Home » Budget Industry » New External DDG-1000 Mast Reduces Ship’s Stealth From Original Design

New External DDG-1000 Mast Reduces Ship’s Stealth From Original Design


A newly revealed configuration of sensors set for next-generation destroyer Zumwalt (DDG-1000) could make the ship less stealthy than originally intended, several naval experts told USNI News on Wednesday.

According to a new artist’s concept of the configuration from the service, the three ships in the Zumwalt-class will position sensors originally designed to be embedded in the ships’ composite deckhouses on a mast positioned on the front of the deck house, with several more sensors on either side of the deck house.

The change will sacrifice some of the benefits of the composite deckhouse design, conceived to make the ship harder to detect by an enemy’s radar. The antennas for the sensors would have been mounted on the superstructure much like the flush antennas on the U.S. fleet of stealth aircraft.

An artists rendering of Zumwalt's original design prior to the Nunn-McCurdy restructure showing the original sensor configuration on the deckhouse.

An artists rendering of Zumwalt’s original design prior to the Nunn-McCurdy restructure showing the original sensor configuration on the deckhouse.

Instead, to save weight and cost, the antennas will be installed on the outside of the superstructure, Naval Sea Systems Command told USNI News.

NAVSEA provided USNI News of a description of the changes, saying the Zumwalt-class would still perform within the Navy’s requirements for the stealth of the ship.

“The current DDG-1000 topside configuration is a performance and weight improvement and cost-avoidance initiative. This configuration adds a mast to the forward part of the deckhouse and relocates several communications systems including Ultra High Frequency (UHF), Very High Frequency (VHF), data link and the wind sensor from the deckhouse to the mast,” read the statement.
“This configuration will be present on all three ships and provides improved performance redundancy, cost avoidance and weight reduction, while still meeting Key Performance Parameters (KPP) requirements for Radar Cross Section (RCS).”

The starboard view Zumwalt DDG-1000 from a Dec. 7, 2016 underway. US Navy Image

The starboard view Zumwalt DDG-1000 from a Dec. 7, 2015 underway. US Navy Image

The RCS is a measure of stealth. The lower a RCS, the smaller a ship or aircraft appears on radar.

(For example, the Lockheed Martin F-22 Raptor is said to have the RCS of a “steel marble,” from certain angles.)

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, Bryan Clark, naval analyst Center for Strategic and Budgetary Assessments (CSBA) and former special assistant to past Chief of Naval Operations Adm. Jonathan Greenert, told USNI News on Wednesday.

However, he said, the design still meets the minimum requirements for what the Navy asked for in its initial DDG-1000 requirements – the “threshold,” in acquisition speak.

“[The RCS] is still lower than their threshold but higher than it could have been,” Clark told USNI News on Wednesday.

Retired Navy captain and naval analyst Chris Carlson told USNI News that mast bore a resemblance to the configuration on the Arleigh Burke guided missile destroyers (DDG-51).

Several sources told USNI News the changes to the mast were a direct result of a downscale in capabilities the service made to the ship class following a 2010 Nunn-McCurdy restructure – a federal law that requires the Defense Department recertify a program after costs have increased of 25 percent per unit above the original estimate. The program tripped the legislation when the Department of Defense cut the program to three hulls from seven, spiking the price-per-unit.

DDG 1000_glass_shipAs part of the Nunn-McCurdy restructure, the Navy shed capabilities – like canceling the ship’s S-band volume search radar– on the hulls to bring the cost down on the $22.1-billion, three-ship program.

Other cost-saving choices have trickled out later, like replacing twin 57mm guns on the ship with a much smaller 30mm pair.

The first ship – Zumwalt – is set to start a round of builders trials later this month ahead of a delivery of the ship’s hull to the Navy from shipbuilder General Dynamics Bath Iron Works (BIW) later this year.

Following delivery, the ship will complete the outfitting of its combat system in San Diego.

  • LewCypher

    “The lower a RCS, the smaller a ship or aircraft appears on radar”

    But what is it’s heat signature?

