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Thursday, January 29, 2026

Parent Design

What’s the Navy’s latest fad in shipbuilding?  Yeah … parent designs. 
 
The concept is that an existing, well established, “parent” design is used in a new shipbuilding program to avoid all the problems associated with new designs.  Being already in existence and thoroughly “wrung out”, the new shipbuilding program will have no problems since it will just use the parent design.  Sounds good.  Sounds logical.  Right?
 
The concept was the foundation of the successful disastrous FREMM/Constellation frigate program.  Of course, the Navy instantly abandoned the parent design as soon as the program became official and, in a shock to no one except the Navy, costs ballooned and schedules crashed.
 
The concept has also been applied to the Burke class although not by name.  When the Navy wanted the next generation surface combatant they didn’t even consider any option other than modifying the Burke parent design.  This eventually became the Burke Flt III despite the severe limitations the parent design imposed on the desired radar equipment and capabilities, stealth signature, weight margins, and so forth.
 
The concept is now being applied to the Constellation’s replacement, the National Security Cutter frigate (NSC-FF).  The new frigate is going to be based on the NSC parent design.  Of course, as we’ve seen, the Navy has already begun implementing fairly significant changes and the parent design is beginning to fade into the rear view mirror even as the program works to become official.
 
So, yes, the Navy has butchered the parent design concept in execution but what if they didn’t?  For the sake of discussion, let’s pretend that the Navy could flawlessly execute the parent design concept, meaning, no change orders, predictable costs, and schedules that can be met thanks to the absence of continuous change orders.  Would that produce a useful product?  Would the parent design result in an affordable, timely, combat-effective ship?
 
At first glance, how could a successful parent design approach not produce a successful, useful product?  By definition, the parent design exists and was, presumably, successful and useful so the “child” design has to be, as well, right?
 
Let’s take a look at some of the issues with a parent design approach.
 
Obsolescence – By definition, a parent design is obsolete.  Consider the timelines for the Navy’s parent design attempts.  The FREMM design dates back to somewhere around 2005 making the design 20 years old.  Would any sane ship designer really want to begin a new program with a 20 yr old design?  The Burke design dates back to the mid 1970’s, making it now a 55 yr old design.  The NSC design dates back to around 2000, making it a 25 yr old design. 
 
Do we really want to be basing our newest ship designs on 2-5 decade old designs?
 
While some characteristics and features can be updated from the parent, such as weapons, software, and sensors, others cannot, such as stealth.  For example, the Burke hull/superstructure stealth is obsolete and no longer effective but there is nothing that can be done about it.  The stealth signature is largely fixed by the hull/superstructure design.  Survivability is also largely fixed by the original design.  The FREMM, for example, was inherently unable to meet Navy survivability and damage control requirements, necessitating a major redesign resulting in the Constellation having less than 15% commonality with the parent design.  The Navy had to abandon the parent design in order to meet survivability standards.  Similarly, acoustic signatures, infrared signatures, etc. that are determined by the hull/superstructure shape, materials, and construction cannot be significantly altered or improved.  They are what they are.
 
Changed Requirements – Every ship design is determined by the operational and tactical requirements of its time and those change over time, especially over several decades.  The design, however, once established, is fixed and cannot be changed without abandoning the parent concept.  Thus, using a design that was intended to meet specific requirements that are decades old, and may no longer be valid, is unwise, to put it mildly.  The Burke, for example, was never designed for today’s electromagnetic environment and advanced stealth requirements and there is very little that can be done about it.
 
Design Limitations – Many design characteristics are inherent to the original design to a very large degree.  Things such as weight margins, stability, metacentric height, fuel capacity, structural strength, armor (or the complete absence thereof), speed, endurance, etc. are largely fixed by the original design barring a major redesign in which case it’s no longer the parent design.
 
 
Conclusion
 
The conclusion is painfully obvious.  The parent design concept has so many inherent flaws and limitations that it is simply not a valid, useful approach even if it were executed flawlessly.
 
This makes one wonder why the Navy even began attempting the parent approach?  Well, the answer is obvious.  The Navy has had so many failed, disastrous shipbuilding programs that the priority changed from a useful, lethal, modern combatant to simply getting hulls in the water without controversy and failure.  It no longer matters to the Navy whether the ship is useful.  They just desperately want a shipbuilding program to “succeed”, meaning, hulls in the water, on time and on budget … effectiveness be damned.
 
