Abstract: A method and apparatus for simultaneously towing and handling multiple airguns are disclosed for use in marine seismic surveying which provide for ease in handling large numbers of airguns and enable them to stream out at a desired depth behind a submerged towing head in a long flexible streamer, or a plurality of simultaneously towed airgun streamers, whose level below the surface can be changed, if desired, while the survey is progressing. A plurality of airguns are included in each streamer extending for a length behind the survey vessel for providing an effective geographic diversity in the location of the airguns which can be simultaneously fired, or can be fired with time delay, for generating very powerful large area seismic energy wavefronts travelling down through the body of water. The buoyancy of the airgun streamer is controllable to provide neutral buoyancy during towing, if desired, and slight positive buoyancy to float the streamer in preparation for taking it on board the towing vessel.

Abstract: A seismic exploration system for use on ice-covered waters is disclosed. The system comprises a housing which contains equipment such as an engine, a compressor, means for boring holes in the ice, and acoustic signal generating means that can be lowered into the water through holes in the ice. The housing is sufficiently lightweight that it easily can be transported from one location to another by helicopter or other aircraft. The heat generated by the engine is sufficient to provide a comfortable working environment for personnel within said housing and helps prevent freezing of equipment located within said housing.

Abstract: A pair of movable pistons are separated within an enclosed, submerged cylinder by an expansible combustion chamber. Piston rods extend from these pistons through the opposite ends of the cylinder. A pair of dish-shaped, circular plates are carried on the respective extremities of these two rods so that their convex surfaces face inwardly toward the ends of the cylinder in spaced relation. Expansion of an explosive gas mixture within the combustion chamber drives the pistons apart so as to accelerate the plates through the water, producing cavitation bubbles at their convex surfaces. Collapse of these bubbles combines efficiently to produce a single energetic acoustic pulse adapted for seismic prospecting.

Abstract: Condensate accumulating in the combustion chamber of a marine gas exploder of the cylinder and piston type is collected by gravity flow in a sump formed in a cylinder side wall or in a face of the piston, depending upon whether the cylinder is oriented horizontally or vertically. One end of an exhaust tube is positioned adjacent the base of the sump so that gaseous combustion products flow through the sump into the exhaust tube so as to collect and remove the accumulated condensate.

Abstract: Apparatus for conducting seismic reflection surveys from oil tankers or other bulk liquid carriers in the course of their normal journeys. Seismic sources and detector apparatus are mounted in the ballast tanks. Pulse compression techniques may be used, and may take the form of a mechanical flail acting on the hull of the ship.

Abstract: A firing device is provided for initiation of delay type seismic charge assemblies, which comprises means for conveying and guiding the charge assemblies, in the seismic test zone, into electrical initiation contact with one of any number of available pairs of electrical conductor surfaces, insulated from the other and adapted to connect with opposite poles of an external firing current source; and means for directing the thus initiated assemblies from the initiation zone, during the delay period, for subsequent detonation.Also provided are elongated end-recessed seismic charge assemblies initiated in the above device; and seismic exploration system, and method, utilizing said device.