    • Eric Arllen

      See Skyking239’s comment at the top.
      Tiny RCS is great source of comfort right until you radiate. Once you radiate the SPY-3 (or anything else either sufficiently distinctive or noisy to attract attention) it’s “Open Kimono!” time. At that point you are in a zero-sum game and what you really, really need a whole bunch more than stealth is the biggest ordnance (kinetic and electronic) you can lay hands on quickly to effectively plant it on both the target and whatever is incoming from the target. In fact, your second outgoing round of whatever sort should be impacting a smoking hole in the ocean, if you are doing it correctly.

  • MikeMike

    “Other cost-saving choices have trickled out later, like replacing twin 57mm guns on the ship with a much smaller 30mm pair.”

    So does that mean we’ve officially abandoned the delusional idea that 30mm rounds are more lethal than 57mm? (Or even 76mm, as the Navy so absurdly tried to claim) and this was nothing more a down gunning chasing after cost and weight cuts? Perhaps the Navy would even admit again that the 57mm guns were originally supposed to have an air defense role as well, which the 30mm have ZERO capability in.

    • Secundius

      Most likely reason for Down-Sizing Caliber Size, IS Magazine Capacity. A Typical BAE/Bofors 2.244-inch (57x438mmR) Magazine is ~1,000-rounds, a 3-inch Oto-Melara (76.2x636mmR) is ~740-rounds. mounting Bushmaster II 1.181-inch (30x173mmR) is ~1,900-rounds…

      • Refguy

        But what’s the effectiveness of each round?

        • Secundius

          The BAE Mk. 44 1.181-inch (30x173mmR/80.3-caliber Bushmaster II) Flat Trajectory Range is ~5,100-meters, Effective Range is ~2,200-meters at Sea and ~3,000-meters on Land. Rated at 200rpm “Peak” (100rpm “Sustained”)…

          • Refguy

            Just using simple physics (no classified info, no manufacturer’s brochures) comparing 76mm and 57 mm, assuming similar projectile shapes, mass of 76mm projectile is 2.36 times that of the 57mm and ballistic coefficient is 33% better. I’ll take 740 of the larger projectiles instead of 1000 of the smaller.

          • Secundius

            Though the Maximum Firing Rate Rating of the Oto Melara is 120rpm, Sustained Firing Rate is Reduced to ~40rpm. The Bofors is 220rpm, reduced to ~72rpm. And the Bushmaster II, from 200rpm to 100rpm because of Barrel Heat and Barrel Drooping. Projectile Weight ALONE for the Oto Melara is ~14#, the Bofors @ ~6# and the Bushmaster II @ ~14-ounces…

          • Refguy

            Oto and Bofors weights are about what physics predicts. Using sustained rates of fire, Oto puts 560# of metal (or HE) on target per minute, Bofors puts 432# per minute. but it should take fewer rounds of the heavier projectile to achieve a kill

          • Curtis Conway

            Lethality (explosive potential) of each round is relevant to the argument. Number of rounds is not with the advent of guided projectiles. Guided projectiles that take out ASCMs are right around the corner. This makes 22 cruisers and 63 destroyers much more lethal almost literally overnight.

          • Refguy

            I’m not aware of guided projectiles for guns smaller than 6 inches. I think I remember a small number of guided 8-inch rounds (RAPS?) being fielded once upon a time, but I don’t know of any ships currently deployed with guided gun rounds. Is there an equivalent of copperhead at sea?
            Not sure how a self-defense system makes a ship more lethal. RAM is already a guided projectile that “can take out an ASCM”
            JSF has been right-around-the-corner since 1995 and rail guns for even longer. Link 16 was supposed to have AJ and be LPI in the mid-80’s.

          • Curtis Conway

            Google search OTO Melara DART/STRALES. There are 30 mm guided projectiles. There is even a .50 Caliber guided projectile now.

          • Refguy


          • Curtis Conway

            Self-defense systems is what the US Navy now says makes a platform more ‘survivable’. According the the New Navy ‘watertight integrity’ and ‘compartmentalization’, like every sailor for over 50 years has been taught, and some lived it, is no longer in vogue. How’s them apples.

