Background
Sealifter Comparisons Landing Craft, Air Cushion |
The LCAC ... Fair is foul, and foul is fair: Hover through the fog and filthy air.
The US Navys Landing Craft, Air Cushion is a radical approach to delivering Marine Corps amphibious
assault forces ashore. Relevant to the development of the San
Antonio LPD , the advantages of hovercraft LCACs are obvious. As air-cushioned vehicles, LCACs are able
to deliver troops, vehicles, and equipment over a beach, not just onto it. A less obvious benefit is
that LCACs can simple glide off of an LPDs well deck ramp (the well deck must be flooded to launch conventional
landing craft). Beach may also be a misnomer. The LCAC can operate just as easily over snow or ice, mud
flats, riverine estuaries, etc in fact, virtually any relatively level terrain can be used.
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LCACs to ...run em ashore...
The US Navy ran an experiment with air-cushioned landing craft in 1977. Having shown that the hovercraft
reduced congestion on landing beaches, the LCAC was ordered into production [1], the first LCAC was
delivered to the US Navy in December 1984.
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Dimensions: |
26.8m long x 14.3m beam x 0m draught |
Displacement: |
200 tons (full load) |
Propulsion: |
4 x 12,280bhp Avco-Lycoming turbines, |
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2 x reversible propellers plus 4 x lift fans |
Carrying capacity: |
60 tons (75 tons overload) |
Vehicle capacity: |
12 x Hummers, 4 x LAVs (or 5t), 1 x tank |
Speed / range: |
74km/h / 485km @ 65km/h (with payload) |
Crew / armament |
Five / 2 x 12.7mm
M2HB (or 40mm AGLs) |
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The LCAC became fully operational in 1987 and the type was involved in the 1991 Gulf War. LCACs had been tested
earlier in tropical and in Arctic conditions. Trials in Alaska showed that, while LCACs could handle thin ice
and calm water, higher sea states, intense cold, and icing-up conspired to limit operational effectiveness.
[2]
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... They were all left behind on the beach ...
Outside of the arctic environment, the LCACs performed well. In any case, the San Antonios (like most LPDs)
arent ice-capable ships. The emphasis is on overseas CF deployments into warmer climes. For such deployments,
LCACs will offer greater flexibility than a conventional landing craft. That the preferred San Antonios
were tailored for LCACs is also an advantage.
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Also see: Joint Support Ship. The JSS
Project is distinct from the Amphibious Assault Ship but the two are related (at least by budget).
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[1] Designed by Bell Aerospace Textron, the LCACs were built by Textron Marine and Land Systems and Lockheed.
A SLEP (Service Life Extension Project) is now underway for the LCAC fleet (adding 10 years of service life to 74
LCACs). It is unlikely that the US Navy will be willing (or able) to spare LCACs, and an eventual replacement is at
a very early planning stage. DND is, therefore, in the position of either ordering new LCACs or designing its own
equivalent air-cushion landing craft perhaps in cooperation with the Canadian Coast Guard?
[2] There are other limitations to air cushion vehicles as landing craft the high operating
costs (incurred through the use of gas turbine engines), excessive propeller noise which can be heard from miles
away (a distinct tactical disavantage when approaching hostile shores).
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