Final stretch: builders of the Navy's littoral combat ship pull out all the stops.

• Author: Jean, Grace V.
• Position: Navy Ships

The stakes could not be higher. When the Navy later this year picks a winner to build its littoral combat ship, no matter which contractor is selected, the decision will be seen as a turning point for the troubled program.

For the Navy, it will be a chance to prove it can-acquire relatively affordable ships. When LCS was first conceived earlier this decade, it was supposed to cost $220 million, but the price tag eventually more than doubled. Now, with a new acquisition strategy, Navy officials are hopeful that they can carry the program through, and procure 66 ships during the next three decades.

For the shipbuilding industry, LCS also will offer an opportunity for redemption. The sector has been under intense pressure to help cut costs so the Navy can avert a precipitous decline in the size of its fleet.

The littoral combat ship is a fast shallow-draft warship that is designed to ply the near-shore seas and coastal waterways through which the Navy's larger surface combatants cannot sail.

The Navy plans to spend more than $28 billion to build a 55-ship class of LCSs by 2035. A total of 66 will be procured in the next three decades to replace older hulls that will have retired from service during that time.

Two industry teams, one led by Lockheed Martin Corp. and the other by General Dynamics Corp., have each delivered to the Navy their versions of LCS. Lockheed Martin's USS Freedom (LCS-1) class is based on a steel semi-planing monohull design, which was built by Marinette Marine Corp. in Marinette, Wis. General Dynamics' USS Independence (LCS-2) class is based on an aluminum trimaran design, built by Austal USA, in Mobile, Ala.

Sailors say they like both variants. The service originally intended to build the two designs concurrently. But because their price tags are too high for the Navy to afford both, officials must choose only one. National Defense spoke with representatives from both teams to learn about the two ships' key characteristics. Following are highlights in a side-by-side comparison:

Hull design

Some sailors have nicknamed the USS Independence the "Klingon warship" because in their eyes the aluminum trimaran bears more resemblance to a futuristic sci-fi spaceship than a traditional naval vessel.

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The trimaran concept is based on a long, slender main hull with two shorter side hulls, or amahs, that provide stability. Independence's 419-foot hull is a derivative of a commercial high-speed trimaran ferry in operation in the Canary Islands. "When we looked at the LCS requirements and the high speed requirements, the trimaran became a solution," said Gene Miller, LCS-2 program manager at General Dynamics Bath Iron Works in Bath, Maine. With a 104-foot beam and 15-foot draft, the design yields high-speed capability and spacious areas for the flight deck, hangar and mission bay, he added. It also provides more stability than traditional ship hulls, said Miller. "It gives you a great deal of flexibility in how you load out the ship or grow it over its 30-year service life."

Those who have served aboard surface combatants say the USS Freedom has a familiar look and feel. It follows the basic contours of a Navy frigate, but its steel semi-planing monohull carves through the water differently. "Folks characterize us as having a traditional hull, but it is a little different under the waterline," said Paul Lemmo, vice president of business development for Lockheed Martin Maritime Systems and Sensors, which is leading the LCS-1 program.

Freedom's 378-foot hull is a hybrid derivative of two Fincantieri commercial ferries--the high-speed Jupiter class ferry in operation in the Mediterranean and Irish seas, and a ferry class based on the semi-planing monohull of the Destriero, an experimental vessel that set the transatlantic speed record of 55 knots in 1992.

Compared to the Oliver Hazard Perry-class frigate (FFG-7), Freedom is about 20 meters, or 60 feet, shorter. But it has a wider beam that provides more stability at higher sea states, said Lemmo. Unlike the frigate's keel, which narrows in the back and draws a deeper draft, Freedom's keel widens and its bottom flattens out as it progresses toward the stern. "That's what gives it the semi-planing shallow draft," and high speed, said Lemmo. Moreover a steel hull gives the ship more survivability and the ability to transit the crew safely from the fight, he said.

Propulsion plants

USS Independence has nine engines: two General Electric LM 2500 gas turbines, two MTU 8000 diesel engines, four electrical generators, and one dedicated diesel engine about the size of an electric generator to power the hydraulic pump for the retractable Azi thruster.

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Located towards the bow of the ship, the Azi thruster is similar to a 600-kilowatt outboard motor that is able to drop below the ship's keel and rotate 360 degrees, explained Miller. It acts like a steerable bow thruster and provides sailors with precision maneuvering capabilities. It also can function as a survivable, take-home power method. "If you lost all four primary shaft lines, you could operate the ship at about 5 knots on the thruster and be able get out of harm's way," he said.

The engines power four water jets in the stern of the main hull--two Wartsila 160 gas turbine water jets, and two Wartsila 150 diesel water jets. Each is steerable and together they offer a great deal of maneuverability, even in primary propulsion, Miller said. They are all reversible to stop the ship quickly, he added.

Sailors who have driven the ship say that she handles like a jet ski.

Independence's hull design is fuel efficient, and the ship can travel 4,500 nautical miles--the distance from Norfolk, Va. to Lisbon, Portugal--on a single tank, depending on the speed, said Miller.

USS Freedom has eight engines: two gas turbines, two diesel engines and four diesel generators. She may not have a bow thruster, said Lemmo, but she boasts a large machinery space to house the two Rolls-Royce MT30 gas turbine engines--the largest marine gas turbines in any navy. Producing 36 megawatts each, they are the most powerful gas turbines ever installed on a Navy ship. Along with the two Fairbanks Morse diesel engines, the combined diesel and gas turbine system provides sailors options for cruising efficiently at low speeds and for sprinting at high speeds. Freedom's range is greater than 3,500 nautical miles at cruise speed.

"At low speed, less than 18 knots, you want to run on diesel engines because they're economical. They don't waste a lot of fuel," explained Lemmo. "Ninety percent of the operation of the ship is going to be at lower speeds. You run on diesels. When we want to go fast is when we kick in the gas turbines. And when we run all four engines together in that combined mode, we can do well over 40 knots."

The four 750-kilowatt Fincantieri Isotta Fraschini diesel generators run a three-megawatt electrical power plant.

All that engine power drives four Rolls-Royce Kamewa water jets. The two outerboard water jets are fixed in place while the two central water jets are steerable.

On her transit from Wisconsin to Norfolk, Va., the ship was able to dock unassisted, without tugs. "She can essentially walk herself parallel to the pier," he said. Under Cmdr. Don Gabrielson, Freedom's first commanding officer, the ship's crew made a zero-radius turn in 90 seconds. "When was the last time you saw a football field go 60 miles an hour and then turn on a dime?" he asked.

Lockheed also opted to ruggedize the engines. "We chose to shock-harden the main propulsion system to allow the ship to survive the fight and be able to transit home and continue to do her mission," said Lemmo.

Berthing

USS Independence's permanent berthing is configured for 76 crewmembers. The berths are spacious with full sit-up capability and plenty of headroom, General Dynamics officials said. To boost the capacity to 100 crewmembers, the double...