A destroyer that was previously characterized by two massive deck guns is being recharacterized by four bigger missile tubes.
The three ship class of Zumwalt made into service by the U.S Navy with a highly developed power plant, a unique low observable hull and a gun system destined to provide long-range fire support. The ships also had a structural reality: the forward architecture of the ship was planned to include two 155mm Advanced Gun Systems and the deep magazines underneath them. In the case of the special ammunition route abort, the class was left with the most obvious equipment and deprived of the mission rationale to use it. The present modernization program seeks to resolve that imbalance by entirely eliminating the guns and refurbishing the forward part with Conventional Prompt Strike (CPS) which is a conventional hypersonic boost-glide missile.
The retrofit does not consist of a simple change of the launcher. Each ship will replace its two gun mounts with four Advanced Payload Module tubes each with a diameter of three CPS rounds to be loaded with 12 missiles in total. The target working value is speed and range -hypersonic flight more than Mach 5and a strike range characterized as more than 1,700 milesbut the engineering payoff is volume and margin. CPS is not compatible with conventional destroyer vertical launch cells, therefore the Zumwalt hull is a unique surface access to oversized missiles and the handling, safety and control systems required with them. That interface starts at the deck but continues down through structural reinforcement and secure routes as well as the reassigning of previously optimized areas used to store ammunition and the support equipment of the guns.
USS Zumwalt (DDG-1000) has offered the best blueprint. The lead ship had spent a lengthy yard period at HII Ingalls Shipbuilding in the meantime the lead ship returned to water, and started at-sea work in its new configuration, including sea trials after the missile refit. The outward modification is the new tube layout that was formerly occupied by the guns but the more significant modification is inside, to incorporate CPS into the combat architecture on board the ship and to re-engineer methods of storing, tracking and preparing huge hypersonic rounds to launch, without interfering with the stealth-driven topside lines and work patterns on the ship.
The DDG-1000 program manager, Capt. Clint Lawler, explained that the gun removal had made the ship open in a manner this original design could not permit. We took off both guns of the ship. We removed both guns from the ship. We’ve recovered some of the space under the second gun system for spaces that were previously used under the forward gun mount, he said. “We’ve essentially recaptured some of that space. Other space is a reservation for future capability.”
The fact that that space was “recaptured” is important since CPS is a system-of-systems issue. The weapon propels a glide body to hypersonic velocity prior to separation and terminal maneuver and that architecture is what drives integration work in launch sequencing and shipboard monitoring and interfaces to targeting and command-and-control. Commonality is also an advantage to the Navy: CPS shares with the Army in the Common Hypersonic Glide Body, and the learning of the testing, and upgrades, are concentrated around a core despite platform disparity.
There are two sister ships behind. Lyndon B. Johnson (DDG-1002) is at Ingalls to activate the combat system and install tubes, and Michael Monsoor (DDG-1001) is ready to go through its own CPS modernization journey. The long-standing issue of how to make an unconventional hull a repeatable fleet utility has been the subject of the long-running question in the case of the class. The modern solution is structural and difficult to undo: a stealth destroyer specifically designed to strike at long range and high speed, the forward deck ceasing to be used as a gun platform but instead hosting a hypersonic magazine.
