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 7,040 bhp (5,250 kW), drove General Electric Company (GE) generators (4,800 kW) that supplied power to two GE electric motors, with an output of 6,000 shp (4,500 kW), for a speed of 20 knots (37 km/h; 23 mph). It had been intended to provide another set of this machinery for an output of 12,000 shp (8,900 kW), to make the design speed of 24 knots (44 km/h; 28 mph), 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 13,500 shp (10,070 kW) steam turbines and generators (9,200 kW). Electric motors for 12,000 shp (8,900 kW) drove the two shafts, each fitted with a three-bladed propeller of solid manganese-bronze that was 8.5 feet (2.6 m) in diameter. This all-electric drivetrain was considered particularly innovative at the time (although the Catherine-class minesweepers had a similar arrangement).
Read more about this topic: Captain Class Frigate