Deepstar Hull Fabrication

Abstract

Deepstar is a self-propelled, manned vehicle for deep-sea research. It is being built as a private venture by Westinghouse Underseas Division, Baltimore, under a technical exchange license with Captain Cousteau and the OFRS (Office Francais de Recherches Sous-Marines) of Marseilles, France. Deepstar is designed to carry a crew of three to depths of 4000 ft for periods up to 24 hr. It is powered by two 4½-hpbattery-operated electric motors which propel it at about 3 knots, with a maximum range of about 20 miles. Overall dimensions of the vehicle are 13 ft long by 7 ft high by 11½ft wide over the fairing. The pressure sphere which houses the crew was built for our Baltimore Underseas Division by Westinghouse, Sunnyvale Marine Division. It measures 70 in. od and was fabricated from two hemispheres of high-strength steel. These hemispheres were spun from alloy plates 1?in. and then machined both inside and outside to 1.2 in. thick. Accurate machining was essential to maintain the sphericity required for pressure stability. After machining, the two hemispheres were welded together by an automatic welding process. The sphere has a total of 11 penetrations through the shell, including an access hatch, 2 viewports, a camera port, 2 electrical passages and 5 shaft openings. Reinforcements for the larger openings were made by welding alloy-steel forgings into the shell. Small openings were reinforced by weld metal buildup through which holes were drilled. All reinforcements were then machined to provide accurate penetrations and sealing surfaces. An extensive metallurgical testing program was conducted to insure that all material and welding used in the sphere had the strength and toughness required for operation at maximum depths. Pressure tests have been conducted in a chamber to 1.2 maximum operating depth. Sunnyvale also made the electric motors for Deepstar. These free-flooded ac motors are suspended outside the pressure hull. Unusual problems solved by special processing included electrical insulation in the salt water environment and water-lubricated bearings. AC power for the motors is provided from the batteries through a rotary inverter with semi-conductor controls.