View source for Zumwalt-class destroyer

{{Short description|Stealth missile destroyer class of the US Navy}}
{{redirect|DD(X)|similarly named topics|DDX (disambiguation)|text=Not to be confused with USN destroyer [[DDG(X)]], USN destroyer [[Spruance-class destroyer|DX]].}}
{{Use dmy dates|date=October 2020}}
{{Infobox ship    <!-- full code -->
|infobox_caption= <!-- keywords: yes, nodab; or caption text -->
|display_title=   <!-- keywords: none, ital; or article title with markup -->
|sclass=          <!-- keyword: 2 -->

|section1={{Infobox ship/image
 |image=USS Zumwalt (DDG 1000).jpg
 |image_size= 
 |image_caption=USS ''Zumwalt'' underway in 2016
 |image_alt=
 }}

|section2={{Infobox ship/class_overview
 |name=''Zumwalt'' class
 |builders=[[Bath Iron Works]], [[Ingalls Shipbuilding]]
 |operators={{naval|United States}}
 |class_before={{sclass|Arleigh Burke|destroyer|4}}
 |class_after=*[[Arleigh Burke-class destroyer|''Arleigh Burke'' class Flight III]]
*[[DDG(X)]] 
 |subclasses=
 |cost=*$22.5&nbsp;billion program&nbsp;cost (FY15)<ref name=GAO-15-342SP>{{cite web |url=http://www.gao.gov/assets/670/668986.pdf#page=81 |title=GAO-15-342SP DEFENSE ACQUISITIONS Assessments of Selected Weapon Programs |publisher=US Government Accountability Office |date=March 2015 |access-date=15 July 2015 |page=73 |archive-url=https://web.archive.org/web/20150924043422/http://www.gao.gov/assets/670/668986.pdf#page=81 |archive-date=24 September 2015 |url-status=live}}</ref>
*$4.24B per unit (excl R&D) as of 2016<ref name=cost_april2016>[https://news.usni.org/2016/04/06/navy-requires-450-million-more-to-complete-zumwalt-class-due-to-shipyard-performance "Navy Requires $450 Million More to Complete Zumwalt-Class Due to Shipyard Performance"] {{Webarchive|url=https://web.archive.org/web/20161018214323/https://news.usni.org/2016/04/06/navy-requires-450-million-more-to-complete-zumwalt-class-due-to-shipyard-performance |date=18 October 2016}}. usni.org, 6 April 2016.</ref>
 |built_range=
 |in_service_range=
 |in_commission_range=15 October 2016<ref>{{cite news |first=Mary |last=Bubala |title=Historic And Cutting Edge USS Zumwalt Commissioned in Baltimore |url=http://baltimore.cbslocal.com/2016/10/16/historic-and-cutting-edge-uss-zumwalt-commissioned-in-baltimore/ |work=[[WJZ-TV]] |date=16 October 2016 |access-date=16 October 2016 |archive-url=https://web.archive.org/web/20161018222200/http://baltimore.cbslocal.com/2016/10/16/historic-and-cutting-edge-uss-zumwalt-commissioned-in-baltimore/ |archive-date=18 October 2016 |url-status=live}}</ref>
 |total_ships_planned=32
 |total_ships_on_order=
 |total_ships_building= <!-- USS Michael Monsoor, USS Lyndon B. Johnson -->
 |total_ships_completed=3 <!-- USS Zumwalt, USS Michael Monsoor -->
 |total_ships_cancelled=29
 |total_ships_active=2
 |total_ships_laid_up=
 |total_ships_lost=
 |total_ships_retired=
 |total_ships_scrapped=
 |total_ships_preserved=
 }}

|section3={{Infobox ship/characteristics
 |hide_header=
 |header_caption=
 |type=[[Guided-missile destroyer]]
 |displacement={{convert|15656|LT|abbr=on}}<ref name=Navy_Fact_File>{{cite web |url=http://www.navy.mil/navydata/fact_display.asp?cid=4200&tid=900&ct=4 |title=Destroyers – DDG fact file |publisher=U.S. Navy |date=28 February 2018 |access-date=2018-04-02 |archive-url=https://web.archive.org/web/20141217090225/http://www.navy.mil/navydata/fact_display.asp?cid=4200&tid=900&ct=4 |archive-date=17 December 2014 |url-status=dead}}</ref>
 |length={{cvt|610|ft|m}}<ref name=Navy_Fact_File/>
 |beam={{cvt|80.7|ft|m}}
 |height=
 |draft={{cvt|27.6|ft|m}}
 |depth=
 |power=* 2 × [[Rolls-Royce MT30]] gas turbines ({{convert|35.4|MW|abbr=on}} each)<ref name=AeroWeb>{{cite web |first=Joakim |last=Kasper |title=About the Zumwalt Destroyer |url=http://www.bga-aeroweb.com/Defense/DDG-1000-Zumwalt-Destroyer.html |work=AeroWeb |date=20 September 2015 |access-date=25 October 2015 |archive-url=https://web.archive.org/web/20151022091216/http://www.bga-aeroweb.com/Defense/DDG-1000-Zumwalt-Destroyer.html |archive-date=22 October 2015 |url-status=live}}</ref> driving [[Curtiss-Wright]] electric generators<ref name="d05752r" />
* 2 × Rolls-Royce RR4500 turbine generators ({{convert|3.8|MW|abbr=on}} each)<ref name=AeroWeb/>
 |propulsion=* 2 × propellers driven by electric motors
* Total: {{convert|78|MW|shp|abbr=on|lk=on}}<ref name=AeroWeb/>
 |speed={{convert|30|kn|lk=in}}<ref name=Navy_Fact_File/>
 |range=
 |endurance=
 |boats=
 |capacity=
 |troops=
 |complement=147 +28 in air detachment<ref name=Navy_Fact_File/>
 |time_to_activate=
 |sensors=[[AN/SPY-3]] Multi-Function Radar (MFR) ([[X band]] [[active electronically scanned array]])<ref>[https://web.archive.org/web/20190416232327/http://opencrs.com/document/RL32109/2010-06-14/download/1013/ CRS RL32109 Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress]. CRS, 14 June 2010.</ref>
 |EW=
 |armament=* 20 × [[Mark 41 Vertical Launching System|Mk 57]] [[Vertical Launch System|VLS]] modules, 4 cells per module, 80 launch cells total<ref>{{cite web |url=http://www.raytheon.com/businesses/rtnwcm/groups/public/documents/content/rtn_bus_ids_prod_mk57_pdf.pdf |title=MK 57 Vertical Launch System |publisher=Raytheon |archive-url=https://web.archive.org/web/20120924063648/http://www.raytheon.com/businesses/rtnwcm/groups/public/documents/content/rtn_bus_ids_prod_mk57_pdf.pdf |archive-date=24 September 2012}}</ref>
* Each cell can contain:
** 4 × [[RIM-162 Evolved SeaSparrow Missile]]s,
** 1 × [[Tomahawk (missile family)|Tomahawk]],
** 1 x [[SM-6]], or
** 1 × [[RUM-139 VL-ASROC|RUM-139 vertical launch anti-submarine rocket]]
* 2 × {{convert|155|mm|abbr=on|0}}/62 caliber [[Advanced Gun System]] (functionally inoperable; only a nominal ammunition supply exists)<ref name=LaGrone/><ref name="auto">{{Cite web|url=https://news.usni.org/2016/11/07/navy-planning-not-buying-lrlap-rounds|title=Navy Planning on Not Buying More LRLAP Rounds for Zumwalt Class|date=7 November 2016}}</ref>
* 2 × {{convert|30|mm|in|abbr=on}} [[Mk44 Bushmaster II|Mk 46 Mod 2 Gun Weapon System]]<ref name="usni5aug14">{{cite web |url=http://news.usni.org/2014/08/05/navy-swaps-anti-swarm-boat-guns-ddg-1000s |title=Navy Swaps Out Anti-Swarm Boat Guns on DDG-1000s |archive-url=https://web.archive.org/web/20141031145059/http://news.usni.org/2014/08/05/navy-swaps-anti-swarm-boat-guns-ddg-1000s |archive-date=31 October 2014 |website= News.USNI.org |date=5 August 2014}}</ref>
 |armor=
 |aircraft=* 1 × [[Sikorsky MH-60R Seahawk|MH-60R]] helicopter
* 3 × [[Northrop Grumman MQ-8 Fire Scout|MQ-8 Fire Scout]] VT-[[Unmanned aerial vehicle|UAVs]]<ref name=Navy_Fact_File />
 |aircraft_facilities=Flight deck and enclosed hangar for up to two medium-lift helicopters
 |notes=
 }}
}}

The '''''Zumwalt''-class destroyer''' is a class of three [[United States Navy]] [[guided-missile destroyer]]s designed as multi-mission [[stealth ship]]s with a focus on land attack. The class was designed with a primary role of [[naval gunfire support]] and secondary roles of surface warfare and [[anti-aircraft warfare]]. The class design emerged from the [[DD-21]] "land attack destroyer" program as "DD(X)" and was intended to take the role of [[battleship]]s in meeting a congressional mandate for naval fire support.<ref>Section 1011 of the National Defense Authorization Act for Fiscal Year 1996 (Public Law 104-106; 110 Stat. 421)</ref> The ship is designed around its two [[Advanced Gun System]]s (AGS), utilizing unique [[Long Range Land Attack Projectile]] (LRLAP) ammunition.<ref name=LaGrone>{{cite web|url= https://news.usni.org/2018/01/11/no-new-round-planned-zumwalt-destroyer-gun-system-navy-monitoring-industry|title= No New Round Planned For Zumwalt Destroyer Gun System; Navy Monitoring Industry|last= LaGrone|first= Sam|date= 11 January 2018|website= USNI News|publisher= U.S. Naval Institute|access-date= 2018-03-02|archive-url= https://web.archive.org/web/20180303050317/https://news.usni.org/2018/01/11/no-new-round-planned-zumwalt-destroyer-gun-system-navy-monitoring-industry|archive-date= 3 March 2018|url-status= live}}</ref> LRLAP procurement was canceled, rendering the guns unusable,<ref name=LaGrone/> so the Navy re-purposed the ships for surface warfare.<ref name=Eckstein>{{cite web|url= https://news.usni.org/2017/12/04/navy-refocus-ddg-1000-surface-strike|title= New Requirements for DDG-1000 Focus on Surface Strike|last= Eckstein|first= Megan|date= 4 December 2017|website= USNI News|publisher= U.S. Naval Institute|access-date= 2018-03-02|archive-url= https://web.archive.org/web/20180304054809/https://news.usni.org/2017/12/04/navy-refocus-ddg-1000-surface-strike|archive-date= 4 March 2018|url-status= live}}</ref> In 2023, the Navy removed the AGS from the ships and replaced them with [[hypersonic missile]]s.<ref name="remove">{{cite web|last=LaGrone|first=Sam|title=Latest Zumwalt Hypersonic Missile Installation Plan Calls For Removing Gun Mounts|date=March 16, 2022|access-date= May 8, 2022|url=https://news.usni.org/2022/03/16/latest-zumwalt-hypersonic-missile-installation-plan-calls-for-removing-gun-mounts|work= USNI News}}</ref>

The ships are classed as destroyers, but they are much larger than any other active destroyers or [[cruiser]]s in the U.S. Navy.<ref name="Marinelink">{{Cite web |author=Lundquist, Edward |title=The Navy's Battlewagon of the 21st Century |url=https://magazines.marinelink.com/Magazines/MaritimeReporter/201312/content/navys-battlewagon-century-211855 |url-status=live |archive-url=https://web.archive.org/web/20190405211159/https://magazines.marinelink.com/Magazines/MaritimeReporter/201312/content/navys-battlewagon-century-211855 |archive-date=5 April 2019 |access-date=5 April 2019 |website=Marinelink.com}}</ref> The vessels' distinctive appearance results from the design requirement for a low [[radar cross-section]] (RCS). The ''Zumwalt'' class has a [[wave-piercing]] [[tumblehome]] hull form whose sides slope inward above the waterline, dramatically reducing RCS by returning much less energy than a conventional flare hull form.

The class has an [[integrated electric propulsion]] (IEP) system that can send electricity from its turbo-generators to the electric drive motors or weapons, the [[Total Ship Computing Environment Infrastructure]] (TSCEI), automated fire-fighting systems, and automated piping rupture isolation.<ref>{{cite journal |last=Sanchez |first=Lucia |title=Electromagnetic Railgun – A "Navy After Next" Game Changer |url=https://www.doncio.navy.mil/chips/ArticleDetails.aspx?ID=2984 |journal=CHIPS – the Department of the Navy Information Technology Magazine |date=January–March 2007 |access-date=13 July 2013 |archive-url=https://web.archive.org/web/20131111060230/http://www.doncio.navy.mil/chips/ArticleDetails.aspx?ID=2984 |archive-date=11 November 2013 |url-status=live}}</ref> The class is designed to require a smaller crew and to be less expensive to operate than comparable warships.

