How the Zumwalt Class Destroyer Works

The Zumwalt class destroyer is a key part of the U.S. Navy's 21st Century Surface Combatant (SC-21) Program, initiated by Navy planners in 1991, to conceive of warships capable of delivering next-generation functionality. The SC-21 Program describes a family of ships designed to fight more effectively in littoral operations, which are those conducted close to the shore. At the same time, SC-21 ships will need to function equally well out in the open ocean. The key is versatility, with ships in the SC-21 family able to handle virtually any mission, from wartime missions in land attack and undersea warfare to noncombatant evacuations to presence, escort and diplomatic missions.

The SC-21 family includes a destroyer class and a cruiser class of ships. The destroyer class was originally designated DD 21, and to bring the first ships in the class to life, the Navy introduced a four-phase development process. Two competing teams oversaw the first two phases, which involved system concept design and initial systems design. Bath Iron Works, with Lockheed Martin Corporation as the systems integrator, led the first team. Northrop Grumman Ingalls, with Raytheon Systems Co. as the system integrator, led the other.

Northrop Grumman won the contract to move forward in phase-three design and development, anchoring what would be known as the DD(X) National Team. Raytheon became the National Team's prime mission systems integrator for all electronic and combat systems. Other major subcontractors included Lockheed Martin, BAE Systems, Boeing and General Dynamics Bath Iron Works.

In November 2005, the DD(X) program received funding approval to enter the fourth and final phase: construction of eight ships. Five months later, the Navy announced that the class and lead ship would carry the designation and hull number DDG 1000 Zumwalt. The first two ships in the class are currently being built, with a targeted delivery date of 2012. When it's commissioned, the DDG 1000 Zumwalt will replace older destroyers of the Spruance class (DD 963 - DD 997) and will complement ships in the Arleigh-Burke class, ushering in a new era of naval warfare.

In 2001, the U.S. Navy suspended the DD 21 program in order to evaluate progress made in the first two phases. The two design teams introduced several innovative concepts and systems never before seen on a modern warship. Unfortunately, the costs to implement these technologies were estimated to be much greater than originally projected. As a result, the Navy reoriented the program to "… focus on technology development and maturation, including robust land-based and sea-based testing of prototype technologies that could be leveraged across multiple ship classes." The Navy also replaced the DD 21 designation with DD(X) to signify the updated vision of the program.

The DDG 1000 has been designed specifically to participate in both traditional military engagements, as well as those that might arise as part of the global war on terrorism. Like destroyers in the Arleigh-Burke class, the DDG 1000 will be multi-mission, capable of providing forward deterrence and presence, and an integral part of joint and combined expeditionary forces. But unlike today's destroyers, the primary mission of the DDG 1000 will be land attack support for ground forces. In fact, one of its most important requirements didn't come from the U.S. Navy, but from the Marine Corps, which, in 2002, requested that the Navy provide 24/7, all-weather, long-range missile-firing capabilities in support of USMC amphibious operations. That means the DDG 1000 will need to operate efficiently in shallow coastal waters - not in quick, hit-and-run missions, but in engagements that may last days or weeks.

Having a persistent presence in littoral areas is one of the most important design requirements of the Zumwalt class destroyers. Now let's look at some of the ship's other requirements, as outlined by Navy planners:

Survivable

While cruising in hostile waters near an enemy's coastline, the DDG 1000 can expect attacks from cruise missiles and small boats. Clearly, it will need to effectively defend against these threats, as well as those from submarines and surface mines. It will also need to have systems in place to minimize damage caused by missile strikes.

Stealthy

It may seem impossible to make a 600-foot long ship invisible to the enemy, but that's one of the DDG 1000's most important requirements. That means the ship will need to dampen engine noise and reduce the amount of electromagnetic energy (radar and infrared, for example) that it reflects to enemy detectors.

Powerful

From the beginning, Navy planners envisioned the DDG 1000 as an all-electric ship to meet ever-increasing power demands. Approximately 80 megawatts of electricity - nearly 10 times the power available on today's Arleigh-Burke class destroyers - will power all of the major systems of the ship, including gun turrets. The electric motor designed to power the propellers will be one of the most advanced in the world, capable of maintaining a top speed of 30 knots.

Beyond the needs to survive, stay invisible to the enemy and run on electric power alone, the Zumwalt class destroyers have other requirements that will make it one of the deadliest, and scariest, destroyers on the planet.

Lethal

While the 16-inch guns of today's U.S. battleships have performed well in supporting ground troops, the Zumwalt class destroyer will be even more lethal. It will be required to fire more rapidly, with greater range and with much greater precision. If the ship can generate enough power (and, as an all-electric ship, it should), it may also include an electromagnetic rail gun, a weapon that uses a magnetic field powered by electricity to accelerate a projectile up to 52,493 feet (16,000 meters) per second.

 

Fully Integrated

The DDG 1000 will feature an open IT architecture, making it easier to use off-the-shelf software and to promote interoperability. Contractors who help the Navy develop the various systems of the ship will work within this single IT framework to make sure all hardware and software is fully integrated.

Economical

The DDG 1000 will cost a great deal to build, but it will be one of the most efficient ships to operate. Many of its critical systems will be fully automated, requiring a smaller crew to keep the ship operational. Its fuel-efficient power system will also reduce fuel costs.

Pioneering

In many ways, the Zumwalt class destroyer will be a working prototype for all ships to be built as part of the Navy's 21^st Century Fleet. Its advanced technologies will be tested and proven in real-world situations and will then be incorporated in ships, such as the DD(X) Cruiser and the Littoral Combat Ship, being planned for the near future. It's also hoped that the DDG 1000 will influence ship design for the remainder of the century, giving rise to even newer, more advanced capabilities.