          • Refguy

            I understand that self defense helps you survive, but not how it makes you lethal. I guess you have the potential to kill someone when you’re alive, which is more than you have when your dead.
            Unfortunately I have allowed myself to get into a debate about the right gun for a ship with an ill-defined mission: too big for anyplace but the open ocean, not the right armament or electronics to replace the Aegis ships, too big and expensive for ASW, not enough self-defense or offensive capability for independent steaming. Does it really matter what guns are in the secondary batteries if the ship doesn’t have defined, useful missions.

          • Curtis Conway

            Make them all Mine Countermeasures, or SOF support. They will be a modern “Two Stacker”. The Raiders are back and they need a Ride!

          • Refguy

            If I understand this comment, the Zumwalt should be renamed USS Caine. In the latest issue of Proceedings Captain Kirk says that the SPY-3 (when fitted) will be able to detect periscopes. If a sub is close enough for you to detect the periscope, you’ve already lost.

          • IMHO

            What matters here is the intended target/usage, and the effectiveness against that target. I don’t care if it fires purple butterflies; if it works as needed and I happen to save money that is a win-win.


      5″ 54 would be much better.

    • airider

      Cost, cost, cost…..oh and also, cost.

  • Skyking239

    Stealth is a waste of money unless you intend to leave all of the RF emitters turned off. Lighting off the SPY-3 instantly announces to any adversary within the battlespace “I am a DDG-1000 and here I am”. Any half competent ESM operator can refine your position within seconds and an over the horizon launched AS-17 Krypton anti-rad missile will ruin your day.

    • B.J. Blazkowicz

      So it’ll need jammer capability to even use it’s own radar.

      • Curtis Conway

        In the future you should be able to do both with the same antenna.

        • B.J. Blazkowicz

          “In the future” do you mean already in development or just technological downsizing like with computers and cell phones.

          • Curtis Conway

            The technology exist. Funding and implementation is the issue. AND then there is classification.

    • Taxpayer71

      This argument applies to the entire surface navy. Engagements with a near peer navy will require operations in EMCON with reliance on ownship passive sensors and offboard active and passive sensor information delivered via broadcast. The key decision will be if and when to transition from passive to active RF operations. Time to start practicing and learning the potential of off board systems to provide situation awareness and threat warning via broadcast.

      • Curtis Conway

        You just put your finger of the reason that more Passive Combat System capabilities are required for all USN Surface Combatants. Some of those ships by nature will have to radiate (CVNs for example) most of the time. With the advent of the FORCENET-21, and very capable passive detection & tracking systems, it will be possible to operate in the future with little or no RF emissions, as other parts of the EM spectrum are used.

        • Taxpayer71

          Carriers “by their nature” have to radiate? When last faced with a near peer (Soviet Navy) carrier task forces made total EMCON transits, and routinely conducted EMCON launch and recovery operations. Perhaps some research into US Navy history of such operations is indicated.

          • Curtis Conway

            Participated in EMCON recoveries as an Air Intercept Controller on the escorting cruiser. Each CAG had its own policy and process. Today it’s easier than ever before.

          • IMHO

            To be fair, he did say “most of the time”. But perhaps “required to radiate” might be too strong of a suggestion. Might depend who you ask.

        • Taxpayer71

          FORCENET-21, as described in Navy literature, is focused on networks, which require RF emissions, which reveal the force to the enemy. FORCENET therefore appears focused on improving fleet defensive performance. What does FORCENET provide a ship in EMCON? Where is the offense??

  • old guy

    Please tell these “I’m living in 1950” Admirals (and SEA 05), That we now have satellite based WAKE TRACKERS that will give you the location of ANY ship, ANY time, in REAL time. There are also laser trackers, self-guided missiles and more. The ONLY stealth possibilities are submaries and sunken ships.

    • IMHO

      Nothing is perfect. They did find the Titanic….

  • John B. Morgen

    The Navy shouldn’t be building too many of these so-called destroyers because of the high costs, and problems of maintaining the stealth images from enemy radars; such stealth programs are going bankrupt the defense budgets. We don’t see both the Plan and Russia are building such counter-parts for the their fleets. What happen to “common sense?”

