Whiskyjack said:
I think a force of LCS (based on the Austal design). It does not have to have all the expensive 'bells and whistles' of the USN design, but would allow for a force of embarked troops, vehicles, cargo as well as the general patrol duties around Australia. I think Austal has a smaller design as well around the 80m mark. The only question I have is around the sea keeping ability of a trimaran in the Southern Ocean.
A favorite design for me, is the Stolkraft as far as creating the most sea keeping ability for the size goes... Its a dynamic lift tri hull with a cat stern....
I would also expect the Tri hull Austal design/ LCS, to have relatively good sea keeping abilities as well.
3 hulls are better than 2 which is better than 1, so long as your design philosophy is to obtain maximum reserve buoyancy. Speed should not be a part of the equation when looking for endurance in the Southern Ocean.
I would expect the LCS design to have a lot of trouble in a TRS, if she attempted to run across the wind. It would probably make it out of the storm, but you may as well run her up on the beach and cut it up as the torsion stresses in a multihull attempting that sort of course are large and structrally damaging. But again 3 hulls reduces the amount of stress that 2 hulls would experience...
The compromise for speed and endurance is the SWATH design (Small water plane area, tripple hull (in this case))...You get your reserve buoyancy, plus you get the weather deck up and away from the water. The torsion stresses are less (or "dampened" might be a better word) because the hull is already submerged and its the most efficient full displacement design out there at the moment.
All of which Austal should have the where-with-all to do.
Make the craft large and stable enough so the helicopter's performance constraints are the limiting factor (not the ship's) to VTOL operations and you have a winner.
got to go
cheers
The Wooki