In the early 1950s, after the invention of the atom bomb, U.S. Navy and Marine Corps planners came to a grim conclusion: the amphibious warfare tactics that were so successful during World War II had now been upended. A single nuclear weapon could easily wipe out an entire invasion fleet. Fleets would have to operate dispersed over a greater geographical area with vehicles that shuttle troops and equipment from ship to shore moving faster to make up the difference.
One outgrowth of this requirement was the Marine Corps’ adoption of the helicopter. A second was the adoption of the LCAC. A hovercraft powered by four gas turbine engines, the LCAC could depart an amphibious ship anchored ten miles off an enemy coastline and deliver cargo to shore in fifteen minutes. The LCAC was nearly four times faster than the Landing Craft, Utility that preceded it.
Despite the similarities, the SSC includes several improvements. The new hovercraft can carry up to 74 tons, an improvement over the 60 tons the LCAC could carry. That’s enough to carry the M1A1 Abrams tank, the heaviest vehicle in the Marine Corps inventory. The newer hovercraft can also be fitted with an enclosed personnel transport module to carry up to 180 people or 54 casualty litters.
The SSC is fitted with four new Rolls Royce MT7 gas turbine engines that deliver a total of 24,640 shaft horsepower (18.4 megawatts), driving the vehicle to speeds up to 35 knots in Sea State 3. The MT7 shares a common engine core with the Rolls Royce AE 1107C-Liberty aircraft engine that powers the MV-22 Osprey tilt-rotor. The rubber air skirt is designed to reduce drag and overall craft weight. Finally, the entire craft is made of aluminum to resist corrosion in salt water environments.
The U.S. Navy plans to eventually purchase 72 SSCs, plus one SSC for testing purposes. According to U.S. Naval Institute News, deliveries were set to begin in 2019 and the first vehicles were supposed to achieve initial operational capability in 2020.
Source: Naval Today