O'Brien Class Destroyer - Design

Design

As built, the O'Brien class ships were 305 feet 5 inches (93.09 m) in length (overall), were 31 feet 2 inches (9.50 m) abeam, and had a standard draft of 9 feet 6 inches (2.90 m). The hull shape featured the distinctive high forecastle typical of U.S. destroyer classes since the 1908–09 Smith class, the first destroyers designed to be truly ocean-going vessels. The ships displaced between 1,020 and 1,090 long tons (1,040 and 1,110 t) with a median of 1,050 long tons (1,070 t).

The ships were equipped with two propeller shafts and two direct-drive, Zoelly 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 inefficiency 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 USS Winslow (DD-53) 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.

The main battery of the O'Brien class consisted of four 4-inch (100 mm)/50 Mark 9 guns, with each gun weighing in excess of 6,100 pounds (2,800 kg). The guns fired 33-pound (15 kg) armor-piercing projectiles at 2,900 feet per second (880 m/s). At an elevation of 20°, the guns had a range of 15,920 yards (14,560 m).

The O'Brien ships were also equipped with four twin 21-inch (533 mm) torpedo tubes, for a total load of eight torpedoes. Although the General Board had called for two anti-aircraft guns for the O'Brien class, they were not originally outfitted with the weapons; the later Sampson class was the first American destroyer class so armed. Likewise, there is no record of any of the O'Brien ships being outfitted with mine-laying apparatus. During World War I, most American destroyers were used in anti-submarine warfare roles, and were equipped with depth charges and delivery systems, such as Y-guns and depth charge racks. O'Brien-class ships were equipped with depth charges during the war, but no specific mentions of the types of depth charges used or delivery system are recorded in secondary sources.