Is there any news on the replacement for the LCM-8, last info is that they were looking into water jet landing craft or pump jet design.
How would water jet go when close inshore and picking up sand and seaweed thru the motors, obviously they could handle a small amount.
Source wiki (pump jet)
Advantages
Pump jets have some advantages over bare propellers for certain applications, usually related to requirements for high-speed or shallow-draft operations. These include:
Increasing the speed before the onset of capitation, due to the raised internal dynamic pressure.
•High power density (with respect to volume) of both the propulsor and the prime mover (since a smaller, higher-speed unit can be used)
•Protection of the rotating element and making operation safer around swimmers and aquatic life
•Improved shallow-water operations, since only the inlet needs to be submerged
•Increased maneuverability, by adding a steerable nozzle to create vectored thrust.
•Noise reduction resulting in a low sonar signature; this particular system has little in common with other pump-jet propulsor and is also known as "shrouded propeller configuration"; applications:
Submarines, for example the Royal Navy Trafalgar class and Astute class, the US Navy Seawolf class, the French Navy Triomphant class, and the Russian Navy Borei class..
Torpedoes, such as the Spearfish and MK.48 weapons.
Disadvantages
•Can be less efficient than a propeller at low speed
•More expensive
•Higher weight in boat due to entrained water
•Will not perform well if boat is heavier than the jet is sized for
•Can become clogged with debris e.g. seaweed.
Obviously with such a large craft the vectoring nozzles in the front will hit the beach, how will it overcome these problems or could they use some thing similar to a hover craft arrangement with large fans on the rear with out the air cushion or maybe go with some thing like the Russian Zubr class LCAC, do the US make some thing similar which could transport an MBT to the shoreline, over kill in our needs but it moves,
[ame="http://en.wikipedia.org/wiki/Zubr_class_LCAC"]Zubr class LCAC - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Soviet_Pomornik_class.JPEG" class="image"><img alt="Soviet Pomornik class.JPEG" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/63/Soviet_Pomornik_class.JPEG/300px-Soviet_Pomornik_class.JPEG"@@AMEPARAM@@commons/thumb/6/63/Soviet_Pomornik_class.JPEG/300px-Soviet_Pomornik_class.JPEG[/ame]
The Zubr landing craft has a cargo area of 400 square meters (4,300 sq ft), and a fuel capacity of 56 tons.It can carry three main battle tanks (up to 131 tonnes), or ten armored personnel carriers with 140 troops (up to 115 tonnes), or up to 500 troops (with 360 troops in the cargo compartment). At full displacement the ship is capable of negotiating up to 5-degree gradients on non-equipped shores and 1.6m-high vertical walls. The Zubr remains seaworthy in conditions up to Sea state 4. The vessel has a cruising speed of 30-40 knots