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Tuesday, October 29, 2013

Zumwalt-class destroyer

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Uss Zumwalt.jpg
Artist rendering of the Zumwalt-class destroyer
Class overview
Name: Zumwalt
Builders: Huntington Ingalls, Bath Iron Works
Operators:  United States Navy
Preceded by: Arleigh Burke-class destroyer
Cost: US$3.45 billion (unit cost),[1] US$7.0 billion (total unit cost including R&D)[2]
In commission: March 2015 (forecast)[3]
Planned: USS Zumwalt,
USS Michael Monsoor,
USS Lyndon B. Johnson
General characteristics
Class & type: Zumwalt
Type: Multi-mission destroyer, emphasis on land attack
Displacement: 14,564 long tons (14,798 t)[4]
Length: 600 ft (180 m)
Beam: 80.7 ft (24.6 m)
Draft: 27.6 ft (8.4 m)
Propulsion: 2 Rolls-Royce Marine Trent-30 gas turbines driving Curtiss-Wright generators[5] and emergency diesel generators, 78 MW (105,000 shp); 2 propellers driven by electric motors
Speed: In excess of 30 kn (56 km/h; 35 mph)
Complement: 140
Sensors and
processing systems:
AN/SPY-3 Multi-Function Radar (MFR) (X-band, scanned array)[6]
Armament: • 20 × MK 57 VLS modules, with a total of 80 launch cells[7]
RIM-162 Evolved Sea Sparrow Missile (ESSM), 4 per cell
Tactical Tomahawk, 1 per cell
Vertical Launch Anti-Submarine Rocket (ASROC), 1 per cell
• 2 × 155 mm/62 caliber Advanced Gun System
920 × 155 mm rounds total; 600 in automated store + Auxiliary store room with up to 320 rounds (non-automatic) as of April 2005
70–100 LRLAP rounds planned as of 2005 of total
• 2 × Mk 110 57 mm gun (CIGS)
Aircraft carried: • One SH-60 LAMPS helicopter or MH-60R helicopter
• Three MQ-8 Fire Scout VT-UAVs[4]
Aviation facilities: Flight deck and enclosed hangar for up to two medium-lift helicopters
The Zumwalt-class destroyers are a planned class of United States Navy destroyers, designed as multi-mission ships with a focus on land attack. The class is a scaled-back project that emerged after funding cuts to the larger DD-21 vessel program. The program was previously known as the "DD(X)". The class is multi-role and designed for surface warfare, anti-aircraft, and naval fire support. They take the place of battleships in filling the former congressional mandate for naval fire support,[8] though the requirement was reduced to allow them to fill this role. The vessels' appearance has been compared to that of the historic ironclad warship.[9]
The class has a low radar profile; an integrated power system, which can send electricity to the electric drive motors or weapons, which may some day include a railgun[10] or free-electron lasers;[11] total ship computing environment infrastructure, serving as the ship's primary LAN and as the hardware-independent platform for all of the ship's software ensembles; automated fire-fighting systems and automated piping rupture isolation. The class is designed to require a smaller crew and be less expensive to operate than comparable warships. It will have a wave-piercing tumblehome hull form whose sides slope inward above the waterline. This will reduce the radar cross-section, returning much less energy than a more hard-angled hull form. As of January 2009, the Government Accountability Office (GAO) found that only four out of 12 of the critical technologies were mature.[12]
The lead ship will be named Zumwalt for Admiral Elmo Zumwalt, and carries the hull number DDG-1000. Originally 32 ships were planned, with the $9.6 billion research and development costs spread across the class, but as the quantity was reduced to 10, then 3, the cost-per-ship increased dramatically.[13][14] The cost increase caused the U.S. Navy to identify the program as being in breach of the Nunn–McCurdy Amendment on 1 February 2010.[15][16]

