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U.S. Navy Fact Sheet

Oceanographic Survey Ships - T-AGS

Military Sealift Command's Special Mission program supports worldwide oceanographic programs with seven ships that perform acoustical, biological, physical and geophysical surveys. These ships gather data that provides much of the military's information on the ocean environment. The collected data helps to improve technology in undersea warfare and enemy ship detection. The oceanographic and hydrographic survey ships' multibeam, wide-angle precision sonar systems make it possible to continuously chart a broad strip of ocean floor. One oceanographic ship surveys the sea bottom and collects hydrographic data. Survey ships have charted three-fourths of the world's coastlines. USNS John McDonnell (TAGS 51) makes it easier for navigators to find their way along both well-traveled and not-so-familiar shipping routes.

The John McDonnell-class survey ships carries 34-foot survey launches for data collection in coastal regions with depths between 10 and 600 m and in deep water to 4,000 m. A small diesel is used for propulsion at towing speeds of up to 6 knots. SIMRAD high-frequency active hull-mounted and side scan sonars are carried. The six Pathfinder-class survey ships have three multipurpose cranes and five winches plus a variety of oceanographic equipment including multibeam echo-sounders, towed sonars and expendable sensors.

USNS John McDonnell (TAGS 51) was laid down Aug. 3, 1989, and launched Aug. 15, 1990. The contract for the Pathfinder-class of surveying ships was awarded in January 1991 for two ships with an option for a third which was taken up May 29, 1992. A fourth ship was ordered in Oct. 1994 with an option for two more. A fifth ship was ordered Jan. 15, 1997. Construction began on the sixth and final ship in the class in 1999. By early 2002, all six ships had been delivered and were performing active missions for MSC.

Point Of Contact
Office of Public Affairs
Military Sealift Command
Washington, DC 20398-5540
(202) 685-5055
General Characteristics, John McDonnell Class
Builder: Halter Marine Moss Point, MS.
Propulsion: 1 GM EMD 12-645E6 diesel; 2,500 horsepower (1.9 MW) sustained; 1 auxiliary diesel; 230 horsepower (172kW); 1 shaft.
Length: 208 feet (63.4 meters).
Beam: 45 feet (13.7 meters).
Displacement: 2,054 tons (2,086.96 metric tons) full load.
Speed: 12 knots (13.8 mph).
Crew: 22 civilians, 11 scientists.
Homeport: No homeport assigned.
USNS John McDonnell (T-AGS 51), No homeport
General Characteristics, Pathfinder Class
Builder: Halter Marine Moss Point, MS.
Propulsion: Diesel-electric; 4 EMD/Baylor diesel generators; 11, 425 horsepower (8.52 MW); 2 GE CDF 1944 motors; 8,000 horsepower (5.96 MW) sustained; 6,000 horsepower (4.48 MW); 2 Lips Z drives; bow thruster, 1,500 horsepower (1.19 MW).
Length: 328.5 feet (100.1 meters).
Beam: 58 feet (17.7 meters).
Displacement: 4,762 tons (4,838.42 metric tons) full load.
Speed: 16 knots (18.4 mph).
Crew: 28 civilians plus 27 scientists.
Homeport: No homeport assigned.
USNS Pathfinder (T-AGS 60), No homeport
USNS Sumner (T-AGS 61), No homeport
USNS Bowditch (T-AGS 62), No homeport
USNS Henson (T-AGS 63), No homeport
USNS Bruce C. Heezen (T-AGS 64), No homeport
USNS Mary Sears (T-AGS 65), No homeport
Last Update: 23 August 2007