The lead ship is named {{USS|Zumwalt|DDG-1000|2}} for Admiral [[Elmo Zumwalt]] and carries the hull number DDG-1000. Originally, 32 ships were planned, with $9.6&nbsp;billion research and development costs spread across the class. As costs overran estimates, the number was reduced to 24, then to 7; finally, in July 2008, the Navy requested that Congress stop procuring ''Zumwalt''s and revert to building more ''[[Arleigh Burke-class destroyer|Arleigh Burke]]'' destroyers.  Only three ''Zumwalt''s were ultimately built.  The average costs of construction accordingly increased, to $4.24&nbsp;billion,<ref name=GAO-15-342SP /><ref name="ndaa69-70" /><ref>{{cite news |title=Cutting-edge Navy warship being built in Maine |url=http://www.foxnews.com/scitech/2012/04/12/cutting-edge-navy-warship-being-built-in-maine/?test=latestnews |publisher=Fox News |date=12 April 2012 |access-date=12 April 2012 |archive-url=https://web.archive.org/web/20120415052649/http://www.foxnews.com/scitech/2012/04/12/cutting-edge-navy-warship-being-built-in-maine/?test=latestnews |archive-date=15 April 2012 |url-status=dead}}</ref><ref name=cost_april2016/> well exceeding the per-unit cost of a nuclear-powered {{sclass|Virginia|submarine}} ($2.688&nbsp;billion),<ref>The US Navy's budget request for two Virginias in fiscal year 2016 (FY2016) was $5,376.9&nbsp;million, including $2,030.4M for advance funding from previous years.</ref><ref>{{Cite web |url=https://fas.org/sgp/crs/weapons/RL32418.pdf |title= RL32418, Navy Virginia (SSN-774) Class Attack Submarine Procurement: Background and Issues for Congress |work=Congressional Research Service |date= 27 May 2016 |access-date=17 October 2016 |archive-url=https://web.archive.org/web/20161006194640/https://www.fas.org/sgp/crs/weapons/RL32418.pdf |archive-date=6 October 2016 |url-status=live}}</ref> and with the program's large development costs now attributable to only three ships, rather than the 32 originally planned, the total program cost per ship jumped.  In April 2016 the total program cost was $22.5&nbsp;billion,<ref name=cost_april2016/> $7.5&nbsp;billion per ship.  The per-ship increases triggered a [[Nunn–McCurdy Amendment]] breach.<ref>"Root Cause Analyses of Nunn-McCurdy Breaches – Zumwalt-Class Destroyer, Joint Strike Fighter, Longbow Apache, and Wideband Global Satellite," Rand Corporation (2011); see Vol. 1, Ch. 3 via http://www.rand.org/pubs/monographs/MG1171z1.html {{Webarchive|url=https://web.archive.org/web/20161019175210/http://www.rand.org/pubs/monographs/MG1171z1.html |date=19 October 2016}}</ref>

==History==

===Background and funding===
Many of the features were developed under the [[DD-21]] program ("21st Century Destroyer"), which was originally designed around the [[Advanced Gun System|Vertical Gun for Advanced Ships]] (VGAS). In 2001, Congress cut the DD-21 program by half as part of the [[SC21 (United States)|SC21]] program; to save it, the acquisition program was renamed DD(X) and heavily reworked.

Originally, the Navy had hoped to build 32 destroyers. That number was reduced to 24, then to 7, due to the high cost of new and experimental technologies.<ref>{{cite web |last1=Francis |first1=Paul L. |title=Cost to Deliver Zumwalt-Class Destroyers Likely to Exceed Budget |url=https://www.gao.gov/assets/gao-08-804.pdf |publisher=United States Government Accountability Office |access-date=2 October 2022 |page=54 |date=July 2008}}</ref> On 23 November 2005, the Defense Acquisition Board approved a plan for simultaneous construction of the first two ships at [[Northrop Grumman]]'s [[Ingalls Shipbuilding|Ingalls yard]] in [[Pascagoula, Mississippi]], and [[General Dynamics]]' [[Bath Iron Works]] in [[Bath, Maine]]. However, at that date, funding had yet to be authorized by Congress.

In late December 2005, the House and Senate agreed to continue funding the program. The [[United States House of Representatives|U.S. House of Representatives]] allotted the Navy only enough money to begin construction on one destroyer as a "technology demonstrator". The initial funding allocation was included in the National Defense Authorization Act of 2007.<ref name="ndaa69-70">{{cite book |title=109th Congress :Department of Defense Appropriations Act, 2007 |url=http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=109_cong_public_laws&docid=f:publ289.109 |date=29 September 2006 |publisher=(109–289) US Government Printing Office |access-date=11 October 2008 |archive-url=https://web.archive.org/web/20090216022149/http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=109_cong_public_laws&docid=f:publ289.109 |archive-date=16 February 2009 |url-status=live}}</ref> However, this was increased to two ships by the 2007 appropriations bill<ref name="AP060926">{{cite news |last=Taylor |first=Andrew |url=https://www.washingtonpost.com/wp-dyn/content/article/2006/09/26/AR2006092601011_2.html |title=House OKs $70B for Iraq, Afghanistan |agency=Associated Press |newspaper=The Washington Post |date=26 September 2006 |access-date=19 September 2017 |archive-url=https://web.archive.org/web/20170709170839/http://www.washingtonpost.com/wp-dyn/content/article/2006/09/26/AR2006092601011_2.html |archive-date=9 July 2017 |url-status=live}}</ref> approved in September 2006, which allotted US$2.568&nbsp;billion to the DDG-1000 program.<ref name="ndaa69-70" />

On 31 July 2008, U.S. Navy acquisition officials told Congress that the service needed to purchase more {{sclass|Arleigh Burke|destroyer}}s and no longer needed the next-generation DDG-1000 class;<ref>{{cite web |title=Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress |url=https://crsreports.congress.gov/product/pdf/RL/RL32109/264 |publisher=Congressional Research Service |access-date=2 October 2022 |page=24 |date=26 August 2022}}</ref><ref name="noneed">{{cite web |url=http://archive.navytimes.com/article/20080731/NEWS/807310319/Navy-No-need-add-DDG-1000s-after-all |title=Navy: No Need to Add DDG 1000s After All |work=Navy Times |publisher=Gannett Government Media |date=31 July 2008 |access-date=25 January 2016}}{{dead link|date=December 2017 |bot=InternetArchiveBot |fix-attempted=yes}}</ref> only the two approved destroyers would be built. The Navy said the world threat picture had changed in such a way that it made more sense to build at least eight more ''Burke''s rather than DDG-1000s.<ref name="noneed" /> The Navy concluded from fifteen classified intelligence reports that the DDG-1000s would be vulnerable to forms of missile attacks.<ref name="Smith and Nakashima">{{cite news |first1=R. Jeffrey |last1=Smith |first2=Ellen |last2=Nakashima |url=https://www.washingtonpost.com/wp-dyn/content/article/2009/03/07/AR2009030702216.html?hpid=topnews |title=Pentagon's Unwanted Projects in Earmarks |newspaper=The Washington Post|date=8 March 2009 |pages=A01 |access-date=19 September 2017 |archive-url=https://web.archive.org/web/20161226111134/http://www.washingtonpost.com/wp-dyn/content/article/2009/03/07/AR2009030702216.html?hpid=topnews |archive-date=26 December 2016 |url-status=live}}</ref> Many Congressional subcommittee members questioned that the Navy completed such a sweeping re-evaluation of the world threat picture in just a few weeks, after spending some 13 years and $10&nbsp;billion on the development of the surface ship program known as DD-21, then DD(X), and finally DDG-1000.<ref name="noneed" /> Subsequently, Chief of Naval Operations [[Gary Roughead]] cited the need to provide area air defense and specific new threats such as ballistic missiles and the possession of anti-ship missiles by groups such as [[Hezbollah]].<ref name="Roughead">{{cite journal |last=Cavas |first=Christopher P |url=http://www.navytimes.com/news/2008/09/defense_roughead_092408/ |title=Roughead pushes for littoral combat ship |date=26 September 2008 |journal=Navy Times}}</ref> The mooted structural problems have not been discussed in public. [[United States Secretary of the Navy|Navy Secretary]] [[Donald Winter]] said on 4 September, "Making certain that we have—I'll just say, a destroyer—in the '09 budget is more important than whether that's a DDG 1000 or a DDG 51".<ref name="Navytimes080916" />

On 19 August 2008, Secretary Winter said that a third ''Zumwalt'' would be built at Bath Iron Works, citing concerns about maintaining shipbuilding capacity.<ref>{{cite web|first=Philip |last=Ewing |url=http://www.defensenews.com/story.php?i=3682875 |title=Lawmaker: Third DDG 1000 Far From Done Deal |work=Defense News |date=19 August 2008}}{{dead link|date=August 2021|bot=medic}}{{cbignore|bot=medic}}</ref> House Defense Appropriations Subcommittee Chairman [[John Murtha]] said on 23 September 2008 that he had agreed to partial funding of the third DDG-1000 in the 2009 Defense authorization bill.<ref>{{cite journal |last=Scully |first=Megan |title=Negotiators agree to buy more F-22s, Zumwalt destroyers |url=http://www.govexec.com/story_page.cfm?articleid=41042 |journal=Congress Daily |date=24 September 2008 |access-date=11 October 2008 |archive-url=https://web.archive.org/web/20090114120319/http://www.govexec.com/story_page.cfm?articleid=41042 |archive-date=14 January 2009 |url-status=dead }}</ref>

{{Quote box|align=right
|title =Est. combined procurement cost for 3 ships<ref name=cost_april2016/>
|quote=
{{Chart|definition=Zumwalt-class destroyer procurement cost.chart|data=Zumwalt-class destroyer procurement cost.tab|Width=300}}
}}
A 26 January 2009 memo from [[John J. Young Jr.|John Young]], the U.S. [[United States Department of Defense|Department of Defense]]'s (DoD) top acquisition official, stated that the per ship price for the ''Zumwalt''-class destroyers had reached $5.964&nbsp;billion, 81 percent over the Navy's original estimate used in proposing the program, resulting in a breach of the [[Nunn–McCurdy Amendment]], requiring the Navy to re-certify and re-justify the program to Congress or to cancel its production.<ref>{{citation |last=Cavas |first=Christopher P. |title=New Destroyer Emerges in US Plans |work=[[Defense News]] |date=2 February 2009 |pages=1}}</ref>

On 6 April 2009, [[United States Secretary of Defense|Defense Secretary]] [[Robert Gates]] announced that the DoD's proposed 2010 budget would end the DDG-1000 program at a maximum of three ships.<ref name="DefNews proposed 2010 budget">{{cite web |last1=Bennett |first1=John T. |first2=Kris |last2=Osborn |url=http://www.defensenews.com/story.php?i=4026294&c=AME&s=LAN |title=Gates Reveals DoD Program Overhaul |work=Defense News |date=6 April 2009}}{{dead link|date=August 2021|bot=medic}}{{cbignore|bot=medic}}</ref> In April, [[the Pentagon]] awarded a fixed-price contract with General Dynamics to build the three destroyers, replacing a cost-plus-fee contract that had been awarded to Northrop Grumman. At that time, the first DDG-1000 destroyer was expected to cost $3.5&nbsp;billion, the second approximately $2.5&nbsp;billion, and the third even less.<ref>{{cite news |last=Drew |first=Christopher |url=https://www.nytimes.com/2009/04/18/business/18ships.html |title=General Dynamics To Build New Destroyer |newspaper=[[The New York Times]] |date=18 April 2009 |access-date=28 February 2017 |archive-url=https://web.archive.org/web/20170701094732/http://www.nytimes.com/2009/04/18/business/18ships.html |archive-date=1 July 2017 |url-status=live}}</ref>

What had once been seen as the backbone of the Navy's future surface fleet with a planned production run of 32 has since been replaced by destroyer production reverting to the ''Arleigh Burke'' class after ordering three ''Zumwalt''s.<ref name="ddg background" /> In April 2016, the [[United States Naval Institute|U.S. Naval Institute]] stated that the total cost of the three ''Zumwalt'' ships is about $22.5&nbsp;billion with research and development costs, which is an average of $7.5&nbsp;billion per ship.<ref name=cost_april2016/>

===Construction===
[[File:US Navy 080214-N-0923G-001 Susan Tomaiko, left, and Brian Cuccias, vice president and DDG 1000 program manager for Northrup Grumman Shipbuilding, sign the $1.4 billion construction contract for the DDG 1000 Zumwalt Class destro.jpg|thumb|left|Representatives from Naval Sea Systems Command and Bath Iron Works sign a construction contract at the Pentagon, February 2008.]]