I completely understand the Navy’s mental state, at the moment.  They’re gun shy in the extreme and terrified of yet another failure.  Congress is incensed at their ineptitude and has begun inserting more and more restrictive oversight and conditions on budget allocations (as they should!) and the Navy is adamantly opposed to oversight.  The only way the Navy can get Congress off their back is to produce a “successful” program, no matter how ineffective it is.  The NSC-FF is barely one step beyond combat canoes but it serves the Navy’s purpose.
 
We should be producing beyond-Visby corvettes and, instead, we’re producing decades old NSC cutters as our “new” frigate.

27 comments:

  1. Well it worked for the Spruance/Kidd/Tico, the difference being that the Navy back then knew exactly what it wanted.

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    1. "Well it worked for the Spruance/Kidd/Tico"

      Did it? The Tico, derived from the Spruance parent, was top heavy, overweight (8100 t Spruance vs 9800 t Tico), aluminum superstructure, and crowded for the equipment fit. That's not a good design. Did they put hulls in the water? Yes. Were those hulls the best design possible, at the time? No, they were crippled by the constraints of the parent.

      On the slight positive side, you're right that the Navy at least was still focused on combat effectiveness back then even if it wasn't the best design.

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    2. Consider Spruance started build in 1972 and Port Royal as commissioned in 1994. 62 hulls in 22 years with 3 classes with one class having 2 flights (Tico). The first NSC was laid down nearly 21 years ago. I think our decision, action and engineering timelines need to speed up as much or more than build times.

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  2. Because the nation has way too many enemies to deal with thus cannot wait.

    Proper way is to design, build prototypes, let Navy operate for a while to find out maturity, if not, another run. Unfortunately, Pentagon cannot wait. Ironically, this is how PLAN does on new ships.

    Every one thinks his war is vital for the nation while others' are fraud and waste. It is hopeless.

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    1. Bottom line is Navy wants a frigate ASAP but at the same time wants to upgrade it to a mini Burke.

      LOL!

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  3. I think that the shift from evolutionary to revolutionary is much to blame, especially after decades of lost time where we weren't more rapidly evolving our designs. I was looking back at destroyer building history, and noticed a pattern, and that we started having problems as soon as we broke that pattern. You can go all the way back to the interwar years, and you'll see that while we built a class of ships, the next class was already under construction before the previous run had finished. This was the standard MO from the 30s, through the war, and all the way until the 1970s. Just by using quick wiki numbers, you can see we had continuous overlapping class construction until it stopped in 1967. At that point no destroyers were built til 1972 with the Spruances. So until 1967, we were designing upgraded, more modern follow-on ships basically right after one went into production. The Spruances broke the mold... since their design phase began the same year we stopped building the previous Charles Adams class. The same 5 year gap occurred between the Spruances and the Burkes. After that.... we mired ourselves in attempted-and-failed design programs that got progressively worse. We went from class overlap to "hopefully we can start building the new class before the last one ages out"!!
    So...I wonder what changed in the 60s that caused the Navy to abandon the formula that had seemingly worked for decades? Was it a pause to integrate new technologies like gas turbines and what would become Aegis? Was it budgetary? Zumwalts influence and his high/low mix that created a stumble in the norm?
    I think we've devolved into looking at parent designs because we're abandoned being evolutionary, in the right ways.

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    1. "I wonder what changed in the 60s"

      What changed is the focus. From the early 1900's (pre-WWI) on, the Navy had an intense focus on combat effectiveness. After the late 1950's and early 1960's, the war veterans (those who understood combat and designed the ships to meet that requirement) retired leaving people whose focus shifted from combat to career. The focus became empire building, budget pursuit, and career enhancement rather than combat-effective ship and fleet design and procurement.

      Without the crucible and filter of combat to weed out the incompetent, incompetent people who were politically adroit took over and foolish policies became the norm.

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    2. "What changed is the focus"

      In 1980 the Navy looked at a SLEP for the World War II class destroyers that had a FRAM update and were still in service. These ships were mainly in the Reserve. This could have resulted in a five to ten year life extension. These ships had been in service for 35 to 40 years and had undergone the above mentioned FRAM upgrade.

