Benham-class destroyer

Except for the 1850-ton Somers class, the Benhams' propulsion plant was the most advanced yet installed in US destroyers. A new Babcock & Wilcox boiler design was used that allowed a reduction from four boilers to three, saving considerable space and weight. Steam pressure was increased from 400 psi (2,800 kPa) to 600 psi (4,100 kPa) (one reference says 565 psi), superheated to 700 °F (371 °C) as in the Gridleys.[2][7][8] Features that improved fuel economy included boiler economizers, double reduction gearing, and cruising turbines. Range was somewhat less than in the Bagleys at 5,390 nmi (9,980 km; 6,200 mi) versus 6,940 nmi (12,850 km; 7,990 mi), possibly due to a smaller fuel capacity of 484 tons versus 504 tons. The main turbines developed 49,250 shp (36,730 kW) on Benham's trials and were manufactured by Westinghouse.[9]

The Benhams had the same armament as the Gridleys and Bagleys: four 5-inch/38 caliber dual purpose guns (anti-surface and anti-aircraft (AA)) in single mounts and sixteen 21-inch (533 mm) torpedo tubes in quadruple mounts.[3] The Mark 15 torpedo was equipped.[10] This was the heaviest armament in torpedoes ever on US destroyers. Compared with the Mahans, they sacrificed one gun for four additional torpedo tubes. It was suggested that these ships could use "curved ahead fire", using the adjustable post-launch gyro angle of their torpedoes to launch a sixteen-torpedo spread ahead of the ship.[3] One reason for the heavy destroyer torpedo armament was that, alone among the major navies, the last nine of the seventeen US Treaty cruisers built in the 1920s and 1930s lacked torpedoes; eventually all of the US Treaty cruisers' torpedoes were removed in 1941 in favor of additional heavy AA guns.[11]

As with most other US destroyers of this period, the 5-inch guns featured all-angle power loading and were director controlled, making them as effective as the technology allowed against aircraft. By late 1942, radio proximity fuses (VT fuses) made them much more effective. As in the last two Maurys, the two forward 5-inch guns were in enclosed mounts, while the after guns were open. However, in the Benhams, the after two mounts were a Mark 30 Mod 1 base-ring type with an integral ammunition hoist fed from a handling room below each gun, as in an enclosed mount.[3][6][12] This allowed some of the class to be fitted with an enclosure for No. 4 gun and an open-top shield for No. 3 gun while on Neutrality Patrol in the Atlantic in 1941; but the shields were removed later to save weight for light anti-aircraft armament.[5][13] In common with all US surface combatants in the 1930s, the as-built light AA armament was weak; only four .50 caliber machine guns (12.7 mm) were equipped. It was apparently felt that the heavy AA armament would shoot down most incoming aircraft in all situations, but the attack on Pearl Harbor showed that this was not true.[14]

While on Neutrality Patrol, some of the class landed their after torpedo tube mounts and .50-caliber machine guns so that their Depth charge and light AA batteries could be increased; photographs show six Oerlikon 20 mm cannon were added along with four K-gun depth charge throwers and, reportedly, a Y-gun on some ships.[15][16] These ships later received two twin 40 mm Bofors mounts on their after deckhouses before being transferred to the Pacific. In 1945, Lang, Sterett, and Wilson also landed their remaining torpedo tubes and after 5-inch gun shields in favor of a total of four 40 mm twin mounts and four 20 mm twin mounts.[5][17]

• Bauer, K. Jack; Roberts, Stephen S. (1991). Register of Ships of the U.S. Navy, 1775-1990: Major Combatants. Westport, Connecticut: Greenwood Press. ISBN 0-313-26202-0.
• Friedman, Norman (2004). US Destroyers: An Illustrated Design History (Revised ed.). Annapolis: Naval Institute Press. ISBN 1-55750-442-3.
• Gardiner, Robert; Chesneau, Roger (1980). Conway's All the World's Fighting Ships 1922-1946. London: Conway Maritime Press. ISBN 0-83170-303-2.
• Silverstone, Paul H. (1965). U.S. Warships of World War II. London: Ian Allan Ltd.
• This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.