History

Background and funding

Many of the features were developed under the DD21 program ("21st Century Destroyer"), which was originally designed around the Vertical Gun for Advanced Ships (VGAS, see below). In 2001, Congress cut the DD-21 program by half as part of the SC21 program; to save it, the acquisition program was renamed as 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.[13] On 23 November 2005, the Defense Acquisition Board approved a plan for simultaneous construction of the first two ships at Northrop’s 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 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.[13] However, this was increased to two ships by the 2007 appropriations bill[17] approved in September 2006, which allotted US$2,568m to the DDG-1000 program.[18]
On 31 July 2008, U.S. Navy acquisition officials told Congress that the service needed to purchase more Arleigh Burke-class destroyers, and no longer needs the next-generation DDG-1000 class,[19] Only the two approved destroyers would be built. The navy said the world threat picture had changed in such a way that it now makes more sense to build at least eight more Burkes, rather than DDG-1000s.[19] The navy concluded from fifteen classified intelligence reports that the DDG-1000s would be vulnerable to forms of missile attacks.[20] Many Congressional subcommittee members appeared incredulous that the navy could have conducted such a sweeping re-evaluation of the world threat picture in just a few weeks, after spending some 13 years and $10 billion on the surface ship program known as DD-21, then DD(X) and finally, DDG-1000. That figure does not include the money spent for the two hulls (DDG-1000 and DDG-1001).[19] Subsequently Chief of Naval Operations Gary Roughead has 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.[21] The mooted structural problems have not been discussed in public. Navy Secretary Donald Winter said on 4 September that "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".[22]
On 19 August 2008, Secretary Winter was reported as saying that a third Zumwalt would be built at Bath Iron Works, citing concerns about maintaining shipbuilding capacity.[23] 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.[24]
A 26 January 2009 memo from John Young, the US DoD's top acquisition official, stated that the per ship price for the Zumwalt-class destroyers had reached $5.964 billion, 81 percent over the Navy's original estimate used in proposing the program. If true, that means that the program has breached the Nunn–McCurdy Amendment, requiring the Navy to recertify and rejustify the program to Congress.[25]
On 6 April 2009, Defense Secretary Robert Gates announced that DoD's proposed 2010 budget will end the DDG-1000 program at a maximum of three ships.[26] Also 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. The first DDG-1000 destroyer is expected to cost $3.5 billion, the second is to cost approximately $2.5 billion, and the third even less.[27]
What had once been seen as the backbone of the navy's future surface fleet[28] with a planned production run of 32, has since been replaced by destroyer production reverting to the Arleigh Burke class after ordering three Zumwalts.[29] The Zumwalt's failure[30] is a result of a negative feedback loop of spiraling costs and plummeting productions numbers described by Chuck Spinney as the death spiral, joining other projects such as the F-22, and Future Combat System.[31]

Construction


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 is the Mission Systems Integrator. Both Northrop Grumman Ship Systems and General Dynamics Bath Iron Works share dual-lead for the hull, mechanical, and electrical detailed design. BAE Systems Inc. has the advanced gun system and the MK57 VLS. Almost every major defense contractor (including Lockheed Martin, Northrop Grumman Sperry Marine, L-3 Communications) and subcontractors from nearly every state in the U.S. are involved to some extent in this project, which is the largest single line item in the Navy's budget. During the previous contract, 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, 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.[17]
Northrop Grumman was awarded a $90M contract modification for materials and production planning on 13 November 2007.[32] On 14 February 2008, Bath Iron Works was awarded a contract for the construction of the USS Zumwalt (DDG-1000), and Northrop Grumman Shipbuilding was awarded a contract for the construction of USS Michael Monsoor (DDG-1001), at a cost of $1.4 billion each.[33]
On 11 February 2009, full-rate production officially began on the first Zumwalt-class destroyer.[34] Construction on the second ship of the class, Michael Monsoor, began in March 2010.[35] The keel for the first Zumwalt-class destroyer was laid on 17 November 2011.[35][36]

