Military bases at sea: no longer unthinkable.

Staging a military campaign the size of Operation Iraqi Freedom entirely from ships at sea--with no access to land bases--would seem inconceivable to most defense planners.

Nonetheless, the notion of "sea basing" forces has gained momentum at the Pentagon in recent months. Advocates point to the decision by Turkey to deny staging rights to U.S. Army units preparing to invade Iraq last year as the reason why sea bases should not be viewed as extravagances, but as necessities, if the United States is to remain a global power.

An August report by the Defense Science Board endorsed the sea base idea, dubbing it a "critical joint military capability" that should be supported by all the services.

So far, however, it appears unlikely that a large-scale sea base could be deployed for at least 20 years, given the technical hurdles and multibillion-dollar price tags associated with a project of this magnitude, experts said. Another issue that may deter future efforts is the potential vulnerability of massive seaborne platforms to missile or submarine attacks.

A sea base, notionally, would combine a carrier strike group, an amphibious ready group (with augmented firepower from submarines and destroyers) and a flotilla of sophisticated cargo vessels that also would serve as both warehouses and maintenance facilities for ground combat vehicles and aircraft. The ships would be staged about 25 miles offshore, but 2,000 miles from a major land base, such as Guam, covering the East Asian theater, or Diego Garcia, supporting the Middle East theater.

Every ship would he part of a multi-service command-and-control network, noted the DSB study. "Special operations forces, soldiers and Marines would assemble together with their equipment, on the sea base.... This combination would enable rapid force projection over the shore."

Among the staunchest advocates of sea bases are Chief of Naval Operations Adm. Vernon Clark and Marine Corps Commandant Gen. Michael Hagee. Clark made "sea basing" one of the pillars of his vision for the Navy of the 21st century, called "Sea Power 21."

In the future, "access is going to become more difficult," Hagee told an industry conference in Panama City, Fla., hosted by the National Defense Industrial Association.

He said U.S. forces must be able to "project combat power from the sea, to enable major operations ashore." To a degree, that is done today, with carrier strike groups and amphibious ships. The Marine Corps has been doing sea basing for a long time, he said. "It may not always have been elegant."

But the latest concept of "sea basing" goes much farther, conceivably to where the entire buildup and preparation for an operation equivalent to the Iraq war could be achieved without any land bases.

Hagee stressed that none of the military services could do that today.

As to whether the goal is realistic, Hagee said, "it's a challenge, but not impossible."

The most difficult hurdles will be logistics-related--transporting enough fuel to support ground and air forcers, and having a large enough aircraft that also can land on ships. "The long pole in the tent is the bulk fuel," in addition to the massive amounts of generators and batteries consumed by military equipment, said Hagee. That level of logistics support may over-stress the sea base.

The ideal aircraft in this scenario would be a vertical takeoff C-130-size vehicle that can land at sea, on a short runway, and has enough range to deliver supplies inland, Hagee said.

Regarding self-defense capabilities, it is too early to say exactly what weapons might be needed to protect the sea base. "We haven't solved that yet," he said. The most pressing concerns are threats posed by sea-skimming missiles, enemy small-boat swarming and diesel submarines.

The Navy plans to allocate funds for sea-basing programs in its fiscal year 2005 and 2006 budgets, said Clark. He declined to offer a cost estimate for the entire sea-basing project. "The financial side is not clear," he said.

The first big-ticket item expected to get a share of the funds is a new class of ships, called the Maritime Prepositioning Force Future, or MPF-F.

"MPF-F is the start," said Clark.

The MPF-F ships are intended to replace the current fleet of 18 prepositioning vessels, but the Navy and the Marine Corps have not settled yet on a design. The recent addition of a Marine Expeditionary Brigade to the Navy's carrier strike group also could increase the requirement for MPF-F ships.

An "analysis of alternatives" for MPF-F is expected to wrap up in February. The AOA will not recommend a specific ship design, but rather compare "capabilities and associated costs," said Robert Souders, from the Center for Naval Analyses.

Options could range from a ship comparable to the current Bob Hope class of sealift vessels, to a much larger ship, or a family of dissimilar ships, Souders said at the conference. "Not all the ships have to look the same." Most likely, it will be a modified commercial design.

The AOA addresses broader sea-basing issues as well, he said. The potential shortage of airlift to bring supplies aboard ships, for example, means the services should have other "connectors," such as inter-theater or intra-theater high-speed ships. To move supplies to the shore, they would need a modern landing craft, to replace the current LCACs. "We are looking at various options," said Souders.

Many of the technologies needed for sea bases are available. "It just takes money," he said.

The protection of the MPF-F will have to come from other ships. "This ship is commercial, not survivable," Souders said. "There is no vision for active defenses on this ship."

