Allen M. Sumner-class destroyer

USS Lyman K. Swenson in 1955
Class overview
Name	Allen M. Sumner class
Builders	Federal Shipbuilding, NJ (18) Bath Iron Works, ME (14) Bethlehem Staten Island, NY (10) San Francisco, CA (6) San Pedro, CA (5) Todd Pacific Seattle, WA (5)
Operators	United States Navy  Argentine Navy  Brazilian Navy  Chilean Navy  Republic of China Navy  Colombian National Navy  Hellenic Navy  Republic of Korea Navy  Turkish Navy  Imperial Iranian Navy  Islamic Republic of Iran Navy  Bolivarian Navy of Venezuela
Preceded by	Fletcher class
Succeeded by	Gearing class
Subclasses	Robert H. Smith class Daegu class Seguí class Mato Grosso class
Cost	$8 million, excluding armament
In commission	1943–75 (USN)
Planned	70
Completed	58
Cancelled	12 (completed as Robert H. Smith class minelayers)
Lost	4, plus 2 not repaired
Preserved	USS Laffey
General characteristics
Type	Destroyer
Displacement	2,200–2,220 tons standard 3,515 tons full load
Length	369 ft (112 m) waterline 376 ft 6 in (114.76 m) overall 376 ft (115 m) overall (DD 725–728 & 730–734)
Beam	41 ft (12.5 m) 40 ft (12 m) (DD 692–709) 40 ft 9 in (12.42 m) (DD 744) 41 ft 3 in (12.57 m) (DD 770–776)
Draft	15 ft 9 in (4.80 m) normal 19 ft (5.8 m) full load 18 ft 9 in (5.72 m) full load (DD 735-40 & 749–751 & 771–773)
Propulsion	4 Babcock & Wilcox or Foster Wheeler boilers; two General Electric or Westinghouse geared steam turbines, 60,000 shp (45 MW) total; two shafts
Speed	34 knots (63 km/h; 39 mph)
Range	6,000 nautical miles (11,000 km; 6,900 mi) at 15 knots (28 km/h; 17 mph) 503 tons oil fuel (except DD 692–709 500 tons, DD 735–740 515 tons)
Complement	336–363
Sensors and processing systems	Mk37 GFCS 1 × SC radar
Armament	As built: 6 × 5 in/38 cal guns (127 mm) (in 3 × 2 Mk 38 DP mounts) 12 × 40 mm Bofors AA guns (2 × 4 & 2 × 2) 11 × 20 mm Oerlikon cannons 2 × Depth charge racks 6 × K-gun depth charge throwers 10 × 21 in (533 mm) torpedo tubes Typical by 1950: 6 × 5 in/38 cal guns (127 mm) (in 3 × 2 Mk 38 DP mounts) 6 × 3 in/50 cal guns (76 mm) (2 × 2, 2 × 1) 2 × Hedgehog ASW weapons 1 × Depth charge rack 6 × K-gun depth charge throwers Typical after FRAM II: (1960–65) 6 × 5 in/38 cal guns (127 mm) (in 3 × 2 Mk 38 DP mounts) 2 × triple Mark 32 torpedo tubes for Mark 44 torpedoes 2 × single 21-inch (533 mm) torpedo tubes for Mark 37 torpedoes 1 × Drone Anti-Submarine Helicopter (DASH) Variable Depth Sonar (VDS)

The Allen M. Sumner class was a group of 58 destroyers built by the United States during World War II. Another twelve ships were completed as destroyer minelayers. The class was named for Allen Melancthon Sumner, an officer in the United States Marine Corps. Often referred to as simply the Sumner, this class was distinguished from the previous Fletcher class by their twin 5-inch/38 caliber gun mounts, dual rudders, additional anti-aircraft weapons, and many other advancements. The Allen M. Sumner design was extended 14 feet (4.3 m) amidships to become the Gearing class, which was produced in larger numbers but did not see significant service in World War II.

Completed in 1943–45, four Sumners were lost in the war and two were damaged so badly they were scrapped, but the surviving ships served in the US Navy into the 1970s. After being retired from the US fleet, 29 of them were sold to other navies, where they served many more years. One still exists as a museum ship in South Carolina.