The Zumwalt class destroyer
(DDG-1000) is 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 Zumwalt-class
destroyers are multi-role and designed for surface warfare, anti-aircraft,
and naval fire support. They take the place of the battleships in filling the
former congressional mandate for naval fire support, though the requirement
was reduced to allow them to fill this role. The vessel's appearance has been
compared to that of the historic ironclad.
The DDG-1000 is planned to feature: a low radar profile; an integrated power
system, which can send electricity to the electric drive motors or weapons,
which may someday include a railgun or free-electron lasers; 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 destroyer is being 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 GAO found
that only four out of 12 of the DDG-1000's critical technologies were mature.
The lead ship will be named Zumwalt for Admiral Elmo Zumwalt, and carries the
hull number DDG-1000. Originally 32 ships were planned for the class, but
this was progressively cut down to two, with three to be built currently. The
Navy expects each ship to cost nearly $3.3 billion. The DOD's proposed 2010
budget called for three DDG-1000 ships to be produced.
Many of the ship's 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 of these destroyers. That number
was later reduced to 24, then to 7, due to the high cost of new and
experimental technologies to be incorporated in the destroyer. On 23 November
2005, the Defense Acquisition Board approved a plan for simultaneous
construction of the first two DDG-1000 ships at Northrop’s Ingalls yard in
Pascagoula, MS and General Dynamics’ Bath Iron Works in Bath, ME. However, as
of that date, funding had yet to be authorized by Congress.
In late December 2005, the House and Senate agreed to continue funding the
DDG-1000 program. The U.S. House of Representatives allotted the Navy only
enough money to begin construction on one DDG-1000 destroyer as a
"technology demonstrator." The initial funding allocation for the
DDG-1000 destroyer was included in the National Defense Authorization Act of
2007. However, this was increased to two ships by the 2007 appropriations
bill approved in September 2006, which allotted US$2,568m to the DDG-1000
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, 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. The Navy concluded from fifteen classified intelligence
reports that the DDG-1000s would be vulnerable to forms of missile attacks.
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). 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. 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".
On 19 August, Secretary Winter was reported as saying that a third Zumwalt
would be built at Bath Iron Works, citing concerns about maintaining
shipbuilding capacity. 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.
A 26 January 2009 memo from John Young, the US DoD's top acquisition
official, stated that the per ship price for the Zumwalt 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.
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. 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.
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.
On 13 November 2007, Northrop Grumman was awarded a $90m contract
modification for materials and production planning. On 14 February 2008, Bath
Iron Works was awarded for the construction of the USS Zumwalt (DDG-1000),
and Northrop Grumman Shipbuilding was awarded for the construction of the DDG-1001,
with price of $1.4 billion each.
As of July 2008, the construction timetable was:
October 2008: DDG-1000 starts construction at Bath Iron Works
September 2009: DDG-1001 starts construction at Ingalls
April 2013: DDG-1000 initial delivery
May 2014: DDG-1001 delivery
March 2015: Initial operating capability
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. Its hull number will be DDG-1000, abandoning the
guided missile destroyer sequence used by the Arleigh Burke-class destroyers,
and continue in the previous "gun destroyer" sequence left off with
the last of the Spruance-class, USS Hayler.
DDG-1001 will be named for Master-at-Arms 2nd Class (SEAL) Michael Monsoor,
the second SEAL to receive the Medal of Honor in the Global War on Terror
(GWOT), the Navy announced on 29 October 2008.
There is an active civilian campaign to persuade the Secretary of the Navy to
name one of the class the USS Robert A. Heinlein.
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 submarine. 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
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). On the down side, the
tumblehome battleships experienced stability problems, especially in high
speed turns or losses in watertight integrity. 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. As mentioned above,
the stability of this hull form in high sea states has caused debate among
Advanced Gun System (AGS)
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-calibre saboted long-range round in a stretched
16"/45 Mark 6 battleship gun in 1967. The Advanced Gun Weapon System
Technology Program (AGWSTP) evaluated a similar projectile with longer range
in the 1980s. After the battleships were decommissioned in 1992, the AGWSTP
became a 5" gun with an intended range of 180 kilometres (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. 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. The barrel is water cooled to
prevent over-heating 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 18 conventional M198 field guns.
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.
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.
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. 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. It seems that the new radar will be The Air
Missile Defense Radar (AMDR), a system currently in the early stages of
development 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.
Each band will have its own signal processors, with the returns combined by
the display sensor manager. This system is thought to provide high detection
and excellent anti-jamming capabilities. But at least one report by Congress'
investigative arm, the GAO, raises concerns that it is too much of a
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
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)
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. 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
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
Integrated Power System (IPS)
The Integrated Power System (IPS) is a step both forward and backwards. 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 impacts the ship's thermal and sound
signature. The IPS has added to weight growth in the Zumwalt-class destroyer
as noted by the GAO.
Automation will reduce crew size on these ships. A smaller crew will reduce a
major component of operating costs.
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.
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.
The Total Ship Computing Environment Infrastructure (TSCEI) is based on GE
Fanuc Embedded Systems' PPC7A and PPC7D single-board computers running
LynuxWorks' LynxOS RTOS.
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 life-cycle cost of a DD(X) at
$3.8–4.0bn in 2007 dollars, $1.1bn more than the Navy's estimate.
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.
On 31 July 2008 Vice Adm. 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." 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". The lack of
anti-ballistic missile capability may represent a lack of compatibility with
SM-3. In view of recent intelligence that China is developing targetable
anti-ship ballistic missiles based on the DF-21, 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
In 2010 the Congressional Research Service reported that the DDG-1000 cannot
be used for BMD because it does not use the standard Aegis system that has
been developed for BMD.
The narrowly defined 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."
The original DD-21 design, displacing around 16,000 tons, would have
accommodated between 117 and 128 VLS cells. However, the final DDG-1000
design was considerably smaller than that of the DD21, resulting in room for
only 80 VLS cells. 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
A controversial point of the DD(X) destroyer(s) is their planned naval
surface fire support role. The original DD21 and the Arsenal Ship had more
serious NFS 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 NFS 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.
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 NFS, 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. 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.
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.
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." The U.S. House of Representatives asked that the
battleships be kept in a state of readiness should they ever be needed again
and directed the Navy to increase the number of Arleigh Burke-class
destroyers that are currently being modernized. 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; However the ERGM was canceled
after it failed firing tests in February 2008. The Navy is studying future
options for naval fire support; Alliant Techsystems’ ballistic trajectory
extended range munition may be one possibility.
The Zumwalt has an unusually large deckhouse as all the major sensors are
buried in its structure. It has been claimed that Northrop Grumman has had
problems sealing the composite construction panels of this area, but Northrop
Grumman has denied this.