DDG(X) Unveiled - What Can We Learn?

The United States Navy's DDG(X) Concept
Our First Look at the United States Navy's DDG(X) concept

The first public concepts for the United States Navy's DDG(X) program have been unveiled, and they reveal quite a lot about the Navy's thinking on this critical program as well as the future of ship design and fleet architecture. Overall, the concept (the images are quite clearly not a final or even preliminary design) has a lot of potential and could shape up to be an excellent successor to the current fleet, but it remains to be seen whether that potential will actually materialize. In many ways the DDG(X) concept attempts to straddle a fine line, paving the way for the introduction of revolutionary new systems while simultaneously appearing extremely conservative and evolutionary. It is understandable why the Navy chose this approach, but it there is no guarantee the gamble will pay off.

The State of the Surface Fleet

Before diving into the details of the DDG(X) concept, we should take a moment to consider where the Navy's surface fleet stands and how it got here. Currently, the Navy operates 22 Ticonderoga-class cruisers, 69 Arleigh Burke-class destroyers, 17 Littoral Combat Ships, and 2 Zumwalt-class destroyers (which are officially commissioned but not fully operational). At first glance, this is a powerful fleet, composed almost entirely of heavily-armed multirole combatants outfitted with the Aegis combat system, powerful radars and sonars, and 90-122 VLS cells. However, what has been the Navy's strength for decades has become its weakness. The Aegis ships that make up the fleet are now aging, older designs that are no longer the undisputed masters of the sea.

The Ticonderoga-class is the worst off, and the oldest member, USS Bunker Hill (GC-52), just turned 35 in 2021. The Arleigh Burke-class isn't much better off, with the lead ship having recently turned 30. Both of these classes were originally designed for service lives of around 30 years, but the Navy has extended that to 35 or more in an attempt to stave off the impending numbers shortfall. Even worse than the physical age of the hulls is the age of their systems and general designs. The Aegis combat system was designed in the 1970s, and large portions of the system are increasingly out of date. While the Navy has put significant effort into upgrading the the system to run on modern computers and generally be more capable and more flexible, much of the actual hardware still dates back to the Cold War, including the centerpiece AN/SPY-1 radar.

While its S-band PESA technology was a generation ahead of anything else afloat when it first deployed, today, AN/SPY-1 is at least a generation behind the newest warships being built by any major naval power. Even the Indian Navy, hardly a bastion of cutting-edge technology, currently operates several destroyers outfitted with multifunction AESA radars (the Kolkata-class and Visakhapatnam-class) - twice as many as the United States Navy with its 2 not-quite operational members of the Zumwalt-class. The Chinese have gone even further, with the Type 055 destroyers carrying a sophisticated multi-band AESA system that may well be more advanced than what was originally planned for the Zumwalt-class before budget cuts eliminated the AN/SPY-4 Volume Search Radar.

Two of China's Latest Type 055 Destroyers
Two of China's Type 055 destroyers - arguably the most advanced surface combatants in service

The ship designs themselves that make up the United States surface fleet are just as obsolete and were never amazing designs to begin with. Although touted as great successes today, both the Ticonderoga-class and the Arleigh Burke-class were forced on a reluctant Navy by a budget-minded Congress. Aegis was originally supposed to go to sea in a nuclear-powered Strike Cruiser (the design of which can still be seen on the official Aegis program office insignia), before being shoehorned into the Spruance-class hull to create the Ticonderoga-class. The result was a ship that was overloaded from day one. The Arleigh Burke-class, rather than being designed as a premier surface combatant, was also the result of budget restrictions and stemmed entirely from the goal of fitting Aegis into something even cheaper than the Ticonderoga-class. While some of the worse compromises have since been rectified with the Flight II and Flight IIA redesigns, the hull remains too small for the tasks it is intended to perform and the latest Flight III redesign has completely used up its remaining growth margins.

But while the Navy recognized these shortcomings from the start, the end of the Cold War and subsequent budget cuts gave it few options. The only upside was that the mass decommissionings of the 1990s allowed the Navy to shed its older ships and standardize on a then state-of-the-art all-Aegis fleet. As fleet size stabilized in the 2000s, the Navy saw its chance to wind down production of the Arleigh Burke-class and shift to a more modern and unconstrained destroyer design. The new ship would introduce an open-architecture computing system for greater flexibility, possess the latest radar technology to defeat modern threats, be armed with large-diameter VLS cells to accommodate future weapons, and have sizable space and weight margins for growth over its service life.

