Modernization of Zumwalt-Class Destroyer Under U.S. Navy–HII Technical Cooperation

HII’s Ingalls Shipbuilding division and the U.S. Navy have completed integrated builder’s sea trials on USS Zumwalt (DDG-1000) following a comprehensive modernization program to equip the vessel as the Navy’s first Conventional Prompt Strike (CPS) platform. The cooperation focused on complex system integration and verification for advanced naval strike capability.

Context of the Cooperation
Huntington Ingalls Industries (HII) operates the Ingalls Shipbuilding division, responsible for constructing and modernizing surface combatants for the U.S. Navy. The Navy’s program aims to retrofit the lead Zumwalt-class destroyer with CPS hypersonic strike capability, addressing challenges in integrating new weapon systems, launch infrastructure, and associated shipboard systems on an existing hull platform. Cooperation was essential due to the scale of mechanical, structural, and systems integration work across multiple engineering domains, including weapons, combat systems, and platform interfaces.

Technical Solution and Partner Responsibilities
The technical scope involved refitting Zumwalt to support CPS weapons, which required replacing the ship’s original twin 155 mm Advanced Gun Systems with new vertical launch missile tubes designed for Intermediate-Range Conventional Prompt Strike missiles. This entailed structural modifications, installation of new launch systems, and integration with the ship’s combat management and power systems. The Navy defined operational requirements and conducted acceptability criteria for CPS integration, while HII led engineering design, fabrication, systems installation, and on-site integration. Standard naval interfaces (e.g., combat system data buses, power and cooling plant connections) were adapted to support the new weapon system and ensure compliance with applicable naval architecture practices and MIL-STD/IEEE communication protocols.

Sea Trials and Implementation Phases
Builder’s sea trials were conducted off the Gulf Coast to verify propulsion, navigation, systems integration, and CPS-related modifications under operational conditions. The ship had been delivered to Ingalls in August 2023 for modernization and moved ashore for major structural and systems work, followed by refloating and outfitting activities completed through late 2024. The trials assessed dynamic response, electrical distribution, mission systems interfaces, and launch system readiness before further Navy acceptance testing.

Applications and Use Cases
The modernization transitions Zumwalt from its original surface fire support role to a long-range strike platform capable of hosting hypersonic weapons, addressing evolving Navy requirements for conventional prompt strike in contested environments. The technical use cases emphasize integrated strike mission planning, tactical engagement with long-range systems, and sustained operations within fleet task forces, improving strike-to-target timelines and maneuver space.

Expected Impact
The successful completion of builder’s trials demonstrates the operational viability of CPS integration on the Zumwalt class, enabling subsequent Navy acceptance trials and further weapon system operational testing. This cooperation establishes a technical precedent for converting additional vessels in the class with CPS, suggesting improved program scalability and repeatability of engineering processes for future modernizations.

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