In the late 1940s, the US Navy developed a requirement for a replacement for the PC-461-class submarine chaser in the coastal convoy escort and patrol roles. The existing submarine chasers were considered too small to carry the required anti-submarine weapons and sensors, and too slow to catch modern submarines, with a ship the size of existing destroyer escorts required. The ships would need to be cheap and quick to build, as large numbers would be required in the event of a war.^[1] By 1950, the requirement had changed to an "Ocean Escort" with a speed of at least 25 knots (46 km/h; 29 mph) at full load and an endurance of 6,000 nautical miles (11,000 km; 6,900 mi) at 12 knots (22 km/h; 14 mph). An ahead-throwing anti-submarine weapon, at first planned to be the Mark 17, a large, trainable Hedgehog anti-submarine spigot mortar, would be fitted.^[2]

The final design, SCB 72, or the Dealey or DE-1006 class,^[3] was 315 feet (96.0 m) long overall and 308 feet (93.9 m) at the waterline, with a beam of 36 feet 8 inches (11.18 m) and a draft of 11 feet 10 inches (3.61 m). Displacement was 1,314 long tons (1,335 t) light and 1,877 long tons (1,907 t) full load.^[4] 2 Foster-Wheeler boilers fed steam to a geared steam turbine, which drove a single propeller shaft. The machinery was rated at 20,000 shaft horsepower (15,000 kW) which gave a design speed of 27 knots (50 km/h; 31 mph).^[4][a] A single-shaft machinery layout was chosen to ease mass production, avoiding potential bottlenecks in gear-cutting which had delayed production of wartime destroyer escorts.^[3][4]

As built, the ships had a gun armament of two twin 3-inch (76 mm)/50 calibre guns, mounted fore and aft. These were open, manually trained dual-purpose mounts which could be used against both surface and anti-aircraft targets. The Mark 17 Hedgehog was cancelled before the ships were built, so in its place two British Squid anti-submarine mortars were fitted ahead of the ship's bridge in Dealey, with a RUR-4 Weapon Alpha anti-submarine rocket launcher fitted in the remaining ships of the class. Launchers for anti-submarine torpedoes were fitted, and depth charge throwers were fitted on the ships' fantail.^[3][4] Sensors included the SPS-6 air-search radar and the SQS-4 low-frequency sonar.^[5]

The prototype ship, Dealey, was built under the Fiscal year (FY) 1952 shipbuilding program, with two ordered in both the FY 1953 and 1954 programs and eight in the 1955 program. Production was stopped at 13 because the Dealey class was considered too expensive at $12 million for mass production. This resulted in the smaller, diesel-powered Claud Jones class being built. The Dealey design formed the basis for the Norwegian Oslo-class and Portuguese Admiral Pereira da Silva-class frigates.^[6][7]

Modifications edit

All of the class except Dealey, Cromwell and Courtney were upgraded in the 1960s by adding facilities for the DASH drone helicopter, with a hangar and helicopter deck replacing the aft 3-inch gun mount and the longer-ranged SQS-23 sonar replaced the SQS-4. The three unmodified ships were fitted with a Variable Depth Sonar (VDS). All ships had their Squid or Weapon Alpha launchers removed late in their US Navy career, while Mark 32 torpedo tubes for Mark 44 or Mark 46 anti-submarine torpedoes were fitted.^[4][8]

• Blackman, Raymond V. B. (1971). Jane's Fighting Ships 1971–72. London: Sampson Low Marston & Co. Ltd.
• Friedman, Norman (1982). U.S. Destroyers: An Illustrated Design History. Annapolis, Maryland, USA: Naval Institute Press. ISBN 0-87021-733-X.
• Gardiner, Robert; Chumbley, Stephen, eds. (1995). Conway's All The World's Fighting Ships 1947–1995. Annapolis, Maryland, USA: Naval Institute Press. ISBN 1-55750-132-7.

• Dealey-class ocean escorts at Destroyer History Foundation