Novel Ship Hull Forms Still a 'Tough Sell'.

• Author: Erwin, Sandra I.

Naval research chief advocates 'risk-taking' in the development of technologies

When it comes to weapons programs, the United States has become "risk-averse," said Rear Adm. Jay M. Cohen. The upshot for the U.S. Navy, he asserted, is that ships have been built in the same manner for more than a century.

Intense media and congressional scrutiny of defense programs naturally leads to risk aversion, said Cohen, who is the chief of naval research. In his job, however, he believes that he has an "obligation to be risk tolerant," he told a conference of naval engineers.

Naval engineers, said Cohen, "are struck by the fact that ships have been built the same way since the [age of the] caveman--they have a frame, stringers and skin." The only difference, he said, is that cavemen used animal skin and today, shipbuilders use steel.

Cohen has been trying to pique the Navy's interest in new ship full forms, which many experts believe would be suitable for small combatant vessels that operate close to the coast. This summer, various U.S. West Coast ports will see one of these novel ships, called Slice, partly funded by the Office of Naval Research (ONR).

The Slice ship is a drastic departure from conventional mono-hull forms. It is a variant of the Swath (small water-plane area twin-hull) design, which was conceived more than two decades ago. The Navy's first Swath ship will be an oceanographic vessel called Agor 26. ONR awarded a contract in 1999 to Lockheed Martin Naval Electronics and Surveillance Systems and Atlantic Marine to build the ship. Atlantic is a commercial shipyard in Jacksonville, Fla.

Agor 26's Swath hull is 182 feet long, with an 88-foot beam. It is powered by an electric drive.

Slice, named for the way the ship moves through rough waters, is a speedier variation of the Swath hull form design, explained R. Robinson Harris, director of business development at Lockheed Martin. It was built at Pacific Marine, a shipyard in Hawaii.

With the Swath, waves do not affect most of the hull of the ship, Harris said in a briefing to reporters. The buoyancy is provided by two large torpedo-shape submerged hulls, one on each side. A small Swath ship is more stable than most larger ships, said Harris. But it lacks speed.

In both Swath and Slice, the twin hulls are submerged, unlike the twin-hull catamaran.

Slice was introduced in 1997. It has four underwater pods. The propellers are on the forward pods. Slice is 104 feet long, with a beam of 55 feet. According to Harris, it is "as stable as you please" in 10-12 feet waves, moving at 30 knots. The waves swirl beneath the primary hull of the ship.

Lockheed Martin hopes to sell this ship commercially in the Seattle area, as a passenger ferry.

It was Adm. Cohen's idea to take Slice to the West Coast on a promotional tour, said Harris. The final stop will be in San Diego, during Fleet Week in October. The tour was funded mostly by ONR. Lockheed Martin contributed $250,000. Slice will retire for the winter and, next spring, it will sail through the Panama Canal and proceed up the U.S. East Coast, said Cohen. Several members of Congress asked for Slice to sail up the Mississippi River. Cohen expects that the novel ship can be used as a recruiting tool. "If I can't get the public or Congress to the facilities, I have to bring naval research to them," he said.

ONR also is trying to promote new technologies in electric propulsion. Slice does not have electric drive, but Cohen said the ship would be a suitable candidate for electric propulsion. In conventional systems, gas turbine or diesel engines drive the shaft, so the engines have to be connected to the shaft, at the bottom of the ship. With electric drive, the prime mover engines on the ship are used to generate electricity. The electricity is transferred from the main power plants to a motor that turns the propellers. The power plants, thus, can be located anywhere on the ship.

The benefits of electric drive, proponents said, are lower fuel costs and the ability to use electricity to power other subsystems on the ship, such as weapons and cargo elevators.

Electric propulsion is among the priority areas that ONR categorize as "future naval capabilities," said Cohen. He expects that this technology will receive "hundreds of millions of dollars" in new funding.

The Slice concept, however innovative, is far from an obvious fir into the current structure of Navy ships, experts said.

"Slice has a future. I just don't know what it is," said Jack E. Hamilton, vice president of AMI International, a naval consulting firm in Bremerton, Wash.

"It provides a good stable platform," he said. "The question is, what mission do I apply it to? And how do I...