The U.S. Navy's huge, nuclear-powered aircraft carriers – capital ships that have long dominated military planning and budgeting – are slowly becoming obsolete, weighed down by escalating costs, inefficiency and vulnerability to the latest enemy weapons.

But if the supercarrier is sinking, what could rise to take its place? Smaller, cheaper flattops; modified tanker ships; and missile-hauling submarines are three cheaper, more efficient and arguably more resilient options.

Navy Capt. Jerry Hendrix, a historian, analyst and futurist, caused a stir by making the case against the Navy's cherished supercarrier fleet. Hendrix's recent study "At What Cost a Carrier?" (.pdf), published by the Washington, D.C.-based Center for a New American Security, urges the Navy to begin drawing down its 10-11 Nimitz-class flattops and follow-on Ford-class vessels.

A single new carrier costs $14 billion to build plus $7 million a day to operate. "Not a good use of U.S. taxpayer money," Hendrix asserts. Moreover, he contends that huge carriers with their five-acre flight decks and scores of warplanes are ill-suited to the American way of war, in which precision and avoiding civilian casualties are more important than overwhelming firepower. Worst, Hendrix warns, the carriers – major symbols of American military might – are increasingly big targets for China's DF-21D ship-killing ballistic missiles.

The Navy is unlikely to decommission its giant flattops, to say the least. But should it start taking Hendrix's advice, one or more of the following vessels could sail in their place.

under construction. Photo: Huntington Ingalls

Flattop Lite ————

Hendrix alludes to "light amphibious carriers" as possible replacements for the supercarriers, but fails to mention the specific vessel type best suited to this role. The future USS America, nearing completion at a shipyard in Mississippi, is roughly half the size of today's Nimitz class and less than a third the cost.

Though technically a transport for Marines and their helicopters, *America *also supports Harrier jump jets and the still-in-development F-35B model of the stealthy Joint Strike Fighter, which like the Harrier can land vertically on small flight decks. Hendrix also called for the development of a long-range, armed drone able to launch from ships such as America. The Pentagon has already taken steps toward that goal.

In theory, the Navy could acquire and operate dozens of America-class vessels for the price of the 10 current carriers – and therein lies the smaller ships' key advantage. According to one popular theory of naval warfare, it's better to deploy large numbers of smaller ships than small numbers of bigger ships.

The idea is that a more numerous and spread out "distributed" fleet is harder to disable with weapons such as the DF-21D. By this way of thinking, the supercarriers represent single points of failure, whereas a larger fleet of "flattop lites" means redundancy and resilience amid combat losses.

If there's a downside to the gas-powered America class, of which the Navy has ordered two, it's the type's limited speed and range compared to a nuclear-powered vessel – plus its lack of a steam catapult. It's the absence of a catapult that prevents* America* from launching F/A-18 Hornets, X-47B jet-powered drones and other high-performance aircraft and instead compels it to wait for the troubled F-35B and brand-new drone types.

. Photo: Navy

Everything's a Carrier ———————-

Taking the notion of a distributed fleet even further, the Navy could potentially replace the aviation capability of today's supercarriers with ... most other ships in the fleet. Increasingly, all new warships – from the small Littoral Combat Ships to the latest Lewis and Clark-class supply vessels – come with extra-large flight decks. More and more, every ship is partially a carrier.

The Navy's latest support vessel stretches this concept to the extreme. The Montford Point, a modified oil tanker launched late last year, is primarily meant to transport hovercraft for beach assaults. But a future version of the $500-million ship will include a roughly 500-foot-long flight deck that could support helicopters, drones and potentially even F-35Bs.

But like the America class, the Montford Points will not have catapults. And as modified tanker ships, they lack armor and defensive systems, making them potentially more vulnerable to enemy attack once located. (Although again, a distributed fleet could have greater overall resilience.) Plus, they're slow, capable of just over half the speed of a supercarrier.

Still, as part of a widely distributed fleet of aviation-capable ships, future flight-deck-equipped Montford Points could support all but the biggest planes. And since they cost just 4 percent the price of a supercarrier, the Navy could afford lots of them.

. Photo: Navy

Underwater Arsenal ——————

One thing supercarriers do better than other ships is deliver tons of high explosives onto distant pinpoint targets fast. The means of delivering this firepower is, of course, the flattop's 40-plus fighter-bombers. But as Hendrix points out, the Navy possesses another method of blasting targets at long-range: precision-guided Tomahawk cruise missiles.

No vessel packs more Tomahawks than the sailing branch's four Ohio-class guided-missile submarines. Converted from their original role carrying nuclear-tipped ballistic missiles, the so-called SSGNs each pack as many as 154 cruise missiles in vertical tubes and can fire them stealthily from underwater.

The SSGNs are getting on in years and could begin retiring in the mid-2020s. The cash-strapped Navy says it can't afford to build new submarines with an equivalent missile load, and instead is planning on slightly increasing the much more modest Tomahawk loadout on some of the smaller Virginia-class attack subs.

But if the pricey supercarriers go away, the Navy could find itself with money to spare for a new class of missile subs or more of the enhanced Virginias with extra cruise missiles. Compared to today's fleet balance, that would mean a radical shift in resources from the surface force to the subsurface force. But if the big flattops end up being replaced by smaller, cheaper aviation vessels – however numerous – more subs could be the best way to maintain the Navy's overall striking power.

In any event, the Navy has options. Sinking the supercarriers, as Hendrix advises, does not mean giving up on naval aviation or on the ability to strike targets at long range. Indeed, the hundreds of billions of dollars the sailing branch would save over a period of decades with the flattops' retirement could lead to new ships, new methods and new attitudes – and, effectively, a revolution in naval warfare.