 The ships were equipped with two propeller shafts and two direct @-@ drive , <unk> steam turbines fed by four White @-@ Forster boilers . The power plant of the ships generated 17 @,@ 000 shaft horsepower ( 13 @,@ 000 kW ) which drive the ships to the design speed of 29 knots ( 54 km / h ) . Because of inherent <unk> of turbines at low speeds , all of the ships were equipped with supplemental cruising engines for travel at speeds under 15 knots ( 28 km / h ) . All except Cushing were equipped with supplemental triple @-@ expansion reciprocating engines : O 'Brien , Nicholson , and Winslow each had a pair of reciprocating engines for cruising ; McDougal and Ericsson were outfitted with only one . Instead of reciprocating engines , Cushing was equipped with a pair of geared steam turbines for cruising . 
