Saturday, December 22, 2012

AGS - DDG-1000 Gun System

The Advanced Gun System (AGS) developed for the DDG-1000 Zumwalt class destroyer is a 155 mm gun in a stealth mount.  The gun (and the ship, in a sense, since it was built around the gun) was developed in response to the retirement of the battleships and the resulting gap in naval gunfire support for troops ashore.

LRLAP 155 mm Round

While 155 mm is a NATO and US Army standard size, inexplicably, the Navy’s AGS will not be able to fire any of the existing rounds thus denying the Navy access to a huge inventory of ammunition.  Bear in mind that the AGS ammunition is the Long Range Land Attack Projectile (LRLAP) which is a rocket assisted projectile with extended glide capability for greater range.  Thus, the AGS is, essentially, a missile launching weapon rather than a standard naval gun.  The LRLAP has a reported range of around 70 miles and uses GPS guidance with canards for flight control.  Efforts are being made to achieve commonality with NATO/Army 155 rounds to the extent possible.  Hmm…  Seems like that should have been the first criteria?  Seeker heads are being investigated for future inclusion.

Other reports state that the AGS cannot be used in an anti-ship role though it is unclear why this is so (the GPS guided nature of the LRLAP, presumably?).  A naval vessel with guns that can’t be used against other ships seems short-sighted.

The AGS is a fully automated system from ammunition strike down and handling to loading and operation of the gun, itself.  While this reduces the crew requirements it also requires an inordinate amount of internal volume especially that devoted to ammunition storage and movement.  The AGS Intra-Ship Rearmament System (AIRS), which is the automated system for moving pallets from the flight deck to the magazine, consumes huge internal volumes.  Both the gun and ammunition handling are all-electric as opposed to previous hydraulic systems.  Power requirements are reported to be 800 kW per mount which precludes fitting the system to other classes of ship.


The rate of fire is 10 rds/min.  Magazine size has been reported as being 304 rounds per gun.  Rounds are stored on pallets of eight to facilitate the automated handling.

Defense Industry Daily reports that approximately $1.4B has been spent so far on the development of the AGS, AIRS, and LRLAP and work is nowhere near complete yet.  That is a lot of money to develop a gun system. 

In summary, what the Navy has is a dedicated land attack weapon with fair range compared to conventional naval guns.  This may well prove to be a very effective naval gunfire support weapon but the value relative to the cost seems suspect and, when the non-surface firing capability is factored in, the system seems overly restricted.  One can’t help but wonder if the already developed Mk71 8” gun wouldn’t have been a better starting point!


  1. I'm curious as to what the cost/projectile will be, compared to existing systems.

    1. I don't have any definitive info but I've read reports that the standard Mk45 5"/62 cal gun uses rounds that cost $1600-$2200. Reports suggest that the LRLAP will cost $50,000+. If I can find anything more definite I'll let you know.

    2. IIRC, the 5-inch ERGM guided round was cancelled in 2009 after its unit costs reached a reported $190,000 per round for a 10,000 round buy.

      Like the 5-inch guided round, the 155mm LRLAP round is in fact a gun-launched gliding missile, it is not a "projectile" as that term is commonly used.

      The USMC's written requirements for Naval Surface Fire Support call for the capability to accurately fire tens of thousands of rounds of 155mm equivalent ammunition at distances up to 100 nautical miles.

      It is impossible for the three DDG-1000's to come anywhere close to supporting the USMC's written requirements for naval fire support. And it would have been equally impossible for ten or twelve such ships to handle the written requirements with the AGS as it is currently designed.

      Regardless, once the 155mm AGS enters service, even if mounted aboard just three warships, it is likely the Navy's leadership will declare that the USMC's fire support requirements have been fulfilled, and that no further work will be done on conventional gun systems larger than 5-inch.

      One of the excuses given for the decision to end research into larger conventional gun-fired ammunition types will be the supposed emergence of practical railgun technology in the decade of the 2020s.

