Surface Effect Ship - United States Navy - The SES100

The SES100

Two experimental SESs (the SES100A and 100B), both of around 100 tons, with 80 ft (24 m) length and 40 ft (12 m) beams, were developed for the US Military in the 1960s and 70s. They both attained speeds in excess of the program goal of 80 knots (150 km/h). The SES 100B, was built by Bell Aerospace (Textron Corporation) at the NASA Michoud Assembly Facility. Driven by 2 semi-submerged, supercavitating controllable, reversible propellers, achieved speeds in excess of 96 knots (approximately 110 mph) in the Gulf outside of St. Andrews Bay in Panama City, Florida.

The speed was verified by the USAF ARIS radar. It also fired the Navy's first vertically launched missile (an SM-2) while doing 60 knots (110 km/h). It was also used to test automatic ride control and high speed collision avoidance and navigation systems. The 100A ship was used to test waterjet propulsion, variable geometry inlets and automatic ride control systems. The 100A and 100B were both capable of operating almost completely out of the water on an air cushion with only 18in (46 cm) of sidewall, the propellers or the waterjet inlets entering the water. The 100 ton SES 100B was built for the US Navy as a 1/10 scale model to test the feasibility of using hovercraft and other Surface Effect Ships in combat situations. The top-secret specifications called for a ship capable of entering a combat zone at a speed of over 80 knots (150 km/h) and disgorging a tank and 100 soldiers onto a beach, turning back out onto water and escaping at high speed.

Unlike the hard sidewall SES's, the full skirted AALCs, JEFF A&B were the prototype vehicles for the LCAC's used by the Navy with such success in the Persian Gulf War.

The 3000 ton SES concept was never designed to go up on the beach, like a landing craft. The AALC (Amphibious Assault Landing Craft) and the SES were very different concepts from the beginning. The AALC was a pure hovercraft that is capable of high speed insertion of troops and vehicles onto a beach. As a hovercraft, the LCAC, derived from the AALC has no rigid hull parts that extend past the air cushion. It therefore can operate across the beach. The SES has rigid side hulls that enclose the air cushion, permitting water propulsion but allowing it to only go to the shore when conducting amphibious operations. Design concepts for a 6000+ ton cargo SES's that Rohr and Ingalls Shipbuilding proposed relied on the idea of the ship loading and unloading from beach, lighter, causeway or conventional dock facilities.