DD(X) CLASS MULTIMISSION DESTROYER, USA
In November 2001, the US Department of Defense announced that the
DD 21 program for the Future Surface Combatant had been revised and
would now be known as DD(X). The program focus would now be on a
family of advanced technology surface combatants, rather than a
single ship class. A revised Request for Proposals was issued and
in April 2002, Northrop Grumman Ship Systems, Ingalls was selected
as the lead design agent for DD(X). Northrop Grumman led the "Gold
Team" which included Raytheon Systems Company as the systems
integrator. The "Gold team" proposal incorporates "Blue team"
leader Bath Iron Works (a General Dynamics company) as a
subcontractor for design and test activities. Other major
subcontractors include Lockheed Martin, United Defense Limited
Partnership (UDLP) and Boeing.
The DD(X) program will build on work already carried out for DD 21
and provide a foundation for development of the DD(X), the CG(X)
cruiser and also the smaller Littoral Combat Ship (LCS), with
emphasis on common hullform and technology. LCS is expected to be
the first to enter service and the Navy requirement is for about 60
LCS ships. In May 2004, it was announced that Lockheed Martin and
General Dynamics Bath Iron Works will each build two LCS vessels to
commission between 2007 and 2009.
Northrop Grumman is to complete DD(X) system design and 11
engineering development models (EDM) by 2005. The EDMs include:
advanced gun system, integrated power system, composite deckhouse,
peripheral vertical launch system, integrated sonar system (with
advanced towed array and high-frequency active sonar) and dual band
radar suite. A decommissioned Spruance Class destroyer (USS Arthur
W. Radford) will serve as the test platform for the DD(X).
The USN is expected to hold a competition for the construction
contract before the end of 2005. Initial operating capability is
planned for 2013.The number of ships required is expected to be
between eight and 12.
DD(X) replaces the DD 21 Zumwalt program which was for a class of
32 multimission destroyers to replace Oliver Hazard Perry class
frigates (FFG 7) and Spruance class destroyers (DD 963) from 2012.
Unlike previous classes of destroyer, which were primarily to
counter deep water threats, the DD 21's primary mission would be to
provide land attack support for ground forces and also to carry out
traditional destroyer missions of anti-air, anti-surface and
undersea warfare.
DESIGN
DD(X) will have a "tumblehome" hull form, i.e. a design in which
hull slopes inward from above the waterline. This will
significantly reduce the radar cross section since such a slope
returns a much less defined radar image rather than a more
hard-angled hull form.
Requirements for the Integrated Deckhouse EDM is that it is fully
EMC (Electromagetic Compatibility) shielded with reduced infrared
and radar signatures. Measures to fulfil these conditions include
an all-composite superstructure, low signature electronically
steered arrays, an integrated multi-function mast and low radar and
infrared signatures. Other measures to reduce the vessel's infrared
signature include the development of an exhaust suppressor.
Harris Corporation has been awarded a contract for the development
of the Common Data Link (CDL) X/Ku-band phased array antenna
systems, which will be integrated into the Integrated Deckhouse
Assembly. The multi-beam electronically-steered antenna will allow
connectivity with up to eight CDL terminals.
The DD(X) is planned to have a displacement of around 12,000t, less
than the 14,000t or more of the DD-21, with a sustained speed of
around 30 knots.
CREW
The number of crew for DD(X) is yet to be defined. DD-21 was to
have a crew of 95, including the helicopter detachment. This
represented major theoretical cost saving compared to crew levels
of 330 on Spruance destroyers and 200 on Oliver Hazard Perry
frigates.
WEAPONS
DD(X) will have a sensor and weapons suite optimised for littoral
warfare and for network centric warfare. Northrop Grumman has put
forward a solution based on a Peripheral Vertical Launch System
(PVLS). The solution consists of a number of four-cell PVLS
situated round the perimeter of the deck, rather than the usual
centrally located VLS. This would reduce the ship's vulnerability
to a single hit. The Advanced Vertical Launch System (AVLS) that
forms the basis of the PVLS is being developed by United Defense
and Raytheon and has been designated the Mk 57 VLS.
Missile systems under consideration include Tactical Tomahawk
(intended to succeed Tomahawk TLAM), Standard Missile SM-3 and the
Evolved SeaSparrow Missile (ESSM) for air defence.
United Defense has been awarded the contract to develop the EDM for
the ship's Advanced Gun System (AGS), building on development work
carried out for DD-21. The vessel's two 155mm guns will be able to
fire up to 100 nautical miles at a sustained rate of 12 rounds per
minute. It will be equipped with a fully automated weapon handling
and storage system and a family of advanced munitions and
propelling charges, including the GPS-guided Long Range Land Attack
Projectile (LRLAP). Lockheed Martin has been awarded the contract
for the LRAP EDM. The family of munitions is expected to include
land attack and ballistic projectiles. Technologies derived from
the US Navy's extended range guided munition (ERGM), the US Army
155mm XM-982 projectiles and the DTRA 5in projectile are being
studied for incorporation into the projectile suite.
United Defense is developing advanced gun barrel technologies for
the new AGS, with improvements to barrel life, overall system
performance and life cycle costs.
The ship's Close-In Gun System (CIGS) will be the United Defense
57mm Mk 110 naval gun.
RADAR
The radar suite will consist of a dual band radar for horizon and
volume search, an L-band volume search radar (VSR) integrated with
the AN/SPY-3 multi-function radar already being developed by
Raytheon for the US Navy. The two radars are to be integrated at
waveform level for enhanced surveillance and tracking capability.
The AN/SPY-3 Multi-Function Radar (MFR) is an X-band active
phased-array radar designed to detect low-observable anti-ship
cruise missiles and support fire-control illumination for the ESSM
and Standard Missiles.
SONAR
At the heart of the ship's Integrated Undersea Warfare System will
be a dual (high frequency/medium frequency) frequency bow array and
a multi-function towed array. The US Navy has already set up the
IUSW-21 program to develop technologies including multifunction
hull array, mine avoidance and shallow water ASW.
AIRCRAFT
The DD(X) ship design includes two landing spots for
helicopters.
PROPULSION
It is envisaged that the DD(X) would have an all-electric drive
with 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 provision of electric
drive eliminates the need for drive shaft and reduction gears and
brings benefits in acoustic signature reduction, an increase in
available power for weapon systems and improvements in the quality
of life for crew.
The IPS would supply power to other ship systems such as the combat
systems and allow the rapid reconfiguration of power
requirements.
DRS Technologies Power Technology unit has received development
contracts for the PMM motors, electric drive and control system for
the IPS. The Rolls-Royce MT30 36MW gas turbine generator set has
been selected to power the IPS EDM and Rolls-Royce delivered the
first set in February 2005. The MT30 has 80% commonality with the
Rolls-Royce Trent 800 aero engine and Rolls-Royce states that it is
the most powerful marine gas turbine in the world. CAE will supply
the integrated platform management system.