In late 2005, the program entered the detailed design and integration phase, for which [[Raytheon]] was the Mission Systems Integrator. Both Northrop Grumman Ship Systems and General Dynamics Bath Iron Works shared dual-lead for the hull, mechanical, and electrical detailed design. [[BAE Systems Inc.]] had the advanced gun system and the Mk 57 [[Vertical Launching System]] (VLS). Almost every major defense contractor (including [[Lockheed Martin]], Northrop Grumman Sperry Marine, and [[L-3 Communications]]) and subcontractors from nearly every state in the U.S. were involved to some extent in this project, which was the largest single line item in the Navy's budget. During the previous contract, the development and testing of 11 Engineering Development Models (EDMs) took place: Advanced Gun System, Autonomic Fire Suppression System, Dual Band Radar [X-band and L-band], Infrared, Integrated Deckhouse & Apertures, Integrated Power System, Integrated Undersea Warfare, Peripheral Vertical Launch System, Total Ship Computing Environment Infrastructure (TSCEI), [[Tumblehome]] Hull Form. The decision in September 2006 to fund two ships meant that one could be built by the Bath Iron Works in Maine and one by Northrop Grumman's Ingalls Shipbuilding in Mississippi.<ref name="AP060926" />

Northrop Grumman was awarded a $90M contract modification for materials and production planning on 13 November 2007.<ref>{{cite web |url=http://www.irconnect.com/noc/press/pages/news_releases.html?d=131314 |title=U.S. Navy Awards Northrop Grumman $90 Million Long-Lead Material Contract for DDG 1000 |publisher=Northrop Grumman Corporation |date=13 November 2007 |access-date=11 October 2008 |archive-url=https://web.archive.org/web/20090102182828/http://www.irconnect.com/noc/press/pages/news_releases.html?d=131314 |archive-date=2 January 2009 |url-status=live}}</ref> On 14 February 2008, Bath Iron Works was awarded a contract for the construction of {{USS|Zumwalt|DDG-1000|3}}, and Northrop Grumman Shipbuilding was awarded a contract for the construction of {{USS|Michael Monsoor|DDG-1001|3}} at a cost of $1.4&nbsp;billion each.<ref>{{cite press release |url=http://www.navy.mil/search/display.asp?story_id=35020 |title=Navy Awards Contracts for Zumwalt Class Destroyers |number=NNS080214-20 |date=14 February 2008 |publisher=Navy News Service |access-date=16 May 2008 |archive-url=https://web.archive.org/web/20080409005030/http://www.navy.mil/search/display.asp?story_id=35020 |archive-date=9 April 2008 |url-status=dead}}</ref>

[[File:The boathouse of USS Zumwalt is moved into position. (8291331134).jpg|thumb|Deckhouse of USS ''Zumwalt'' being installed in December 2012]]
On 11 February 2009, full-rate production officially began on the first ''Zumwalt''-class destroyer.<ref name="BIW News February 2009">{{cite web |url=https://www.gdbiw.com/sites/default/files/docs/BIW%20News/BIWNews_Feb09_web.pdf |title=BIW News February 2009 |date=1 March 2009 |publisher=General Dynamics Bath Iron Works |url-status=dead |archive-url=https://web.archive.org/web/20120414205133/https://www.gdbiw.com/sites/default/files/docs/BIW%20News/BIWNews_Feb09_web.pdf |archive-date=14 April 2012}}</ref> Construction on the second ship of the class, ''Michael Monsoor'', began in March 2010.<ref name="autogeneratedmil">{{cite web |url=http://www.navsea.navy.mil/Newswire2011/17NOV11-01.aspx |title=Keel Laid for First DDG 1000 Destroyer |website= NavSea |archive-url=https://web.archive.org/web/20141029223027/http://www.navsea.navy.mil/Newswire2011/17NOV11-01.aspx |archive-date=2014-10-29 |id=NOV17-01}}</ref> The [[keel]] for the first ''Zumwalt''-class destroyer was laid on 17 November 2011.<ref name="autogeneratedmil" /> This first vessel was [[Ship naming and launching|launched]] from the shipyard at Bath, Maine, on 29 October 2013.<ref>{{cite web |url=https://gizmodo.com/americas-21st-century-destroyer-set-sail-for-the-first-1443932986/1454286967/@andrewtarantola |last=Tarantola |first=Andrew |title=America's Newest and Deadliest Destroyer Has Finally Set Sail |publisher=Gizmodo.com |date=29 October 2013 |access-date=12 April 2016 |archive-url=https://web.archive.org/web/20140326114441/http://gizmodo.com/americas-21st-century-destroyer-set-sail-for-the-first-1443932986/1454286967/@andrewtarantola |archive-date=26 March 2014 |url-status=live}}</ref>

The construction timetable in July 2008 was:<ref name="GAO-08-804">{{cite web |url=http://www.gao.gov/products/GAO-08-804 |title=GAO-08-804, Defense Acquisitions: Cost to Deliver Zumwalt-Class Destroyers Likely to Exceed Budget |date=31 July 2008 |publisher=Government Accountability Office |access-date=29 September 2013 |archive-url=https://web.archive.org/web/20131013145032/http://www.gao.gov/products/GAO-08-804 |archive-date=13 October 2013 |url-status=live}}</ref><!-- has some useful history of program-->
* October 2008: DDG-1000 starts construction at Bath Iron Works
* September 2009: DDG-1001 starts construction at Bath Iron Works.
* April 2012: DDG-1002 starts construction at Bath Iron Works
* April 2013: DDG-1000 initial delivery
* May 2014: DDG-1001 initial delivery
* March 2015: DDG-1001 Initial operating capability
* December 2018: DDG-1002 initial delivery

The Navy planned for ''Zumwalt'' to reach initial operating capability (IOC) in 2016. The second ship, ''Michael Monsoor'', was commissioned in 2019, and the third ship, {{USS|Lyndon B. Johnson|DDG-1002|3}}, was to have reached IOC in 2021.<ref>{{cite web |url=http://www.dodbuzz.com/2014/01/14/ddg-1000-preps-for-heavy-weather-trials/ |title=DDG 1000 Preps for Heavy Weather Trials |last=Osborn |first=Kris |website=DoDBuzz.com |date=14 January 2014 |access-date=15 January 2014 |archive-url=https://web.archive.org/web/20140116091714/http://www.dodbuzz.com/2014/01/14/ddg-1000-preps-for-heavy-weather-trials/ |archive-date=16 January 2014 |url-status=live}}</ref>

== Ships in class ==
In April 2006, the Navy announced plans to name the first ship of the class ''Zumwalt'' after former Chief of Naval Operations Admiral [[Elmo Zumwalt|Elmo R. "Bud" Zumwalt Jr.]]<ref name="GAO-08-804" /> The vessel's hull number would be DDG-1000, which abandoned the guided-missile destroyer sequence used by the ''Arleigh Burke'' class destroyers (DDG-51–) and continued the previous "gun destroyer" sequence from the last of the {{sclass|Spruance|destroyer|4}}, {{USS|Hayler|DD-997|3}}.

The Navy announced on 29 October 2008 that DDG-1001 would be named for Master-at-Arms 2nd Class [[Michael A. Monsoor]], the second [[United States Navy SEAL|Navy SEAL]] to receive the [[Medal of Honor]] during the [[Battle of Ramadi (2006)]]<ref>{{cite news |url=http://hamptonroads.com/node/486137 |title=Navy to name newest destroyer after SEAL who died in Iraq |first=Cindy |last=Clayton |work=[[The Virginian-Pilot]] |date=30 October 2008 |access-date=22 April 2010 |archive-url=https://web.archive.org/web/20110522121457/http://hamptonroads.com/node/486137 |archive-date=22 May 2011 |url-status=live}}</ref> in the [[Iraq War]]. Monsoor had deliberately [[Falling on a grenade|fallen upon a grenade]] to reduce danger to his SEAL teammates.

On 16 April 2012, [[Secretary of the Navy]] [[Ray Mabus]] announced that DDG-1002 would be named for former naval officer and U.S. President [[Lyndon B. Johnson]].<ref>{{cite web|url=http://www.defense.gov/releases/release.aspx?releaseid=15190 |title=Navy Names Zumwalt Class Destroyer USS Lyndon B. Johnson |publisher=Office of the Assistant Secretary of Defense (Public Affairs), [[United States Department of Defense]] |date=16 April 2012 |access-date=2012-04-16 |url-status=dead |archive-url=https://web.archive.org/web/20120515081343/http://www.defense.gov/releases/release.aspx?releaseid=15190 |archive-date=15 May 2012}}</ref>

The Navy chose to use an unusual two-part [[Ship commissioning|commissioning]] scheme for the ships. The initial commissioning was done prior to weapons systems integration, and the ships were placed in the status of "in commission, special" before sailing to San Diego for weapons installation and final acceptance. The first two ships used this approach, while the last one will use the more traditional approach with formal commissioning after final acceptance.<ref name="special commissioning">{{cite web
 |url=https://seapowermagazine.org/geurts-third-zumwalt-ddg-will-be-commissioned-after-combat-systems-activation/
 |title=Geurts: Third Zumwalt DDG Will Be Commissioned After Combat Systems Activation
 |last=Burgess
 |first=Richard R.
 |date=April 28, 2020
 |website=
 |publisher=Seapower Magazine
 |access-date=February 12, 2021
}}</ref>

{| class="wikitable sortable plainrowheaders"
|+ Ships of the ''Zumwalt'' destroyer class
|-
! scope="col" | Name
! scope="col" | Hull no.
! scope="col" | Laid down
! scope="col" | Launched
! scope="col" | Commissioned
! scope="col" | Accepted
! scope="col" | Homeport
! scope="col" | Status
|-
! scope="row" | {{USS|Zumwalt||2}}
! scope="row" style="white-space: nowrap;" | DDG-1000
| 17 November 2011
| 28 October 2013
| 15 October 2016
| 24 April 2020
| San Diego, California
| Active
|-
! scope="row" | {{USS|Michael Monsoor||2}}
! scope="row" | DDG-1001
| 23 May 2013
| 20 June 2016
| 26 January 2019
| 27 August 2024
| San Diego, California
| Active
|-
! scope="row" | {{USS|Lyndon B. Johnson||2}}
! scope="row" | DDG-1002
| 30 January 2017
| 9 December 2018<ref>{{Cite web|url=https://www.defensenews.com/naval/2018/12/10/the-us-navys-last-stealth-destroyer-is-in-the-water/|title = The US Navy's last stealth destroyer is in the water|date = 11 December 2018}}</ref>
| Planned for 2027<ref>{{Cite web |last=Abott |first=Rich |date=2025-01-16 |title=Zumwalt To Finish Hypersonic Weapon Tube Install By End Of 2025, DDG-1002 to Start Mod in 2026 |url=https://www.defensedaily.com/zumwalt-to-finish-hypersonic-weapon-tube-install-by-end-of-2025-ddg-1002-to-start-mod-in-2026/navy-usmc/ |access-date=2025-05-10 |website=Defense Daily |language=en-US}}</ref>
|
| Pascagoula, Mississippi{{cn|date=December 2024}}
| Under sea trials
|}

== Design ==
[[File:DD(X).png|thumb|upright=1.25|Features of the DDG-1000]]

In January 2009, the [[Government Accountability Office]] (GAO) found that four out of 12 of the critical technologies in the ship's design were fully mature. Six of the critical technologies were "approaching maturity", but five of those would not be fully mature until after installation.<ref>"[http://www.gao.gov/new.items/d09326sp.pdf GAO Assessments of Major Weapon Programs.] {{Webarchive|url=https://web.archive.org/web/20141206115911/http://www.gao.gov/new.items/d09326sp.pdf |date=6 December 2014}}" [[Government Accountability Office]]</ref>

===Stealth===
{{main|Stealth ship}}

According to a [[Naval Sea Systems Command]] spokesman, despite being 40% larger than an ''Arleigh Burke''-class destroyer, the [[radar cross-section]] (RCS) is more akin to that of a fishing boat.<ref name="CNN2014" /> The tumblehome hull and composite deckhouse reduce radar return. Overall, the destroyer's angular build makes it "50 times harder to spot on radar than an ordinary destroyer."<ref name="CNN2014" />

[[File:Zumwalt Deckplate Transit.jpg|thumb|left|upright|''Zumwalt''{{'}}s deckhouse in transit in November 2012]]
The [[acoustic signature]] is comparable to that of the {{sclass|Los Angeles|submarine}}s.<ref name="global_dd-x" /> Water sleeting along the sides and passive cool air induction in the [[Mack (naval architecture)|mack]] reduces [[infrared signature]].{{citation needed|date=December 2015}}

The composite deckhouse encloses many of the sensors and electronics.<ref name="IDHA">{{cite web |url=http://www.raytheon.com/capabilities/products/ddg_1000/tech/idha/index.html |title=Zumwalt Class Destroyer Integrated Composite Deckhouse & Apertures (IDHA) |publisher=Raytheon Company |date=22 March 2007 |url-status=dead |archive-url=https://web.archive.org/web/20090107084853/http://www.raytheon.com/capabilities/products/ddg_1000/tech/idha/index.html |archive-date=7 January 2009}}</ref> In 2008, ''[[Defense News]]'' reported there had been problems sealing the composite construction panels of this area; Northrop Grumman denied this.<ref>{{cite web |last=Cavas |first=Christopher P |title=Will DDG 1000 Produce Any Ships at All? |url=http://www.defensenews.com/story.php?i=3722533 |date=12 September 2008 |work=Defense News}}{{dead link|date=August 2021|bot=medic}}{{cbignore|bot=medic}}</ref>