The result was the Zumwalt-class, the most powerful surface combatant the world had ever seen. Today, the Zumwalt-class is far too often considered an embarrassing failure because of a combination of cost increases and the well-publicized decision not to procure any ammunition for its 155mm guns. But if you look beyond the spin and the inexplicable amount of attention its guns get, you will see a ship that quite literally is everything a modern navy could desire. The design has powerful AESA radars, an electric drive system, huge amounts of room for future growth, and more. However, a combination of the Global War on Terror and economic recession cut the program short before it could shine, leaving the Navy to continue producing the increasingly obsolescent Arleigh Burke-class instead.

The Role of DDG(X)

As it became clear that relying on the Arleigh Burke-class forever was not a viable strategy, the Navy began exploring a future Large Surface Combatant. This program became official in June 2021, with the creation of the DDG(X) program office. Although not widely remarked on at the time, the decision to use the DDG designation now appears to be telling. Previous public discussion of the next large surface combatant had often thrown the term "cruiser" around, usually accompanied by talk of how a replacement was urgently needed to take over the air warfare commander role usually assumed by the Ticonderoga-class. Commentators may have assumed that the DDG(X) nomenclature was merely a way to make a new cruiser program appear more affordable, but it now appears that the Navy was entirely serious about the new ship being a destroyer rather than a cruiser.

Zumwalt and Arleigh Burke destroyers moored at a pier
The Zumwalt-class and Arleigh Burke-class are both destroyers, but you might not guess it at first glance

Of course, cruiser and destroyer is a rather arbitrary distinction when the Zumwalt-class destroyers are roughly 50% larger than the Ticonderoga-class cruisers. Things get even stranger when you remember that the Ticonderoga-class itself was originally supposed to be a DDG (which is why the class started at CG-47 rather than CG-42, the next number in the CG sequence, and why there is a four-number gap between the final ship of the Farragut-class and the first ship of the Arleigh Burke-class). Currently, the primary difference between a CG and a DDG is that a CG is commanded by an O-6 instead of an O-5 and hosts the air warfare commander and his staff. However, this difference is largely the result of the cramped penny-pinching design of the Arleigh Burke-class rather than any historic difference between cruisers and destroyers. The Ticonderoga-class design received a cruiser designation to justify its high costs and signify its revolutionary capabilities, not because it can fit an air warfare commander. While internet commentators often make a large deal about the additional VLS cells and guns of the Ticonderoga-class when compared to the Arleigh Burke-class, the truth is that the additional armament is virtually meaningless.

By using the DDG(X) designation, the Navy effectively said that it was not interested in continuing the current split between "cruiser" and "destroyer" roles, and would combine them into a single hull. While people often get caught up in the way things are currently done, and most speculative future fleet designs include around 22 cruisers to replace the 22 members of the Ticonderoga-class (which already fails to grasp that the number 22 was entirely arbitrary and purely the result of when the Arleigh Burke-class reached full-rate production and the Ticonderoga-class production line could be wound down), there is really no good reason to have two separate hull types performing such similar missions. Simply adding space for an air warfare commander to a destroyer is a far cheaper solution than building a limited number of specialized cruisers to do the job.

Further, by using "DDG(X)" instead of "CG(X)," the Navy indicated that it was largely satisfied with the current capabilities of its cruiser/destroyer fleet and was not interested in pursuing anything significantly different. Again, while the internet is filled with fantasy ships the displace more than an Iowa-class battleship and are loaded with unimaginable numbers of every weapon possible, the Navy's decision is a rather sensible one. Simply adding more weapons to a hull is rarely a great idea since modern naval warfare is based as much on sensor density as weapon density, and a smaller number of larger hulls provides less sensor coverage. Concentrating firepower instead of dispersing it also increases the fragility of the fleet if it starts taking losses, and is the antithesis of the Navy's current move towards "distributed lethality."

