Tuesday, April 22, 2014

Flt III VLS

Military.com News website has an article (1) about the Zumwalt.  It’s just a sales brochure fluff piece but it did mention an interesting point.

Wade Knudson, Raytheon DDG 1000 program manager, had this to say about the Zumwalt’s Mk57 Peripheral VLS system.

“The ship is also built with a new kind of vertical launch tubes that are engineered into the hull near the perimeter of the ship. Called the Peripheral Vertical Launch System, the tubes are integrated with the hull around the ship's periphery in order to ensure that weapons can keep firing should the ship be damaged. Instead of having all of the launch tubes in succession or near one another, the DDG 1000 has spread them out in order to mitigate risk in the event [of] attack, Knudson said.

‘This divides the weapons up so if you take a hit, you don't lose all your weapons. This is a survivability enhancement,’ he added.”

I’m not at all sure that the Mk57’s placement was a survivability issue but let’s assume it was.  That begs the question why would the Navy consider moving forward with the Burke Flt III which will form the backbone of the fleet for the next four decades and carries the traditional clustered VLS system.  If the Mk41 VLS clustering has been deemed a sufficient survivability weakness to justify a radical VLS relocation in the Zumwalt, wouldn’t it also justify a redesign of the forthcoming Burke Flt III’s?  I understand that it would be nearly impossible to rework existing Burkes but the Flt III’s are new construction and are going to be extensively reworked anyway.

When you consider that the Flt III has been deemed by the Navy as unable to meet the full AMDR performance specs due to the inability to carry the full size AMDR and you combine that limitation with the survivability issue of clustered VLS, you really have to wonder why the Navy insists on moving ahead with a clearly sub-optimal Flt III rather than a new design.


Mk41 VLS - Unsafe?


Of course, the reason is obvious.  By calling the Flt III a modification to an existing design, the Navy hopes to avoid a great deal of oversight and scrutiny that would come with an officially new design.  By being unwilling to stand up a new design, take it to Congress, and justify it, the Navy is knowingly saddling itself with a sub-optimal vessel with no growth margin.  That’s just sad.




19 comments:

  1. The Flt III Burke will be less expensive than any new design, and available sooner.

    The next-gen destroyer currently penciled in for the mid 2020's may take advantage of PVLS, if it ever comes to fruition.

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    1. B.Smitty, c'mon, I feel like you're not even trying! [he said in a very friendly, lightly kidding tone] There's so many deeper issues that could be explored, here.

      What's better? To build a cheaper ship that is less survivable or a more expensive ship that is more survivable? Is a cheap, sunk ship really cheaper than a more expensive, floating ship?

      What does this say about the USN warship design philosophy?

      Is short term cost now the main design criteria for Navy warships? If so, what does that suggest about our prospects in a fight with China over the next 40 years?

      Is the Navy focused on warfighting or accounting as its primary job?

      Is accounting going to force us to build a flawed Flt III (too small AMDR, too crowded, no growth margin, sub-optimal survivability, etc.)?

      Is the lack of an in-house, dedicated ship design group (General Board and BuShips) negatively impacting our warship designs?

      Have we lost our focus on combat?

      Do you want to go to combat and bet your life in a "cheap" ship?

      What does this say about Navy leadership and their focus?

      Penny wise, pound foolish?

      Step up your game! [he said, full of respect for the many excellent previous comments]

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    2. IIRC, CNO's most important war-winning factor is numbers, right? ;)

      “Numerical superiority is the force attribute that is consistently the most advantageous.”

      For a given budget, a larger number of "good enough" ships is better than fewer "exquisite" ships.

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    3. B.Smitty, you did understand that when I spoke of numbers I meant relative to the enemy's numbers, not relative to an alternative of our own. A few more ships (especially less survivable ones) aren't going to make much difference if the enemy significantly outnumbers us regardless of which version of a ship we build.

      If we can build a significantly larger number of good-enough ships so that we'll have a large margin over the enemy, then that's fine. Being able to build a few more ships that are less survivable doesn't gain us much.

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    4. Marginal extra survivability probably won't matter that much either. ;)

      DDG-1000 incorporated a number of survivability enhancements besides PVLS (e.g. extensive signature reduction, automatic fire suppression, sheer size). If survivability now matters more than numbers, do we incorporate those as well?

      Unless we use the DDG-1000 as a basis for our new destroyer, we won't see a brand-new, PVLS-armed ship in the fleet for 10+ years. Using the DDG-1000 hull, you are still talking years to integrate AMDR.

      Getting AMDR-equipped Flt IIIs will have a far more immediate impact on the fleet.

      Outside of the force-on-force benefits, increased numbers also reduces the deployment strain on the fleet. For every four ships you add, you can keep one more forward deployed.

      I can see a case for a modified DDG-1000 to be this new destroyer. But waiting for a completely new design before we introduce any new capabilities to the destroyer fleet isn't my favorite option.


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    5. B.Smitty: "Marginal extra survivability probably won't matter that much either" - That's the point I raised in the post. I have doubts that the PVLS is really that significant an improvement in survivability. But, if it is, one has to seriously question going ahead with a Flt III design that would have a known, significant survivability issue.

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    6. I really don't think PVLS alone produces "leap ahead" survivability improvements. Just MHO. It certainly reduces the likelihood of a catastrophic magazine detonation. And it adds what amounts to spaced armor to the hull. But it comes at a cost in terms of ship weight, space and ultimately price. And hits are more likely to detonate some VLS cells, even if they are isolated.

      All else being equal, a ship with PVLS will have fewer cells for offensive and defensive munitions than one using Mk41 cells. So while it increases the staying power term in the Salvo equation, it reduces the offensive and/or defensive striking power terms.

