Streamlined, towable, marine
seismic energy vibrator for creating intense swept-frequency and pulse-coded seismic signals in a body of water has a sleek, fish-like configuration designed for
towing with minimum drag. The vibrator has a streamlined hollow
towing head and a streamlined hollow
tail head mounted onto front and rear of a long cylindrical tubular wall which is modular, comprising cylinder sections joined in end-to-end axial alignment. Within this long tubular cylinder wall is an axially vibratable multi-
piston assembly having a plurality of pistons on a long
piston rod. One
piston is positioned in each of the cylinder chambers. These chambers hive multiple ports opening out through the long cylindrical wall. An elongated circular cylindrical elastomeric bladder forms a water-filled bladder chamber encircling the wall. An
actuator piston is vibrated by a remotely controllably
hydraulic circuit, thereby vibrating the multi-piston
assembly for vibrating water out and in through multiple ports communicating with the water-filled bladder chamber for vibrating the exterior of the bladder shown having
diameter "D" of 18 inches and length "L" of 118.5 inches, providing a 6,700 square inch vibration area contacting the
ambient water. A multi-piston
position sensor enables synchronization of the vibrator with companion sources being towed. An axial passage in the long
piston rod feeds low-pressure
compressed air into the cylinder chambers forming air cushions behind the pistons vibrating water in these cylinder chambers.