GB907711A - Hydrofoil craft - Google Patents

Abstract

907,711. Hydrofoil craft. GRUMMAN AIRCRAFT ENGINEERING CORPORATION. Jan. 3, 1959, No. 302/59. Classes 113 and 114. A hydrofoil craft includes in combination a hull 10 and a main hydrofoil system 25 positioned relative to the centre of gravity of the hull for supporting above the water most of the weight of the hull when moving through the water. The main hydrofoil system 25 comprises at least two hydrofoils 30 having upwardly inclined faces and being disposed at a fixed angle of incidence of from 0 degrees to approximately 40 degrees with a fixed sweepback angle of approximately from 20 degrees to 50 degrees a fixed dihedral angle of from approximately 20 degrees to 40 degrees and a fixed thickness ratio of approximately 4 to 10% of the chord. The craft is also provided with a stablizing hydrofoil system 40 which is conformed to remain constantly submerged during movement through the water. The main system 25 is located at the outermost edges of sequifoils 14; which are provided to prevent the craft rolling over whilst at rest, and are retractable to the positions shown by chain-lines for Fig. 3. The system 40 comprises hydrofoils 42 joined to the strut 41 which is supported by a shaft 45 mounted rotatably in a tube 46 and is adapted to be rotated about a substantially vertical axis, for steering, by axial movement of the tube 51 joined to the crank 50 which is connected to the tube 46, and about a transverse pivot 48 for retracting to a position over the top side of the hull 10. The forward end of the tube 51 (not shown) is connected through a bell crank and worm gear to a steering wheel. The main system 25 may comprise a pair of hydrofoils which are supported by three struts and which completely span the underside of the craft.