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FEATURE ARTICLE  

Novel Ship Hull Forms Still a ‘Tough Sell’ 

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by Sandra I. Erwin 

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 fit 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 fit that into the total force. That is not clear right now.”

Commercially, it has a viable opportunity, as a fast commuter ferry on which passengers would not get sea sick, said Hamilton. “I am not sure how Slice would fit into a naval environment.”

The U.S. Navy would be unlikely to build a ship for the sole purpose of preventing seasickness, he said. “That has not been a primary concern in any ship. Sailors get over it.”

AMI’s president, Guy Ames Stitt, agreed that there are “great benefits to new hull forms.” But there are few organizations willing to take the risk in funding and proving that those hull forms can work, he said. “Except for the Scandinavian countries, very few navies in the world will accept the risk of applying novel hull forms. They are very tough to sell.”

Lockheed Martin, meanwhile, has proposed to the Navy a concept for a more advanced version of Slice, which company officials hope will fill a niche for the Navy: a fleet of small, fast, stealthy, multi-purpose ships to conduct operations near the shore. The director of the Naval War College, Vice Adm. Arthur Cebrowski, coined the term “Streetfighter,” to describe such a ship.

The Streetfighter concept consists of a fleet of small vessels that would run to and from the large capital ships. This would keep the large ships safely away from the coast. Cebrowski said the Navy should consider deploying such a fleet within the next 20 years or so.

His vision for a Streetfighter fleet has stirred controversy within the Navy, which, like the other military services, is a conservative organization. But Cebrowski’s message appears to have resonated among some Navy leaders at the Pentagon. According to a senior Navy official, six three-star admirals recently met to discuss “how to put the dollars in the budget to fund Cebrowski’s idea.”

If the Navy, one day, decided to build Streetfighter, Lockheed Martin already has a five-year plan to make that happen using Slice technology, said Harris. The company would develop a “littoral combat ship,” which Harris nicknamed “Slice on steroids,” to demonstrate the role of a fast, stable small ship. It would be stable in high seas, with an operational range of 4,000 nautical miles and a maximum speed of 50-60 knots. Harris would not specify a price tag for this ship, but speculated it would be at least $90 million.

The 50-knot ship, said Harris, “could be a modification of Slice, but we are not going to limit ourselves to that. The design could be different.”

But even though the technology might be available to develop a Streetfighter in the near future, the Navy, logistically, is not set up to operate with such a ship, said retired admiral Donald Pilling, who recently served as vice chief of naval operations. “Cebrowski’s idea of having small netted platforms fits nicely into the concept of network-centric warfare,” said Pilling in an interview. But there is a problem. Streetfighters would need “mother-ships,” they would not be able to operate autonomously. In the Navy, said Pilling, “we live in our ships for six months. So we need things like stores, barber shops. These ships would not be big enough.”

Currently, he explained, “we deploy our ships and they don’t have to go to their mother-ship every three or four days to refuel.”

Cebrowski is proposing not only a new ship, but a new way of operating, said Pilling.

Capt. Deborah Deacon, from the Naval Sea Systems Command, cautioned that Streetfighter would be used as a “pick-up truck.” It’s not designed to operate independently, but as part of a force, she said during a conference of naval engineers. “We are not talking about designing Streetfighter with today’s technology. ... The goal is to design and deploy Streetfighter in 2020.”

Some naval experts noted that other nations’ navies have successfully deployed small combatants, so there is no reason to think that the technologies are not mature enough. “If the Navy decides to develop a small, fast combatant, there are technologies out there and ships have been built in other countries and in the commercial marine industry that begin to address the technical challenges,” said Kai A. Skvarla, a naval engineer at John J. McMullen & Associates.

Skvarla co-authored a paper called “Streetfighter: Sampling Alternatives of Analysis for Future Small Combatants,” which was presented during the annual conference of the American Society of Naval Engineers.

Streetfighter, he said, has been loosely defined as a small frigate-type ship that probably displaces between 250 and 2,500 tons, it’s likely between 40 and 120 meters in length, capable of speeds between 35 and 65 knots.

Examples of successful small combatants include:

For the U.S. Navy, however, the problem is not the technology, but how to apply it to its operational realities, said Stitt. “Just because a ship works for the Swedish Navy, it may not work for the U.S. Navy.

“Other navies’ operational concepts are fundamentally different than ours. They don’t work in a battle group,” said Stitt.

The commercial yachting industry has developed advanced technology. The caveat, said Stitt, is that “yachtsmen can afford to pay high dollar for capabilities, even if the capability has to be developed. Not all navies are willing to do that.”

Nevertheless, Stitt believes that Streetfighter has a future, because it could be used as a vehicle to bolster the U.S. shipbuilding industry.

An exportable Streetfighter is what the U.S. industry needs, he said. “Our builders don’t have designs that are exportable. No one is buying DDG-51s [destroyers]. More buyers are interested in light frigates and corvettes.”

France, Germany and the United Kingdom collectively earn about 30 percent of their annual defense budget from exports, said Stitt. “They purposely design their equipment to meet their own naval operational requirements, but always have a mind toward the export potential. We have none of that. They rely on these exports to finance their defense budget. We don’t.”

The U.S. Navy, he added, takes “no responsibility for any export potential for our industry. Our exports equal about 4 percent of U.S. defense spending.”

Streetfighter is needed, said Stitt, so the Navy can “reasonably and cost effectively maintain an industrial base.” He estimated that these vessels’ price tags would range from $120 million to $275 million, including weapons and sensors.

The U.K. government has been promoting a prototype triple-hull — or trimaran — as a possible Streetfighter. A trimaran called the Research Vessel (RV) Triton, developed by the British Defense Evaluation Research Agency (DERA), has been touring the United States this summer. The RV Triton is 297 feet in length, with a beam of 74 feet.

For the past five years, the U.K. government has evaluated the potential use of the trimaran hull form in future warship designs.

This hull form, said U.K. officials, offers advantages over an equivalent mono-hull, such as reduced hull resistance at higher speeds, more stability and flexibility in the design. The RV Triton was built by Vosper Thornycroft, a British shipyard. The ship, said DERA officials, will reach a speed of 20 knots and has the endurance to cross the Atlantic Ocean without refueling.

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