USS Zumwalt (DDG-1000) deckplate in transit on 6 November 2012
The construction timetable in July 2008 was:[3]
  • October 2008: DDG-1000 starts construction at Bath Iron Works
  • September 2009: DDG-1001 starts construction at Ingalls
  • April 2012: DDG-1002 starts construction at Bath Iron Works[37]
  • April 2013: DDG-1000 initial delivery
  • May 2014: DDG-1001 delivery
  • March 2015: Initial operating capability
  • Fiscal 2018: DDG-1002 delivery

Names and hull numbers

In April 2006, the navy announced plans to name the first ship of the class Zumwalt after former Chief of Naval Operations Admiral Elmo R. "Bud" Zumwalt Jr.[3] Its hull number will be DDG-1000, which abandons the guided missile destroyer sequence used by the Arleigh Burke-class destroyers (DDG-51– ), and continues the previous "gun destroyer" sequence from the last of Spruance-class, USS Hayler (DD-997).
DDG-1001 will be named for Master-at-Arms 2nd Class (SEAL) Michael A. Monsoor, the second SEAL to receive the Medal of Honor in the Global War on Terror (GWOT), the navy announced on 29 October 2008.[38]
On 16 April 2012, the Secretary of the Navy Ray Mabus announced that DDG-1002 will be named for former naval officer and U.S. President, Lyndon B. Johnson.[39]
There is an active civilian campaign to persuade the Secretary of the Navy to name one of the class the USS Robert A. Heinlein.[40]

Design elements


Planned features of the DDG-1000

Stealth

Despite being 40% larger than an Arleigh Burke-class destroyer the radar signature is more akin to a fishing boat and sound levels are compared to the Los Angeles-class submarines. The tumblehome hull reduces radar return and the composite material deckhouse also has a low radar return. Water sleeting along the sides, along with passive cool air induction in the mack reduces thermal emissions.[41] In January 2013, the Navy solicited bids for a steel deckhouse as an option for DDG-1002.[42][43]

Tumblehome wave piercing hull

A return to a hull form not seen since the Russo-Japanese War in 1905, the Zumwalt-class destroyer reintroduces the tumblehome hull form. Originally put forth in modern steel battleship designs by the French shipyard Forges et Chantiers de la Mediterranee in La Seyne in Toulon, French naval architects believed that tumblehome, in which the beam of the vessel narrowed from the water-line 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 (canals).[44] On the down side, the tumblehome battleships experienced stability problems, especially in high speed turns or losses in watertight integrity.[45] 21st century tumblehome is being reintroduced to reduce the radar return of the hull. The bow is designed to cut through waves rather than ride over them.[41][46] As mentioned above, the stability of this hull form in high sea states has caused debate among naval architects. The tumblehome has not featured in USN concept designs since the Zumwalt class.

Advanced Gun System

There has been research on extending the range of naval gunfire for many years. Canadian engineer Gerald Bull and Naval Ordnance Station Indian Head tested an 11 inch sub-caliber saboted long-range round[47] in a stretched 16-inch/45 Mark 6 battleship gun in 1967.[48] The Advanced Gun Weapon System Technology Program (AGWSTP) evaluated a similar projectile with longer range in the 1980s.[47] After the battleships were decommissioned in 1992, the AGWSTP became a 5-inch gun with an intended range of 180 kilometers (110 mi), which then led to the Vertical Gun for Advanced Ships (VGAS). The original DD-21 was designed around this "vertical gun", but the project ran into serious technology/cost problems and was radically scaled back to a more conventional 6.1 inch Advanced Gun System (AGS). One advantage of this move was that the gun was no longer restricted to guided munitions.
The Advanced Gun System is a 155 mm naval gun, two of which would be installed in each ship. This system consists of an advanced 155 mm gun and the Long Range Land Attack Projectile.[49] This projectile is in fact a rocket with a warhead fired from the AGS gun; the warhead weighs 11 kg / 24 lb and has a circular error of probability of 50 meters. This weapon system will have a range of 83 nautical miles (154 km) and the fully automated storage system will have room for up to 750 rounds.[41][49] The barrel is water-cooled to prevent overheating and allows a rate of fire of 10 rounds per minute per gun. The combined firepower from a pair of turrets gives each Zumwalt-class destroyer firepower equivalent to 12 conventional M198 field guns.[50]
In order to provide sufficient stability to fire these guns, the Zumwalt will use ballast tanks to lower itself into the water.[51]