The U.S. Navy solicited bids for a lower-cost steel deckhouse as an option for DDG-1002, the last ''Zumwalt'' destroyer, in January 2013.<ref name=Fabey20130125>{{cite news |title=U.S. Navy Seeks Alternate Deckhouse For DDG-1002 |url=http://www.aviationweek.com/Article.aspx?id=/article-xml/asd_01_25_2013_p03-01-540970.xml |first=Michael |last=Fabey |work=Aerospace Daily & Defense Report |date=25 January 2013 |access-date=30 July 2019 |archive-url=https://web.archive.org/web/20131103205853/http://www.aviationweek.com/Article.aspx?id=%2Farticle-xml%2Fasd_01_25_2013_p03-01-540970.xml |archive-date=3 November 2013 |url-status=live}}</ref><ref>{{cite web |last=Schneider |first=David |title=The Electric Warship |url=https://spectrum.ieee.org/the-electric-warship |work=IEEE Spectrum |publisher=IEEE |date=31 July 2013 |access-date=1 August 2013 |archive-url=https://web.archive.org/web/20130804100839/https://spectrum.ieee.org/aerospace/military/the-electric-warship |archive-date=4 August 2013 |url-status=live}}</ref><ref name=DN_Navy_Switches /> On 2 August 2013, the U.S. Navy announced it was awarding a $212&nbsp;million contract to General Dynamics Bath Iron Works to build a steel deckhouse for destroyer ''Lyndon B. Johnson'' (DDG-1002).<ref name=DN_Navy_Switches>{{cite web |url=http://www.defensenews.com/article/20130802/DEFREG02/308020010/ |archive-url=https://archive.today/20131120142654/http://www.defensenews.com/article/20130802/DEFREG02/308020010/ |url-status=dead |archive-date=20 November 2013 |title=Navy Switches from Composite to Steel |website= Defense News |date=2 August 2013}}</ref> The U.S. Naval Institute stated, "the original design of the ship would have had a much smaller RCS, but cost considerations prompted the Navy over the last several years to make the trades in increasing RCS to save money."<ref>{{cite web |url=https://news.usni.org/2016/03/03/new-external-ddg-1000-mast-reduces-ships-stealth-from-original-design |title=New External DDG-1000 Mast Reduces Ship's Stealth From Original Design |date=3 March 2016 |work=USNI News |archive-url=https://web.archive.org/web/20161018214036/https://news.usni.org/2016/03/03/new-external-ddg-1000-mast-reduces-ships-stealth-from-original-design |archive-date=18 October 2016 |url-status=live}}</ref>

To improve detection in non-combat situations by other vessels, such as traversing busy shipping channels or operating in inclement weather, the Navy is testing adding onboard reflectors to improve the design's radar visibility.<ref>{{cite web |url=https://www.engadget.com/2016/04/11/stealth-on-the-navys-newest-destroyers-might-be-too-good/ |title=Stealth on the Navy's newest destroyers might be too good |website=engadget.com |last=Tarantola |first=Andrew |date=11 April 2016 |access-date=11 April 2016 |archive-url=https://web.archive.org/web/20160412113459/http://www.engadget.com/2016/04/11/stealth-on-the-navys-newest-destroyers-might-be-too-good/ |archive-date=12 April 2016 |url-status=live}}</ref>

The usefulness of the stealth features has been questioned. The class's role was to provide Naval Surface Fire Support, which requires the ship to be in typically crowded near-shore waters where such large and distinctive ships can be tracked visually, and any surface ship becomes non-stealthy when it begins firing guns or missiles.<ref name=Fredenburg/>

===Tumblehome wave-piercing hull===
{{main|Tumblehome|Wave-piercing hull}}

The ''Zumwalt''-class destroyer reintroduces the tumblehome hull form, a hull form not seen to this extent since the [[Russo-Japanese War]] in 1905. The appearance has been compared to that of the historic {{USS|Monitor}}<ref>{{cite news |date=5 July 2000 |title=New Zumwalt-Class Destroyer Is Not Your Father's Tin Can |work=Los Angeles Times |url=https://www.latimes.com/archives/la-xpm-2000-jul-05-mn-47870-story.html |url-status=live |archive-url=https://web.archive.org/web/20110520092359/http://articles.latimes.com/2000/jul/05/news/mn-47870 |archive-date=20 May 2011}}</ref> and her famous antagonist {{ship|CSS|Virginia}}.<ref>{{Cite web |title=Jalopnik.com |date=31 October 2013 |url=https://www.jalopnik.com/captain-kirk-will-command-americas-newest-stealth-dest-1456000112/amp |url-status=live |archive-url=https://web.archive.org/web/20190405211158/https://jalopnik.com/captain-kirk-will-command-americas-newest-stealth-dest-1456000112/amp |archive-date=5 April 2019 |access-date=5 April 2019}}</ref><ref name="Marinelink" /> The hull form was originally put forth in modern steel battleship designs by the French shipyard [[Forges et Chantiers de la Méditerranée]] in [[La Seyne-sur-Mer|La Seyne]], [[Toulon]]. French naval architects believed that tumblehome, in which the [[Beam (nautical)|beam]] of the vessel narrowed from the waterline to the upper deck, would create better freeboard, greater seaworthiness, and, as Russian battleships were to find, would be ideal for navigating through narrow constraints (e.g., canals).<ref>Forczyk. p. 18, 76</ref> On the downside, the tumblehome battleships leaked – partly due to their riveted construction – and could be unstable, especially when turning at high speed.<ref>Forczyk p. 32, 76</ref> The tumblehome has been reintroduced in the 21st century to reduce the radar return of the hull. The [[inverted bow]] is designed to cut through waves rather than ride over them.<ref name="global_dd-x" /><ref>{{cite web |url=http://www.raytheon.com/capabilities/products/ddg_1000/tech/wpth/index.html |title=Wave Piercing Tumblehome Hull |publisher=Raytheon Company |date=22 March 2007 |url-status=dead |archive-url=https://web.archive.org/web/20081119042754/http://www.raytheon.com/capabilities/products/ddg_1000/tech/wpth/index.html |archive-date=19 November 2008}}</ref> The stability of this hull form in high sea states has caused debate among naval architects, with some charging that "with the waves coming at you from behind, when a ship pitches down, it can lose transverse stability as the stern comes out of the water—and basically roll over."<ref>{{cite magazine|url=https://www.wired.com/2015/12/the-new-3b-uss-zumwalt-is-a-stealthy-oddity-that-may-already-be-a-relic/|title=The New $3B USS Zumwalt Is a Stealthy Oddity That May Already Be a Relic|first=Jordan|last=Crucchiola|magazine=Wired|access-date=17 October 2016|archive-url=https://web.archive.org/web/20161017183257/https://www.wired.com/2015/12/the-new-3b-uss-zumwalt-is-a-stealthy-oddity-that-may-already-be-a-relic/|archive-date=17 October 2016|url-status=live}}</ref>

===Advanced Gun System===
{{main|Advanced Gun System}}

The Advanced Gun System is a 155&nbsp;mm [[Naval artillery|naval gun]], two of which are installed in each ship. This system consists of an advanced 155&nbsp;mm gun and its [[Long Range Land Attack Projectile]] (LRLAP).<ref name="BAE AGS" /> This projectile is a rocket with a warhead fired from the AGS gun; the warhead has an 11&nbsp;kg / 24&nbsp;lb bursting charge and has a [[circular error probable]] of 50 meters. This weapon system has a range of {{convert|83|nmi|km}}.<ref name="CNN2014" /> The fully automated storage system has room for up to 750 rounds.<ref name="global_dd-x" /><ref name="BAE AGS">{{cite web |url=http://www.baesystems.com/product/BAES_020037/advanced-gun-system-ags?_afrLoop=1030138509801000 |title=Advanced Gun System (AGS) |publisher=BAE Systems |year=2008 |access-date=14 June 2012 |archive-url=https://web.archive.org/web/20131112063627/http://www.baesystems.com/product/BAES_020037/advanced-gun-system-ags?_afrLoop=1030138509801000 |archive-date=12 November 2013 |url-status=live}}</ref> The barrel is water-cooled to prevent overheating and allows a rate of fire of 10 rounds per minute per gun. Using a [[Artillery#Multiple round simultaneous impact|Multiple Rounds Simultaneous Impact]] (MRSI) firing tactic, the combined firepower from a pair of turrets gives each ''Zumwalt''-class destroyer initial strike firepower equivalent to 12 conventional [[M198 howitzer|M198]] howitzers.<ref name="Raytheon AGS">{{cite web|url=http://www.raytheon.com/capabilities/products/zumwalt/tech/index.html|title=Zumwalt-Class Destroyer Critical Technologies|publisher=Raytheon|url-status=dead|archive-url=https://web.archive.org/web/20080808000240/http://www.raytheon.com/capabilities/products/zumwalt/tech/index.html|archive-date=8 August 2008}}</ref><ref name="DI20140223">{{cite web |url=http://www.defenseindustrydaily.com/next-gen-naval-gunfire-support-the-usas-ags-lrlap-07171/ |title=Next-Gen Naval Gunfire Support: The USA's AGS & LRLAP |website=Defense Industry Daily |date=23 February 2014 |access-date=10 May 2016 |archive-url=https://web.archive.org/web/20160603221625/http://www.defenseindustrydaily.com/next-gen-naval-gunfire-support-the-usas-ags-lrlap-07171/ |archive-date=3 June 2016 |url-status=live}}</ref> The ''Zumwalt''s use [[ballast tank]]s to lower themselves into the water for a reduced profile in combat.<ref name="dodbuzz16april12">{{cite web |last=Ewing |first=Philip |url=http://www.dodbuzz.com/2012/04/16/sas12-approach-of-the-gray-elephant/ |title=SAS12: Approach of the Gray Elephant |website=DoD Buzz |date=16 April 2012 |access-date=16 April 2012 |archive-url=https://web.archive.org/web/20120419211833/http://www.dodbuzz.com/2012/04/16/sas12-approach-of-the-gray-elephant/ |archive-date=19 April 2012 |url-status=live}}</ref> In November 2016, the Navy moved to cancel procurement of the LRLAP, citing per-shell cost increases to $800,000–$1&nbsp;million resulting from trimming of total ship numbers of the class. Since the AGS was tailor-made to use the LRLAP, it was unable to fulfill the naval gunfire support role it was designed for.<ref>{{cite web|url=https://www.military.com/dodbuzz/2018/01/12/navys-stealthy-mega-destroyer-still-doesnt-have-round-its-gun.html|title=Navy's Stealthy Mega-Destroyer Still Doesn't Have a Round for Its Gun|first=Hope Hodge|last=Seck|date=12 January 2018|website=military.com|access-date=15 January 2018|archive-url=https://web.archive.org/web/20180115124812/https://www.military.com/dodbuzz/2018/01/12/navys-stealthy-mega-destroyer-still-doesnt-have-round-its-gun.html|archive-date=15 January 2018|url-status=live}}</ref><ref name="Cavas">{{cite web|url=http://www.defensenews.com/articles/new-warships-big-guns-have-no-bullets|title=New Warship's Big Guns Have No Bullets|last=Cavas|first=Christopher P.|website= DefenseNews|date=2016-11-06}}</ref><ref>[https://news.usni.org/2016/11/07/navy-planning-not-buying-lrlap-rounds Navy Planning on Not Buying More LRLAP Rounds for Zumwalt Class] {{Webarchive|url=https://web.archive.org/web/20161111061427/https://news.usni.org/2016/11/07/navy-planning-not-buying-lrlap-rounds |date=11 November 2016}} – News.USNI.org, 7 November 2016</ref>

''Lyndon B. Johnson'', the last ''Zumwalt'', was being considered for the installation of a [[railgun]] in place of one of the 155&nbsp;mm naval guns after the ship was built. This would be feasible because the installed Rolls-Royce turbine generators are capable of producing {{convert|78|MW}}, enough for the electrically powered weapon.<ref>{{cite web|last1=Sharp|first1=David|title=Admiral: Shipbuilders won't install railgun on new Navy destroyers|url=http://www.militarytimes.com/story/military/tech/2016/03/22/admiral-shipbuilders-wont-install-railgun-new-navy-destroyers/82126978/|website=militarytimes.com| date=22 March 2016 |access-date=8 November 2016|archive-url=https://web.archive.org/web/20161011155138/http://www.militarytimes.com/story/military/tech/2016/03/22/admiral-shipbuilders-wont-install-railgun-new-navy-destroyers/82126978/|archive-date=11 October 2016|url-status=live}}</ref><ref>{{cite web |url=https://www.engadget.com/2016/02/15/railguns-on-zumwalt-class-ships/ |title=The Navy wants to deploy railguns on its latest destroyer |last=Dent |first=Steven |date=15 February 2016 |publisher=AOL |website=engadget.com |access-date=19 September 2017 |archive-url=https://web.archive.org/web/20170822054823/https://www.engadget.com/2016/02/15/railguns-on-zumwalt-class-ships/ |archive-date=22 August 2017 |url-status=live}}</ref> In 2021, U.S. Navy funding for railgun development ceased with no plans to continue the project.<ref>{{Cite web|last=Trevithick|first=Joseph|title=The Navy's Railgun Looks Like It's Finally Facing The Axe In New Budget Request|url=https://www.thedrive.com/the-war-zone/40875/the-navys-railgun-looks-like-its-finally-facing-the-axe-in-new-budget-request|access-date=2021-08-01|website=The Drive| date=June 2021 |language=en}}</ref> Both guns on all three ships were scheduled to be removed and replaced with hypersonic missiles starting in 2023.<ref name="remove"/>