    • Don Hanson

      Yes both Russia and China have simular programs. But soon the 5″ main gun will most likely be replaced with a 5″ rail gun using magnetics to population of the projectile with a range of ruffly 100 miles.

      • John B. Morgen

        The Navy has been working on the [rail gun] for many decades, and $ millions of USDs have been sunken into a program that has produced with very little results.
        Why not shoot for a 8 inch rail gun than a 5 inch gun instead?
        Are you referring to the Jiangkai class frigates for the PLAN’s stealth program? And for Russia, are you referring to the Steregushchiy class frigates or the Admiral Gorshkov class frigates; or both?

        • old guy

          In 1977 SEA003 evaluated alternate advanced gun systems including the electromechanical (rail) gun and the Electro-thermal-chemical (ETC) gun. It was concluded that the rail gun would be best as an A/C catapult and it was turned over to Lakehurst for development. How it got back, I don’t know. The ETC gun was prototyped and successfully fired in conjunction with its co-developer, DOE.
          I would appreciate info from anyone who knows what happened after that.

  • Chesapeakeguy

    Do tell: WHAT ‘next generation’ “Zumwalt” ships? They reduced production to three ships. Has the decision been made to build more of them? When was that done?

  • John B. Morgen

    If stealth can be defeated by radar, then spending $billions on stealth designed warships that can be picked up on radar is bloody pointless. Instead of wasting $billions which could be spend on building more Ticonderoga class CGs or more Arleigh Burke class DDGs. Because I have read a report during the first Gulf War that a Royal Navy frigate had picked up a F-117 fighter flying over the Gulf, and frigate even had a missile locked on our aircraft. If the report is correct, then everyone is wasting valuable naval funds that could have been better spent on much needed programs. What really works, and that is radar jammers, more so than the weapons system built with stealth materials.
    What I see here is the old [battlecruiser paradigm]–speed is armor. A paradigm that failed in battle, and stealth will end up by the same error of thinking. Instead of building so-called stealth warships, however, what we need is building warships with better radar jammers…..

    • IMHO

      Speed is armor because it makes a fire-control solution harder to obtain and execute. A low RCS would do the same. But putting all eggs into one basket (speed, armor, RCS, firepower, range, etc) is likely to leave gaping vulnerabilities. Yet it can achieve huge advantages in return. Perhaps battle cruisers didn’t achieve this, but there are plenty of things that do. It’s about timing and execution. A knife is great and can get the job done, but don’t bring it to a gunfight.

      Remember opponents must field a defense. It is easier to field a system that can detect and prosecute all “medium stealthy” units than it is to field one that can detect and prosecute all “very stealthy” units. But when you field he “medium” defense, the “very stealthy” unit gets thru.

      The F-117 was an effort to make the best low-RCS aircraft possible, and it achieved its goal until technology and defenses caught up (which it always will). It showed the power of “stealth is armor” and since then most every platform pays close attention to RCS. Your first-gen will be quickly overcome but is an important spark. Bashing the F-117 as a waste is like bashing the first iPhone.

      For every defense, there is a counterattack. Radar jammers can be defeated too. It’s a struggle to always be better or one step ahead, and that is Warfare.

      Think of the Zumwalt as the F-117. Who knows if it will prove useful, but it may be worth a try. I am certainly skeptical myself. Perhaps we just find cost-effective designs that we can apply to future platforms.

      • John B. Morgen

        Speed is armor was a complete folly because it did not protect the four British battlecruisers from being blown up by German capital warships. Nor stealth will protect the F-117 so-called fighters or the B-2 bombers from being shot down. Already we have lost one F-117 aircraft over the former Yugoslavia. Outstanding radar systems will defeat stealth, and we better wake up to that fact, and the best way to resolve this problem, is to designed better ESM systems to protect our aircraft and warships from enemy radar systems. In sum, we are making the same mistakes over again, as we did during the early 1900’s by building battlecruisers.

