The new craft will have a 60-hertz electrical distribution system, which is common to ships, instead of the LCAC’s 400-hertz system that is more typical for aircraft. That would allow greater access to parts and lower component costs.

The SSC will have two gearbox-driven craft service generators, which will be more fuel efficient than the LCAC’s auxiliary power units. The SSC will also add windows to the port side cabin, which is closed in on the LCAC. That will provide better visibility and reduce fatigue for the loadmaster and deck engineer, who serve as lookouts when the craft is underway.

The SSCs, however, will play a bigger role in another important Navy-Marine warfighting concept, using a “Sea Base” to conduct amphibious operations. Seabasing is intended to avoid the need to build up large quantities of supplies and equipment ashore, which would be vulnerable to attack by air, artillery, or missiles, by providing logistical support to the forces ashore from ships at sea.

The craftmaster, engineer, and navigator operate in the larger starboard cabin, which on SSC will be equipped with dual controls to allow a pilot and co-pilot arrangement, rather than the single pilot setup in LCAC, and will have “state-of-the-practice flight and engineering control technology,” NAVSEA said.

The SSC’s two 11.75-foot diameter propellers will have six blades and seven stators encased in a protective shroud, all of which will be of composite material intended to reduce the excessive wear on the props that adds to the LCAC’s maintenance burden. The props are variable pitch and reversible, like an airplane, to improve efficiency and maneuverability, and will have anti-icing systems. The SSCs will have the same external dimensions as LCAC, which will make them compatible with all the existing and planned amphibious ships with well decks. That avoids expensive modifications of the gators.

The new craft are expected to function with essentially the same operating concepts as the LCACs. That means they will be used to transport larger weapon systems, equipment, cargo, and personnel of the assault elements of a Marine or Army brigade, “in a non-permissive environment,” but not the first wave, the Navy said.

For the Marines, who have been the primary users of LCACs, the high-speed craft are a key component in the ship-to-objective maneuver concept, which is aimed at avoiding heavily contested beach assaults by launching from farther off shore and landing where the enemy does not expect them.

The SSCs, however, will play a bigger role in another important Navy-Marine warfighting concept, using a “Sea Base” to conduct amphibious operations. Seabasing is intended to avoid the need to build up large quantities of supplies and equipment ashore, which would be vulnerable to attack by air, artillery, or missiles, by providing logistical support to the forces ashore from ships at sea.

A key enabler of seabasing, the Mobile Landing Platform (MLP) ships are now being built and the first should be in service as the SSCs begin to reach the fleet. The MLP will not only carry supplies and troops to the assault area, but will serve as a transfer facility between the large pre-positioning force supply ships and craft that can take the material and men ashore, including SSCs.

In their printed and Web-based material and oral comments, the rival teams have been extolling their qualifications to produce the SSC.

Textron claims “55 years of combined and proved” air cushion vehicle construction and “the only facility that has produced 10 SSC-like vessels a year,” a reference to the LCACs. It says its 600,000-square-foot shipyard near New Orleans is “specifically designed to optimize the production of ACV materials based on years of experience and proprietary research that streamlines the construction process with a highly efficient assembly station configuration that cuts time and effort by consolidating production.”

Textron also cites the experience of the corporation’s subsidiary, Bell Helicopter, in rotary wing aircraft, which it says has relevance to air cushion operations.

The team’s website notes that its partner, L-3 Communication, “is a leader in command and control, guidance and navigation systems and secure communications,” and the other team member, Alcoa, is “a world leader in aluminum.” That means the team “has the technology and experience to reduce risk and successfully deliver the SSC to the Navy within budget, at weight and on schedule.”