It spans the seas like a ferry boat and traverses dry land like an oversized truck, but from the cockpit, you fly it like a helicopter. Late last week, when California needed assistance transporting firefighting equipment 25 miles offshore to battle wildfires on Catalina Island, the US Navy's biggest hovercraft proved to be the ideal vehicle to get the job done.
In Navy jargon, the hovercraft are called Landing Craft, Air Cushion, or LCAC vehicles. First introduced during the late 1980s, LCACs are primarily intended for use in ferrying Marines and their equipment from amphibious assault ships to onshore landing zones. As Globalsecurity.org explains:
The LCAC is capable of carrying a 60 ton payload (up to 75 tons in an overload condition) at speeds over 40 knots. Fuel capacity is 5000 gallons. The LCAC uses an average of 1000 gallons per hour. Maneuvering considerations include requiring 500 yards or more to stop and 2000 yards or more turning radius. The LCAC, like all "hovercraft," rides on a cushion of air. The air is supplied to the cushion by four centrifugal fans driven by the craft's gas turbine engines. The air is enclosed by a flexible skirt system manufactured of rubberized canvas. Unlike the Surface Effect Ship (SES), no portion of the LCAC hull structure penetrates the water surface; the entire hull rides approximately four feet above the surface.
LCAC operates in waters regardless of depth, underwater obstacles, shallows or adverse tides. It can proceed inland on its air cushion, clearing obstacles up to four feet, regardless of terrain or topography), including mud flats, sand dunes, ditches, marshlands, riverbanks, wet snow, or slippery and icy shorelines. Equipment, such as trucks and tracked vehicles, can disembark via ramps located both forward and aft, there by shortening critical off load time.
Those features were much appreciated on Catalina, where LCACs operated by the sailors of Assault Craft Unit (ACU) 5 from Camp Pendleton, Calif. assisted Los Angeles County firefighters after the fire broke out on May 10. According to the Los Angeles Times:
As firefighters on the island regrouped, Los Angeles County dispatch began moving heavy equipment into place.
The command center put a convoy of 35 fire engines on the road to Camp Pendleton, where several hovercraft waited to make the hourlong trip. The first load of five engines reached the island about 8:45 p.m., as flames charged out of the backcountry.
Tossing a two-story-high wake, the massive craft looked as wide as Pacific Coast Highway.
The ships landed on the rocky Catalina shore like a seal throwing its body out of the water, with a deafening roar from the twin propellers. Within seconds, the massive balloon that suspends the ship on the water is deflated and a ramp lowered.
The hovercraft ran throughout the night and into Friday delivering more engines, 1,500-gallon water trucks, bulldozers and trucks full of inmate firefighters.
And what's a story like that without a happy ending? By Friday, not only was the massive blaze contained, but firefighters were able to bring it under control in time to save Avalon, the biggest town on Catalina.
(Hat tip: Paul Saffo)
Video: Navy Hovercraft Carry Fire Crews to Catalina Island (from MyFox Los Angeles)
Landing Craft, Air Cushion [LCAC] (at Globalsecurity.org)
LCAC aboard the USS Bonhomme Richard (Telstar Logistics photos from 2006)
LCAC-16's photostream (Flickr photos from a LCAC crew member)
News video of a Japanese Defense Forces LCAC delivering humanitarian relief to Indonesia:
(Photo: Top, An LCAC offloads a California Department of Forestry fire truck on Catalina Island, by the Associated Press.)