To make sure the requirements outlined in the previous two sections are met, the DDG 1000 will feature numerous innovations never before seen on a warship. Here are some of the most critical technologies being built into the Zumwalt class destroyer:

The low, angular deckhouse gives the Zumwalt class destroyer a sleek, modern look quite unlike any warship that has come before it. This distinctive appearance is only enhanced by the DDG 1000's hull, which slopes inward from above the waterline. Known as a "tumblehome" hull, this feature allows the ship to slice cleanly through waves, optimizing speed and maneuverability while decreasing acoustic and infrared signatures.

Weapons

The firepower of the DDG 1000 will be formidable. At the heart of the ship's weapons systems is something called the Advanced Gun System, or AGS, a pair of 155-mm guns capable of firing Long Range Land Attack Projectiles (LRAPs). An LRAP is a GPS-guided shell that can provide a precision strike on a target located as far as 100 miles away. Six hundred LRAPs can be fired from Zumwalt class destroyers in 30 minutes, giving the ship true rapid-fire capabilities that exceed those provided by the twelve 155-mm howitzers present on Arleigh-Burke class destroyers.

In addition to the AGS, the DDG 1000 also features 80 vertical missile launchers staggered around the ship's perimeter. Each launching system comes with modular electronic architecture, making it easy to accommodate both existing and future missiles for land attack, anti-ship, anti-submarine and anti-air warfare. Each system is also self-contained and fully armored to limit and isolate battle damage.

Finally, two 57-millimeter close-range guns fire 220 rounds per minute from the bow of the ship. Both guns fold down and tuck away for stealth.

Radar

The dual-band radar of the DDG 1000 integrates S-band and X-band radar capabilities in a single system. X-band radar operates on a wavelength of 2.5-4 cm and a frequency of 8-12 GHz. Because of its smaller wavelength, X-band radar is more sensitive and can detect smaller objects. S-band radar operates on a longer wavelength, about 8-15 cm and a frequency of 2-4 GHz. This higher frequency radar will improve the ability of the destroyer to track aircraft and missiles and to counterattack shore-based gun or missile batteries that attempt to strike the ship.

Design

Look at a typical battleship, and you'll see an array of spinning dishes and antennas sitting atop a high-profile mast. Unfortunately, this design, which provides a greater area to reflect energy, makes the ship much easier to detect on enemy radar. To overcome this problem, the DDG 1000 will integrate its communications hardware directly in the deckhouse "skin," which will be made with rugged, lightweight composites.

Sonar

Two types of sonar arrays are gathered together in a single solution known as the Integrated Undersea Warfare system. High-frequency sonar is able to detect underwater minefields, while medium-frequency sonar sniffs out submarines and torpedoes. The dual-band sonar array is located in the bow of the ship, in a bulbous compartment that provides complete 360-degree coverage of the underwater environment.

Propulsion

Most warships today use a traditional mechanical-drive propulsion system with two separate sets of turbines - one for propulsion, the other for generating electricity for shipboard use. The drawback to this type of propulsion system is an inability to shift power to where it's needed most on the ship. Weapons, for example, can't borrow power from the propellers during battle. The Zumwalt class destroyer will overcome this problem with an Integrated Power System, or IPS.

Here's how the IPS works. The ship's engines will no longer be connected to the propellers. Instead, the engines - four marine gas turbines that Rolls-Royce describes as the most powerful gas turbines available today - will power generators that produce a total of 80 megawatts of electricity. That electrical power will then be distributed to most of the ship's systems and the electric motors that will drive the propellers. Because the power is centralized, it can be distributed as necessary to high-demand systems.

Safety and Damage Control

Ship designers have included an advanced damage-control system in the DDG 1000 to increase response time to ship-threatening events. The system combines sensors, cameras and automated firefighting capabilities and will improve survivability while reducing the number of crew members needed for damage control.

Aircraft Support

The stern deck of the DDG 1000 serves as a landing pad for helicopters, unmanned aerial vehicles or other aircraft.

Crew

A Spruance-class destroyer requires a crew of 330. An Oliver Hazard Perry frigate requires 200 personnel. Because so many of its systems are automated, the DDG 1000's crew will number 140. This reduces the ship's operational costs, but it also has benefits for crew members, who will enjoy larger rooms and improved living conditions.

Although the DDG 1000 Zumwalt will be designed to be efficient and cost-effective, its up-front construction costs, estimated at $3 billion per ship, will be significant. Such a hefty price tag has raised some eyebrows and caused some controversy. The U.S. House of Representatives has been skeptical about the program from the outset and, indeed, congressional concerns over the budget contributed to the decision to suspend the DD 21 program in 2001. Certain technologies have also been scaled back to cut costs. For example, the Integrated Power System was originally based on permanent magnet synchronous motors. But to keep the project on schedule and budget, the design was shifted to advanced induction motors, an older technology.

Despite these issues, the 2007 appropriations bill passed on September 26, 2006, by the House and later by the Senate allotted funds to build the first two Zumwalt-class destroyers. One is being built in Pascagoula, Mississippi, home of Northrop Grumman's Ingalls shipyard. The other is being built by General Dynamics in Bath, Maine.

The ships should be delivered in 2012, but how many will follow remains uncertain. Much depends on how well the Zumwalt class destroyer performs in real-world combat situations. If it lives up to its promise, it could become one of the most successful ships in U.S. Navy history.

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