Boston Herald April 04, 2004
Yard workers will help flip new ship's switch
The Navy's next-generation destroyer will have an advanced electrical power system designed largely by engineers in Newport News
By Peter Dujardin
NEWPORT NEWS - When you think of Northrop Grumman Newport News, Navy destroyers aren't typically the first ships that jump to mind.
For decades, the shipyard has been almost exclusively a maker of nuclear-powered aircraft carriers and submarines, with some commercial ship-repair business on the side. And it's clear that the company doesn't plan to change its focus soon. But in its largest effort in years on a ship that's not a flattop or a sub, Northrop Grumman Newport News is designing, developing and testing one of the most vital systems for the Navy's next-generation DD(X) multi-mission destroyer - its integrated power system, one of the more dramatic changes on the new class of ships from the current destroyers.
The DD(X) will have electric drive - meaning that two electric motors, rather than gas-turbine engines and reduction gears, will directly spin the ship's two propeller shafts. Gas-turbine generators will provide the power to run the electric motors and other systems on the ship.
The DD(X) will be the first Navy combat ship in decades to use electric drive and the first to use a new kind of motor that packs a big punch.
"The technology has finally come to where it's small enough to fit into a ship," said Peter C. Diakun, Northrop Grumman Newport News' director for the Marine Integrated Power Systems program.
But the electric-drive motor is just one part of the revolutionary integrated power system on the DD(X). That total structure is expected to be more fuel-efficient than the old systems. It's expected to allow rapid changes in power distributions - either to provide peak energy for future advanced weaponry or to redirect fire in case of an attack. And it's designed for more flexibility regarding where large gas-turbine engines can be placed.
The two electric motors on the DD(X) - 50,000 horsepower each - are being designed and built by DRS Power Systems of Hudson, Mass, which has been partnering for more than 15 years with Newport News on power work. Newport News' expertise is in the total system architecture - how the motors, gas turbines, generators, cabling, switchboards and other parts work together. More than 50 engineers from Newport News are working on the project.
Newport News' background to the destroyer business - or, at least, the destroyer system business - actually began as a sub initiative.
In the early 1990s, Newport News Shipbuilding invested heavily in researching new power systems, foreseeing quiet electric motors as a future benefit for subs. The theory is that electric-driven propellers are inherently less noisy than turbine-driven ones, giving an advantage in stealth.
In 1996, Newport News Shipbuilding partnered with Kaman Electromagnetics Group of Hudson, Mass. (later bought out by DRS Technologies of Parsippany, N.J.), and Northrop Grumman Marine Systems of California to develop an electric-drive motor. The motor used advanced high-density magnets to get more power than old electric-drive systems. It soon became clear, however, that the new motors were still too big for subs, where space is at an even greater premium than in surface ships. But the technology was timed perfectly for the DD(X), which needs the technology now.
"We were working on this technology and had invested in it, and it had matured enough, and the Navy had confidence that this was the right application," explained Irwin F. Edenzon, the shipyard's vice president of technology development and fleet support. "So we were in the right place at the right time."
In and of itself, electric drive is nothing new. Electric-drive systems, using an older conventional electric-motor technology, are very common in the cruise-ship industry, for example. "Cruise ships have all kinds of space, so they can put a big motor on there," Diakun said. "They're using it purely to save fuel."
And the Navy is no stranger to electric drive, either. Lots of World War II-era ships used electric drive, including the Langley, the first aircraft carrier. Two decommissioned nuclear-powered subs built by Electric Boat, the Tullibee and the Glenard P. Lipscomb, also used it. And a new Navy logistics ship is also being designed with an electric motor. But technological advances - using advanced magnets - to be used on the DD(X) are making the new electric-drive motors less bulky - and packing more of a punch - than those used in cruise ships and Navy ships of old. That makes the new systems competitive with other systems for ships that have high power needs. The shipyard has dabbled in enacting the new-style systems, putting it on the LSV2, a small test sub that built in 2000.