Peripheral Vertical Launch System (PVLS)

The Peripheral Vertical Launch System is an attempt to reclaim the prized center space of the hull while increasing the safety of the ship from the loss of the entire missile battery and the loss of the ship in the case of a magazine explosion. The system scatters pods of VLS around the outer shell of the ship having a thin steel outer shell and a thick inner shell. The design of the PVLS would direct the force of the explosion outward rather than ripping the ship in half. Additionally this design keeps the loss of missile capacity down to just the pod being hit.[41][52]

Boat and helicopter arrangements

Two spots will be available on a large aviation deck while boat handling is to be dealt within a stern mounted boat hangar with ramp. The boat hangar’s stern location meets high sea state requirements for boat operations.[41]

Dual-band radar

Originally, the AN/SPY-3 Active Electronically Scanned Array primarily X-band radar (high altitude near airspace) was to be married with Lockheed Martin's SPY-4 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 beams give it an excellent ability to focus in on targets. SPY-3 will be the primary DBR radar used for missile engagements.[53] On 2 June 2010 Pentagon acquisition chief Ashton Carter announced that they will be removing the SPY-4 S-band Volume Search Radar from the DDG 1000's dual-band radar. The new radar is believed to be the Air Missile Defense Radar (AMDR), a system in early development.[54] The AMDR will provide multi-mission capabilities, supporting both long range, exoatmospheric detection, tracking and discrimination of ballistic missiles, as well as Area and Self Defense against air and surface threats. For the Ballistic Missile Detection capability, increased radar sensitivity and bandwidth over the current SPY system is needed to detect, track and support the SPY-3's engagements of advanced ballistic missile threats at the required ranges. For the Area Air Defense and Self Defense capability, increased sensitivity and clutter rejection capability is needed to detect, react to, and engage stressing Very Low Observable / Very Low Flyer (VLO/VLF) threats in the presence of heavy land, sea, and rain clutter.[55] Each band will have its own signal processors, with the returns combined by the display sensor manager.[56] This system is thought to provide high detection and excellent anti-jamming capabilities.[41] But at least one report by Congress' investigative arm, the GAO, raises concerns that it is too much of a technology leap.[5]

Sonar

A dual-band sonar controlled by a highly automated computer system will be used to detect mines and submarines. It is claimed that it is superior to the Burke's sonar in littoral ASW, but less effective in blue water/deep sea areas.[57]
  • 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)[58]

Propulsion

The DDX proposed to use a Permanent Magnet Motor (PMM) within the hull. 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 is considered to be another technology leap and is the cause of some concern (along with the radar system) from Congress.[41] As part of the design phase, Northrop Grumman had built the world's largest permanent magnet motor, designed and fabricated by DRS Technologies. This proposal was dropped when the PMM motor failed to demonstrate that it was ready to be installed in time.
Zumwalt will have Converteam's Advanced Induction Motors (AIM), rather than DRS Technologies' Permanent Magnet-Synchronous Motors (PMM).
"...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"..."[59]

Integrated Power System (IPS)

The Integrated Power System (IPS) is, in some ways, similar to the old turbo-electric drive, the addition of PMMs and integration of all electrical power systems gives ten times the power available on current destroyers. It also reduces the ship's thermal and sound signature. The IPS has added to weight growth in the Zumwalt-class destroyer as noted by the GAO.[5]

