The Zumwalt program didn’t collapse because the ship couldn’t sail it collapsed because its signature weapon couldn’t be fed. The most unconventional destroyer in U.S Navy service was commissioned with two automatic 155mm Advanced Gun Systems (AGS) and its mission then suffered as its special ammunition was no longer tenable. In its place came not a depart and turn but a costly, steel-and-wire-overhaul that transformed a dead end concept into a long-range strike platform based on hypersonic missiles.
The initial concept was simple a raidable, survivable, “land-attack destroyer” capable of approaching the coast at a slower rate than an ordinary surface combatant, and firing naval guns precisely at scale. The plan relied to a great extent on the Long Range Land-Attack Projectile (LRLAP), which was a GPS-fired, rocket-asteroid round. The economics was never in stable ground. When the class was down to a mere three hulls, the unit cost increased; LRLAP was much quoted at $800,000 round, and the Navy had ceased to procure rounds, leaving the AGS with no purpose-built round.
This ruling reopened an earlier debate that has raged over decades among naval engineers: at what point does a “smart” shell cease to be a low-cost substitute of a missile? An analysis published in Proceedings in 2017 presented the dilemma also in physical terms rather than financial ones. Guidance electronics also has to endure the severe launch shock, which has been pushing the price upwards and eliminating the traditional gunfire edge. Even practical alternatives had tradeoffs, the conversion of artillery-based rounds might result in an enormous loss of range, and the entire calculus of standoff would be altered, making the stealth form taken by the ship in the original design ultimately invalid.
It was more a structural problem, as well. The design of Zumwalt came as the result of a very professional mission-keynote, and when the centrepiece of the shore-bombardment failed, the peculiar engineering of the ship was like an answer that needed a question. Nevertheless the platform had still rare features, namely a large hull, deep power and cooling margins, and a stealthy shape designed to make them hard to spot and shoot. The practical response of the Navy was that the ship should not be used as a guns system and rather as a volume-and-signature problem to resolve the future weaponry.
The only breakthrough was in the 2023 pledge to erase the two 155mm mounts and clear space to fit the Conventional Prompt Strike (CPS) weapon system. The forward gun mount and space support were reduced and four large diameter missile tubes were installed at Ingalls shipbuilding and each was three all-up round in diameter, bringing the total missile count to 12 CPS. The ship was reintroduced into the water following a significant amount of structural work and heralded a literal conclusion to the era of the “paperweight guns” and the commencement of an entirely new era associated with canisters, adapters, and integration tests.
CPS revolves around a boost-glide strategy: a rocket accelerates a hypersonic glide vehicle to a speed of more than Mach 5, then the glide vehicle decelerates and turns to its destination. That architecture places strange handling and launch requirements on the Navy surface fleet than does that of traditional vertical launch missiles. The size of the system, the sequencing of launches required have been highlighted by Navy authorities, which is indicative of the fact that much of the technical problem has moved to safe integration and reproducibility of shipboard operations but not the hull itself.
The general conversion did not forget such former innovations of Zumwalt; but it reapplied them. The ship still has 80 peripheral vertical launch cells spaced along the hull, a survivability-enhancing arrangement that should minimize the chance that a single hit will cause an untenable sympathetic explosion. Its built-in electric design, to which it has been previously hinted as relating to future electric weapons, remains the basis of the type of sensor, cooling, and computing expansion large missile payloads and the development of combat systems will need. Even the vacancy created by the deletion of the second gun mount was termed by Navy authorities as an area of possible future capability, an unusual, though by no means unprecedented, concession that the type is now a platform to make a series of payload choices as opposed to a dedicated gunship.
The Zumwalt story is a case study in engineering, where a single consumable (ammunition) can nullify an entire weapons concept, and that a hull intended to fulfill one mission can be redeemed by another when volume, signature management and margins are still important. The class never served as the coastal gun platform it was meant to be, but its redesign demonstrates how fast one such unsuccessful centerpiece can be changed when the Navy is feeling that the ship has most to offer is not what it fires, but what it can be converted to carry.
