What happens when a ship constructed with two large guns loses one of the guns? In the case of the Zumwalt-class of the U.S. Navy, the solution lies in the complete overhaul of mission. USS Zumwalt (DDG 1000) went through a series of builder’s sea trials in Mississippi, passing a significant milestone towards service in a configuration that has substituted its initial concept of naval gunfire with hypersonic strike. The change is obvious even at a glance: the unique stealth destroyer does not have the twin 155mm Advanced Gun Systems that initially determined its existence.
The play was not an ordinary availability. In August 2023, Zumwalt was installed at the Huntington Ingalls Industries plant at Pascagoula where it was relocated onto land so that significant structural modifications could be performed, an unusual practice that highlighted the scope of the redesign. The sea trials that followed on the ship after the changes were on the basis of fundamentals like propulsion, hull integrity, generation of power as well as performance of systems on the ship. Such tests are significant since the new weapon installation has the same integrated electric drive and a complex signature-management design and the internal organization, topside structures, and support systems on the shipboard must work efficiently on the water.
The main item in the conversion is the Conventional Prompt Strike weapon system of the Navy. The CPS concept combines a rocket booster and a maneuvering hypersonic glide body to deliver long range conventional effects at Mach 5 plus speeds. Practically what it implies is that a ship is able to put high-value targets at risk without having to move near the shore or use an aircraft to destroy defenses. The engineering design can be characterized as an “all-up-round” that has a two-stage booster and has a Common Hypersonic Glide Body, a similar design utilized in the Long-Range Hypersonic Weapon effort of the U.S. Army, which was an overt attempt at commonality in support of testing, upgrades, and logistics.
The cost of entry on the part of CPS in the case of Zumwalt was the sacrifice of volume firepower. The forward gun positions in the ship were eliminated to allow large-diameter launch infrastructure and open accounts of the refit to be a magazine of 12 CPS missiles in the forward housing. The resulting minimized loadout is what propels a different model of employment than a surface combatant heavily armed with a lot of smaller weapons: selective fire, to be reserved to targets where speed and shortened warning time are operationally decisive. The vessel turns into a less versatile shooter and more of a specialized prompt strike node.
The troubled history of the class is also re-packaged with that tradeoff. Zumwalt was designed as a multi-mission, stealthy, and wave piercing tumblehome hull with high-tech sensors and communications and electric propulsion large enough to grow. The increase in the cost of the program and the unfeasibility of the intended gun ammunition reduced the intended narrative of a “modern battleship” to an outlier of three ships. CPS provides the hull with a new rationale: a survivable platform on the surface, capable of giving a distributed force a hypersonic range, disrupting the planning of the opponent because of mobility and the difficulty in knowing where to launch.
The size and cooperation of the modernization itself have been underlined by industrial statements, with the president of Ingalls Shipbuilding, Brian Blanchette, declaring that the modernization had reached a milestone with the Navy and industry partners to build the Zumwalt-class first. That precedent is now stretched out past the lead ship. USS Lyndon B. Johnson (DDG 1002) is undergoing CPS integration, and USS Michael Monsoor (DDG 1001) will be available in the future.
Without the guns, the story of Zumwalt no longer concerns naval gun fire support. It is concerning whether a dedicated stealth hull, upgraded by exerting much effort, can provide a few immediate, conventional hypersonic hits as a component of an overarching fleet framework- and do so with the processes, command-and-control fusion, and operational discipline that a weapon like this entails.
