For the uninitiated, the Navy has just about completed its production run of Arleigh Burke-class (DDG-51) destroyers. The 60+ Burkes are highly capable, versatile ships that were designed to do it all and do it well. In capability and survivability, they’re a throwback to the general-purpose destroyer of World War II, meant to be equally adept in air-defense, surface warfare and anti-submarine roles. The class has been a great success and will serve for many years to come.
But as capable as these ships are, they can’t last forever and the Navy has been hard at work designing their replacements. The problem is that the Navy doesn’t seem to know what it wants and appears determined to push the design and technology envelope beyond proven, mature technologies. While the hull form and stealth characteristics of the Burkes were new, the propulsion plant, weapons and electronics were evolutionary, not revolutionary.
Not so the planned replacement, designated the Zumwalt-class (DDG-1000). The Zumwalts represent a revolutionary departure in just about every category. While the Navy has touted the class as a “general purpose” design, its primary function is land-attack, being armed with Tomahawk TLAMs and either one or two 155mm naval guns of a new, longer-range design with the possibility that a naval rail gun could be retrofitted at a later date. The ship will be equipped with the AN/SPY-3 radar and advanced shipboard data processing systems.
But it is the hull design and propulsion plant that raise the most eyebrows. The hull-form is a throwback to the “tumblehome” design in which the deck area tapers outward to its widest point at or beneath the waterline, while incorporating a wave-piercing bow shape that does not ride above the water, but moves through it. There are serious concerns about the design’s stability in following seas.
While the original design incorporated a Permanent Magnet Motor for main propulsion, because of technical problems the designers have shifted to an Advanced Induction Motor instead with both ship-service and propulsion power being supplied by an integrated system of gas turbine generator sets. In some respects, this is a throwback to the the older, turbo-electric designs of the 1920s and 1930s. Because of the shift to the AIM, however, the plant will require more space, more power and create more noise.
For survivability and to free up center line space, missile cells are dispersed throughout the periphery of the ship with the bulk of the missile load being Tomahawk Land Attack Missiles (TLAMs). The radars will be housed in a very high deckhouse structure constructed of composite materials, not steel. There are reportedly fabrication issues with the structure.
But the principal issues with DDG-1000 are (a) price and (b) mission. While the Navy originally wanted to build 30+ copies, the design’s $4B per copy price tag has forced a reduction to three, all of which are to be built by Bath Iron Works, with the composite deckhouses being fabricated by Northrop-Grumman at its Pascagoula shipyard.
When it comes to mission, does this class even have a future? If it’s a land-attack design, it’s meant to operate in the littorals. But couldn’t this job be done more effectively by purpose-built littoral combat ships? There have been disagreements as to whether the Zumwalts even have the air-defense and anti-ballistic missile capabilities of the Burkes or the later-flight Ticonderoga-class cruisers. According to Wikipedia,
In January 2005, John Young, Assistant Secretary of the Navy for Research, Development and Acquisition, was so confident of the DD(X)’s improved air defense over the Burke class that between its new radar and ability to fire Standard Missiles and SM-6, “I don’t see as much urgency for [moving to] CG(X)” – a dedicated air defense cruiser.
On 31 July 2008 Vice Adm. Barry McCullough (deputy chief of naval operations for integration of resources and capabilities) and Allison Stiller (deputy assistant secretary of the Navy for ship programs) stated that “the DDG 1000 cannot perform area air defense; specifically, it cannot successfully employ the Standard Missile-2 (SM-2), SM-3 or SM-6 and is incapable of conducting Ballistic Missile Defense.” Dan Smith, president of Raytheon’s Integrated Defense Systems division, has countered that the radar and combat system are essentially the same as other SM-2-capable ships, “I can’t answer the question as to why the Navy is now asserting…that Zumwalt is not equipped with an SM-2 capability”. The lack of anti-ballistic missile capability may represent a lack of compatibility with SM-3. In view of recent intelligence that China is developing targetable anti-ship ballistic missiles based on the DF-21, this could be a fatal flaw.
On 22 February 2009 James Lyons, the former commander in chief of the U.S. Pacific Fleet, stated that the DDG-1000′s technology was essential to a future “boost phase anti-ballistic missile intercept capability”.
So, it would appear that the Navy isn’t quite sure about its capabilities. And Congress apparently has some heartburn about the class as well. The House likes the Burke class and wants the Navy to build more. The Senate, however, wants the Zumwalts. Earlier this year, the warring factions compromised by assigning all three Zumwalts to Bath while re-starting the Burke production line at Pascagoula.
What do I think? DDG-1000 looks to me like the USS Timmerman, an experiment that never worked right and had a short and unhappy life, although it did serve as a test-bed for future technologies. I have to wonder, though, whether there aren’t more cost-effective ways to test new technologies.