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Future Carrier Designed for Evolution

December 2001
By Robert K. Ackerman
E-mail About the Author

The Navy opts for the march of technology rather than leap-ahead wishes.

The next generation of U.S. Navy aircraft carriers will feature evolutionary rather than revolutionary advances in technologies and capabilities. The new vessels are being designed with an open architecture to permit growth in virtually every key component and system, and special allowances are being made for adding complex electronics systems as the Navy focuses on network-centric warfare.

Core technologies already earmarked for inclusion on the earliest ships of this generation include a new nuclear propulsion plant that will provide more power with less machinery, which in turn will reduce maintenance requirements. An electromagnetic launch system will replace steam catapults. Advanced radar will reduce ship profiles while improving self-defense capabilities. And, better electrical infrastructure enabling broad command, control and communications (C3) capabilities will place the carrier at the heart of network-centric operations.

These planned advances also clear the way for future technology improvements. An electromagnetic aircraft arresting system ultimately will replace the hydraulic cable configuration currently in use. The new C3 capabilities can allow the carrier to serve as a command ship controlling fleets of unmanned combat aerial vehicles (UCAVs) as they are introduced into the force structure. And, the new radar systems will open the door to incorporating future defensive technologies still on the drawing boards.

Known as the CVNX program, the evolutionary improvement effort begins with CVN-77, originally planned to be the final ship in the CVN-68 Nimitz class. This vessel will serve as the first recipient of some of the new carrier technology. The next ship, currently designated CVNX-1, will break with the Nimitz-class model by incorporating several core technologies, beginning with the new nuclear propulsion plant. The third vessel, CVNX-2, will add hull improvements and a new flight deck to go with more innovations.

The new technologies incorporated into the future carriers promise a range of improvements. The ships’ survivability will be increased through better defensive systems. The new vessels will have a greatly increased sortie generation rate over that of the Nimitz-class carriers. When combined with future aircraft and ordnance capabilities, each new carrier will be able to strike more than 1,000 aimpoints per day.

Rear Adm. Isaac E. Richardson III, USN, head, aircraft carrier and air traffic control systems branch of the Navy’s Air Warfare Division, explains that several goals dominate the planning for the new carriers. Total ownership cost amid fiscal constraints is a key determinate, he allows. For example, the new vessels will be able to operate with progressively smaller crews, and this will provide considerable cost savings. CVN-77 will see force reductions in the range of 60 to 210 people. CVNX-1 will go to sea with from 300 to 500 fewer crew members than standard Nimitz-class ships, and CVNX-2 may be able to operate with 800 fewer people. These manpower reductions could translate to total ownership cost reductions estimated to be as much as $4.7 billion.

“Manpower is the biggest cost driver that we have,” the admiral emphasizes.

The new carriers also are being designed to serve as testbeds. This aspect suits the goal of incorporating new technologies into the vessels as they become available. These advances also may be incorporated into older carriers where feasible. Key ship components and entire systems are being designed for plug-and-play replacement as laboratory innovations become deployable technology.

“In my career, I have never seen a vessel have not only such an initial capability, but also such an ability to grow with the times,” the admiral declares.

The Navy sought to develop its new class of aircraft carriers in an evolutionary manner from the Nimitz-class vessels instead of introducing a revolutionary new concept. A 1991 National Research Council report on future aircraft carrier technology suggested radical designs such as a monohull vessel twice as massive as Nimitz-class ships and even a giant submersible vessel that would pop up to launch its aircraft. As an interim development to prepare for these dramatic advances, the report also proposed building an advanced Nimitz-type ship that would incorporate new technologies. This is the approach selected by the Navy, and Adm. Richardson cites several reasons for this decision.

“We decided to go with the evolutionary strategy so that we did not put all our eggs into one basket,” he explains. “We are trying to come out with a more-combat-capable vessel at the very end instead of trying to do everything all at once. If the technology does not prove itself out, then we will not have gone down a costly road.”

Another factor is feasibility. Experts considered 70 different designs before choosing the current plan. Requirements forced the elimination of many vessel designs that did not meet safety or capability minimums. Some of the more advanced proposals represented “a step too far,” the admiral relates.

“We have a great history from the 1930s to now where we have learned a lot of lessons, and a lot of people learned them in blood,” he emphasizes. “You don’t throw that type of knowledge away by trying to take a horrendous leap when you can take just a large leap—the risk is too great.”

The CVN-77 is the transition ship in the program, the admiral relates, with delivery to replace the USS Kitty Hawk slated for 2008. Its improvements begin with a new integrated warfare system. The admiral describes this suite as a new concept beyond that of any existing carrier. It features an integrated combat system design that includes phased array radar, flat plane array antennas, integrated databases and controls, and knowledge-centric displays.

In addition to improved signal capabilities, the new antenna technologies also will help reduce the giant vessel’s radar cross-section. “Is a carrier ever going to be stealthy? No,” the admiral declares. “But, we are making strides in that area.”

