New concept for the US Marine Corps A potential replacement for the Marines' 20-year-old air cushioned ship-to-shore craft has foam runners and a massive payload.
Officials with the Marine Corps Warfighting Lab, in conjunction with the Office of Naval Research, conducted a technical assessment earlier this month with a half-scale version of the Ultra Heavy-Lift Amphibious Connector, a high-tech craft being developed as an option to replace the Landing Craft Air Cushioned as a vehicle to bring troops, vehicles and gear ashore. The UHAC has also been discussed as a replacement for the Landing Craft Utility, another Navy ship-to-shore connector, but Warfighting Lab officials said they were especially interested in how the UHAC stacked up against the LCAC.
The Navy's LCACs traditionally deploy with and operate from amphibious well deck ships and often transport Marines to and from shore as part of training or Marine Expeditionary Unit deployments.
Unlike the LCAC, which acts as a hovercraft with an inflatable skirt, the UHAC has air-filled tracks made out of foam that can propel it through the water and on land. The footprint of the UHAC is significantly larger: 2,500 square feet of deck area to the LCAC's 1,800. But this means the UHAC can handle a much larger payload. While the LCAC can carry 65 tons of gear, the UHAC can handle 150 tons, or 190 with an overload payload.
Capt. James Pineiro, Ground Combat Element branch head for the Warfighting Lab's Science and Technology Division, said the UHAC would be able to carry three main battle tanks ashore, at some 60 tons apiece.
Another advantage to the UHAC, Pineiro said, is its range: 200 nautical miles to the LCAC's 86. And unlike the LCAC, when the UHAC arrives onshore, it can keep on going, thanks to low pressure captive air cells in the tracks. At about a pound per square inch, the UHAC can cross mud flats and tidal marsh areas. And the tracks can crawl over a sea wall of up to 10 feet, he said — all important features during a beach assault.
"You could look at the amphibious invasion of Inchon, during the Korean War," Pineiro said. "there were significant mud flats there, and a 26-foot tide difference. At low tide it went a couple of miles out. That was a problem during the invasion of Inchon."
Where the UHAC does come up short is in water speed. Because of the drag created by the foam tracks, it can only travel at 20 knots, half the speed of the LCAC.
But Pineiro said he anticipated that mission commanders would be able to work around this drawback.
"When you get into planning ops, you kind of plan for your capability," he said.
Officials with the project said the concept for the UHAC originated in 2008, with a goal to design an amphibious vehicle with low PSI. The Office of Naval Research accepted a concept design for the vehicle from the company Navatek, Inc., and the project has been in development since then, with the construction of a half-scale demonstrator and an at-sea demonstration in 2012.
The half-scale model is still massive at 42 feet long, 26 feet wide and 17 feet high. It was in Honolulu in early March to complete a limited technical assessment to demonstrate its capabilities. The test, Pineiro said, involved launching the UHAC from a simulated ship's well deck with an internally transported vehicle aboard. The UHAC brought the vehicle to the shore and then returned to the ship, he said.
The assessment is preparation for a larger demonstration of the UHAC's abilities at the Advanced Warfighting Experiment, also in Hawaii, that will take place in conjunction with the international exercise Rim of the Pacific 2014 this summer.
"We want to make sure the UHAC can perform," Pineiro said.
Future steps following this summer's experiment remain unclear as testing continues. But according to the Marines Seabasing Required Capabilities Annual Report for 2013, published in December, product managers with ONR are working with Defense Department agencies to secure funding for continued development.
"Development of a full-scale technology demonstrator is a possibility," the report said.
Amid budget cutbacks, one feature is sure to catch the eye of acquisition officials: because of the technology involved in constructing and operating a UHAC, ONR estimates per-unit production and maintenance costs would be less than half that of an LCAC, officials with the project said.
The Navy began purchasing its 91 LCACs in the early 1980s at per-unit costs ranging from $22 million to $32 million, or between $45 and $75 million with inflation adjusted.