The largest question about the role of the new DDG(X) is how it relates to the Constellation-class frigate program. Because the Constellation-class is still just entering production, it remains to be seen what its final capabilities will actually look like and how it will be deployed. The Constellation-class was born from a desire to up-gun the Littoral Combat Ship, and still reflects that origin with its emphasis on relatively low costs and independent patrols. However, at the same time, the Constellation-class possesses an Aegis-derived combat system and the AN/SPY-6(V)3 radar, which promises similar performance to AN/SPY-1. Add in 16 anti-ship missiles and the potential for SM-6, and the Constellation-class looks like a workable replacement for the Arleigh Burke-class in some roles.

the Constellation-class frigate
The Constellation-class frigate will be the compliment to DDG(X) in the future fleet

This leaves the Navy with two potential paths to pursue. On one hand, it could remain with a variant on the current fleet architecture, ramping up production of DDG(X) and having it replace the Ticonderoga-class and Arleigh Burke-class on a roughly 1:1 basis while a smaller number of the Constellation-class takes over low-end duties. On the other hand, DDG(X) could be procured at a lower rate, primarily to replace the Ticonderoga-class in its air-warfare commander role, while the Navy ramps up production of the Constellation-class to replace the bulk of the current destroyer fleet. Both are plausible paths, but the details of the DDG(X) concept, combined with some other statements, suggests that the Navy plans on taking the first route.

Breaking Down the DDG(X) Concept

It may appear space-age (and slightly Russian to my eye at least), but once you get past the first impression, you will see that the DDG(X) concept is actually extremely conservative. This likely comes as no surprise to anyone following recent United States Navy developments, as the Navy has come under intense criticism for its attempts to roll out advanced technology with the Zumwalt-class, the Gerald R Ford-class, and the Littoral Combat Ship. While I find much of the criticism to be ill-founded, it doesn't change the fact that there is currently no tolerance for anything even suggesting revolutionary development. The Navy even turned to the Italians for the hull of the Constellation-class to give the impression of restrained, evolutionary development (an impression that I find somewhat amusing given that virtually every aspect of the Constellation-class has been drastically altered from the original FREMM).

There was no foreign hull to base DDG(X) on, as no foreign navy is building surface combatants of this size other than the Chinese (although there was some odd internet speculation about cutting down the Japanese Izumo-class carriers), but the concept displays a decided conservative hullform nonetheless. Although there were plenty of rumors that the Navy would reuse the Zumwalt-class hull, it does make sense why the Navy would choose a new hull rather than trying to fit new systems into a hull designed for older tech - especially since there wouldn't even be any real production efficiencies from using a hull that was last ordered a decade ago.

One of the primary goals of DDG(X) is to move to an even more advanced form of the Zumwalt-class Integrated Power System (IPS), known as an Integrated Power & Energy System (IPES). Not only is IEPS planned to include backup battery power (which will also help power energy weapons without diverting power from propulsion), but it will use a fully integrated modular architecture to enable future growth. This updated power system was actually under development for several years before work on DDG(X) was formally started and could well be considered the revolutionary "Aegis" equivalent for the new ship. Attempting to make IEPS work with the Zumwalt-class hull would probably have been a less than optimal choice and there is little reason to make such major compromises on a class that could well see the year 2100.

DDG(X) planned weapons and systems
A slide from the DDG(X) concept presentation listing planned capabilities

Aside from the larger hull and new power systems, the most important take-away from the DDG(X) concept is that it effectively a Flight III Arleigh Burke-class destroyer. Although the headlines will focus on the mention of lasers, large-diameter missile cells, and other novel weapons, it is important to stress that the concept only mentions these systems as potential upgrades over the life of the design. The baseline combat systems that the DDG(X) program office desires to put on the first ship are effectively those of the Flight III and little more. We can see the standard 14-foot aperture AN/SPY-6(V)1 radar supplemented with an AN/SPQ-9 rotating X-band radar, and what appears to be an AN/SQS-53 bow sonar (there is no mention of other sonars or view of the stern, but we can assume the presence of a TB-37 multi function towed array, if not a variable depth sonar as well).

