155 mm Advanced Gun System (AGS) Manufacturer: United Defe…

155 mm Advanced Gun System (AGS)


United Defense [UDI] produces the AGS for the DD(X) future surface combatant program led by Northrop Grumman [NOC]. A team comprising Lockheed Martin [LMT] and Science Applications International Corp. (SAIC) produces the Long-Range Land Attack Projectile (LRLAP) for AGS.


United Defense has been developing the AGS since 1999, when the weapon was originally intended for the DD-21 warships. The Bush administration canceled the DD-21 program and the AGS was later slated for fitting on DD(X).AGS was originally designed with a "twin cell" load package. “In a twin cell, the barrel went up to 45 degrees, a twin arm cradles it, went down and picked up the round, then brought the round up and loaded it into the gun. [It’s] clearly a complicated mechanism to go do that. In a vertical load, the gun goes vertical–it’s got a direct path in,” Capt. Chuck Goddard, the Navyís program manager for DD(X), told Defense Daily in November 2003The Navy after a June 2003 spiral review of the program decided to change the configuration of AGS from a “twin cell” setup to a “vertical load” structure lightened the weight of the weapon. This move reduced the deck penetration of the gun onboard the DD(X) hull and guarantees a rate of fire of 10 rounds per minute.Preliminary Design Review for AGS was completed in late September 2003. Each DD(X) will be armed with a pair of AGS weapons

Combat Use:

As the weapon is still in development, none.

Foreign Users:



Ever since the Navy decommissioned the last of the great multi-gunned battleships in the post-Cold War draw down, its partners in the Marine Corps have searched for a weapon that could provide credible Naval Surface Fire Support(NSFS) for forces deploying ashore. AGS could be a viable part of a future NSFS solution, as well as serving as an operational level asset as well. Equipped with the rocket-assisted LRLAP, AGS has a likely engagement range of 100 nautical miles.