Book Description

This report provides a feasibility analysis of the application of a physically well-defined buoyancy/fuel tank and hydrofoil system to a specific craft, an existing USCG 95-foot WPB. The purpose of this modification is to enhance the Craft's mission capabilities in terms of speed, range/endurance and motions in a seaway. It is concluded that the concept (design M174) is technically feasible, has merit, and provides considerable improvement over that of the WPB, particularly in the areas of speed, range, and motions. The 181.3 long ton design is all steel, has 2 pielstick diesel engines and carries 38.1 tons of usable fuel in addition to a mission load of 15 tons. Full load maximum speed is 34.0 knots, maximum foilborne endurance is 53 hours at 22.5 knots, and maximum range is 1,314 nautical miles at 27.5 knots. Hullborne range at 12.5 knots is 2,594 N. miles. There is adequate fuel (with a 10% reserve) to carry out a 5-day mission of 24 hours at 30 knots, plus 96 hours at 13 knots for a total range of 1,968 N. miles. Additional studies are required in conjunction with a detailed design of such a demonstrator. It is recommended that a new design (similar to M174) be investigated in which the upper hull would be modified to improve intact stability, overall structural efficiency, and the machinery room layout. Also, an optimum propeller should be designed to accommodate the entire foilborne speed regime. Tables, Blueprint drawings and charts are presented. Keywords; Hydrofoil, Hybrid, HYSWAS, Small Water-Plane Area, Strut, and Foils.