=== Advanced Payload Module ===
In March 2021, the Navy solicited information from the industry on how to reconfigure the ''Zumwalt''-class ships to host [[Long-Range Hypersonic Weapon]]s (LRHW). Since they would be too large to fit in the VLS tubes, it has been suggested that the two AGS, having no use since the cancellation of their ammunition, could be replaced with three-pack advanced payload modules to fulfill a conventional prompt strike deterrence role.<ref>[https://www.navytimes.com/naval/2021/03/25/what-should-become-of-the-zumwalt-class-the-us-navy-has-some-big-ideas/ What should become of the Zumwalt class? The US Navy has some big ideas.] ''[[Navy Times]]''. 25 March 2021.</ref> The Navy will request FY 2022 funding to replace the 155&nbsp;mm AGS turrets with Advanced Payload Modules for the Conventional Prompt Strike (CPS) hypersonic missile.<ref>{{Cite web |title=Department of Defense: Fiscal Year (FY) 2022 Budget Estimates |url=https://www.secnav.navy.mil/fmc/fmb/Documents/22pres/OPN_BA1_Book.pdf |website=www.secnav.navy.mil}}</ref><ref>{{Cite web|url=https://sgp.fas.org/crs/nuke/R41464.pdf|title=Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues}}</ref> The conversion would be part of the DDG-1000 Dry-Docking Selected Restricted Availability (DSRA) beginning FY 2024.<ref>{{Cite web|last=Ong|first=Peter|date=2021-10-28|title=Latest Details on Hypersonic Missile Integration Aboard Zumwalt-class Destroyers|url=https://www.navalnews.com/naval-news/2021/10/latest-details-on-hypersonic-missile-integration-aboard-zumwalt-class-destroyers/|access-date=2021-11-03|website=Naval News|language=en-US}}</ref> The LRHW is also slated for [[Virginia-class submarine#Block V|Block V ''Virginia''-class]] [[attack submarine]]s (SSN). The larger tubes for the VLS will be based upon the [[Virginia-class submarine#Virginia Payload Module|Virginia Payload Module]] (VPM) used in the ''Virginia'' SSNs.<ref>{{cite web|url=https://www.navalnews.com/naval-news/2021/10/latest-details-on-hypersonic-missile-integration-aboard-zumwalt-class-destroyers|title=Latest Details On Hypersonic Missile Integration Aboard Zumwalt-Class Destroyers|publisher=navalnews.com|date=8 October 2021|access-date=5 November 2021}}</ref> The first ''Zumwalt''-class destroyer will be ready to test the CPS in 2025.<ref>[https://news.usni.org/2022/11/03/navy-details-hypersonic-missiles-on-zumwalt-destroyers-virginia-submarines Navy Details Hypersonic Missile Plan for Zumwalt Destroyers, Virginia Submarines]. ''[[USNI News]]''. 3 November 2022.</ref> In mid-August 2023 the lead vessel arrived at Pascagoula to have the AGS replaced by the LRHW tubes and the integration of the [[Conventional Prompt Strike|new weapons system]].<ref>Jerusalem Post staff. (20 August 2023). "US Navy destroyer to be fitted with hypersonic missiles". [https://www.jpost.com/international/article-755443 JP website] Retrieved 21 August 2023.</ref><ref>Congressional Research Service. (10 January 2023). Hypersonic Weapons: Background and Issues for Congress. [https://news.usni.org/2023/01/11/report-to-congress-on-hypersonic-weapons-10 USNI website] Retrieved 22 August 2023.</ref>

===Peripheral Vertical Launch System===
The [[Mark 41 Vertical Launching System#Mark 56 (Mk 56) VLS and Mark 57 (Mk 57) PVLS|Mk 57 Peripheral Vertical Launch System]] (PVLS) is a missile launch system designed to avoid intrusions into the prized center space of the hull while reducing the risk of loss of the entire missile battery or the ship in a magazine explosion. The system consists of pods of VLS cells distributed around the ship's outer shell, with a thin steel outer shell and a thick inner shell. The design of the PVLS directs the force of any explosion outward rather than into the ship. Additionally, this design reduces the loss of missile capacity to only the affected pod.<ref name="global_dd-x" /><ref>{{cite web|url=http://www.raytheon.com/capabilities/products/ddg_1000/tech/pvls/index.html |title=Zumwalt Class Destroyer Peripheral Vertical Launch System (PVLS) Advanced VLS |publisher=Raytheon Company |date=22 March 2007 |url-status=dead |archive-url=https://web.archive.org/web/20090107085100/http://www.raytheon.com/capabilities/products/ddg_1000/tech/pvls/index.html |archive-date=7 January 2009}}</ref>

===Aircraft and boat features===
Two spots are available on a large aviation deck with a hangar capable of housing two full-size [[Sikorsky SH-60 Seahawk|SH-60]] helicopters.<ref>{{cite web|url=http://www.defensenews.com/article/20130802/DEFREG02/308020010/ |archive-url=https://archive.today/20131120142654/http://www.defensenews.com/article/20130802/DEFREG02/308020010/ |url-status=dead |archive-date=20 November 2013 |title=Navy Switches from Composite to Steel |website= Defense News |date=11 June 2014 |access-date=2014-06-15}}</ref> Boats are handled within a [[stern]]-mounted boat hangar with a ramp. The boat hangar's stern location meets high sea state requirements for boat operations.<ref name="global_dd-x" />

===Radar===
[[File:3d-radarp.jpg|thumb|Diagram of AN/SPY-3 vertical electronic [[Pencil (optics)|pencil beam]] radar conex projections]]

Originally, the primarily [[X band]] [[AN/SPY-3]] [[active electronically scanned array]] radar was to be married with Lockheed Martin's [[AN/SPY-4]] [[S band|S-band]] volume [[search radar]]. Raytheon's X-band, active-array SPY-3 Multi-Function Radar (MFR) offers superior medium to high altitude performance over other radar bands, and its [[Pencil (optics)|pencil beams]] give it an excellent ability to focus on targets. SPY-3 will be the primary radar used for missile engagements.<ref name=DID_DBR>{{cite web |url=http://www.defenseindustrydaily.com/The-US-Navys-Dual-Band-Radars-05393/ |title=The US Navy's Dual Band Radars |publisher=Defenseindustrydaily.com |date=11 August 2010 |access-date=2011-12-27 |archive-url=https://web.archive.org/web/20100211102549/http://www.defenseindustrydaily.com/The-US-Navys-Dual-Band-Radars-05393/ |archive-date=11 February 2010 |url-status=live}}</ref> A 2005 report by Congress' investigative arm, the Government Accountability Office (GAO), questioned that the technology leap for the [[Dual Band Radar]] would be too much.<ref name="d05752r">{{cite book |title=GAO-05-752R Progress of the DD(X) Destroyer Program |url=http://www.gao.gov/htext/d05752r.html |publisher=U.S. Government Accountability Office |date=14 June 2005 |access-date=11 October 2008 |archive-url=https://web.archive.org/web/20081004212227/http://www.gao.gov/htext/d05752r.html |archive-date=4 October 2008 |url-status=live}}</ref>

On 2 June 2010, Pentagon acquisition chief [[Ashton Carter]] announced that they would be removing the SPY-4 S-band Volume Search Radar from the DDG-1000's dual-band radar to reduce costs as part of the Nunn–McCurdy certification process.<ref name="ddg background" /> Due to the SPY-4 removal, the SPY-3 radar will have software modifications for volume search functionality. Shipboard operators will be able to optimize the SPY-3 for either horizon search or volume search. While optimized for volume search, the horizon search capability is limited. The DDG-1000 is still expected to perform local area air defense.<ref name="ddg background">{{cite web |url=https://fas.org/sgp/crs/weapons/RL32109.pdf |title=Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress |last=O'Rourke |first=Ronald |date=10 March 2016 |publisher=Congressional Research Service |access-date=4 April 2015 |archive-url=https://web.archive.org/web/20150328211730/http://www.fas.org/sgp/crs/weapons/RL32109.pdf |archive-date=28 March 2015 |url-status=live}}</ref><ref>{{cite web|url=http://www.navsea.navy.mil/nswc/dahlgren/Leading%20Edge/Sensors/03_Development.pdf |title=(Archived copy) |access-date=28 October 2014 |url-status=dead |archive-url=https://web.archive.org/web/20141212012332/http://www.navsea.navy.mil/nswc/dahlgren/Leading%20Edge/Sensors/03_Development.pdf |archive-date=12 December 2014}}</ref> This system is thought to provide high detection and excellent anti-jamming capabilities, particularly when used in conjunction with the [[Cooperative Engagement Capability]] (CEC). It is, however, not reported if the CEC system will be installed on the ''Zumwalt''-class destroyers upon commissioning, but it is scheduled for eventual incorporation in the ship type.<ref>{{cite web |url=http://www.dote.osd.mil/pub/reports/FY2011/pdf/navy/2011ssds.pdf |title=Navy Programs: Ship Self-Defense |publisher=Director of Operational Test and Evaluation |access-date=17 November 2013 |archive-url=https://web.archive.org/web/20131111025233/http://www.dote.osd.mil/pub/reports/FY2011/pdf/navy/2011ssds.pdf |archive-date=11 November 2013 |url-status=live}}</ref><ref>{{cite web |first=William D. |last=O'Neil |title=The Cooperative Engagement Capability (CEC): Transforming Naval Anti-air Warfare |url=http://ctnsp.dodlive.mil/files/2006/12/Case-11-CEC-Transforming-Naval-Anti-Warfare.pdf|publisher=Center for Technology and National Security Policy, [[National Defense University (Washington, D.C.)|National Defense University]] |date=August 2007 |access-date=29 October 2014 |archive-url=https://web.archive.org/web/20151222110439/http://ctnsp.dodlive.mil/files/2006/12/Case-11-CEC-Transforming-Naval-Anti-Warfare.pdf |archive-date=22 December 2015 |url-status=dead}}</ref>

In that the ''Zumwalt'' class has no [[AN/SPG-62]] fire-control radars, which are used for terminal guidance for Standard and [[RIM-162 ESSM|Evolved SeaSparrow Missile]] (ESSM) Block 1 in anti-aircraft engagements, the SPY-3 will generate Interrupted Continuous Wave Illumination (ICWI) rather than the Continuous Wave Illumination of the AN/SPG-62 fire-control radars. Significant software modifications are required to support the ICWI and transmit and receive link messages to the missiles. Standard Missile (SM)-2 IIIA and the ESSM slated for ''Zumwalt'' class require modified missile receivers, transmitters, encoders, decoders, and a redesigned digital signal processor to work with the ship's system. These modified missiles will not be able to be used on Aegis class ships.<ref name="defensesystems.com">{{cite web|url=https://defensesystems.com/articles/2016/11/28/dna.aspx|title=Navy updates radar software on stealthy Zumwalt – Defense Systems|website=Defense Systems|access-date=28 October 2017|archive-url=https://web.archive.org/web/20171028150243/https://defensesystems.com/articles/2016/11/28/dna.aspx|archive-date=28 October 2017|url-status=live}}</ref>

The SPY-3 had to be reprogrammed to do the volume search that the SPY-4 was supposed to have performed. With the duties of volume and surface search and terminal illumination, there is concern that a [[Saturation attack|large-scale missile attack]] could overwhelm a radar's resource management capacity. In such a case, the radar may be unable to manage incoming threats properly or guide offensive missiles.<ref name="defensesystems.com"/>

The Dual Band Radar in its entirety (SPY-3 & SPY-4) is to be installed only on the {{sclass|Gerald R. Ford|aircraft carrier}} {{USS|Gerald R. Ford|CVN-78|2}}. With the development of the [[AN/SPY-6]] Air and Missile Defense Radar (AMDR), it seems unlikely the DBR will be installed on any other platforms, as it is on the DDG-1000 class, or in total, as it is on ''Gerald R. Ford''. The Enterprise Air Surveillance Radar (EASR) is a new design surveillance radar that is to be installed in the second ''Gerald R. Ford''-class aircraft carrier, {{USS|John F. Kennedy|CVN-79|2}}, instead of the Dual Band radar. The {{sclass|America|amphibious assault ship|1}}s starting with LHA-8 and the planned {{sclass2|LX(R)|amphibious warfare ship|1}}s will also have this radar.<ref>{{cite web |title=Navy C4ISR and Unmanned Systems |url=http://www.seapower-digital.com/seapower/january_2016?pg=93#pg93 |work=Sea Power 2016 Almanac |publisher=[[Navy League of the United States|Navy League of the U.S.]] |date=January 2016 |page=91 |access-date=8 February 2016 |url-status=usurped |archive-url=https://web.archive.org/web/20170128204404/http://www.seapower-digital.com/seapower/january_2016?pg=93#pg93 |archive-date=28 January 2017 }}</ref>

The AN/SPY-6 AMDR was originally proposed to be installed in the hull of DDG-1000 type under the [[CG(X)]] program. However, the CG(X) program was canceled due to cost growth. The AMDR has continued in fully funded development for installation on the ''Arleigh Burke'' class destroyer Flight III ships, with plans to be also installed on Flight IIA ships. However, a smaller than optimally planned aperture of {{convert|14|ft}}, the AMDR for the Flight III ships is to be less sensitive than the {{convert|22|ft|m}} variant that had been planned for CG(X).<ref name="O'Rourke 11 p9">{{Cite web |last=O'Rourke |first=Ronald |date=2010-06-14 |title=Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress |url=http://assets.opencrs.com/rpts/RL32109_20100614.pdf |url-status=dead |archive-url=https://web.archive.org/web/20140822162447/http://assets.opencrs.com/rpts/RL32109_20100614.pdf |archive-date=2014-08-22 |publisher=Congressional Research Service |page=9 |id=RL32109}}</ref><ref>{{Cite web |last=Freedberg Jr. |first=Sydney |date=2012-10-05 |title=Navy Bets On Arleigh Burkes To Sail Until 2072; 40 Years Afloat For Some |url=https://breakingdefense.com/2012/10/navy-bets-on-arleigh-burkes-to-sail-until-2072-40-years-afloat/ |url-status=live |archive-url=https://web.archive.org/web/20220821041205/https://breakingdefense.com/2012/10/navy-bets-on-arleigh-burkes-to-sail-until-2072-40-years-afloat/ |archive-date=21 August 2022 |access-date=2022-11-18 |website=Breaking Defense |language=en-US}}</ref>

