Key Points and Summary: The US Navy’s Zumwalt-class destroyers are visually striking and technologically advanced warships, designed with a unique tumblehome hull for stealth.
-However, the program has been marred by problems, including unreliable deck guns and a high cost per round of ammunition, leading to their removal.
-The ships’ small crew size relies heavily on automation, and a breakdown in the Panama Canal highlighted design vulnerabilities.
-Despite these setbacks, the Navy plans to repurpose the Zumwalts as platforms for Conventional Prompt Strike (CPS) hypersonic missiles.
-This shift could potentially salvage the program, offering a mobile and powerful offensive capability in a future naval environment.
Can Hypersonic Weapons Save the Troubled Zumwalt-Class Destroyer Program?
Of all the new-generation US naval vessels, the Zumwalt destroyers are, without a doubt, the most ambitious and unparalleled in the designers’ approach to the use of modern defense technologies.
The ships are classified as destroyers but are considerably more significant than any other destroyers or cruisers in the US Navy.
The shaping and configuration of the hull is a departure from most previous US naval vessels.
The odd visual appearance is a function of the requirement that the ship present a low radar cross-section (RCS) return when “painted” by any other ship or aircraft’s radar.
The hull for the Zumwalt class is described as a tumblehome form, which means the sides of the ship slope inward above the waterline.
This decreases the RCS by creating a shape that presents a lower return of a radar signal than the conventional flare hull.
What this means in more conventional terms is that the ship is 40 percent larger than an Arleigh Burke-class destroyer but then has the RCS of a fishing boat.
Space Age Sophistication, Back on Earth Problems
The highly ambitious goal for the design of the ship was that although for a vessel its size up to 300 sailors would generally crew it.
Instead, the crew is only about 130, so operating the ship depends on a sophisticated array of onboard systems that make the ship far less expensive to run.
The ship’s internal systems include an integrated electric propulsion (IEP) system that relies on turbo-generators that can send power to the electric drive motors or weapons systems.
An onboard computerized infrastructure automates many onboard functions, such as fire-fighting systems and automated piping rupture isolation.
But the ship’s design has proven problematic, so much so that its main deck guns are to be removed for unreliability.
FROM 2016: The U.S. Navy’s newest warship, USS Zumwalt (DDG 1000) passes Coronado bridge on its way to Naval Base San Diego. Zumwalt is the lead ship of a class of next-generation multi-mission destroyers, now homeported in San Diego. (U.S. Navy photo by Petty Officer 3rd Class Anthony N. Hilkowski/Released)
After a breakdown by one of the Zumwalt-class ships in the Panama Canal, one naval analyst commented that the design flaws “are emblematic of a defense procurement system that is rapidly losing its ability to meet our national security needs.”
“The Zumwalt is an unmitigated disaster,” he commented in National Review.
“Clearly it is not a good fit as a frontline warship. With its guns neutered, its role as a primary anti-submarine-warfare asset in question, its anti-air-warfare capabilities inferior to those of our current workhorse, the Arleigh Burke-class destroyers, and its stealth not nearly as advantageous as advertised, the Zumwalt seems to be a ship without a mission.”
The other disaster was the ship’s on-board gun system. When the number of ships to be procured dropped from 32 to three the cost of manufacturing ammunition for the guns became impractical due to the complete loss of economies of scale.
The cost per round rose to $800,000–$1 million, making it impractical for them to be used on the ship and prompting their removal.
Conventional Prompt Strike and Zumwalt
The innovation that might save the otherwise troubled program is the on-board Conventional Prompt Strike (CPS) system that would replace its gun system.
This is described as a boost-glide hypersonic weapon system that consists of a two-stage solid-fueled rocket booster to get the missile to a faster than Mach 5 speed and the Common Hypersonic Glide Body (CHG-B).”
SAN DIEGO (Dec. 7, 2018) The Pre-Commissioning Unit (PCU) Michael Monsoor (DDG 1001) arrives in homeport of San Diego. The future USS Michael Monsoor is the second ship in the Zumwalt-class of guided- missile destroyers and will undergo a combat availability and test period. The ship is scheduled to be commissioned into the U.S. Navy Jan 26, 2019 in Coronado, Cailf. (U.S. Navy photo by Mass Communication Specialist Seaman Apprentice Nicholas Huynh/Released) 181207-N-IW125-1021
The Army and the Navy jointly developed the latter of these two stages for their respective hypersonic weapon developmental efforts.
Originally, the CPS was to be installed aboard the Zumwalt ships by this year. This would put this Mach 5 weapon being installed initially on these very sophisticated destroyers instead of on submarines, which are usually the first vessels to receive a new weapon of this type.
Speaking in 2021, the previous CNO, Adm. Mike Gilday, explained the utility of this class of weapon is that hypersonic weapons “may be the best example of how we want to bring that kind of capability forward in a distributed fashion, using distributed maritime operations, that come at the adversary at a variety of different vectors, to make it very difficult for them to target us,” he explained.“The other thing that naval forces bring to bear, which is not insignificant in the day and age of hypersonics, is the ability to be mobile. Not that we’re going to be able to completely hide in the future, right? One would think that over time there’ll be ubiquitous imagery coverage over the Pacific, whether those are military satellites or whether they’re commercial. That information will be available to an adversary, whether he or she purchases it, or whether they steal it, but it’s going to be difficult to hide.”
About the Author: Reuben F. Johnson
Reuben F. Johnson is a survivor of the February 2022 Russian invasion of Ukraine and is now an Expert on Foreign Military Affairs with the Fundacja im. Kazimierza Pułaskiego in Warsaw. He has been a consultant to the Pentagon, several NATO governments and the Australian government in the fields of defense technology and weapon systems design. Over the past 30 years he has resided in and reported from Russia, Ukraine, Poland, Brazil, the People’s Republic of China and Australia.
