Dec. 3 (UPI) -- The Navy told Congress in a recent hearing that the Advanced Gun System on the Zumwalt-class destroyer is a dead letter for the foreseeable future, despite the long-range gun designed for shore bombardment being one of the cornerstones of the troubled stealth destroyer.
Even as the second-in-class USS Michael Monsoor departs from Guantanamo Bay for San Diego to receive commissioning and combat testing, the Navy is only starting to figure out what they will do with the troubled multi-billion dollar Zumwalt-class destroyer.
The Zumwalt has been billed as the most advanced destroyer ever built, with stealth capabilities and a gun system that could provide precision fire support deep inland ahead of advancing amphibious forces.
It is also equipped with an electrical propulsion system that the Navy hopes can manage future power-intensive systems such as lasers. For a surface combatant, it is large at nearly 15,000 tons, making it the heaviest destroyer ever built by the United States.
But the Zumwalt's gun system has been put on the backburner -- if it will ever be activated at all -- its stealth features may be degrading and out of an originally planned 32, only two have been built, with one more on the way. Of those three, only one is considered active and none are yet deployable despite years of delays.
During a hearing before the Senate Seapower subcommittee last week, Vice Adm. William Merz said the 155mm Advanced Gun System has never reached the capabilities that were desired and that if the Navy could not find cost-effective ammunition the gun might be scrapped entirely and the space used to be replaced with something else.
He said the ship is being repurposed as a surface strike platform, using its vertical launch missile system to engage land and sea targets with long-range cruise missiles.
The Zumwalt mounts two Advanced Gun Systems for shore bombardment and anti-ship purposes. Designed to fire up to ten rounds per minute, it would provide intense, precise fire support for amphibious assaults and shore bombardment duties, according to the Navy and the gun's designer BAE.
The AGS was originally designed to use the Long Range Land Attack Projectile with a maximum range of over 60 miles. The 155mm round produced by Lockheed Martin is rocket assisted, precision guided and was successful in testing, but ballooning costs left the projectile costing over $800,000 a round, roughly as much as a Tomahawk cruise missile.
That left it untenable as a mass fire support weapon, which was a large part of the gun's and Zumwalt's mission, and the Navy decided to cease purchases in 2016 after buying only a few LRLAPs for testing and trials.
The problems have lead the Navy to designate the Zumwalt-class as an anti-ship and strike platform rather than a shore bombardment vessel. The modifications include integrating the long-range SM-6 missile which has anti-air and anti-ship capabilities.
The high cost of the LRLAP ammunition has left the Navy looking for alternatives. Under consideration are a number of already deployed munitions like the Excalibur GPS-guided 155mm round, which would require extensive modifications to the AGS and has a much smaller range.
Navy officials said that although they have not given up on the Advanced Gun System, they have decided to shelve any replacement rounds for the immediate future.
The Navy has had a troubled history trying to develop a new long range round for naval fire support. In an attempt to extend the range and accuracy of the standard 5-inch Mk 46 gun already in use aboard Arleigh Burke-class destroyers, the Navy developed the Extended Range Guided Munition.
The shell was a gun-fired guided missile that propelled itself to extremely high altitudes before descending on its target using GPS guidance.
Long development times, heavy cost overruns and reliability issues led to the ERGM's cancellation in 2008. The shell faced many of the same cost issues as the LSRAP by being too expensive to use in training or in a mass fire support role like traditional amphibious assault doctrine calls for.
Merz pointed out that the Zumwalt is still capable of carrying plenty of firepower in its 80-cell Mk 41 Vertical Launch system, including Tomahawk cruise missiles, surface-to-air-missiles and ASROC anti-submarine rocket delivered torpedoes along with smaller guns.
Merz testified that the rest of the ship "is doing fine" and that it will be operating as a class by 2021. He maintained that the ship would retain significant missile and other weapon capabilities with or without the gun, and that its VLS system has larger cells which could mount future weapons.
"We determined that the best future for that ship is to get it out there with the capability that it has and separate out the Advanced Gun System, leaving everything else in place," Merz said.
The gun is not the only problem facing the ship. Due to modifications and additional equipment put on its superstructure and hull, the ship is not as stealthy as originally designed, with extra equipment being added on rather then built into a stealth profile, as reported by The Drive.
The much touted electrical system, meant to power the weapons of the future, has also faced a number of issues. Both the USS Zumwalt and the future USS Michael Monsoor have suffered serious turbine and propulsion problems, leading to testing failures and deployment delays.
The Navy and Marine Corps, however, maintain that the ship will still be highly capable and useful for theatre commanders.