By MARCUS J. FISK

Philadelphia, the city synonymous with the American Revolution and the birth of the United States Navy, is experiencing an engineering renaissance that may well revolutionize the Navy as it moves into the next century.

Navy Engineers have had a kinship with the city of Philadelphia since 1910, when the Fuel Oil Test Plant opened at the Philadelphia Naval Shipyard. After the 1991 BRAC (Base Closure and Realignment) hearings, however, the Navy was directed to close the shipyard. Simultaneously with the shipyard’s closure, the Navy consolidated the Naval Ship Systems Engineering Station (NAVSSES) in Philadelphia—where the tests and evaluations as well as in-service engineering for all hull, mechanical, and electrical (HM&E) systems laboratories were located—with the R&D (research and development) arm of the Naval Sea Systems Command (NAVSEA) at the David W. Taylor Research Center in Carderock, Md.; the new entity was named NSWC (Naval Surface Warfare Center) Carderock Division (NSWCCD).

BRAC-95 later consolidated the machinery R&D functions of the Annapolis Detachment of NSWCCD with NAVSSES Philadelphia so that all machinery R&D and machinery engineering could be conducted "under one roof."

Today, the Naval Ship Systems Engineering Station Philadelphia has the mission of carrying out, among other things, " … Science and Technology, R&D, and Test and Evaluation engineering and In-Service Engineering services for naval and other maritime surface and undersea vehicle machinery systems." The realignment effort has made NAVSSES Philadelphia not only responsible for core engineering knowledge, but integral to the future development of components, equipment, and system life-cycle management for surface ships and undersea vessels.

Shortly after the BRAC consolidation, the Navy determined that the new DD 21 land-attack destroyer might be an ideal candidate to benefit from the support services available through NAVSSES. The lead ship of the class is named for the Navy’s youngest CNO, Adm. Elmo R. Zumwalt, Jr., who died on 2 January 2000. One of the most innovative, and controversial, CNOs of the post-WWII era, Zumwalt revitalized the warfighting capabilities of the fleet by outfitting ships with more sophisticated and efficient weapons systems as well as by initiating wide-ranging reforms throughout the Navy. The Zumwalt-class ships will be able to deliver unprecedented levels of offensive firepower from the sea.

Under the Navy’s still-evolving Network-Centric Warfare operational concept, the Zumwalts will be able to give a naval or joint task force commander the multimission flexibility needed to engage land targets while simultaneously countering maritime threats.

The ship’s primary mission will be to provide Naval Surface Fire Support (NSFS) for the Marine Corps, as envisioned in the Marine Corps’ Operational Maneuver From the Sea (OMFTS) doctrine. But to do so it must have the ability to engage, suppress, and neutralize enemy targets ashore through the coordination of precision-strike weapons and advanced naval guns.

Among the principal weapons included in the DD 21 arsenal will be the 155mm Advanced Gun System (AGS) and the Advanced Land Attack Missile (ALAM).

The AGS consists of two trainable, single-barrel 155mm guns fitted with integrated gun and fire control systems complemented by magazines with a storage capacity of up to 1,500 rounds of ammunition.

The offensive capability of the Zumwalt-class ships also will include the Long-Range Land-Attack Projectile (LRLAP) being built by United Defense. The Analysis of Alternatives for the ALAM began in September 1999 with a contract award; Engineering and Manufacturing Development is scheduled to begin in 2004. IOC (initial operational capability) is expected in 2010.

The Zumwalt-class destroyer is seen by the Navy as the platform that will "push the envelope" in advanced computing systems and in reducing radar cross-section as well as the ship’s infrared, acoustic, and magnetic signatures. Lessons learned by the Navy from operating the Arleigh Burke-class Aegis guided-missile destroyers, which have crews of almost 350 officers and men, will allow the DD 21 to operate with a crew less than half that size.

The ship’s tactical and quality-of-life innovations come under the jurisdiction of the DD 21 Program Office at NAVSEA in Crystal City, Va.; the lion’s share of management, research, and coordination will be carried out, however, at NAVSSES Philadelphia.

Perhaps no other initiative in the development and fielding of the Zumwalt-class ships has attracted as much attention as the decision to incorporate electric-drive technology into the ship’s Integrated Power System (IPS).

"The technology revolution underway at NAVSSES is a revolution in power," is how Michael E. Collins, program manager for Integrated Power Systems at the NAVSEA Program Executive Office Surface Strike, characterizes the IPS initiative. Collins says that the technology has finally reached maturity and is enjoying broad acceptance within the maritime community. "Electric-drive power has been around a long time. The first major uses of electric-drive power can be traced back to USS Langley (the Navy’s first aircraft carrier) in the 1920s," he pointed out. "IPS also is attractive because the acoustic requirements are projected to exceed the acoustic reduction levels well beyond what today’s mechanical systems can achieve."

