US R/V Gilbert
The R/V G.K. GILBERT is a 50-ft aluminum semi-V-hulled Munson Hammerhead built in 1993. Powered by three 6V92 turbo-diesels coupled to Hamilton Jets, it can make 34 knots. The shallow draft of 2.5 ft and quiet jets permit seismic surveys to be performed in shallow water with little noise interference. It is equipped with 2 generators that provide 25 kilowatts of clean, 220 volt, 3-phase power to operate equipment, instruments, and computers.
The vibracorer consists of a pneumatically actuated, reciprocating head mounted on a cart that slides down a 22-ft stayed-aluminum mast attached to a 400-lb rectangular, steel-channel, base-frame. Two 7 hp electric compressors produce 70 scfm of air at 70 psi to drive a 0-ft-long by 3-in.-diameter aluminum core barrel (clamped to the bottom of the head) into the sediment. A check-ball valve and core catcher assure recovery of samples during extraction from the seabed by the vessel's 6-ton Hiab Sea-Crane. In four years of operation, over 500 cores have been taken from South Carolina to Texas in water depths ranging from 0 to 120 ft. (To accommodate the 0-ft depth, the vibracorer was set on the bank of a bayou in Louisiana to core marsh sediments while the R/V GILBERT floated alongside in 3 ft of water).