Automation

Automation will reduce crew size on these ships. A smaller crew will reduce a major component of operating costs.[41] 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.[41]
Water spray or mist systems are proposed for deployment in the Zumwalt-class destroyer but the electronic spaces remains problematic to the designers. Halon/Nitrogen dump systems are preferred but do not work when the space has been compromised by a hull breach. The GAO has noted this system as a potential problem yet to be addressed.[41][60]

Computer network

The Total Ship Computing Environment Infrastructure (TSCEI) is based on GE Fanuc Embedded Systems' PPC7A and PPC7D single-board computers[61] running LynuxWorks' LynxOS RTOS.[62] These are contained in 16 shock, vibration and electromagnetic protected Electronic Modular Enclosures.[63]

Controversy

Lawmakers and others have questioned whether the Zumwalt class costs too much and whether it provides the capabilities the U.S. military needs. In 2005 the Congressional Budget Office estimated the acquisition cost of a DD(X) at $3.8–4.0bn in 2007 dollars, $1.1bn more than the navy's estimate.[64]
The 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) stated the following: “The committee understands there is no prospect of being able to design and build the two lead ships for the $6.6 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 over 14,000 tons and by the Navy’s estimate, cost almost $3.3 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.”[citation needed]
Concerns have been raised about the design. These are described below.

Ballistic missile/air defense capability

In January 2005, 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 Burke class that between its new radar and ability to fire SM-1, SM-2, and SM-6, "I don't see as much urgency for [moving to] CG(X)" – a dedicated air defense cruiser.[65]
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."[57] 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".[22] 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,[66] unlike the DDG-1000's Raytheon TSCE-I targeting and tracking software,[61] 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).[29] The Aegis system, on the other hand was used in the Aegis Ballistic Missile Defense System. Since the Aegis system 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/SM3 capable, as a legacy of the Aegis Ballistic Missile Defense System only the DDG-51 with the Aegis combat system is BMD capable, although the DDG-1000's TSCE-I combat system had both BMD and IAMD upgrades planned. And in view of recent intelligence that China is developing targetable anti-ship ballistic missiles based on the DF-21,[67][68] this could be 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".[69]
In 2010, the Congressional Research Service reported that the DDG-1000 cannot currently be used for BMD because the BMD role was deferred to the DDG-1000 derived CG(X) program (The DDG's 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')[70] and used much more energy and cooling capacity than the DDG-1000's.[29] Since then, the 22' radar system has been canceled with the CG(X) and it has been determined that a 14' radar could be used either on DDG-51 or on DDG-1000, though it would not have the performance the Navy predicts would be needed "to address the most challenging threats".[70] 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.[71]
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 limited changes from the Flight II to the Flight III Burkes. However costs for the Flight III Burkes have increased rapidly "as the possible requirements and expectations continue to grow."[72] While the Flight III design and costs have been studied by the Navy, there is very little reliable data available on what the cost would be to modify 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 Burkes and the Zumwalts and if they were both upgraded to the same combat system then the only limitation of the Zumwalts in this role would be their limited missile magazines.[73]

Missile capacity

The original DD21 design, displacing around 16,000 tons, would have accommodated between 117 and 128 VLS cells.[74] However, the final DDG-1000 design was considerably smaller than that of the DD21, resulting in room for only 80 VLS cells.[75] Given the vessel's expected role, the Zumwalt-class destroyers will likely carry many more Tomahawk missiles than either the Ticonderoga- or Arleigh Burke-class ships.