      One of the factors against spending the money was habitability. Which tracks exactly with the change in focus away from warfighting. Ironically the final assessment was this modernization could be done bringing these ships to a baseline Knox or Perry class, but the Navy did away with the "requirement" driving the question (escorts for convoys) and thus the subject became moot.

      https://www.gao.gov/assets/lcd-80-76.pdf

      From the gao report:

      "It appears that ship construction and design would restrict attempts to upgrade habitability on the FRAM destroyers to a level comparable to the Knox class. (included a reading area, television, and game room.)"

      It is interesting that some of the Arleigh Burke class is now undergoing a SLEP at 30 years of service. So what is old is new again.

      https://www.navy.mil/Press-Office/Press-Releases/display-pressreleases/Article/3480104/navy-approves-service-life-extension-for-four-arleigh-burke-class-destroyers/

      Looking4NSFS

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    3. As a bit of an aside, when I was surfing in relation to above comment, I came across the CGBL (Guided Missile Cruiser Baseline) project- A study the Navy did, looking at Tico capabilities but with an enlarged variant of the Burke (620x69) hull. I hadn't heard of it before, but it's fascinating in that it integrated a lot of excellent design features, including stealthy shaping, and even mentions some armoring. It was oddly created strictly as a study, although elements of it were rolled into the later CG(X). Not sure if you're familiar with it, but it's interesting how they seemingly had an outline for a decent ship, but never followed through with what they had. It's kinda funny that the graphics of the BBG are reminiscent of the CGBL.

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  4. Something interesting I've heard is that part of the problems with Constellation are also the differing doctrine and ideas in the designers. On the original Italian FREMM design, for instance, power distribution and the generators are seperate from the engine deck, the idea being that you want to increase survivability by spreading critical parts out so that one hit is not catastrophic.

    On the other hand, the USN practice is to concentrate power subsystems into a single point, in order to avoid the risk of multiple points of failure spread throughout the ship.

    The intent is the same, but the ideas are completely different.

    I wonder if this is trauma from SoDak's duel with Kirishima, where an early hit took out an electrical relay and left her helpless...

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    1. The FREMM design put the gas turbine and 2 (of 4) Diesel Alternators in one compartment. If the main engine compartment was hit, you were reduced to 2 Diesel Alternators assuming the electric distribution system held up. That is not a high level of redundancy. The original FREMM was built to a cost and it shows. On that basis it was a questionable choice in the first place if USN redundancy requirements were going to be applied.

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    2. I doubt anyone currently in the USN looks at WWII battles or lessons learned. Probably not from any era...

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    3. "I wonder if this is trauma from SoDak's duel with Kirishima, where an early hit took out an electrical relay and left her helpless."

      The SD electrical casualties resulted from shock from her own main guns firing. Various breakers, fuzes, and transfer switches failed to operate properly and a cascading series of electrical failures then occurred. This is all documented in the official Navy damage report from the battle which can be found here: https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/w/war-damage-reports/uss-south-dakota-bb57-war-damage-report-no57.html

      I have also read that the SD engineer incorrectly wired the breakers so that if one failed, they all failed. However, this is not supported in the official Navy damage report from that battle.

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  5. Fincantieri on receipt of contract for Constellation allowed a margin of 250 tons for changes. Then the NAVSEA mandated an ever changing stream of changes over 5 years! Congress had specified that build should not begin until design complete which Navy ignored. The individual NAVSEA bureaucrats/engineers had their own set of requirements, V&V tables and risk registers, which totally miss the fundamental point that small changes tend to have a painful knock-on effect if they don’t know what they're doing as shown with Constellation when it reached the best part of a 1,000 tons increase in weight, appears there was their no naval architect employed at NAVSEA to control the bureaucrats/engineers, comes across as total mismanagement - weight management is a basic to ship design.

    The Navy had specified a weight/percentage Service Life Allowance, SLA, as all ships put on weight over their ~30 year life, for the Constellation it was 5% built in, approx. 400 tons and with the weight added by NAVSEA bureaucrats/engineers, it calls into question Constellation's basic seakeeping ability, reduced speed, zero growth ability, etc. etc.

