Razing Amphibian Screw Propelled -RASP-

The shallow-water and surf-zone mine clearance mission is being addressed by existing U. S. Navy programs. The clearance of manmade obstacles from the surf-zone and beach comprises an equal priority for the amphibious assault mission in littoral warfare. The effectiveness of non-explosive obstacles to deter a U. S. amphibious assualt mission has been increased somewhat by the introduction of the Navy's LCAC into the force structure. Marine Corps Engineers routinely utilize tractor crawlers, tracked loaders and rough terrain crane/shovels over land to effect the clearance of trees, rocks, and manmade structures and to fill pits and trenches. However, the surf-zone obstacle clearance mission requires operations on the beach, in plunging surf, loose sand, soft sediments, and in shallow water up to a depth of at least 10 ft. What is required is a fully-amphibious bulldozer/loader/crane which can operate effectively over all types of marginal terrains and sediments. The technical key to developing this surf-zone vehicle is to develop an amphibious propulsor which will meet the demanding performance requirements proposed. The propulsor should be highly reliable and rugged with exceptional invulnerability to damage from non-explosive and explosive obstacles. The candidate propulsor proposed, herein, is the screw-rotor and the proposed vehicle is designated the Razing Amphibian, Screw Propelled (RASP). The screw-rotor is sometimes referred to as an Archimedes Screw and is a single device comprising a helical rib arranged on a rotating cylinder. The screw-rotor has a proven capability to provide continuous, efficient propulsive thrust in water and over land, silt, mud, clay, coral, rubble and weed. The rotor design can be tailored exactly to the vehicle power/speed/thrust requirements. The entire propulsion system is extremely simple and rugged and the rotor can be armored against shrapnel and shock.