History
United States
Name	Edwin H. Duff
Namesake	Edwin H. Duff
Owner	War Shipping Administration (WSA)
Operator	McCormack Steamship Co.
Ordered	as type (EC2-S-C5) hull, MC hull 3142
Builder	J.A. Jones Construction, Panama City, Florida[1]
Cost	$817,101[2]
Yard number	102
Way number	3
Laid down	18 May 1945
Launched	29 June 1945
Sponsored by	Mrs. Edwin H. Duff
Completed	27 July 1945
Identification	Call sign: AOEM [2]
Fate	Placed in the, National Defense Reserve Fleet, James River Reserve Fleet, Lee Hall, Virginia, 17 October 1945 Acquired by US Navy, 10 May 1957
United States
Name	Interdictor
Namesake	One who prohibits
Commissioned	7 April 1958
Decommissioned	5 August 1965
Reclassified	Guardian-class radar picket ship
Refit	Charleston Naval Shipyard, Charleston, South Carolina
Stricken	1 September 1965
Identification	Hull symbol: YAGR-13 (1957–1958) Hull symbol: AGR-13 (1958–1965) Call sign: NVVB [3]
Fate	Placed in National Defense Reserve Fleet, Suisun Bay Reserve Fleet, Suisun Bay, California, 1 September 1965 Sold for non-transportation use, 13 June 1974
General characteristics [4]
Class and type	Liberty ship type EC2-S-C5, boxed aircraft transport
Tonnage	10,600 LT DWT 7,200 GRT
Displacement	3,380 long tons (3,434 t) (light) 14,245 long tons (14,474 t) (max)
Length	441 feet 6 inches (135 m) oa 416 feet (127 m) pp 427 feet (130 m) lwl
Beam	57 feet (17 m)
Draft	27 ft 9.25 in (8.4646 m)
Installed power	2 × Oil fired 450 °F (232 °C) boilers, operating at 220 psi (1,500 kPa) 2,500 hp (1,900 kW)
Propulsion	1 × triple-expansion steam engine,  (manufactured by Filer and Stowell, Milwaukee, Wisconsin) 1 × screw propeller
Speed	11.5 knots (21.3 km/h; 13.2 mph)
Capacity	490,000 cubic feet (13,875 m3) (bale)
Complement	38–62 USMM 21–40 USNAG
Armament	Varied by ship Bow-mounted 3-inch (76 mm)/50-caliber gun Stern-mounted 4-inch (102 mm)/50-caliber gun 2–8 × single 20-millimeter (0.79 in) Oerlikon anti-aircraft (AA) cannons and/or, 2–8 × 37-millimeter (1.46 in) M1 AA guns
General characteristics (US Navy refit)[3]
Class and type	Guardian-class radar picket ship
Capacity	443,646 US gallons (1,679,383 L; 369,413 imp gal) (fuel oil) 68,267 US gallons (258,419 L; 56,844 imp gal) (diesel) 15,082 US gallons (57,092 L; 12,558 imp gal) (fresh water) 1,326,657 US gallons (5,021,943 L; 1,104,673 imp gal) (fresh water ballast)
Complement	13 officers 138 enlisted
Armament	2 × 3 inches (76 mm)/50 caliber guns

USS Interdictor (AGR/YAGR-13) was a Guardian-class radar picket ship, converted from a Liberty ship, acquired by the US Navy in 1954. She was reconfigured as a radar picket ship and assigned to radar picket duty in the North Pacific Ocean as part of the Distant Early Warning Line.

Interdictor (YAGR-13) was laid down on 18 May 1945, under a Maritime Commission (MARCOM) contract, MC hull 3142, as the Liberty ship Edwin H. Duff, by J.A. Jones Construction, Panama City, Florida. She was launched 29 June 1945; sponsored by Mrs. Edwin S. Duff; and delivered 27 July 1945, to the McCormack Steamship Co.^[3][5]

She carried aircraft until entering the James River Reserve Fleet, Lee Hall, Virginia, 17 October 1945. Except for brief cargo service, she remained there until being acquired by the US Navy, 10 May 1957.^[5]

She was converted to a radar picket ship at the Charleston Navy Yard, Charleston, South Carolina, and commissioned Interdictor (YAGR-13), 7 April 1958.^[3][5]

Fitted with the latest and best electronic search and tracking equipment, Interdictor sailed 2 May 1958, for shakedown training in the Caribbean. She departed Charleston, 18 July 1958, and sailed to her new home port, San Francisco, California.^[5]

Arriving 13 August, the ship assumed her role as an ocean radar station ship, part of America's vast early warning defense system. Operating with search aircraft, Interdictor could detect, track, and report enemy aircraft at great distances, supplementing land-based radar stations, and controlling high-speed interceptor aircraft in case of attack. She also carried out weather reporting duties during her three to four week cruises in the Pacific Ocean.^[5]

Interdictor's hull classification was changed 28 September 1958, to AGR-13. She continued on radar picket patrols for the Continental Air Defense Command (CONAD) out of San Francisco, until decommissioned 5 August 1965.^[5]

Her name was struck from the Navy Directory 1 September 1965, when she transferred to the US Maritime Administration (MARAD) for lay-up in the Suisun Bay Reserve Fleet, Suisun Bay, California, where she remained until she was sold 13 June 1974. Her subsequent fate is not known.^[3][5]

Interdictor's crew was eligible for the following medals:

• National Defense Service Medal

^[3]

• United States Navy
• Radar picket

• Photo gallery of USS Interdictor at NavSource Naval History