A study to place the AN/SPY-6 on a DDG-1000 hull was done with the {{convert|22|ft|adj=on}} aperture primarily for Ballistic Missile Defense (BMD) purposes. In that the DDG-1000 does not have an [[Aegis Combat System]], as does the DDG-51 class ships, but rather the Total Ship Computing Environment Infrastructure (TSCEI), the Radar/Hull Study stated:

{{blockquote|1=... that developing a BMD capability "from scratch" for TSCE was not considered viable enough by the study team to warrant further analysis, particularly because of the investment already made in the Aegis program. The navy concluded that developing IAMD software and hardware specifically for TSCE would be more expensive and present higher risk. Ultimately, the navy determined that Aegis was its preferred combat system option. Navy officials stated that Aegis had proven some BMD capability and was widely used across the fleet, and that the navy wanted to leverage the investments it had made over the years in this combat system, especially in its current development of a version that provides a new, limited IAMD capability.<ref>{{cite web |url=http://assets.opencrs.com/rpts/RL32109_20121018.pdf |title=Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress |publisher=Congressional Research Service |page=23 |first=Ronald |last=O'Rourke|date=18 October 2012 |access-date=2014-06-15 |url-status=dead |archive-url=https://web.archive.org/web/20140512222940/http://assets.opencrs.com/rpts/RL32109_20121018.pdf |archive-date=12 May 2014}}</ref>}}

===Common Display System===
The ship's Common Display System is nicknamed "keds": Sailors operate keds via [[trackball]]s and specialized button panels, with [[touchscreen]]s option to the interface. The technology array allows sailors to monitor multiple weapons systems or sensors, saving manpower, and allowing it to be steered from the ops center.<ref name="CNN2014" />

===Sonar===
A dual-band sonar controlled by a highly automated computer system will be used to detect [[Naval mine|mines]] and submarines. It is claimed that it is superior to the ''Arleigh Burke'' class{{'}}s sonar in littoral ASW but less effective in blue water/deep sea areas.<ref name="McCullough" />
* Hull-mounted mid-frequency sonar (AN/SQS-60)
* Hull-mounted high-frequency sonar (AN/SQS-61)
* Multi-function towed array sonar and handling system (AN/SQR-20)<ref>{{cite web |url=http://raytheon.mediaroom.com/index.php?s=43&item=1151 |title=Zumwalt Undersea Warfare Combat System Receives Official Navy Nomenclature |publisher=Raytheon |date=9 December 2008 |access-date=10 December 2008 |archive-url=https://web.archive.org/web/20110714064946/http://raytheon.mediaroom.com/index.php?s=43&item=1151 |archive-date=14 July 2011 |url-status=live}}</ref>

Although ''Zumwalt'' ships have an integrated suite of undersea sensors and a multi-function towed array, they are not equipped with onboard [[torpedo tube]]s, so they rely on their helicopters or VL-ASROCs to destroy submarines that the sonar picks up.<ref name="dodbuzz16april12" />

===Propulsion and power system===
[[File:161017-N-CE233-184 (29879671774).jpg|thumb|View of the stern of USS ''Zumwalt'', 2016.]]

''Zumwalt''-class ships use an [[integrated electric propulsion|Integrated Power System]] (IPS), a modern version of a [[Turbo-electric transmission|turbo-electric drive]] system. The IPS is a dual system, with each half consisting of a gas turbine prime mover directly coupled to an electrical generator, providing power for an electric motor that drives a propeller shaft. The system is "integrated" because the turbo-generators provide electrical power for all ship systems, not just the drive motors. The system provides much more available electrical power than is available in other types of ships.<ref>{{cite web |url=https://www.naval-technology.com/projects/dd21/ |title=DDG 1000 Zumwalt Class – Multimission Destroyer |website=naval-technology.com |access-date=29 December 2021 }}</ref>

The DDX proposed using [[Permanent-magnet electric motor#Permanent-magnet motors|permanent-magnet motor]]s (PMMs) within the hull, which was abandoned in favor of a more conventional [[induction motor]]. An alternate twin pod arrangement was rejected as the ramifications of pod drives would require too much development and validation cost to the vessel. The PMM was considered to be another technology leap and was the cause of some concern (along with the radar system) from Congress.<ref name="global_dd-x" /> As part of the design phase, Northrop Grumman had the world's largest permanent magnet motor designed and fabricated by [[DRS Technologies]].<ref>{{cite press release |url=http://www.businesswire.com/news/home/20040922005135/en/DRS-Technologies-Introduces-Line-High-Performance-Permanent-Magnet |title=DRS Technologies Introduces New Line of High-Performance Permanent Magnet Motors for Industrial Applications |website=businesswire.com |access-date=15 February 2017 |archive-url=https://web.archive.org/web/20170216133230/http://www.businesswire.com/news/home/20040922005135/en/DRS-Technologies-Introduces-Line-High-Performance-Permanent-Magnet |archive-date=16 February 2017 |url-status=live}}</ref> This proposal was dropped when the PMM motor failed to demonstrate that it was ready to be installed in time.

''Zumwalt'' has [[Converteam]]'s Advanced Induction Motors (AIM) rather than DRS Technologies' Permanent Magnet-Synchronous Motors (PMM).
<blockquote>The exact choice of engine systems remains somewhat controversial at this point. The concept was originally for an integrated power system (IPS) based on in-hull permanent magnet synchronous motors (PMMs), with Advanced Induction Motors (AIM) as a possible backup solution. The design was shifted to the AIM system in February 2005 in order to meet scheduled milestones; PMM technical issues were subsequently fixed, but the program has moved on. The downside is that AIM technology has a heavier motor, requires more space, requires a "separate controller" to be developed to meet noise requirements, and produces one-third the amount of voltage. On the other hand, these very differences will force time and cost penalties from design and construction changes if the program wishes to "design AIM out" …<ref>{{cite web |url=http://www.defenseindustrydaily.com/dead-aim-or-dead-end-the-usas-ddg1000-zumwalt-class-program-02574/ |title=Dead Aim, Or Dead End? The USA's DDG-1000 Zumwalt Class Program |work=Defense Industry Daily |date=21 September 2008 |url-access=subscription |access-date=23 October 2007 |archive-url=https://web.archive.org/web/20071023092744/http://www.defenseindustrydaily.com/dead-aim-or-dead-end-the-usas-ddg1000-zumwalt-class-program-02574/ |archive-date=23 October 2007 |url-status=live}} <!-- Needs subscription – can someone find another reference? --></ref></blockquote>

The system reduces the ship's thermal and sound signature. As noted by the GAO, the IPS has added to weight growth in the ''Zumwalt''-class destroyer.<ref name="d05752r" />

Electric power is provided by two [[Rolls-Royce MT30]] [[gas turbine]]s (35.4 MW ea.)<ref name=AeroWeb/> driving [[Curtiss-Wright]] [[electric generator]]s.<ref name="d05752r"/>

The second ship of the class, ''Michael Monsoor'', will require a new gas turbine after she experienced problems during sea trials resulting in damaged turbine blades.<ref>{{cite web|url=https://news.usni.org/2018/07/11/second-zumwalt-destroyer-needs-new-engine-turbine-blades-damaged-sea-trials|title=Second Zumwalt Destroyer Needs New Engine After Turbine Blades Damaged in Sea Trials|publisher=usni.org|date=11 July 2018|access-date=25 September 2018|archive-url=https://web.archive.org/web/20180925104336/https://news.usni.org/2018/07/11/second-zumwalt-destroyer-needs-new-engine-turbine-blades-damaged-sea-trials|archive-date=25 September 2018|url-status=live}}</ref>

===Automation and fire protection===
Automation reduces crew size on these ships: the ''Zumwalt''-class destroyer's minimum complement is 130, less than half that of similar warships.<ref name="CNN2014" /> Smaller crews reduce a significant component of operating costs.<ref name="global_dd-x" /> Ammunition, food, and other stores are all mounted in containers able to be struck below to magazine/storage areas by an automated cargo handling system.<ref name="global_dd-x" />

Water spray or mist systems are proposed for deployment in the ''Zumwalt''-class destroyer, but the electronic spaces remain problematic to the designers. [[Halomethane#Fire extinguishing|Halon]]/nitrogen dump systems are preferred but do not work when space has been compromised by a hull breach. The GAO has noted this system as a potential problem yet to be addressed.<ref name="global_dd-x" /><ref>{{cite web |url=http://www.raytheon.com/capabilities/products/ddg_1000/tech/afss/index.html |title=Zumwalt Class Destroyer Autonomic Fire Suppression System (AFSS) |publisher=Raytheon Company |date=22 March 2007 |url-status=dead |archive-url=https://web.archive.org/web/20090107135259/http://www.raytheon.com/capabilities/products/ddg_1000/tech/afss/index.html |archive-date=7 January 2009}}</ref>

===Computer network===
The Total Ship Computing Environment Infrastructure (TSCEI) is based on [[General Electric]] Fanuc Embedded Systems' PPC7A and PPC7D [[single-board computer]]s<ref name="TSCEI/GEFanuc">{{cite web |url=http://www.gefanuc.com/news-events/detail/1047 |title=GE Fanuc Embedded Systems Selected By Raytheon For Zumwalt Class Destroyer Program |date=25 July 2007 |publisher=GE Fanuc Intelligent Platforms |url-status=dead |archive-url=https://archive.today/20130124020939/http://www.gefanuc.com/news-events/detail/1047 |archive-date=24 January 2013}}</ref> running [[LynuxWorks]]' [[LynxOS]] [[Real-time operating system]] (RTOS).<ref>{{cite web |url=http://www.lynuxworks.com/corporate/news/2007/ge-fanuc-raytheon.php |title=GE Fanuc Embedded Systems Selected By Raytheon For Zumwalt Class Destroyer Program |date=25 July 2007 |publisher=Lynuxworks |url-status=dead |archive-url=https://web.archive.org/web/20071011031020/http://www.lynuxworks.com/corporate/news/2007/ge-fanuc-raytheon.php |archive-date=11 October 2007}}</ref> These are contained in 16 shock, vibration, and [[Electromagnetism |electromagnetic]] protected Electronic Modular Enclosures.<ref>{{cite web |url=https://arstechnica.com/information-technology/2013/10/the-navys-newest-warship-is-powered-by-linux/?sf892043=1 |title=The Navy's newest warship is powered by Linux |last1=Gallagher |first1=Sean |date=18 October 2013 |website=arstechnica.com |access-date=18 October 2013 |archive-url=https://web.archive.org/web/20131019123824/http://arstechnica.com/information-technology/2013/10/the-navys-newest-warship-is-powered-by-linux/?sf892043=1 |archive-date=19 October 2013 |url-status=live}}</ref> ''Zumwalt'' carries 16 pre-assembled IBM blade servers.<ref name="mayakamath">{{cite web |url=http://www.techworm.net/2015/02/linux-used-build-us-navys-powerful-destroyer-yet.html |title=Linux used to build US Navy's most powerful destroyer yet |last=Kamath |first=Maya |date=6 February 2015 |website=techworm.net |access-date=19 September 2015 |archive-url=https://web.archive.org/web/20151002071556/http://www.techworm.net/2015/02/linux-used-build-us-navys-powerful-destroyer-yet.html |archive-date=2 October 2015 |url-status=live}}</ref> The network allows seamless integration of all onboard systems, e.g., [[sensor fusion]] and easing operation and mission planning.<ref>{{cite web |url=http://investor.raytheon.com/phoenix.zhtml?c=84193&p=irol-newsArticle&ID=1069491 |title=Navy Approves Raytheon's Zumwalt Total Ship Computing Environment Infrastructure |date=30 October 2007 |publisher=Raytheon |access-date=10 May 2016 |archive-url=https://web.archive.org/web/20170417100520/http://investor.raytheon.com/phoenix.zhtml?c=84193&p=irol-newsArticle&ID=1069491 |archive-date=17 April 2017 |url-status=live}}</ref>

==Criticism==
An April 2018 GAO report said the total cost of the three Zumwalt destroyers, including research and development, was $24.5&nbsp;billion—an average of about $8&nbsp;billion per ship.<ref>{{Cite web |date=April 2018 |title=Weapons Systems Annual Assessment. GAO Report to Congressional Committees |url=https://www.gao.gov/assets/gao-18-360sp.pdf }}</ref>