      That claim will be completely specious if and when it is eventually made, given that a railgun which could handle guided long-range ammunition types in the 155mm size class, in support of indirect fire missions, is complete science fiction at this point in time and will remain so far into the future.

  2. AGS-the gun which fires missiles.

    The Navy couldnt do the logical thing of just building on the MK-71 8in gun and developing guided rounds for medium range (20+mi)and just use Tomahawks for the long range strikes...nope had to have the AGS.

    Hell I guess the navy forgot AGS was supposed to be able to fire standard unguided rounds. Infact its the reason it was picked over its competator.....and it cant even do that.

  3. The Mk 71 was cancelled in part because the accuracy of its unguided rounds was poor. But that is true of the AGS as well as any long range artillery. Only a battleship gun could make up for that somewhat with it's huge lethal radius on impact.

    The Mk 71 showed so much promise at one point that the Spruance class was designed from the beginning to accommodate the 8" gun in place of the forward 5". The hull there was reinforced to handle the heavier recoil.

    What baffled me was that when the Iowas were retired the Spruances (and Kidds) could have been modified easily for a Mk 71 or improved variant. A "land attack" Spruance would have a 8", 5"/62 aft, 61 VLS, and a large helipad and hangar for UAVs and MH-60s.

    But it is easier to justify LCS and even Zumwalt if there are no options like using older platforms such as Spruances and Perrys. So all the Spruances are sunk or scrapped, and the Kidds and Perrys are given to other navies.

    1. Exactly. But to be fair the MK-71 wasn't really anyless accurate at the range the 5in was and it carried far more HE pr round.

      And yes i think the amount of people who immediatly saw through the Navies reasons for murdering all the spruances is kegion

  4. From what I have read they originally chose 155mm so that they could use cheap army shells for close in firing but they then found that they needed different rifling twist for the long range shells so they designed the gun for just long range.

    Seems someone should have asked some artillery experts about what kind of rifling was needed back when this project was still in the PowerPoint stage. They might then have gone with the 8 inch and smaller/lighter/rocket assisted saboted 155mm projectiles for the long range and full size 8 inch for shorter range.

  5. I thought it was an excuse to cancel the Mk 71 for poor accuracy. The USN got away with it because a couple of years later Iowas started to be recommissioned. That ended talk about rejuvenating naval gunfire for over a decade.

    Larger caliber guns can always fire sabot rounds. I agree the 8" could have been adapted to fire 155mm with sabots. The 16" gun in the 1980's experimented with cluster and 13" sabot rounds that would have added 50% more range.

    But the AGS is barely big enough as is to get the job done. And the 5"/62 is too small as it is. What would they do, make a 3" sabot

  6. Did navy type classify AGS with MKxx designator yet?

  7. The Germans were smart.They adaptived their 155m land howizer to fit on their new destroyers without breaking the bank.

    1. I assume you're talking about the MONARC project. Yes, the German's attempted to adapt the 155 mm to naval use but, according to NavWeaps website, the project was dropped due to the difficulties and, presumably, cost of navalizing the gun's internals to protect against corrosion from the saltwater environment. As with most land systems that have attempted to undergo adaptation to naval use, the corrosion proved its undoing. To the best of my knowledge, the MONARC is not currently in service or planned for any future ships. Do you know something different?

      Thanks for stopping by.

  8. Another billion and a half wasted when we already have an 8" naval gun ready to go - the M-71. AND it cannot fire standard 155mm!?! REALLY? That's criminal. Are all Spruance class scrapped or museum ships like the Iowas?

  9. Don't take this as fact, but my understanding is that the AGS doesn't work in an anti-ship role because the target coordinates need to be entered into the round before firing and their is no terminal homing capability. So, if the target ship were to move, then the round would hit where the target was at firing time. That's how it was explained to me, but I'm not sure about the reliability of the source.


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