And unlike cruise ships and the older Navy ships that used electric drive, the DD(X) will have a fully integrated power system. That means, in part, that the DD(X)'s electric-drive motor and the auxiliary systems - lighting, cooling, cooking and weaponry - will both get their electricity from the same place: a set of gas-turbine electrical generators.
In current Arleigh-Burke ships, for example, there are four gas-turbine engines - two to turn each of the propellers - as well as three smaller gas-turbine generators for auxiliary systems. But each propeller's engines and the generators for auxiliary systems operate independently.
On the DD(X), by contrast, a unified set of two large gas-turbine generators and two smaller ones will create a common shipboard electricity supply. Both propellers' electric motors and the auxiliary systems can draw from that power pool. And because the turbines work as a unit, they can draw off each other, and excessive power generation is reduced. The result is a fuel-efficiency gain of up to 20 percent. Ed Bartlett is president of DRS Technologies, the company that makes the motors for Newport News. He compared the efficiencies in the new motor to hybrid cars that use both electrically charged batteries and gasoline, depending on the situation.
"It's like the Toyota Prius," he said.
"Hybrid cars use the electric motor to supplement the gas motor for acceleration. Cars are not efficient when they're accelerating, but you can optimize the operation to take advantage of the best fuel economy at different times."
Just as important, the DD(X)'s system will be able to better distribute power throughout the vessel to allow the ship's future weapons systems - possibly including lasers - to draw huge amounts of power for peak periods.
And whereas in current ships the gas turbines must be near the drive shafts, they can be placed elsewhere with the new system, giving better flexibility in basic ship design.
In the late 1990s, two teams vied for the contract to design the DD(X).
Ingalls Shipbuilding, the Pascagoula, Miss.-based company that later became Northrop Grumman Ship Systems, led one team.
Raytheon, Newport News, Kaman and a host of others were also in that group.
The rival team was led by General Dynamics' Bath Iron Works in Maine, and it also included Lockheed Martin.
In April 2002, the Navy selected the Northrop Grumman Ship Systems team for a $2.9 billion contract to come up with a full-scale design and begin building the DD(X).
One reason that the Navy selected Northrop's team was that the integrated power system was considered less risky than the General Dynamics system, read a report on the program on the GlobalSecurity .org Web site.
The General Dynamics team, the report said, had mounted some of the components in external pods below the hull, whereas the Northrop Grumman team kept the equipment inside the ship.
When the Northrop Grumman Ship Systems team won the competition, the Newport News division and DRS Power Systems decided how they would break out their responsibilities, Bartlett of DRS said.
They decided that DRS would design and build the motors, the drive control; that other companies would build other components; and that Newport News would be responsible for the total system architecture.
That architecture, the integrated power system, is the largest of 11 advanced technologies that Northrop Grumman Ship Systems is testing for the DD(X).
All the efforts will come together in a big way in June 2005, when Northrop Grumman is planning to begin a test at a Navy site in Philadelphia.
The Navy plans to ask Congress for money for at least eight new destroyers by 2010, with the construction expected to take place at Northrop Grumman Ship Systems and at Bath Iron Works.
Newport News isn't expected to build any of the ships.
And what will its efforts in the DD(X) mean for Newport News' core business of carriers and subs in the long term?
Some of the data collected through the program can be to help build electrical systems on CVN-21 program, the yard's next big carrier, which will have a big need for electricity.
But using electric drive systems on aircraft carriers is still a long way off.
One day, electric-drive motors might be small enough to power aircraft carriers - but Edenzon said it would be long after he retired.
For now, it's still more practical for aircraft carriers to use mechanical drive systems than electrical ones.
Carriers often have to operate full-bore, rather than at slower cruising speeds, during flight operations to help give warplanes adequate lift to take off. pdujardin@dailypress.com, 247-4749
© Copyright 2004, Daily Press
