The use of semisubmerged ships for oceanic research

The Naval Undersea Center has developed a new range support surface craft utilizing a design that should offer considerable advantage for oceanic research as compared to a conventional monohull ship. The 190-ton, 25-knot craft is called the SSP (Stable Semisubmerged Platform). It was designed to permit operations under adverse wind and wave conditions in deep water. Unusual features of the craft include greatly reduced motion in waves relative to a conventional monohull when at rest or underway, a large deck area and internal volume, and sustained speed capability even in large waves. The 89-foot SSP consists of two submerged, parallel, torpedo-like hulls which support a cross structure above water by means of four streamlined, surface-piercing struts. A stabilizing fin spans the gap between the hull tailcones. Small fins attached near the hull noses and flaps in the stabilizing fin provide control over heave, pitch, and roll when underway. A 12 1/2-by-23-foot well in the center of the cross structure permits devices to be raised and lowered from the platform. The craft has thus far operated as predicted in preliminary trials. The concept scales readily to larger sizes. Possible 500-ton and 3000-ton versions for oceanic research are also discussed.