Patent ID: 7621230

Claim:
A flow-through transportation vessel for the at-sea and underway launching and loading of air-cushion vehicles, the flow-through vessel comprising: a hull having; a forward end, an aft end, a continuous planar deck running from the forward end to the aft end, a waterline region having a waterline that coincides with the level at which the hull floats in open water; a forward ramp at the forward end for launching air-cushion vehicles, the forward ramp having a hinged edge pivotally attached to the hull, and a front edge that downwardly extends at least to about the waterline, the forward ramp inclined at a forward inclination angle, the forward ramp having a forward ramp width; an aft ramp at the aft end for loading air-cushion vehicles, the aft ramp having a hinged edge pivotally attached to the hull, and a front edge that downwardly extends at least to about the waterline inclined at an aft inclination angle, the aft ramp having an aft ramp width, wherein the aft width is about 1.4 times the forward ramp width, and wherein the continuous deck is located above the waterline, wherein the forward ramp has a forward ramp length and the aft ramp has an aft ramp length, wherein the aft ramp length is about 1.5 times the forward ramp length, and wherein the forward ramp further includes two longitudinal guide walls that guide air-cushion vehicles down the forward ramp by brushing against the sides of the air-cushion vehicles, each longitudinal guide wall positioned substantially perpendicular to the hinged edge and the front edge, the longitudinal guide wall spaced apart from each other by a distance of the forward ramp width.