Vulnerability of the JEFF(A) and JEFF(B) Amphibious Assault Landing Craft (AALC) to Impact during Docking with an LPD/LSD

Two prototype air cushion vehicle ACV amphibious assault landing craft AALC designated the JEFFA and JEFFB are being respectively developed by Aerojet General Corporation, Tacoma, Washington, and Bell Aerospace Company, New Orleans, Louisiana. Each craft weighs approximately 170 tons, fully loaded, and is supported on a cushion of air contained by a flexible skirt system which circumscribes the lower outer perimeter of the craft. The JEFFAALC craft are able to operate at high speeds over both water and land and will serve to deliver personnel, equipment, and supplies from an offshore amphibious assault ship to a shore landing area. Docking impact can occur when a JEFF craft enters the well deck of an amphibious assault ship such as the LPD amphibious transport, dock or LSD landing ship, dock. The impacts that can occur during docking are potentially dangerous because of the lightweight construction of the JEFF. Accordingly, the rigid body motions of the craft were investigated for an assumed set of docking cases, and energy-absorbing capabilities and characteristics were calculated for the pressurized skirt system, the protective bumpers, and the hard structure of both configurations of the experimental prototype craft. The present report analyzes vulnerability to docking collision, recommends modifications to the proposed bumper protection system, and makes suggestions concerning operational methods of docking to reduce collision hazards. Author