Lawmakers and others questioned whether the ''Zumwalt'' class costs too much and whether it provides the capabilities that the military needs. In 2005, the Congressional Budget Office estimated the acquisition cost of a DD(X) at $3.8 billion to $4 billion in 2007 dollars, $1.1 billion more than the Navy's estimate.<ref>{{cite book|last=Gilmore |first=J. Michael |title=Statement on The Navy's DD(X) Destroyer Program before the Subcommittee on Projection Forces |url=http://www.cbo.gov/doc.cfm?index=6561 |date=19 July 2005 |publisher=US House of Representatives}}</ref> The National Defense Authorization Act For the Fiscal Year 2007 (Report of the Committee on Armed Services House of Representatives on H.R. 5122 Together With Additional And Dissenting Views) stated:
{{blockquote|The committee understands there is no prospect of being able to design and build the two lead ships for the $6.6&nbsp;billion budgeted. The committee is concerned that the navy is attempting to insert too much capability into a single platform. As a result, the DD(X) is now expected to displace more than 14,000 tons and by the navy's estimate, cost almost $3.3&nbsp;billion each. Originally, the Navy proposed building 32 next generation destroyers, reduced that to 24, then finally to 7 in order to make the program affordable. In such small numbers, the committee struggles to see how the original requirements for the next generation destroyer, for example providing naval surface fire support, can be met.<ref>{{cite web |url=https://www.gpo.gov/fdsys/pkg/CRPT-109hrpt452/pdf/CRPT-109hrpt452.pdf |title=National Defense Authorization Act for Fiscal Year 2007 : report of the Committee on Armed Services, House of Representatives, on H.R. 5122, together with additional and dissenting views (including cost estimate of the Congressional Budget Office) |date=5 May 2006 |publisher=US Government Publishing Office |access-date=15 February 2018 |archive-url=https://web.archive.org/web/20160327054053/https://www.gpo.gov/fdsys/pkg/CRPT-109hrpt452/pdf/CRPT-109hrpt452.pdf |archive-date=27 March 2016 |url-status=live}}</ref>}}

Mike Fredenburg analyzed the program for ''[[National Review]]'' after ''Zumwalt'' broke down in the [[Panama Canal]] in November 2016. He concluded that the ship's problems "are emblematic of a defense procurement system that is rapidly losing its ability to meet our national security needs."<ref name=Fredenburg>{{cite web |last1=FREDENBURG |first1=MIKE |title=How the Navy's Zumwalt-Class Destroyers Ran Aground |url=http://www.nationalreview.com/article/443165/zumwalt-class-navy-stealth-destroyer-program-failure |website=NationalReview.com |date=19 December 2016 |access-date=19 December 2016 |archive-url=https://web.archive.org/web/20161220215118/http://www.nationalreview.com/article/443165/zumwalt-class-navy-stealth-destroyer-program-failure |archive-date=20 December 2016 |url-status=live}}</ref> Fredenburg went on to detail problems relating to the skyrocketing costs, lack of accountability, unrealistic goals, a flawed concept of operations, the perils of designing a warship around stealth, and the failure of the Advanced Gun System. He concludes: 
{{blockquote|The ''Zumwalt'' is an unmitigated disaster. 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.<ref name=Fredenburg/>}}

===Ballistic missile/air defense capability===
[[File:USS Zumwalt is on the final leg of its three-month journey to its new homeport in San Diego. (31620613005).jpg|thumb|USS ''Zumwalt'' sailing alongside the [[littoral combat ship]] {{USS|Independence|LCS 2|6}} in 2016]]

In January 2005, [[John J. Young Jr.|John Young]], Assistant Secretary of the Navy for Research, Development, and Acquisition, was so confident of the DD(X)'s improved air defense over the ''Arleigh Burke'' class that between its new radar and ability to fire [[RIM-66 Standard|SM-1]], [[RIM-67 Standard|SM-2]], and [[SM-6]], "I don't see as much urgency for [moving to] CG(X)" – a dedicated air defense cruiser.<ref>{{cite journal|title=John Young – Assistant Secretary of the US Navy For Research, Development And Acquisition |url=http://www.chinfo.navy.mil/navpalib/.www/rhumblines/rhumblines634.doc |journal=Jane's Defence Weekly |date=12 January 2005 |url-status=dead |archive-url=https://web.archive.org/web/20090219085757/http://www.chinfo.navy.mil/navpalib/.www/rhumblines/rhumblines634.doc |archive-date=19 February 2009}}</ref>

On 31 July 2008, Vice Admiral Barry McCullough (Deputy Chief of Naval Operations for Integration of Resources and Capabilities) and Allison Stiller (Deputy Assistant Secretary of the Navy for Ship Programs) stated that "the DDG 1000 cannot perform area air defense; specifically, it cannot successfully employ the Standard Missile-2 (SM-2), SM-3 or SM-6 and is incapable of conducting Ballistic Missile Defense."<ref name="McCullough">{{cite book |last1=McCullough |first1=Vice Adm. Barry |last2=Stiller |first2=Allison |title=Statement on Surface Combatant Requirements and Acquisition Strategy |url=http://www.armedservices.house.gov/pdfs/SPEF073108/McCullough_Stiller_Testimony073108.pdf|date=31 July 2008 |publisher=House Armed Services Committee |url-status=dead |archive-url=https://web.archive.org/web/20081014000648/http://armedservices.house.gov/pdfs/SPEF073108/McCullough_Stiller_Testimony073108.pdf |archive-date=14 October 2008}}</ref> Dan Smith, president of Raytheon's Integrated Defense Systems division, has countered that the radar and combat system are essentially the same as other SM-2-capable ships, "I can't answer the question as to why the Navy is now asserting … that ''Zumwalt'' is not equipped with an SM-2 capability".<ref name="Navytimes080916">{{cite journal |last1=Cavas |first1=Christopher P |title=Troubled DDG 1000 faces shipyard problems |url=http://www.navytimes.com/news/2008/09/navy_zumwalt_091508w/ |date=16 September 2008 |journal=Navy Times}}</ref> The lack of anti-ballistic missile capability may represent a lack of compatibility with SM-2/SM-3. The ''Arleigh Burke''-class ships have BMD systems with their Lockheed-Martin AEGIS tracking and targeting software,<ref>{{cite web |url=http://www.mda.mil/system/aegis_bmd.html |title=Aegis Ballistic Missile Defense |publisher=U.S. Department of Defense Missile Defense Agency |date=7 March 2011 |access-date=2012-12-15 |url-status=dead |archive-url=https://web.archive.org/web/20140125154343/http://www.mda.mil/system/aegis_bmd.html |archive-date=25 January 2014}}</ref> unlike the DDG-1000's Raytheon TSCE-I targeting and tracking software,<ref name="TSCEI/GEFanuc" /> which does not, as it is not yet complete, so while the DDG-1000, with its TSCE-I combat system, does have the SM-2/SM-3 missile system installed, it does not yet have the BMD/IAMD upgrade planned for the derived CG(X).<ref name="ddg background" /> The Aegis system, on the other hand, was used in the [[Aegis Ballistic Missile Defense System]]. Since Aegis has been the Navy's chief combat system for the past 30 years, when the Navy started a BMD program, the combat system it was tested on was the Aegis combat system. So while the DDG-51 platform and the DDG-1000 platform are both SM-2/SM-3 capable, as a legacy of the Aegis Ballistic Missile Defense System, only the DDG-51 with the Aegis combat system is BMD capable. However, the DDG-1000's TSCE-I combat system had both BMD and IAMD upgrades planned. Combined with recent intelligence that China is developing targetable anti-ship ballistic missiles based on the [[DF-21]],<ref>{{cite book |title=Military Power of the People's Republic of China 2008 |url=http://www.defenselink.mil/pubs/pdfs/China_Military_Report_08.pdf|publisher=Office of the Secretary of Defense |page=2 (p12 of PDF) |access-date=12 October 2008 |archive-url=https://web.archive.org/web/20121012082939/http://www.defense.gov/pubs/pdfs/China_Military_Report_08.pdf |archive-date=12 October 2012 |url-status=live}}</ref><ref name="Chinese missile">{{cite journal |last1=Cavas |first1=Christopher P |url=http://www.defensenews.com/story.php?i=3657972 |title=Missile Threat Helped Drive DDG Cut |date=4 August 2008 |journal=DefenseNews}}{{dead link|date=August 2021|bot=medic}}{{cbignore|bot=medic}}</ref> this may be considered a fatal flaw.

On 22 February 2009, [[James "Ace" Lyons]], the former commander in chief of the U.S. Pacific Fleet, stated that the DDG-1000's technology was essential to a future "boost phase anti-ballistic missile intercept capability."<ref>{{cite news |url=http://www.washingtontimes.com/news/2009/feb/22/naval-shipbuilders-sinking/ |title=LYONS: Naval shipbuilders sinking |newspaper=The Washington Times|date=22 February 2009 |access-date=26 February 2009 |archive-url=https://web.archive.org/web/20090228054821/http://www.washingtontimes.com/news/2009/feb/22/naval-shipbuilders-sinking/ |archive-date=28 February 2009 |url-status=live}}</ref>

In 2010, the Congressional Research Service reported that the DDG-1000 could not currently be used for BMD because the BMD role was deferred to the DDG-1000 derived CG(X) program (the DDGs had the strike role, the CG had the BMD role, but they shared both the SM3 missile and the TSCE-I), the proposed radar of the CG(X) was much larger (22')<ref name="CG(X) Background">{{cite web |url=https://fas.org/sgp/crs/weapons/RL34179.pdf |title=Navy CG(X) Cruiser Program: Background for Congress |last=O'Rourke |first=Ronald |date=10 June 2010 |publisher=Congressional Research Service |access-date=4 April 2015 |archive-url=https://web.archive.org/web/20150924135809/http://www.fas.org/sgp/crs/weapons/RL34179.pdf |archive-date=24 September 2015 |url-status=live}}</ref> and used much more energy and cooling capacity than the DDG-1000's.<ref name="ddg background" /> Since then, the {{convert|22|ft|m|adj=on}} radar system has been canceled with the CG(X), and it has been determined that a {{convert|14|ft|m|adj=on}} radar could be used either on DDG 51-or DDG-1000, though it would not have the performance the Navy predicts would be needed "to address the most challenging threats".<ref name="CG(X) Background" /> Were the CG(X)'s BMD requirement adopted by the DDG-1000, the DDG-1000 would have to get the TSCE-I upgrade slated for the CG(X) to support that mission.<ref>{{cite web |url=http://opencrs.com/document/RL33745/2010-04-08/?24749 |title=CRS RL33745 Navy Aegis Ballistic Missile Defense (BMD) Program: Background and Issues for Congress 8 April 2010 |publisher=Opencrs.com |access-date=2014-06-15 |archive-url=https://web.archive.org/web/20110716022902/http://opencrs.com/document/RL33745/2010-04-08/?24749 |archive-date=16 July 2011 |url-status=live}}</ref>

The study that showed a cost benefit to building Flight III ''Arleigh Burke''-class destroyer with enhanced radars instead of adding BMD to the ''Zumwalt''-class destroyers assumed very few changes from the Flight II to III ''Burke''s. However, costs for the Flight III ''Burke''s have increased rapidly "as the possible requirements and expectations continue to grow."<ref>{{cite web |last=Fabey |first=Michael |url=http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=defense&id=news/asd/2011/06/10/01.xml |title=Potential DDG-51 Flight III Growth Alarms |website= Aviation Week |date=10 June 2011}} {{dead link|date=April 2016}}</ref> While the Flight III design and costs have been studied by the Navy, there is very little reliable data available on the cost of modifying a DDG-1000–class ship to provide a BMD capability. However, if the Air Missile Defense Radar is adopted in common on both the Flight III ''Burke''s and the ''Zumwalt''s, and if they were both upgraded to the same combat system, then the only limitation of the ''Zumwalt''s in this role would be their limited missile magazines.{{verify source|Text not directly supported by reference. Reword to follow source or change references.|date=November 2013}}<ref>{{cite web |last=Cavas |first=Christopher P. |url=http://www.defensenews.com/article/20100604/DEFSECT04/6040314/Axing-DDG-1000-Radar-May-Save-Cash-Enable-BMD |archive-url=https://archive.today/20130121135553/http://www.defensenews.com/article/20100604/DEFSECT04/6040314/Axing-DDG-1000-Radar-May-Save-Cash-Enable-BMD |url-status=dead |archive-date=21 January 2013 |title=Axing DDG 1000 Radar May Save Cash, Enable BMD |website= Defense News |date=4 June 2010}}</ref>

With the awarding of the development contract to the next generation Air and Missile Defense S-Band Radar to Raytheon, deliberation to put this radar on the ''Zumwalt''-class destroyer is no longer being actively discussed.<ref>{{cite web|url=http://www.defensenews.com/article/20131010/DEFREG02/310100022/ |archive-url=https://archive.today/20131104183224/http://www.defensenews.com/article/20131010/DEFREG02/310100022/ |url-status=dead |archive-date=4 November 2013 |title=Raytheon Wins Key US Navy Radar Competition |website= Defense News |first=Christopher P. |last=Cavas |date=10 October 2013 |access-date=2014-06-15}}</ref>

It is possible for the ''Zumwalt''-class destroyers to get the more limited BMD hardware and software modifications that would allow them to use their existing SPY-3 radar and Cooperative Engagement Capability to utilize the SM-3 missile and have a BMD capability similar to the BMD-capable {{sclass|Ticonderoga|cruiser}}s and ''Arleigh Burke''-class Flight IIA destroyers. Procurement of a BMD-specific version of the ''Zumwalt''-class destroyer was also proposed.<ref name="ddg background" /><ref>{{cite web |url=http://www.defenseindustrydaily.com/the-us-navys-dual-band-radars-05393/ |title=The US Navy's Dual Band Radars |work=Defense Industry Daily |date=2013-10-01 |access-date=2014-06-15 |archive-url=https://web.archive.org/web/20131112034338/https://www.defenseindustrydaily.com/the-us-navys-dual-band-radars-05393/ |archive-date=12 November 2013 |url-status=live}}</ref>

''Zumwalt'' PLAS cells can launch the SM-2 Standard missile, but the ships have no requirement for ballistic missile defense. The tubes are long and wide enough to incorporate future interceptors, and although the ship was designed primarily for littoral dominance and land attack, Raytheon contended that they could become BMD-capable with few modifications.<ref name="dodbuzz16april12" />

===Missile capacity===
The original DD-21 design would have accommodated between 117 and 128 VLS cells. However, the final DDG-1000 design provides only 80 cells.<ref name="NGSS">{{cite web|url=http://www.ddg1000.com/overview/ddg1000_brief.php |title=DDG 1000 Flight I Design |year=2007 |publisher=Northrop Grumman Ship Systems |archive-url=https://web.archive.org/web/20070915203606/http://www.ddg1000.com/overview/ddg1000_brief.php |archive-date=15 September 2007}}</ref> ''Zumwalt'' uses Mk 57 Peripheral Vertical Launching System (PVLS) cells, which are larger than the [[Mark 41 Vertical Launching System|Mk 41]] cells found on most American destroyers.

