The expanding use of amphibious ships for a wide range of missions has increased the importance of a Navy program to produce an upgraded replacement for its Landing Craft Air Cushion (LCAC), a high-speed hovercraft that supports amphibious operations in both combat and humanitarian situations. The replacement for the LCAC, called the Ship to Shore Connector (SSC), would bring new technology and increased performance to handle current and future missions, plus better fuel efficiency and reduced maintenance to meet the demand for lower total ownership cost.
The project to build the SSC has drawn proposals from two powerful contractor teams, both of which would bring considerable experience in hovercraft construction. A team combining aerospace giant Boeing, shipbuilder Marinette Marine, Griffon Hoverwork, and Oceaneering International will compete with a partnership of Textron Marine & Land Systems, which produced most of the LCACs; L-3 Communications; and Alcoa Defense.
The rival teams have aggressively touted their qualifications to produce the SSC because the contract to build 73 of the new air cushion craft could be worth $4 billion, a highly desirable prize in light of the expected tightening of defense budgets.
An artist’s rendering of the Ship to Shore Connector proposed by Team SSC (Boeing, Marinette Marine, Griffon Hoverwork, and Oceaneering International). Image courtesy of Team SSC
After months of delay, Naval Sea Systems Command released the formal request for proposals (RFP) on May 20, 2011. But the competing teams have been refining their concepts based on the information released since the program started in 2008 and a draft RFP issued in March.
The artists’ renderings of their proposals look nearly identical and the limited technical details they have revealed also are similar. But that is to be expected due to the fact that they are starting with the same set of requirements and because the SSC must be the same size and perform primarily the same missions as the LCACs.
LCACs are unique in that, as that name and the generic term hovercraft imply, they can hover above the surface on a cushion of air, which enables them to travel over dry land as well as water. That means as a landing craft, they can skim across the water at up to 50 knots and then ride up onto the beach to off-load their cargo. The air cushion also allows the LCAC to sail, or fly, as the craft crewmen prefer, up into the well deck of the amphibious ships that carry them.
“The increasing weight of expeditionary equipment and subsequent craft performance requirements exceeds LCAC SLEP capabilities and precludes the continuation of the aging LCAC,” NAVSEA said. And “technology has evolved to enable greater availability, performance and reliability for the SSC.”
The Navy noted that the air cushion capability gives LCACs access to 70 percent of the world’s coastlines, compared to about 15 percent for conventional landing craft. Had they been available in 1943, LCACs could have saved a lot of Marines at Tarawa by flying over the reefs that stopped the Higgins boats hundreds of yards from the beach.
The first practical hovercraft were built in England in the late 1950s and began operating as ferries across the English Channel and among the British Islands in the late 1960s, while smaller craft were used for rescue and as personal watercraft. The British military adopted hovercraft for transport and even as small warships about the same time, and copies of the British craft, made by Bell Helicopter, were used by the U.S. Navy in Vietnam. The Bell design was chosen as the basis for the LCAC when the Navy tested two prototypes between 1977 and 1981.
The initial production, funded in the fiscal 1982-86 defense bills, was split between Textron Marine & Land Systems and Avondale Gulfport Marine, but Textron won a later contract for the remaining craft. The first LCAC was delivered to the Navy in 1984 and initial operational capability was achieved in 1986. A total of 91 were built, with the final LCAC delivered in 2001. Textron also produced six LCACs for Japan.The craft got their first operational use in a combat environment in 1991 when 11 deployed on amphibious ships into the Persian Gulf to support a possible amphibious assault into Kuwait during Operation Desert Storm.
The LCAC is powered by four turbojet engines that provide propulsion through large propellers mounted on the stern and create the air cushion by filling a flexible rubber “skirt” that lines the bottom of the hull.
At rest, the LCAC is 88 feet long and 47 feet wide. But that increases to 92 and 48 feet when the skirt is inflated. The craft has a normal carrying capacity of 60 tons – which does not support the M1A1 tank, but can haul 75 tons in limited overload conditions.
Although LCACs are used primarily to haul vehicles, other heavy equipment, and supplies, an enclosed personnel transport module can be loaded aboard that can hold 145 combat-equipped Marines or 108 casualty litters. They have an all-enlisted crew of five led by the craftmaster, usually a first class or chief petty officer. The unarmored LCACs are not considered assault vehicles and would be used in an amphibious attack after the beach had been secured. They have proven to be very useful in supporting non-hostile amphibious operations and were vital in delivering life-saving equipment, food, water, and medical supplies in humanitarian relief efforts after disastrous floods in Bangladesh, Indonesia, and Pakistan and the devastating earthquake in Haiti.