Some of the other phased array antennae above the bridge are likely the SEWIP electronic warfare system, and midship Nulka decoy launchers are evident as well. The largest surprise is that the concept displays the same trio of AN/SPG-62 illuminators as the Arleigh Burke-class even though the Constellation-class took advantage of the Navy's new family of active radar homing surface to air missiles (SM-6, SM-2 Block IIIC, and ESSM Block II) to dispense with dedicated illuminators. This may be so that DDG(X) can make use of the sizable stocks of semi-active homing SM-2 and ESSM that remain in the Navy's inventory, or it may be that the Navy believes powerful illuminators still have tactical value in their own right (although looking at recent foreign designs, the United States Navy appears to be in the minority here).

When it comes to weapons, we see what appears to be a 64-cell Mk 41 VLS cluster on the bow and what is likely a second VLS cluster amidships. The second cluster could be another set of 64 cells, but it may also be a 32-cell group, which would match the armament of the Arleigh Burke-class. If it is a 32-cell cluster, then the only meaningful difference in armament is the addition of two 21-cell RAM launchers amidships to replace the aft Phalanx mount. This is a fairly obvious upgrade given the obsolescence of gun-based CIWS and is similar to the armament of the Constellation-class, which includes a single 21-cell RAM launcher aft. However, this is a departure from current United States Navy practice, as the only previous missile ships to receive a dedicated point defense missile were the Arleigh Burkes-class destroyers assigned to ballistic missile defense patrols in Europe, and that was thought to be because early versions of the Aegis BMD software could not simultaneously defend against air-breathing threats.

USS Porter (DDG-78) firing a Rolling Airframe Missile
USS Porter (DDG-78) is one of the few Arleigh Burke-class destroyers armed with an 11-cell SeaRAM launcher instead of an aft Phalanx CIWS

Rounding out the standard armament we see the typical 5" lightweight deck gun, a pair of 25mm remote weapon stations, and a pair of 12.75" torpedo tubes. However, there is one additional weapon that is worth mentioning for its absences - the Naval Strike Missile or any other dedicated anti-ship missile. The Constellation-class broke with United States Navy practice by mounting no fewer than 16 Naval Strike Missiles, but DDG(X) does not appear to follow suite. However, it is probably too early to draw any conclusions from this as the heavy anti-ship missile battery was a late addition to the Constellation-class. Altogether, there isn't too much to say about the baseline armament of DDG(X) given that it is effectively the same armament that is going into the Flight III and little changed from the dozens of Arleigh Burke-class destroyers currently in service. While commentators who advocate massive cruisers loaded with hundreds of VLS cells will likely be sorely disappointed, this is a more than reasonable weapon fit for the current destroyer missions and reflects a ship that will slot into the current fleet architecture with no issues.

Future Weapons

For most people looking at the DDG(X) concept, the really interesting part is the proposed future upgrades, particularly the numerous laser weapons and the large-diameter VLS cells. That the 600 kW lasers are suggested to replace the 21-cell RAM launchers (along with the fact they are not given valuable center-line space) suggests the Navy sees the lasers as a highly capable point-defense weapon but not as a primary weapon. The 150 kW laser mounted ahead of the bridge is possibly envisioned as an upgraded version of the 60 kW HELIOS system that is being installed on USS Preble (DDG 88) this year. Having two different types of lasers appears to be an odd choice unless the 150 kW system is seen as an early upgrade with the 600 kW lasers being added further down the road.

The large-diameter VLS cells are a more interesting future capability. Currently, the only publicly-known missile that would require such a large launcher is the joint Army-Navy Long-Range Hypersonic Weapon. However, replacing 32 Mk 41 VLS cells that can be used for a wide variety of tactical missiles with 12 cells that can only be used for a near-strategic land-attack weapon is a debatable choice. Balancing the desire for longer-ranged and more sophisticated weapons with the need to increase magazine depth is a difficult question and it will be interesting to see which way the debate goes.

Nearly as important as what is included among the possible future weapons is what is not included - a rail gun. While the fact that a potential system is not listed on a single extremely early concept means very little, it does imply that the Navy does not see railguns as a high-priority near-future weapon. This would seem to match up with reports that rail gun development has stagnated in favor of lasers. Still, the fact the most powerful lasers listed are "only" 600 kW units and not the holy grail 1 MW weapons may mean that the future weapons displayed on the DDG(X) concept are only the first rounds of desired upgrades and more will be added further down the road.


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