The CVN-77 will be powered by the standard Nimitz-class nuclear plant. However, the new ship will feature centralized electric plant controls and integrated propulsion plant controls. Improved electronic systems management will allow the CVN-77 to provide sufficient additional power for the new integrated warfare system.

The admiral notes that Newport News Shipyard in Virginia will be in charge of prototype competition under government oversight. Lockheed Martin will be the integrator for the electronic system.

The new integrated warfare system will fit the Navy’s thrust into network-centric warfare by allowing “almost instantaneous sharing of the complete battlespace information that is available,” Adm. Richardson warrants. The automated system will provide a common operating picture so that the carrier will be a true fusion center.

The ability to fuse all data to ensure that all personnel are looking at a common operating picture is central to network-centric warfare, the admiral states. New sensor systems will permit better collection and dissemination of information from land, sea, air and space sources.

The phased array radar will differ from the familiar versions deployed on the DDG-51 Arleigh Burke-class destroyers. A volume search radar automatically will begin to track any aircraft that flies into its volumetric space. Other sensors include multifunction radar and advanced aircraft tracking devices. Multiband antennas will reduce the number and profile of existing antennas.

Testing of active defensive missiles already is underway on existing ships. The rolling airframe missile currently is undergoing tests on the USS Nimitz. These tests include exploring possible frequency conflicts. The North Atlantic Treaty Organization’s evolved Sea Sparrow missile (ESSM) also is under consideration.

More exotic weapons such as laser beams eventually could be deployed aboard the advanced carriers. However, no plans currently exist for their incorporation.

The CVNX-1 will include the integrated warfare system along with a new nuclear propulsion system, a new electrical generation and distribution system, and the electromagnetic aircraft launch system, or EMALS. It is scheduled to replace the venerable USS Enterprise, the Navy’s first nuclear aircraft carrier, in 2013.

The new nuclear propulsion plant for CVNX-1 will provide more power despite its simplified design, the admiral points out. It offers fewer pumps and valves and less piping. Less complex maintenance will allow force reductions of about 228 people per ship. While earlier plans called for employing an adaptation of a nuclear submarine power plant, engineers ultimately chose to develop a new design from the ground up. This design, while not based on submarine reactors, does draw on lessons learned from the Navy’s nuclear power plant expertise. The seven-year effort “is starting to come together,” Adm. Richardson states.

“The electrical plant is critical for growth” of future warfighting improvements, he emphasizes.

Accompanying this nuclear plant is a new electrical distribution system that offers a substantial improvement over Nimitz-class carriers. Adm. Richardson notes that these vessels currently have reached their maximum electrical power distribution capabilities, and this was achieved after exceeding original design limits. This severely restricts the ability of these older vessels to incorporate new warfighting enhancements comprising electronic technologies and systems.

The new system provides 2.5 times the electrical generation capacity of the Nimitz class, and it offers an electrical availability growth potential of 23 percent over planned CVNX consumption. Adm. Richardson compares this to the 10 to 12 percent growth margin designed in the original USS Nimitz. By doubling this growth potential, designers are allowing room for incorporating unforeseen advances that could require considerable amounts of additional power.

At the forefront of CVNX-1 deck improvements will be EMALS. Long a designer’s dream, this technology has been improving steadily to the point where safety and reliability now can meet carrier standards. “Only in the past year or two has the technology matured enough,” the admiral relates. Reliability now is on a par with that of steam catapults. The electromagnetic launchers will have the same aircraft shuttle system, so existing aircraft need not be modified to use the new launchers.

Incorporating all of these advances will be the last of the three-ship evolution line, the CVNX-2. This ship will include a new hull design, a state-of-the-art flight deck and an electromagnetic aircraft recovery system, or EARS.

“This will be the state-of-the-art design for the future carrier,” Adm. Richardson declares.

A larger flight deck will provide more flexibility to accommodate new types of aircraft. UCAVs, for example, may become a key combat element around 2025. This new flight deck will permit their operation from the carrier, Adm. Richardson notes.

The admiral foresees UCAVs playing a significant role in combat operations. The Predator unmanned aerial vehicle already has been deployed carrying air-to-surface missiles, and high-risk flights increasingly will become the purview of these unmanned craft. The new integrated warfare system will permit control of large numbers of UCAVs in air operations.

This advanced network-centric warfare capability may portend a return of the aircraft carrier to the heart of an operational command. Adm. Richardson sees the potential for running multicarrier operations from a single carrier. While amphibious command ships currently have substantial capabilities, the integrated warfare system’s ability to present real-time displays will return command capability to the carriers. Experts are analyzing options for using a carrier as a command ship if desired.

The CVNX-2’s new flight deck will feature EARS and other functional improvements. Unlike EMALS, however, the electromagnetic arresting system is still several years away. It still will employ an arresting cable with the electromagnetic technology replacing the hydraulic system.