줌왈트급 구축함 (DDG-1000)에 레일건을 탑재하는 검토가 미 해군 해상 시스템 사령부
(NAVSEA-Naval Sea Systems Command)에서 시작되었다.
줌왈트급으로 공간, 전력, 냉각이 가능한지를 검토하고,
155mm BAE사제 고성능 주포 (Advanced Gun Systems-AGS)를 한개 혹은 두개를 철거하게 된다고
NAVSEA를 이끄는 윌리엄 힐러리데스 중장이 USNI News에 밝혔다.
레일건의 탑재는 3번함인 린든 B 존슨 (Lyndon B. Johnson, DDG-1002)이 될 것으로, 
제너럴 다이내믹스사의 버즈아이언 웍스에서 건조중인 동함은 2018년에 취역할 예정이다.
줌왈트(DDG-1000)호와 마이클 몬수어 (DDG-1001)호는 공정 관계 문제로 고려 대상에서 제외되었다.
미 해군은 레일건 실증 시험을 시작해, 지금까지 포탄의 추진원이었던 화약이 필요 없는, 
고출력 전자기 펄스를 레일 사이에 달리게 하는 것으로 탄두를 가속해 초음속으로 발사되도록 할 예정이다.
실증 실험은 BAE 시스템즈사제의 시작형 레일건을 공유 고속정 밀리노켓 (USNS Millinocket, JHSV- 3)에 탑재해
내년부터 실시한다.
줌왈트급은 배수량 16,000톤으로 고출력의 롤스 로이스 MT-30 가스 터빈 2기 및 소형 롤스 로이스 RR450 
가스 터빈 2기를 탑재해 80메가 와트의 발전 용량을 가져 기존 미 해군 함정의 발전 규모를 웃돈다.
줌왈트급은 세척 건조되며 당초의 구상은 AGS 함포 2개에 의한 
장거리 육상 공격탄 (Long-Range Land Attack Projectile-LRLAP)을 
75마일의 유효 사정 거리에서 발사해 해군에 의한 화력 지원의 부족을 보충하게 되어 있었다.
줌왈트급 1번함인 줌왈트호는 내년에 취역한다.

Navy Considering Railgun for Third Zumwalt Destroyer

By: Sam LaGrone
February 5, 2015 4:13 PM • Updated: February 11, 2015 7:19 PM

An electromagnetic railgun prototypes on display aboard the joint high speed vessel USS Millinocket (JHSV 3) in port at Naval Station San Diego, Calif. US Navy Photo

WASHINGTON, D.C. – Engineering studies to include an electromagnetic railgun on a Zumwalt-class destroyer (DDG-1000) have started at Naval Sea Systems Command, NAVSEA’s head said Thursday.

The work will do the math to determine if the Zumwalt-class will have the space, power and cooling to field a railgun – likely replacing one of the two 155mm BAE Advanced Gun Systems (AGS) ahead of the ship’s deck house, Vice Adm. William Hilarides told USNI News following remarks at the Office of Naval Research Naval Future Force Science and Technology Expo.

“We have begun real studies – as opposed to just a bunch of guys sitting around – real engineering studies are being done to make sure it’s possible,” Hilarides said.

The likely candidate for the weapon would be the third planned Zumwalt, Lyndon B. Johnson (DDG-1002) currently under construction at General Dynamics Bath Iron Works (BIW) with an expected delivery date of 2018.

He said the first two ships – Zumwalt (DDG-1000) and Michael Monsoor (DDG-1001) – would be less likely to field the capability initially due to the schedule of testing with the new class.

“The team is working diligently now but it would not happen until after delivery of the ships – probably the third ship is where we’d have it,” Hilarides said.
“That would certainly be my recommendation.”

The Navy is in early stages of testing and fielding a railgun – which forgoes the gunpowder in the shells of conventional naval guns and instead uses high powered electromagnetic pulses along a set of rails to shoot a projectile at super sonic speeds.

The Navy plans to test a BAE Systems prototype railgun onboard the Joint High Speed Vessel USNS Millinocket (JHSV- 3) next year.

Last year, then Navy director of surface warfare now commander of U.S. Surface Forces Command, Vice Adm. Thomas Rowden told USNI News the Zumwalts would be likely used as test beds for emerging technologies like railguns and directed energy weapons the Navy wants for its next large surface combatant due to the ship’s size an ability to generate power.

The integrated power system (IPS) on the 16,000-ton ships– powered by two massive Rolls Royce MT-30 gas turbines and two smaller Rolls-Royce RR450– allow the ships to route and generate 80 mega-watt power – much more electrical power than the current crop of U.S. destroyers and cruisers.

On Wednesday, Chief of Naval Operations Adm. Jonathan Greenert said a Zumwalt would likely be the first ship to get the capability.

The inclusion of the railgun does mean a capabilities trade for the ship.

Zumwalt-class guided-missile destroyer DDG 1000 is floated out of dry dock at the General Dynamics Bath Iron Works shipyard on Oct. 28, 2013. US Navy Photo

“We’ll go do the studies and I suspect they’ll say ‘yes,’ but it’s going to come at a cost of some of the capabilities on this ship – of course,” Hilarides said.
“It’s physics. Without taking something off, you’re not putting on a many ton system, so a gun would be a logical thing to take off and put the railgun in its place.”

The three ship Zumwalt-class were – in part – originally designed to address a gap in naval surface fire support with the AGS firing the Long-Range Land Attack Projectile (LRLAP) at a range of up to 75 nautical miles.

Each ship is designed to field two AGS.

Zumwalt is expected to deliver to the service next year.