 The ships were equipped with two propeller shafts and two Curtis steam turbines fed by four Yarrow boilers , providing a minimum of 17 @,@ 000 shaft horsepower ( 13 @,@ 000 kW ) to achieve the design speed of 29 @.@ 5 knots ( 54 @.@ 6 km / h ) . For all of the ships except Wadsworth , the pair of main turbines was supplemented with a cruising turbine geared to one of the shafts . Wadsworth had no cruising turbines , but instead had her twin turbines geared directly to the propeller shafts — the first American destroyer so outfitted . She served as a testbed , and had a considerable effect on U.S. destroyer design after her trials in July 1915 . 
