimated . The design had relatively light armour with for example the steel plate used on the Buckleys ranging from 1/2 inch to 7/16 inch with 1/4 inch plate being used for the majority of the hull and deck plating. The result was a vessel that could be produced quickly (for example Halsted was built in just 24 and half days) at half the cost of a fleet destroyer, ($3.5 million compared to $10.4 million for a 1,620-ton destroyer such as the US or $6.4 million for British Hunt-class destroyer.) On 15 August 1941 President Franklin D. Roosevelt authorised the construction of 50 of the new Evarts-class design as BDE 1–50 (British destroyer escort) as part of the 1799 program. The turbo-electric powered Buckley class were not part