Abstract: A test rig for measuring wear on flexible membrane material used as seal gers on air cushion vehicles includes a pump and nozzle for producing a shallow, high speed water flow and hydraulic actuators for moving the seal fingers into the flow. The fingers are moved into and out of the flow to simulate the effect of the ship crossing waves at high speed. A fan and air plenum inflate the seal fingers in a manner similar to normal operation.

Abstract: The purpose of this invention is to improve the life of transversely stiffened membrane (TSM) seals. To this end the inventors have introduced a segmented glass reinforced plastic (GRP) plank into the lower stiffened lobe portion, which is positioned beneath the bag segments of the TSM seal. The segmented (GRP) planks consist of planks separated by rubber spacers and sandwiched between two sheets of rubber coated nylon fabric.

Abstract: A deep depth underwater simulator is illustrated for determining the dual effects of nuclear type underwater explosion shockwaves and hydrostatic pressures on a test vessel while simulating, hydrostatically, that the test vessel is located at deep depths. The test vessel is positioned within a specially designed pressure vessel followed by pressurizing a fluid contained between the test and pressure vessels. The pressure vessel, with the test vessel suspended therein, is then placed in a body of water at a relatively shallow depth, and an explosive charge is detonated at a predetermined distance from the pressure vessel. The resulting shockwave is transmitted through the pressure vessel wall so that the shockwave impinging on the test vessel is representative of nuclear type explosive shockwaves transmitted to an underwater structure at great depths.

Abstract: A method and system for experimentally determining response characteristics and strength capacity of submerged hull structures subjected to underwater explosion. This method and system allows testing in relatively shallow water, near the shore and in close vicinity of data recording and process equipment. Moreover, the test item is more accessible for inspection and modification/s, as necessary. This method and system also allow a more controlled environment independent of waves and weather.

Abstract: A seal structure for an air cushion vessel includes an inflatable bag secured to the hull and a transversely stiffened lobe portion maintained therebeneath. The stiffened lobe portion consists of a membrane with an array of spaced, transverse stiffener members connected thereto. The colinear stiffener members are interconnected in end-to-end relationship. According to one embodiment, the end portions of the stiffener members are connected to support stays which are connected either to the bag structure or to the forward portion of the hull. The support stays may comprise cable elements or membranes which form continuations of the stiffened lobe membrane. Additional support for the stiffened lobe portion is provided in the form of a plurality of rear support elements which set the orientation and configuration of the stiffened lobe portion and limit the downward deflection of the stiffened lobe portion.

Abstract: A seal structure for an air cushion vessel includes an inflatable bag secd to the hull and a transversely stiffened lobe portion maintained therebeneath. The stiffened lobe portion consists of a membrane with an array of spaced, transverse stiffener members connected thereto. The colinear stiffener members are interconnected in end-to-end relationship.Generally, the end portions of the stiffener members are connected to support stays which are connected either to the bag structure or to the forward portion of the hull. The support stays may comprise cable elements or membranes which form continuations of the stiffened lobe membrane.Additional support for the stiffened lobe portion is provided in the form of a plurality of rear support elements which set the orientation and configuration of the stiffened lobe portion and limit the downward deflection of the stiffened lobe portion.

Abstract: A seal structure for an air cushion vessel includes an inflatable bag secd to the hull and a plurality of juxtaposed, interconnected planer members maintained in operative position beneath the bag by a plurality of support straps. Each planer member includes a transversely reinforced shell portion and a flexible, resilient membrane secured to the longitudinal edge portions of the shell portion to form a flexible planing surface for the seal structure. The planer members may have tapered aft end portions and curved planing surfaces to provide a gradual change of the interface between the planer members and the water.

Abstract: In an Air Cushion Vehicle having spaced depending sidewalls, a seal struce which includes an inflatable bag secured to the hull and a plurality of juxtaposed pivotally interconnected planer members maintained in operative position beneath the bag by a plurality of support stays. The support stays are connected to the hull and extend along the longitudinal edge portions of the planer members and are connected to the hinge members, which pivotally interconnect the planer members, to adjustably secure the planer members to the support stays. Fixed length geometry straps and adjustable length retracting straps are connected to the hinge members for limiting the downward deflection of the aft end of the planer members.