Navy Propulsion System Approaches Critical Stage.

• Author: Kennedy, Harold
• Position: Navy wants contract by April 2001 to make electric drive for destroyers

Within the next 30 days or so, the U.S. Navy is scheduled to take a major step toward development of a futuristic new propulsion system that will substantially change the way that its ships are designed and built. That's the plan, anyway, providing the Bush administration allows the controversial project to go forward.

By the first of April, the Navy intends to choose a single team of contractors to design and build the first of its Zumwalt-class 21st century land-attack destroyers (DD-21), which will include an electric-drive propulsion system, featuring an integrated power architecture.

The Navy decided last year to install electric drive in the DD-21. Making that change will be as important to the Navy as the transition "from sail to steam or from propeller to jet engines," according to Richard Danzig, who was Navy secretary at the time.

"Electric drive will reduce the cost, noise and maintenance demands of how our ships are driven," he said. "More importantly, electric drive--like other propulsion changes--will open immense opportunities for redesigning ship architecture, reducing manpower, improving shipboard life, reducing vulnerability and allocating a great deal more power to warfighting capability."

Because electric drive is significantly quieter than traditional propulsion systems, Navy officials explained, it increases a ship's stealth capability, the ability to avoid enemy detection.

Electric drive is a transmission system, nor an engine, Navy officials explained. The engine can be almost anything, a diesel, gas turbine or even steam turbine. Electric drive is a new way of transferring power from the engine to the rest of the ship.

A key design element of the new system is a single-source generator for all of the ship's power needs--an integrated power system--including both propulsion and combat systems, officials said. This design eliminates the drive shaft and reduction gears found in traditional Navy ships, freeing up large amounts of internal space for other uses, such as habitat improvements.

Electric drive eventually will be used on most future Navy surface ships and submarines, officials said. Danzig announced last year that the first vessel to get the new system will be the DD-21.

The DD-21 is intended to be a multi-mission destroyer, designed specifically for land-attack warfare. One of its primary missions will be to support ground forces, the latest evolution in the way that destroyers have been used by the Navy.

Known as "greyhounds of the sea," destroyers first evolved a century ago to protect world shipping against an emerging class of small, fast torpedo boats. The first U.S. destroyer was the USS Bainbridge (DD-1), launched on August 27, 1901. In World Wars I and II, destroyers turned their weapons primarily against submarines. During the Cold War, guided missiles were added to their armament, greatly strengthening their ability to strike enemy aircraft, surface combatants and targets deep inland.

The DD-21 is intended to follow the Arleigh Burke (DDG-51) class of destroyers, which was first deployed in 1991. The Navy plans to build 58 of the DDG-51s, which feature the Aegis electronic combat system, before the end of the decade.

The DD-21 class of ships will be named for the late Navy Adm. Elmo Zumwalt, chief of naval operations from 1970 to 1974, the youngest man ever to hold that job.

The DD-21s are scheduled to replace the 1970s-era Spruance (DD-963) class of destroyers and Oliver Hazard Perry...