      PVLS cells are larger, which adds some growth margin for future weapons.

      So is all of this worth the cost to reduce the chance of a catastrophic magazine explosion? I don't know.

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  2. BTW, The PVLS design and placement was most certainly related to survivability.

    All systems involve tradeoffs. The Mk41 trades survivability for compactness and lighter weight. You can fit more cells on a given sized ship.

    This is not a new issue. Magazine vulnerabilities have been around for as long as cannon-armed ships have existed. Turreted ships concentrated gun magazines in similarly small areas. Even pre-VLS, missile-armed ships had similar vulnerabilities with their missile magazines.

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  3. If they Navy can redesign the wing of the F-18 and call it a modification, then anythingis fair game.

    I know from working on DDG 1000 that putting the VLS outboard caused ALOT of effort. THe article also exlcudes the rationale that they protected the ship by being outboard.

    You raise an excellent point. If it was such a great idea why not...? Obviously it is not such a great cost effective idea.

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  4. I just don’t get what the USN is doing with its premier designs. Just like SeaWolf you have designed a massively superior ship. A technical leap forward with some cutting edge technologies and the room to carry the USN forward for decades.
    Then build 3!
    Yes they are expencive, but part of that ( a big part ) is because you just divided the HUGE R&D and design budget by 3 not 40.
    And because invariably as you build more of the class and develop and improve the build process price comes down.
    Otherwise your pretty much waisting your upfront money.
    Yes quantity has a quality all its own,
    But we arnt the USSR people. QUALITY has a quality all its own, and its called a 10 to 0 kill ratio.
    When you have technology that far superior many people wont even try it on, because they know they cant even understand never mind compete with the continuous advancements.
    And you can put a price on the deterrence effect. Because it’s the price we would all willingly pay to NOT have to go to war.
    Beno

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    1. 10-to-0 kill ratio against whom? The poorly armed, poorly trained, poorly lead Iraqis?

      Ignoring numbers in your force structure leads to "tactical instabilities" in wartime. If for some reason the enemy closes the tech gap, or your tech isn't as good as you think it is, you'll find yourself on the wrong end of the Lancaster/Salvo equations.

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    2. B.Smitty, c'mon, be fair. Beno isn't saying that numbers don't matter. He's pointing out that we tend to waste the sunk cost of programs when we cut the production runs short. Of course, for some programs, like the JSF, if the product is poor then trying to leverage up front costs is pointless and counterproductive.

      He's also making an interesting point about technological superiority as a deterrent.

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    3. The technologies designed for the DDG-1000 may yet make their way into other ships.

      IMHO, the jury is still out on whether the design decisions made in the DDG-1000 really moved the needle. It's primary NGFS mission never was as important to our country as the USMC made it out to be, IMHO. It never got the VSR portion of its radar suite. It certainly feels like a "Ferrari", to me, when we need "Fords".

      There is deterrent value in presence too. A larger number of ships can give you more presence. And savvy enemies can run the Salvo models too. They understand the value of numbers.

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    4. ComNavOps, the Navy needs to produce destroyers today and in numbers. Zumwalts have problems left to sort out. They'll get there someday but in the meantime the fleet needs DDGs and the shipyards need work to stay in business and to keep our skilled workforce available to us. Other navies incrementally develop their designs, such as China Type 052 series DDGs and Russia's Varjag, Kresta I, Kresta II and Sovremmeny classes, all of which share the same hull and machinery with different weaponry and superstructure. Don't let perfect be the enemy of good enough. Burkes are fine ships, as good or better than any other navies DDG.

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  5. Another change in the Flight 111 from the Flight 11A is a larger hull achieved by increasing the width of the stern so as to take the increased mass and height of the AMDR .
    Nick

    http://www.janes.com/article/36512/navy-league-2014-usn-arleigh-burke-flight-iiis-to-feature-wider-stern-design


    The preliminary design of the US Navy's (USN's) Flight III Arleigh Burke-class guided-missile destroyer features a wider stern than the current Flight IIA ships in order to accommodate the new Air and Missile Defense Radar (AMDR), the DDG 51 programme manager said on 7 April.

    Captain Mark Vandroff explained that because the AMDR arrays are heavier than the AN/SPY-1D(V) radar arrays on board Flight IIA ships, the stern modification was necessary to lower the Flight III destroyer centre of gravity.

    "The wider stern will displace more water, so you get more buoyant force .... That allows you to make the ship heavier and still keep the same waterline," he told IHS Jane's at the Navy League Sea Air Space Exposition in National Harbor, Maryland.

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  6. My feeling is that if the US navy can get the Flight III ships in the water on time and at a reasonable cost then that is good enough for now. I think B.Smitty made a good case for that.

    As to the PVLS design, I wonder if a combination hot and soft launch missiles might be a better idea. Hot launched missiles remain in the bow of the ship (a reduced number with more spacing and armour) while cold launch missiles could be dispersed around the ship.

    The new RN type 26 frigate will have CAMM missiles (equivalent to the Sparrow) placed on either side of the ships superstructure.

    A replacement Harpoon missile with cold launch ability could similarly be dispersed around the ship.

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  7. I am not sure if this is true but I have read that the greater size of PVLS tubes allows double packing a PVLS with SM-6 and some other weapons like VLA. Of course that requires developing and testing new VLS containers.

    The Zumwalts are innovative but lets get them fully sorted before series building them. AGS is far from sorted out and AMDR is not integrated yet. In time I think the Zumwalt minus AGS, replaced with more VLS cells and a five incher, may become the air defense cruiser the Navy needs. I really think that is its ultimate destiny.

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    1. No, I don't think that's true. The Standard SM-6 has a width of 21 in. and the width of the Mk57 cell is around 28 in. so there's not enough room to fit two.

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