of the first order and were authorised later by Public Law 440 effective 6 February 1942. The Royal Navy placed orders in November 1941 with four shipyards: the Boston Navy Yard, the Mare Island Navy Yard, the Philadelphia Naval Shipyard and the Puget Sound Navy Yard. When the United States entered the war, they too adopted the BDE design. The BDE designation was retained by the first six destroyer escorts (BDEs 1, 2, 3, 4, 12 and 46) transferred to the United Kingdom. Of the initial 50 ordered, these were the only ones the Royal Navy received; the rest were reclassified as destroyer escorts (DE) on 25 January 1943 and taken over by the United States Navy. By the end of World War II the Royal Navy had received 31 Evarts from Boston Navy Yard, 1 from Philadelphia Navy Yard and 46 Buckleys from Bethlehem-Hingham. The Royal Navy classified these ships as frigates, as they lacked the torpedo tubes needed for a destroyer classification. For those used to Admiralty-designed ships the Captains were unfamiliar: they had no break forward of the forecastle but instead had a graceful shear to deck-line from the forecastle to midship, and the Evarts had raked cowls on top of the funnels. Those who served on these ships came to view these features as being very handsome. Amongst the differences with British-designed vessels were using bunks instead of hammocks and welds instead of rivets. Propulsion The Evarts subclass had diesel-electric machinery, based on an arrangement used for submarines. There were two shafts. Four Winton 278A 16-cylinder engines, with a combined rating of , drove General Electric Company (GE) generators (4,800 kW) that supplied power to two GE electric motors, with an output of , for a speed of . It had been intended to provide another set of this machinery for an output of , to make the design speed of , but hull production greatly outstripped that of the machinery; therefore, only one set of machinery was used per ship. In order to make the designed speed, the Buckley subclass had turbo-electric machinery. Two Foster Wheeler Express "D"-type water-tube boilers supplied steam to GE steam turbines and generators (9,200 kW). Electric motors for drove the two shafts, each fitted with a three-bladed propeller of solid manganese-bronze that was in diameter. This all-electric drivetrain was considered particularly innovative at the time, although the s (known as