Each VLS cell can be quad packed with [[RIM-162 ESSM|RIM-162 Evolved SeaSparrow Missiles (ESSM)]]. This gives a maximum theoretical load of 320 ESSM missiles. The ESSM is considered a point defense weapon not generally used for fleet area defense.

The ''Zumwalt''-class destroyer is not an Aegis system. It instead uses the class-unique Total Ship Computing Environment Infrastructure (TSCEI) integrated mission system. The Mk 57 PVLS is capable of accommodating all Standard missile types.<ref>{{cite web |url=https://www.navalengineers.org/flagship/meetings/Documents/Downey_DDG1000_4-17-13.pdf |title=DDG1000_ASNE_Program_Overview_04.17.13|access-date=2014-06-15 |url-status=dead |archive-url=https://web.archive.org/web/20131112144815/https://www.navalengineers.org/flagship/meetings/Documents/Downey_DDG1000_4-17-13.pdf |archive-date=12 November 2013}}</ref> It has not been publicly stated if the TSCE will be modified to support the Standard missile or the ballistic missile defense mission.

===Naval fire support role===
{{main|United States battleship retirement debate}}

The design concept for the ''Zumwalt'' class developed from the "Land Attack Destroyer (DD 21)" development effort. A primary goal for DD 21 was to provide sea-based fire support for on-shore troops as part of the force mix that would replace the retiring {{sclass|Iowa|battleship|1}}s as mandated by Congress. There was considerable skepticism that the ''Zumwalt'' class could succeed in this role.
{{blockquote|In summary, the committee is concerned that the navy has foregone the long range fire support capability of the battleship, has given little cause for optimism with regard to meeting near-term developmental objectives, and appears unrealistic in planning to support expeditionary warfare in the mid-term. The committee views the navy's strategy for providing naval surface fire support as 'high risk', and will continue to monitor progress accordingly.|Evaluation of the United States Navy's naval surface fire support program in the [[National Defense Authorization Act]] of 2007|<ref name="NDAA 2007">{{cite web|url=http://www.gpoaccess.gov/serialset/creports/pdf/hr109-452/title2.pdf |title=National Defense Authorization Act of 2007 |access-date=7 November 2008|page=194 |url-status=dead |archive-url=https://web.archive.org/web/20080923200449/http://www.gpoaccess.gov/serialset/creports/pdf/hr109-452/title2.pdf |archive-date=23 September 2008}}</ref>}}

The ''Zumwalt'' class was intended to provide [[Naval gunfire support|naval surface fire support]] (NSFS) using the AGS and additional land attack using Tomahawk missiles from its PVLS launchers. As deployed, the ''Zumwalt'' class cannot provide NSFS since there are only 90 rounds of ammunition available that are compatible with the AGS in total.<ref name="auto"/> The ''Zumwalt'' class were re-purposed as surface attack vessels and are no longer intended for use as land attack destroyers.

===Tumblehome design stability===
[[File:US Navy 050823-N-7676W-052 The Advanced Electric Ship Demonstrator (AESD), Sea Jet, funded by the Office of Naval Research (ONR), is a 133-foot vessel located at the Naval Surface Warfare Center Carderock Division.jpg|thumb|left|''Sea Jet'' out of the water and showing the unique hull design]]

The stability of the DDG-1000 hull design in heavy seas has been a matter of controversy. In April 2007, naval architect Ken Brower said, "As a ship pitches and heaves at sea, if you have tumblehome instead of a flare, you have no righting energy to make the ship come back up. On the DDG 1000, with the waves coming at you from behind, when a ship pitches down, it can lose transverse stability as the stern comes out of the water – and basically, roll over."<ref>{{cite web |url=http://www.defenseindustrydaily.com/2007/04/defense-news-will-ddg1000-destroyers-be-unstable/index.php |title=Will DDG-1000 Destroyers Be Unstable? |date=12 April 2007 |work=Defense Industry Daily |access-date=23 April 2007 |archive-url=https://web.archive.org/web/20070427085350/http://www.defenseindustrydaily.com/2007/04/defense-news-will-ddg1000-destroyers-be-unstable/index.php |archive-date=27 April 2007 |url-status=dead |postscript=,}} quoting {{cite journal |first=Christopher P |last=Cavas |title=Is New U.S. Destroyer Unstable? |date=2 April 2007 |journal=DefenseNews}}</ref> The Navy had decided not to use a tumblehome hull in the CG(X) cruiser before the program was canceled, which may suggest that there were concerns regarding ''Zumwalt''{{'}}s seakeeping abilities.<ref name="Chinese missile" /> However, the tumblehome hull proved seaworthy in a 1/4-scale test of the hull design named ''[[Sea Jet]]''.

''Sea Jet'', funded by the Office of Naval Research (ONR), is a 133-foot (40-meter) vessel located at the [[Naval Surface Warfare Center Carderock Division]], Acoustic Research Detachment in [[Bayview, Idaho]]. ''Sea Jet'' was operated on [[Lake Pend Oreille]], where it was used to test and demonstrate various technologies. Among the first technologies tested was an underwater discharge waterjet from [[Rolls-Royce plc|Rolls-Royce]] Naval Marine, Inc. called AWJ-21.

While underway during the spring of 2019, USS ''Zumwalt'' sailed through a storm causing [[Sea state|sea state six]] (maximum wave height between {{convert|13|ft|m|spell=in}} and {{convert|20|ft|m|spell=in}}) conditions off the coast of Alaska. The test indicated that the ''Zumwalt'' class possesses greater stability compared to typical hull forms. During an interview, Captain Andrew Carlson, the commanding officer of USS ''Zumwalt'' at the time, related, "All told I'd rather be on that ship than any other ship I've been on." According to Captain Carlson, during the storm, he summoned his executive officer from his cabin to inform him of the sea state six conditions. Based on the rolls he had been experiencing in his cabin, the executive officer thought that, at most, they were at sea state three, where wave height only reaches a maximum of {{convert|4|ft|m|spell=in}}. A combination of the ''Zumwalt'' class's hull form, rudder stop locations, and propeller size contribute to its improved seakeeping.<ref>{{cite web |last1=Larter |first1=David |title=Here's how the destroyer Zumwalt's stealthy design handles stormy seas |url=https://www.defensenews.com/naval/2020/01/23/heres-how-the-ddg-1000s-stealthy-hull-design-handles-stormy-seas/ |website=Defense News |date=23 January 2020 |access-date=28 January 2020}}</ref>

===Secondary guns===
In 2005, a Critical Design Review (CDR) of the DDG-1000 led to the selection of the [[Bofors 57 mm Naval Automatic Gun L/70|Mk 110]] {{convert|57|mm|in|abbr=on}} cannon to defend the destroyer against swarming attacks by small, fast boats; the Mk 110 has a rate of fire of 220 rpm and a range of {{convert|9|nmi|abbr=on}}. From then to 2010, various analysis efforts were conducted to assess potential cost-saving alternatives. Following a 2012 assessment using the latest gun and munition effectiveness information, it was concluded that the [[Mk44 Bushmaster II|Mk 46 {{convert|30|mm|in|abbr=on}} Gun System]] was more effective than the Mk 110 with increased capability, reduced weight, and significant cost avoidance. The Mk 46 has a rate of fire of 200 rpm and a range of {{convert|2.17|nmi|abbr=on}}.<ref name="usni5aug14" />

Naval experts have questioned the decision to replace the close-in swarm defense guns of the ''Zumwalt''-class destroyers with ones of decreased size and range. The 57&nbsp;mm can engage targets at two to three miles, while the 30&nbsp;mm can only start to engage at around one mile. However, the DDG-1000 program manager said that the 57&nbsp;mm round's lethality was "significantly over-modeled" and "not as effective as modeled" in live test-firing, and "nowhere near meeting the requirements"; he admitted that the results were not what he expected to see. When the [[Naval Weapons Laboratory]] re-evaluated the Mk 46, it met or exceeded requirements and performed equal to or better than the 57&nbsp;mm in multiple areas, even coming just ahead of the {{convert|76|mm|in|abbr=on|0}} naval cannon. A 30&nbsp;mm gun mount also weighs less, around 2 tons compared to 12–14 tons for the 57&nbsp;mm, but the Navy is adamant that weight had nothing to do with the decision.<ref>{{cite web |url=http://www.defensenews.com/article/20141012/DEFREG02/310120010/Experts-Question-US-Navy-s-Decision-Swap-Out-DDG-1000-s-Secondary-Gun |archive-url=https://archive.today/20141018192310/http://www.defensenews.com/article/20141012/DEFREG02/310120010/Experts-Question-US-Navy-s-Decision-Swap-Out-DDG-1000-s-Secondary-Gun |url-status=dead |archive-date=18 October 2014 |title=Experts Question US Navy's Decision To Swap Out DDG 1000's Secondary Gun |website= Defense News |last=Cavas |first=Christopher P. |date=12 October 2014}}</ref>

==See also==
* [[List of naval ship classes in service]]

==References==

===Citations===
{{Reflist|colwidth=30em|refs=
<ref name="global_dd-x">{{cite web |url=http://www.globalsecurity.org/military/systems/ship/dd-x.htm |title=DDG-1000 Zumwalt / DD(X) Multi-Mission Surface Combatant |date=1 September 2008 |website=globalSecurity.org |access-date=29 July 2004 |archive-url=https://web.archive.org/web/20161224090549/http://www.globalsecurity.org/military/systems/ship/dd-x.htm |archive-date=24 December 2016 |url-status=live}}</ref>
<ref name="CNN2014">{{cite news |url=http://www.cnn.com/2014/06/14/tech/zumwalt-operations-center |title=Navy's stealth destroyer designed for the video gamer generation |first1=Thom |last1=Patterson |first2=Brad |last2=Lendon |publisher=CNN |date=14 June 2014 |access-date=29 October 2014 |archive-url=https://web.archive.org/web/20141010211012/http://www.cnn.com/2014/06/14/tech/zumwalt-operations-center |archive-date=10 October 2014 |url-status=live}}</ref>
}}

===Sources===
{{Refbegin}}
* Army Regulations 600-8-27 dated 2006
* {{cite book |last=Forczyk |first=Robert |title=Russian Battleship vs Japanese Battleship, Yellow Sea 1904–05 |date=2009 |publisher=Osprey |isbn=978-1-84603-330-8}}
{{Refend}}

==Further reading==
*{{citation | first= Anthony | last= Capaccio | title= Navy's $7.8 billion destroyer due for delivery 5 years late | website= [[Bloomberg News]] | date= 27 March 2019 | url= https://www.bloomberg.com/news/articles/2019-03-27/navy-s-7-8-billion-destroyer-now-due-for-delivery-5-years-late}}

==External links==
{{Wikiquote}}
{{Commons category|Zumwalt class destroyer}}
* [https://web.archive.org/web/20070501063525/http://www.raytheon.com/products/ddg_1000/ Raytheon's official DDG 1000 Program web page]
* [http://www.navweaps.com/Weapons/WNUS_61-62_ags.htm Advanced Gun System set to be installed on the DD(X) destroyers]
* [https://fas.org/man/dod-101/sys/ship/weaps/docs/C1031.htm Concept of employment for naval surface fire support (near term capability)]
* {{cite web |first=Mackenzie |last=Eaglen |title=Changing Course on Navy Shipbuilding: Questions Congress Should Ask Before Funding |url=http://www.heritage.org/Research/NationalSecurity/bg2193.cfm |date=7 October 2008 |publisher=The Heritage Foundation |url-status=unfit |archive-url=https://web.archive.org/web/20081010075538/http://www.heritage.org/Research/NationalSecurity/bg2193.cfm |archive-date=10 October 2008}}

{{Zumwalt class destroyer}}
{{Active ship classes of the United States Navy}}

[[Category:Destroyer classes]]
[[Category:Zumwalt-class destroyers| ]]
[[Category:Stealth ships]]