        • IMHO

          There is a difference in “armor” and “preventing something from being destroyed.” Everything that has armor can be destroyed, it’s just harder. The idea of making yourself harder to kill by equipping armor is not a fallacy and, generally speaking, will make you harder to kill. “Speed is armor” is a metaphor that points out that speed can/could/might accomplish the same goal of armor against certain threats. Speed can make you harder to kill.

          EW/ESM is also armor.

          The selection of types of “armors” to use should be matched against the expected threat. But anything designed to be armored against an expected threat is vulnerable to the unexpected threat.

          This dance between adversaries to patch vulnerabilities and exploit weakness is just your run-of-the-mill warfare.

          • John B. Morgen

            Metaphor or not, speed is armor was nothing than a delusional way of thinking that battlecruisers could escape from plunging shells from battleships. Battlecruisers were inferior capital warships, and they only good for going up against inferior warships; a good example, two British battlecruisers destroyed the Admiral Graf Spee’s squadron during the Battle of Falklands in 1914. During the Battle of Jutland (1916) the Royal Navy lost three battlecruisers, but almost lost four additional battlecruisers. All of them were sunk or severely damaged by plugging heavy shells. We must [not] forget the Battle of the Denmark Strait (1941) whereby the German battleship Bismarck sunk the battlecruiser HMS Hood. However, speed might have a protective value, but only, if the target vessel is quite small, and can do over 40+ knots or faster. I am referring to FAC or armed hover craft.

            EW/ESM is only good if the opposition cannot obtain successful counter-measures against an attacking warship. In either case, armor is a defensive measure, but there must be a balance of armor protection applications.

            My apologies for this belated response.

  • Curtis Conway

    Concerning the gun, once again technology (guided projectiles, their current and future capability and range, and how many platforms will receive greater lethality with their introduction) has proven a better investment than the new Advanced Gun System, particularly with its unique configuration and all the special support required for that installation across three platforms. That budgeted treasure would have represented a much greater return on investment, with many more solutions provided, if those monies had gone to advanced guided projectile development, testing and production for 5″ 54/62 Cal guns. With the advent of more space based national intelligence assets by potential adversaries, demonstrated by the Chinese evidence presented in support of the Malaysia Airlines Flight 370 disappearance, stealth shipbuilding as a warfare element is somewhat dubious. Increased capabilities of potential adversaries missile and seeker technology also do not bode well for survivability unless the attacked platform has a very robust defense capability.

    Given the realities on the ground (and water) around the planet, one is left to wonder if an investment in National Patrol Frigates in numbers would have been a better bet than all that new technology that will yield nearly no advantage except in limited fashion in specific locations, instead of providing meaningful and capable presence in multiple locations around the planet. Our situation in the South China Sea would most likely not be happening right now if those ‘Frigates’ were still in the fleet.

    The United States Navy needs 50+ multi-warfare guided missile frigates to replace our decommissioned Oliver Hazard Perry Class Frigates, that can at a minimum engage Tactical Ballistic Missiles, shell the beach in support of the Marines as they have since WWII until the FFG-7, and are perhaps an introductory platform for Directed Energy Weapons. It should have a very capable and efficient propulsion system, and a hull that is Arctic capable.

  • old guy

    Why don’ we identify the Capt’s cabin, CIC, And the ammo lockers, too?

  • Benjamin Abrams

    There should be no compromise in the first rate quality of this latest floating fighting machine. E.g. reduction of canons to 30mm from 57mm, higher radar signature, use of steel rather than carbon, etc.
    To win on the battlefield there are no “cost-effective” compromises. Have we altogether surrendered winning a war to saving a few pennies along the way? This is not my America. BMA

  • old guy

    A ship with NO redeeming features. Let’ see:
    1. Tendency to roll over in hard maneuver, due to tumblehome design.
    2. Low radar cross section is USELESS with precision satellite tracking, laser targeting and GPS locator.
    3.Steel deckhouse is unimprovable
    4. Disregard for the composite work done by my people in 1993.

    I believe that my old boss should ask for the ship to be renamed.
    How about”The MERRIMAC” (C.S. Virginia)