The Navy used turbo-electric AC drive in several shipbuilding programs—encompassing some 50 platforms, including five battleships and two aircraft carriers—between the World Wars. The submarine community used diesel-electric drive propulsion exclusively in its entire fleet until the 1960s, when it shifted to nuclear power. Advances in metallurgy that improved reduction gear mechanical systems also slowed the adoption of electric-drive propulsion. Most warships today take energy from their engines, gas turbine, diesel, or steam, and send it through a series of reduction gears down the shaft to the propellers.

Unlike these traditional machinery propulsion systems, the IPS will use a generator to take electric current from a ship’s engines and transfer the power to a motor drive or controller. The electric current then will be modulated for use by the ship’s electric motor. The IPS essentially creates a common "pool" of energy that can be used for ship’s propulsion or for a myriad of other services such as onboard computing, operating combat systems, and other auxiliary or "hotel" services. "This gives us flexibility to direct power where we need it and when we need it," says Capt. Jim Wilkins, technical director for the DD 21 program at NAVSEA.

Philadelphia’s NAVSSES has set up an advanced-development technology demonstrator for IPS. The demonstrator’s principal components are a 21-megawatt-output GE LM 2500 gas turbine that serves as the prime mover, a three-megawatt generator set, a series of AC/DC converters with a 4.160-volt AC switchboard, and a frigate-size induction-type electric motor. The demonstrator provides the information NAVSSES needs to effectively evaluate the proposals from industry on the best system to employ in the DD 21.

The Navy’s acquisition strategy for the Zumwalt-class destroyers and the consolidation of NAVSSES Philadelphia have given it the opportunity both to exploit acquisition reform and to embrace the future of IPS.

"The Zumwalts ... [will be] fundamentally different from anything else we have ever built," Wilkins said. "We are now able to draw on the NAVSSES staff and match it with the direction that acquisition reform is taking us with DD 21."

The Navy’s acquisition approach imposes certain additional risks on industry, though. In the past the Navy would determine the specifications for industry; with the DD 21 the Navy is giving industry operating requirements of the baseline ship and requiring that electric-drive be the power source, but leaving the specifics of the design up to industry.

"We wanted to look outside shipbuilding," said NAVSEA’s Collins. "Our goal is to make the maximum use of ... new technology with DD 21. What is particularly exciting is that industry is receptive."

Two multitalented industry teams are competing for the DD 21 contract: a Blue team under Bath Iron Works (lead) and Lockheed-Martin (systems integrator), and a Gold team under Litton/Ingalls (lead) and Raytheon (systems integrator). Each team will provide an initial design concept to the Navy that incorporates electric-drive into the overall engineering systems design and integrates other ship systems into the design. The Navy plans to announce the award of a full-service contract on 31 March 2001. The lead ship is expected to enter the fleet in 2010. It will be a total of 32 ships in the class.

"From that point it will be up to the team. It will be responsible for the remainder of the design for Zumwalt," Wilkins said.

The acquisition strategy does not use the lead-yard/follow-yard concept. "One ship will be completed in two yards," said Wilkins. "Each team knows that we [NAVSEA] have postulated that the procurement cost ... of the fifth ship in each shipyard [must] not exceed $750 million in 1996 dollars," he said.

The Navy also has stipulated that the operating and support (O&S) cost of the Zumwalts be no more than $2,700 per hour underway (again, in 1996 dollars), or about one-third the O&S costs of the current Navy surface combatants of similar size and capabilities.

The potential of IPS and the future applications of electric-drive technology has not been lost on Congress. However, a 31 July Congressional Research Service report on the risks and advantages of electric-drive warns that, although the technology can improve ship stealth, payload, and survivability, it also has several possible disadvantages, including higher short-term costs, increased program risk, and system complexity, "and less efficiency in full power operations." The report also concedes, though, that the long-term savings that might be achieved "could be substantial."

Senate Majority Leader Trent Lott (R-Miss.) sent a letter on 1 August to Secretary of Defense William S. Cohen urging him to create a new high-level office to oversee the development of IPS technology. The Navy itself should establish "a new Navy-wide office to incorporate electric-drive propulsion in the fleet," Lott said, "in a manner similar to the way nuclear power has been incorporated."

The Navy obviously concurs with that recommendation. "We want people to know that we can accommodate any platform. We want to apply IPS to any ship in the fleet from destroyers to submarines," Collins said.

If the Zumwalt-class destroyers live up to the potential of their name, that goal is likely to be achieved both expeditiously and efficiently—but perhaps with a smattering of controversy also mixed in.