He cautioned that the AOA report will not give definitive answers to sea-basing questions. "It will lay out options for capabilities to support a MEB, and the cost."

Although the Navy typically is in charge of U.S. military shipbuilding projects, officials now believe that sea basing, to be successful, has to be a joint program.

William Howard, co-chair of the DSB study on sea basing, said this project goes "well beyond what the Marines and Navy alone can do." A lead service is a good idea, but there is a risk that the Army and the Air Force may not take the program seriously, because they assume the sea services take care of all ship-related matters.

The Army, particularly, needs to "pay special attention," he said. In the 20th century, more Army soldiers came across the shore in expeditionary operations than Marines.

The land force also needs to help address the survivability problem, he said. After the initial landing of forces ashore, they will pause to resupply and reorganize. That creates a vulnerability gap, "once the enemy realizes that is where you are going," said Howard.

On the logistics side, cargo handling could become a significant stumbling block. That seems like a mundane problem, but it's not, because the sea base must be able to operate in sea state 4--with winds of up to 24 miles an hour and up to 6-foot high waves.

The Defense Science Board concluded that the sea base would have to operate at sea state 4, "to have freedom of action in any of the major conflict areas," said Howard.

The type of long-range heavy-lift aircraft needed for sea-based operations would have to haul 20-25 tons and fly 200 miles un-refueled.

In addition to the MPF-F ships, the Navy also will need to build a new amphibious ship, called the LHA-R, to replace the four LHAs in the current fleet.

The DSB did not examine the cost of any of these capabilities. Coming up with funds to pay for these new ships and aircraft will take a "miracle," said Howard. "Developing these capabilities will take at least 20 years."

Relatively mundane tasks, such as transferring containers, can become nightmarish in rough seas. Steve Michetti, a ship engineer at the Naval Surface Warfare Center, said the Navy today has no capability to transfer containers in sea state 4.

The inter-ship transfer of containers and the cumbersome ship elevators present further logistics bottlenecks, said Michetti. The current process, he said, is time consuming and labor intensive.

The packaging is another impediment to the speedy transfer of cargo. There are "too many different boxes" that are not compatible among various types of ships.

The difficulties of launching and managing a major ground combat operation from ships offshore should not be underestimated, said retired Navy Rear Adm. Joe Carnevale, a shipbuilding architect and vice president of EDO Corp.

"Even in a sheltered harbor, mother nature can be pretty harsh," he said in an interview. Sea state 4 is "not really dangerous, if you design for it."

He cautioned that commercial ships, although advanced in many ways, often don't meet tough naval specifications.

In the U.S. Navy, he said, "we design our ships to survive. We have the highest level of survivability of any navy in the world."

Commercial ships are not designed to the standards of survivability of the Navy. "That doesn't mean you can't take a fundamentally commercial design and modify the design to meet the requirements of sea state 4."

Landing and launching aircraft in sea state 4 could be problematic, however. "Taking off is the greater challenge," said Carnevale.

Army Role

Army officials, meanwhile, generally support the concept of sea basing, but remain skeptical about the practicality of massing and launching large-scale operations from ships.

"It's a phenomenally resource intensive effort," said Army Brig. Gen. Phillip D. Coker, assistant deputy chief of staff for developments, Training and Doctrine Command.

Notably, the Army staged a sea-based operation in 1994, when the 10th Mountain Division deployed to Haiti from a Navy aircraft carrier.

"The Army has conducted more amphibious operations than any other service," Coker said. "But we do not purport to be a center of excellence in that area. We don't have an extensive doctrine. But we have begun thinking about it."

A mounted ground force is a "huge beast," he said. An armored battalion on the ground covers 5 km, including 50 meters in between each vehicle. That is just the combat vehicles, without any logistics tail.

To support the 133,000 troops in Iraq today, the Army deployed 1,200 helicopters, which require regular maintenance and repairs.

"If we had a base, we could station a logistics element and leave it offshore, where we would not have to worry about force protection or about logistics over the shore, or access," Coker said. "The power of an offshore base makes sense."

Brig. Gen. David A. Fastabend, director of capabilities development and experimentation at TRADOC, noted that the "anti-access problem is inherently joint."

On the sea basing effort, he said, "we are engaged with the Marines and Navy."

Nevertheless, "it's premature at this point to have any conclusion as to whether or not it addresses the requirements of the Army," Fastabend said in an interview,

The sea basing concept has "excellent potential" to solve a problem that is common to the Navy, the Marine Corps and the Army, he said. That is the shortage of "intra-theater" lift platforms, such as a helicopter than can carry 20 tons across several hundred miles.