Naval fire support role

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.
A controversial point of the DD(X) destroyer(s) is their planned naval surface fire support (NSFS) role. The original DD21 and the Arsenal Ship had more serious NSFS capabilities, which would meet a Congress-mandated requirement related to the Iowa-class battleships. The requirement was eventually relaxed, the battleships stricken from the registry, and the navy left with small tonnage ships for NSFS or alternative methods such as air support. The official position of the U.S. Marine Corps and the U.S. Navy is that the Zumwalt-class destroyer(s) will be adequate as naval surface gunfire support ships, although there are dissenters.[76]

AGS being fired in September 2009 to test a new coating intended to extend barrel life at Dugway Proving Ground, Utah
While smaller caliber guns (and missiles) have been used for centuries in naval fire support, very large guns have special capabilities beyond that of mid-range calibers. US battleships were re-activated three times after WWII specifically for naval fire support, and their 16 inch gunfire was used in every major engagement of the U.S. from WWII through Operation Desert Storm in January/February 1991.[77] The Zumwalt class will have two 6.1 inch (155 mm) guns with limited ammunition. The ships will fire a specially designed "guided" artillery shell some 63 nautical miles (117 km) inland.[78] However, this shell has a reduced warhead size and uses new technology, so most of the shells carried on the DDG would have vastly shorter range.[citation needed]
In March 2006, the Iowa and Wisconsin were struck from the Naval Vessel Register, having been kept on in part to fill a naval fire support role. However, Congress was "deeply concerned" over the loss of naval surface gunfire support they could provide and noted that "navy efforts to improve upon, much less replace, this capability have been highly problematic",[79] The U.S. House of Representatives asked that the battleships be kept in a state of readiness should they ever be needed again[80] and directed the navy to increase the number of Arleigh Burke-class destroyers that are currently being modernized.[80] The modernization includes extending the range of the 5-inch guns on the Flight 1 ships with extended range guided munitions (ERGMs) that would enable the ships to fire projectiles about forty nautical miles inland;[81][82] However the ERGM was canceled after it failed firing tests in February 2008.[83] The Navy is studying future options for naval fire support; Alliant Techsystems’ ballistic trajectory extended range munition may be one possibility.[83] Adapting the 155 mm LRLAP to the 5"/54 Mk 45 gun is another option the navy is pursuing with BAE and Lockheed Martin as contractors.

Structural problems

The Zumwalt has a deckhouse made from composite material which encloses much of the sensors and electronics.[84] In 2008, Defense News reported there had been problems sealing the composite construction panels of this area, but Northrop Grumman has denied this.[85]

Tumblehome design stability


Sea Jet, out of the water and showing the unique hull design

Sea Jet, an Advanced Electric Ship Demonstrator
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 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."[86] The decision to not use a tumblehome hull in the CG(X) cruiser, before the program was canceled, may suggest that there were concerns regarding the Zumwalt's seakeeping.[68] However, in a 1/4 scale test of the hull design, named Sea Jet, the tumblehome hull proved seaworthy.[87]
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, Acoustic Research Detachment in Bayview, Idaho. Sea Jet was operated on Lake Pend Oreille, where it was used for test and demonstration of various technologies. Among the first technologies tested was an underwater discharge water jet from Rolls-Royce Naval Marine, Inc., called AWJ-21, a propulsion concept with the goals of providing increased propulsive efficiency, reduced acoustic signature, and improved maneuverability over previous destroyer class combatants.[citation needed]

In popular culture

  • The theft of a fictional radar system intended for the Zumwalt-class was a central part of the plot in the episode "Stakeout" of the U.S. television series NCIS. The episode first aired on 8 April 2008. In the episode, a character claims that a Zumwalt-class destroyer has scheduled sea trials in a week's time, even though delivery of the first Zumwalt was not scheduled before 2013.
  • The variation of Zumwalt-Class appeared in 2012 Japanese anime movie, 009 RE:Cyborg. Named USS Sentinel, this version of the ship was Aegis equipped and armed with SM-3 Standard Missiles. In the film, the Sentinel use hijacked by 00 Cyborgs to use the ship's anti-ballistic missile capacities to shoot down flight of Nuclear Armed Intercontinental Ballistic Missiles launched from rogue US SSBN.
  • In PC Game, Supreme Ruler 2010, Zumwalt appear as DDX-21 Zumwalt Destroyer Class Ship which only accessed if user play as United States and already have research point above 105.

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