Each Zumwalt-class destroyer has two stealthy triangular 155mm Advanced Gun Turrets (AGS) in the forward hull. When stored, the AGS’s metal gun barrel is nestled inside the angled turret housing with the turret’s doors closed for maximum stealth profile. For firing shells, the turret doors open and the gun barrel elevates outward as the turret rotates. The AGSs were originally intended to provide Long-Range Precision Fires (LRPF) shore bombardment of approximately 37 to 62 miles (60 to100 kilometers) in support of amphibious assaulting U.S. Marines; however, the AGSs never lived up to their intended roles because the extended-range GPS-guided shells cost anywhere from $800,000 to $1 million each, an exorbitant cost that the U.S. Navy found too hard to justify. Thus, the 155mm AGSs never fired a shot and all were deemed “Inactive Status” by the U.S. Navy’s Naval Sea Systems Command (NAVSEA) as the Navy and NAVSEA contemplated what to do with them. Discussions ran from exploring cheaper 155mm shells to fielding Hypervelocity Projectile (HVP) to removing the gun turrets for more Vertical Launch System (VLS) cells. The naval media, defense blogs, think tanks, and public comment forums were abuzz with suggestions, recommendations, rumors, and speculation for years as how best to use or replace the AGSs.
In FY2021, the U.S. Navy decided on replacing all of these 155mm AGS turrets with Hypersonic missile VLS tubes for the Conventional Prompt Strike (CPS) Hypersonic missile.
The CPS Hypersonic missile is a joint program collaboration between the U.S. Army and the U.S. Navy. The first limited U.S. Navy CPS Hypersonic missile use and deployment will be aboard the Ohio-class guided-missile submarines (SSGNs) around FY2025. The U.S. Army will be the first service branch to receive the Hypersonic missiles (termed the “Long-Range Hypersonic Weapon (LRHW)” for the U.S. Army), slated for Army service around the 2023 timeframe. The CPS uses a Common Hypersonic Glide Body (C-HGB) that separates from the missile body and flies down on the target at five times greater than the speed of sound (Mach 5+), destroying the target with massive kinetic force. The CPS missile will reportedly have a range of more than 1,724 miles (2,775 kilometers), and two CPS missile canisters can fit on an U.S. Army M870A3 trailer that is approximately 45.5 feet (1,385.1cm) long and 8.6 feet (259.2cm) wide. The CPS Hypersonic missile to too large to fit inside the standard MK 41 VLS cell aboard U.S. Navy AEGIS warships and the MK 57 Vertical Launch System aboard the three Zumwalt-class destroyers.
Naval News asked the U.S. Navy’s Office of Information Department (CHINFO) for details on how the Navy plans to integrate the CPS Hypersonic missile into the three Zumwalt-class destroyers, and when construction will start to meet the intended FY2025 goal. Lt. Lewis Aldridge, CHINFO, replied via email on 28 October, 2021.
Naval News: When will retrofit construction start to meet the FY2025 goal?
U.S. Navy: “The DDG 1000 Dry-Docking Selected Restricted Availability (DSRA) will begin in FY 2024.”
Naval News: Will the Hypersonic missiles occupy only the 155mm AGS turret spaces, or will the entire forward hull half interior be modified for the Hypersonic VLS tubes?
U.S. Navy: “Conventional Prompt Strike (CPS) Hypersonic Missiles will only occupy the AGS turret spaces when implemented aboard Zumwalt-class destroyers.”
Naval News: How many Conventional Prompt Strike Hypersonic Missile VLS tubes are envisioned for each Zumwalt? Can the US Navy provide a ballpark goal number of Hypersonic VLS cells to replace the two 155mm AGSs?
U.S. Navy: “The Navy began engineering planning efforts to accommodate integration of CPS on Zumwalt-class destroyers, which includes removal of advanced gun system mounts and installation of Advanced Payload Module (APM) launcher technology.”
Naval News: Will any remaining hull spaces be filled with MK 41 or MK 57 VLS cells in one or quad cell layout, or will the Zumwalts still retain the same number of MK57 VLS cells?
U.S. Navy: “There are currently no plans for additional hull space on the Zumwalt-class destroyers to be filled with MK 41 or MK 57 VLS cells.”