I thought we were discussing concepts with a view to testing later, if interesting? You could assign a big defense contractor with scores of engineers and simulation software to test every concept drempt up, but it would cost more than the GNP and take too long to get a final design choice into production. Such an iterative process would make dull reading on the messageboard too. I thought that since REAL engineers are exploring multi-hulls (Triton) and modular construction techniques (CVF, T45) it might be interesting to see where this line of thinking might extend. I would welcome any 'in the know' criticism of smaller ship hulls as outriggers and the drag quatilies of parallel hull sides when shorter hulls are extended in a modular manner.

"...Finally to cap off all those problems have you ever noticed why an aircraft carriers forecastle is placed where it is? Its because of turbulence thats caused by the ships passage. Placing it in the middle of a ship as would nominally be warranted in a trimaran design causes landing aircraft to experience anywhere from moderate to severe turbulence. NOT a good thing in an aircraft carrier..." The starboard location of the island on all modern carrier designs put the island squarely in line with the the approach path of the aircraft just as it nears the ramp. The turbulance is noticable but managable. If you really want to modernize a carrier design, move away from the island concept altogether. The island, when the yard picks it up and puts it on the flightdeck weighs something like 600 tons. Put the navigation, flag bridges and crow's nest belowdecks with mast mounted cameras projecting images below. By mounting the masts to the side and offsetting them away from the edge of the deck, it would be possible to use the entire extent of the edge for spotting aircraft. A great efficiency gain. Reliability is not a valid issue. For the cost of a carrier, you could put hundreds of cameras around the deck. They could have their own backup battery that would supply power for hours and they would still only be the size of your fist. Oh heck, this thread's been slow for a while. While I'm at it, why don't I design a carrier! Let's make a small conventional carrier. Instead of the 800 foot offset deck, make the landing deck straight down the centerlline. This sets the length of the ship at 220-240 meters. The landing zone needs to be 30 meters wide. You need at least 20 meters on each side in order to spot aircraft along the sides. This sets the deck width at 70 meters. This is approaching the width of a Nimitz, but not quite. Four catapults are placed side by side up front. The holdbacks on the catapults need to be ~15 meters apart to allow aircraft to sit side by side with their wings extended. C-2s and E-2s are wider, but they operated less frequently. Launch them from outboard cats and accept that they will tie up two of them. There are no aircraft planned that have the 64 foot wingspan of the F-14 so they may not be a valid design criteria anymore. The center line landing zone and outboard cats allow for simultaneous launch and landing operations. Four cats allow for rapid sequential launches during alpha strikes. The brake end of the cats can be canted towards the centerline allowing the deck to be a pentahedron 220-240 meters long and 70 meters wide with the forward 80-90 meters tapering somewhat towards the bow. Now I have a flight deck with a aspect ratio of about 3. It might be possible to stick a short fat monohull under such a large deck and still have sufficient stability to provide decent seakeeping, especially since I've already described how to get rid of the 600 ton island on top. It might struggle to make 30 knots though. And the hanger deck will be 1/2 to 2/3 the Nimitz's which may be too small to support the air wing on the big deck. So what if I put a catamaran under it? The nice thing about catamarans is that while trimarans suffer for volume, catamarans wallow in it. Following the design of the fast catamaran ferries, think of two really big rowing shells (without the oars, of course) with a warehouse sitting on top of them. The internal volume of the superstructure would be almost 200 meters long, 70 meters wide and the height of the aircraft. A single hanger deck that actually looks like a hanger at an air base. Then put a standard deck above and below the hanger deck to allow for the crossover structure (about 1.4 hectares each). OH MY GOD what am I going to do with all that space! If the hulls were 17 meters wide, and drew about 11 meters, square bilge to limit draft, reasonable pismatic efficiency........call it 50-60,000 tons.

Fast through-put for aircraft is a force multiplier, so I like the idea of more cats up front. However, I don't see why you see trimarans as limited in volume, but a catamaran as able to support a warehouse. What prevents you from placing you warehouse over three hulls instead of two? Forgive my ignorance, but doesn't that work even better because the load is spanning half the width rather than the full with of the vessel?

The trimaran usually has a single large center hull and two substantially smaller outriggers. You don't get the ability to pile on superstructure because the outriggers provide limited bouyancy. This leaves you with the center hull having to carry much of the usable volume. In order to make it hydrodynamically efficient, it needs to be long and slender. This reduces the volumetric efficiency. You may get some extra volume in the spans between the hull and outriggers. The hulls are the outriggers on a catamaran, each with half of the bouyancy of the whole ship. This makes them astoundingly stable. They are so stable with respect to the surface of the water that the tradeoff with a catamaran tends to be a very rocky ride as the hulls ride over the top of each wave. A deep discplacement hull damps out a lot of wave motion. A catamaran feels every inch of movement. It's a trade off you have to make. No one has built a really big catamaran to see how they will ride in heavy seas. The fast ferries have reach 100 to 120 meters and the ride in rough seas (at 40 knots) is described as "interesting".

One of the aussie posters did an evaluation of the HMAS Jervis Bay during the East Timor Crisis. His own comments were that initially troops took a lot of time to adapt to pitch and yaw - it was a different kind of motion that even had some of the sailors looking over the rails (initially) I'm sure the yanks have been going through similar discoveries with HSV1 and 2 and the larger Austal platform. My own experience is that its akin to an elongated "wobble" or "flutter" rather than a cyclical "dip".

A catamaran carrier may not suffer the seakeeping problems of the fast ferries quite so much. A carrier is more interested in persistence. Run fast once in a while, but most of the time stay at slower speeds to operate aircraft. The Jervis Bay ran all out the whole route. A carrier would spend most of its time at half that speed or less.

I have seen a presentation about the Trimaran Carrier and the problem with it is it is just a small fast carrier with little logistics capabilty - kind of like an auxiliary air field. The Naval Post Grad School study proposes a high tech "solution" for a low threat which could be easily handled by a FFG-7 which the Navy is decomming and/or giving away! Why do you need a high speed ship to protect a low speed or stationary seabase? dahhh! The name of the game in seabasing is summed up in the following words: TONNAGE, THROUGHPUT, TRANSHIPPMENT, DEADWEIGHT IS WHAT MATTERS! All you navy wishful thinkers better adjust your mindset away from fast & little ships to big & slow like merchant mariners have known for centuries. FACT: 95% of all material shipped to warzones is carried on SHIPS, mostly merchant ships at that.

Does anyone by chance have the cost estimates as to just how much money, manpower/man hours, and resources (how many shipments of "stuff") it will take to build a sea base on station? Surely, one sea base will be in the neighborhood, costwise, of easily 3, or 4 CVNs. And what kind of manpower requirement will it take to operate the system. Anyone have any really useful info/links to info on just what it's supposed to do, support it's supposed to provide, and mission it's intended to perform (and most of all, what programs will have to be cut to fund the massive thing) ?

There are some very very interesting designs coming out of BGV. Although not traditional carriers - they are interesting variations of HS platforms able to carry and deploy organic air. There are 3 models of interest the BGV 120, 133 and 188. (numbers denote M's in length)

Can't see Sea Basing ever making it. There is really no reason for it, we could use places like Guam, Okinawa and Diego Garcia to keep our resources forward deployed, and rotate crews or parts of crews from there. (I admit I am ignoring certain aspects of Sea Basing)