The bigger the better, if you can afford them. But only the US can. The real issue which most observers forget is the escort force may cost almost as much as the carrier. And this escort force has to be roughly the same size whether you have a big or a small carrier. One of the Brit commentaries after the Falklands was they seriously questioned whether the Harrier Carrier "justified" the level of escorts; their conclusion was that if you're going to all that trouble yiu might as well have a proper carrier, and if one, then you need two. Don't forget that IN WAR a carrier goes to see with a dozen escorts and support vessels. The anti-air screen, the anti-submarine screen, the close-in defense screen, at least 1 nuclear sub and several support vessels rotating through the group. The area is so large that most of this force is over the horizon and you never see them. As to pure size, the sea-keeping (and aircraft handling) will always be easier from a bigger deck and a larger ship will always maintain a higher speed in rough weather. A larger ship will always withstand battle damage better. Of course I'm a fan of nukes because the absence of ships fuel means you can carry more avaition fuel and stores and you replenish less frequently (enemy will always try to track your supply ships); but then the size of the Brits support fleet (21) ships means this is not a problem for them. And, of course, you need two - landing and launching; and in case one gets sunk.

Before beginning the discussion decide whether you are talking about the most efficient size of ship dedicated to being an aircraft carrier or the most efficient allocation of resources wrt to aircraft carriers. One is a question of naval architecture, the other is a question of strategic choices. Northernguy

I'd question the capacity of some nations to be able to field adequate support and protection assets for a carrier in time of war. The only nations that have a capcity to double the support fleet without substantially degrading the capability of the rest of the fleet to undertake other duties are the US, UK and France. This assumes that in a war situation you double the number of protective assets on each carrier. In real terms 3 is a minimum. 1 on, 1 in maint and 1 "on float". Otherwise the rotation times can be challenged. 1 vessel is useless, as on the day that it goes into dry dock for refurb and refit for 12 months, you are platform and element blind until it returns. In that case the efficiency and cost issues are relative to the owner. Size and it's associated perceived flexibility is a damocles sword.

"Before beginning the discussion decide whether you are talking about the most efficient size of ship dedicated to being an aircraft carrier or the most efficient allocation of resources wrt to aircraft carriers. One is a question of naval architecture, the other is a question of strategic choices." I am thinking of both, but primarily the first one - naval architecture.

Worcester, that is very true. The need for escorts significantly adds to the efficiency of large carriers in strategic choice terms. Would it, therefore, make sense for the US to increase the size of its carriers further in the CVN-X program? How far is it optimal to go? I think the current Nimitz class carriers carry up to 80 aircraft (including the helicopters) and displace about 100,000 tons - would it make sense to go to say 100 aircraft and 120,000 tons with the new carriers?

gf0012-aus, I though you the U.S. works on a 4 level cycle of which each lasts 6 months. So, the minimum for constant deployment of 1 carrier would be 4 carriers if you follow the U.S. model. On the other hand, the U.S. is now transitioning to a new surge model and still different models of use could perhaps make do with 3 carriers.

I think carrier size efficiency all depends on the required sortie rate at a give range. That in turn will define the size of the air group, and then the size of the carrier. If for example, piloted aircraft were eliminated for UAV's, one could theroize that the planes would be significantly smaller and thus a would require less space and fuel for a given amount of bombs on target.

Realistically, everything about about carrier size will come down to logistics. As others have said, how important is escort forces consideration going to be given? Also how often will resupply be done? What hasn't really been addressed is mission profile. Not every carrier is an aircraft carrier per se, its entirely possible to make a helicopter carrier that can be very efficient (think of the US LHA/LHD class size vessels) with regards to their purpose. Depending on their purpose, that will serve as a big chunk in determining their size. For instance you may not want a Nimitz size vessel for doing ASW work, and especially towards littoral areas.

I think there is a definite limit on the sortie rate of a carrier no matter how large it gets, because only 1 airplane (assuming CTOL) can use the runway at a time, no matter how long. I suppose in theory, it would be possible to have a carrier large enough to carry 2 runways, but in practice that is unrealistic, though it could work with a catamaran or triraman hull aircraft carrier.

The USN has studied this question repeatedly and keeps coming back to the same solution - something about the size of a Nimitz is the most cost-effective. A Nimitz-size hull gives a high sortie rate, a high surge rate (more important), can conduct flight ops in almost any weather and at night, has the capacity for a large and diverse air wing etc. A smaller carrier, just under a Midway in size was nearly built for the USN during the Carter administration instead of a repeat Nimitz. What ended up happening was we found that for 2/3 the cost of a Nimitz, we could buy 1/2 the capability. Not a great bargain. From a cost effectiveness standpoint, bigger is better when it comes to carriers.