Accession Number : ADD001544

Title :   Semisubmerged Ship with Bow Impact Alleviator.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Lang,Thomas G

Report Date : 22 Oct 1974

Pagination or Media Count : 7

Abstract : The patent relates to a design whereby an improvement is provided for the semisubmerged ship which reduces the impact effect of large waves when they strike the ship's platform. A semisubmerged ship by having at least one submerged elongate hull supporting a platform above the water's surface by at least one water-surface piercing strut is capable of high-speed operation and a large wave directly striking the platform could damage the ship. Including pairs of lifting hydrofoils on the upper reaches of the forwardly disposed water-surface piercing struts raises the platform to reduce the impact force and the possibility of damage to the platform. Similarly configured bow-shaped projections on the underside of the platform generate lifting forces which raise the platform over the waves to reduce the impact force. Designing the bow shaped projections to be cusp-shaped also helps them cleave into the waves to further reduce the impact and the effects of impact on the underside of the platform. The concave surfaces of the cusps translate the impacting force to tensile stresses in their sheet-metal surfaces. These sheet metal surfaces are capable of bearing greater tensile forces without yielding whereas conventional flat surfaces are deformed and end up irregularly shaped.

Descriptors :   *Catamarans, *Ship hulls, *Patents, Hydrofoils, Hydrodynamic control surfaces, Configurations

Subject Categories : Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE