Missile Loadouts: Zumwalt (2019-2026)

Zumwalt (DDG-1000), the lead ship of her class, before the removal of her 155mm guns

The exact missile armament of the Zumwalt-class has always been a rather opaque topic and the United States Navy itself has issued a variety of contradictory statements over the years as the ships' capabilities were adjusted during construction. The mission of the Zumwalt-class has also changed substantially over the years as the ships were reworked from littoral land-attack specialists into blue water ship-killers and deep strike platforms to match the Navy's shifting strategic realities.

New Weapons For A New Ship

Despite the Zumwalt-class’s impressive 16,000-ton displacement, they were originally armed with just 80 vertical launch cells compared with the 90-96 of the Arleigh Burke-class or the 122 of the Ticonderoga-class. However, the Zumwalt-class is equipped with the significantly larger Mk 57 VLS instead of the legacy Mk 41 VLS of the other classes, with 25-inch by 23-foot cells instead of 22-inch by 21.5-foot cells. Unfortunately, this additional volume is largely wasted as there are currently no missiles in the Navy’s inventory that can take advantage of it and it is highly unlikely that any new weapons will be developed for the Mk 57 as there appear to be no plans to fit it to future vessels.

Still, the lower VLS count is not that great of a handicap. The Zumwalt-class was originally intended to replace the Spruance-class destroyers, the most heavily-armed of which were equipped with a 61-cell VLS, 24 Sea Sparrow, and 8 Harpoon - a 75-cell equivalent when considering the ability to quadpack Sea Sparrow’s successor, ESSM. While the Zumwalt-class required some additional cells for more capable air defense weapons to counter the increased air threat of the modern era, this was mitigated by a lesser need for point defense missiles and ASROC. When compared with the Arleigh Burke-class, the 10-16 cell difference is largely consumed by the anti-ballistic missiles now carried by the older destroyers.

The Mk 57 VLS is advertised as being compatible with all the weapons that function with the Mk 41 VLS. However, this does not mean that those weapons necessarily work with the new combat systems of the Zumwalt-class. This became a significant talking point in the Navy's 2008 testimony as to why it desired to cancel the Zumwalt-class, as it claimed the ship was incompatible with SM-2 and could not perform area air defense. But this was a half-truth at best. Unlike the Aegis ships, the Zumwalt-class makes use of the AN/SPY-3 X-band multifunction radar with intermittent continuous wave illumination, thus it can not employ the the S-band uplink installed on the typical SM-2 or illuminate targets for the weapon. However, a version of SM-2 had already been created for export to overcome identical issues with the APAR X-band multifunction radar installed on several European frigates and destroyers, such as the Dutch De Zeven Provinciën-class.

A Land-Attack Focus

In 2016, the Navy began procuring kits to modify existing SM-2 Block IIIA missiles into Block IIIAZ weapons that are compatible with the Zumwalt-class. A total of 94 kits were procured before the program ended in 2022. While some weapons will undoubtably be expended in testing, this is sufficient to provide roughly 30 SM-2 per hull. While there are currently no published plans to equip the Zumwalt-class with the more capable SM-6 and SM-2 Block IIIC, which use active homing and do not require terminal illumination, it is possible that this will be done in the future.

As with SM-2, the Zumwalt-class required a special version of ESSM. However, the fielding of this weapon was never in doubt and a small batch of these missiles was procured in 2012, with a larger number in 2016. Although only 30 ESSM Mk 57 have been purchased, this is because ESSM Block II, in addition to adding active homing, uses new hardware and software that makes the dedicated versions of Block I unnecessary. Procurement of the more capable weapon began in 2018 and did not ramp up until the 2020s, so it is unlikely that the Zumwalt-class originally received many of these missiles.

Finally, the Zumwalt-class are equipped with Tomahawk and VL-ASROC. Given the small number of the latter in the inventory, it is unlike that more than a handful will ever be carried, even though the Zumwalt-class is a remarkably capable ASW platform. In contrast, Tomahawk will certainly make up the bulk of the ships' weapons, befitting the ships' original focus on land attack. Thus, when the lead ships became operational in 2019, they were equipped with a solid self-defense capability and a substantial land-attack punch even if their 155mm guns lacked ammunition.

Zumwalt in 2019: 18x SM-2MR, 8x ESSM, 4x VLA, 56x TLAM

Anti-Surface Warfare Upgrades

Since the commissioning of the Zumwalt-class, the Navy has ramped up its focus on peer warfare against a major naval power (i.e. the People's Republic of China) and has substantially overhauled the weapons available to these ships. The most obvious change has been the removal of the non-functional 155mm gun mounts to replace them with four launch tubes for the new Conventional Prompt Strike - a hypersonic weapon with an official range of 1,725 miles. Since CPS has a diameter of 34.5 inches, it does not come close to fitting in even the larger Mk 57 VLS of the Zumwalt-class. Instead, the Navy has developed a new launcher, each tube of which can fit three of the massive new weapons, for a total of 12 per hull.

Zumwalt (DDG-1000) herself was the first ship to undergo this upgrade, returning to service in early 2025. However, CPS itself is not expected to become operational until 2026. The Zumwalt-class will be the only surface ships to carry this weapon, although it will also be compatible with the Virginia-class attack submarines. As a historical footnote, the addition of CPS bears a remarkable similarity to the short-lived plans to fit the Polaris ballistic missile to Long Beach (CGN-9) and other surface combatants during the 1950s before it became an exclusively submarine-launched weapons.

In addition to installing new launch tubes for CPS, there have also been less visible updates to the weapons themselves. Most importantly, the Navy began procuring Maritime Strike Tomahawk kits to upgrade existing Tomahawk missiles into antiship weapons in 2020. While only a limited number of MST are currently in available, over 1000 of these kits are planned, so it will likely fill a substantial portion of the ships' VLS cells in the future.

Zumwalt in 2026: 28x SM-2MR, 16x ESSM, 4x VLA, 12x CPS, 44x TLAM

More Upgrades Coming?

While it is not yet final, there is also talk of integrating SM-6 with the Zumwalt-class, and possibly even replacing the current combat system with a version of Aegis to make adding new weapons easier. As the Zumwalt-class is limited to the relatively short-ranged AN/SPY-3 radar, utilizing SM-6's impressive capabilities against air targets would only be possible through Cooperative Engagement Capability. However, the weapon could still serve as an extremely effective high-speed antiship missile, especially its upcoming Block IB variant.