    If the Navy had wanted a frigate designed to USN survivability standards they should have never used the Italian FREMM as the parent design but designed it in US but assume Navy assumed that was not possible in the time required due to the lack of naval architects etc.

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    1. The quote above with:

      "If the Navy had wanted a frigate designed to USN survivability standards they should have never used the Italian FREMM as the parent design but designed it in US but assume Navy assumed that was not possible in the time required due to the lack of naval architects etc. "


      Got me thinking maybe we should be trying to find and get those "real naval architects" to teach us as below for Stinger missile:


      https://www.defenseone.com/business/2023/06/raytheon-calls-retirees-help-restart-stinger-missile-production/388067/

      Yes I know whole ships are more complex but if any retirees of naval engineering are out there you, out of love and honor for your country, should be trying to teach another generation.

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    2. "Fincantieri on receipt of contract for Constellation allowed a margin of 250 tons for changes."

      Where did you get that pieced of information from? I have not seen that.

      "SLA ... for the Constellation it was 5% built in, approx. 400 tons"

      Again, where did you get that?

      "assumed that was not possible in the time required due to the lack of naval architects"

      The Navy no longer designs ships. Design work is done by companies such as Gibbs & Cox.

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    3. "you, out of love and honor for your country, should be trying to teach another generation."

      I don't believe that we lack competent naval architects in industry. What we lack is a willingness to heed them. For example, the Independence LCS was built without cathodic protection - an issue understood and solved a couple hundred years ago - despite the designers calling for it. It was dropped as a cost savings measure by the Navy along with a host of other ill-advised cost saving measures. We know how to build ships. We just choose not to do so in our misguided pursuit of illusory cost savings. For example, the naval architects emphatically told the Navy that the Burke was unable to accommodate the required radar and support and utilities for the Flt III and the Navy's response was to reduce the capability of the radar in order to cram it into the Burke. Naval designers are telling us what we should do but we're ignoring them.

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    4. Source of the 250 tons margin comes from the Cavasships podcast Dec. 4, a Constellation post mortem ref Retd Rr Adm Chuck Goddard who was a member of the Fincantieri winning bid team for the FFG(X), the podcast worth a listen.

      The 5% SLA was specified in the USN FFG(X) 2019 RFP, which these days does not appear to show on internet.

      Personally think the Adm in charge of NAVSEA should be fired and replaced by an experienced professional naval architect. Unbelievable as it appears the Adm did not bother to rein in the NAVSEA bureaucrats/engineers who made over 500 or so design changes over 5 years which reported as requiring 20,000 new drawings with a three year program delay, increase in weight of near 1,000 tons and costs and which killed the Constellation (Fincantieri suing the Navy over the changes and it will be interesting if cases ever reach court or will Navy buy Fincantieri off with new contracts as too embarrassing).

      To avoid the "frigate fiasco" of the previous program the new SecNav Phellan has mandated that he will personally oversee, control and approve any design changes for the new FF(X). It's a direct response to the "design creep" that plagued the previous Constellation class program and highlights the total lack of management of Constellation that is resulted in the SecNav not trusting in any of his Admirals, so decided he has to do the job personally.

      PS Would note the NSC/FF(X) survivability design was the old Level I, whatever one may say about European survivability standards I'm sure the bid Constellation standard was way above FF(X) level.

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    5. "Cavasships podcast"

      Thank you for that reference. I hadn't heard that podcase but I've listened to it now. It was interesting but worthless.
      I've got a post coming on it.

      "SecNav Phellan has mandated that he will personally oversee, control and approve any design changes"

      Which have already begun to run rampant.

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  6. “The concept has also been applied to the Burke class although not by name. When the Navy wanted the next generation surface combatant they didn’t even consider any option other than modifying the Burke parent design. This eventually became the Burke Flt III despite the severe limitations the parent design imposed on the desired radar equipment and capabilities, stealth signature, weight margins, and so forth.“

    I believe you’ve mistaken the Flt III for the DDGX program. The DDGX program is slated to be the next generation large surface combatant of the USN. As the Arleigh Burke uses the same hull as previous flights, it is the same class of ship. The DDGX is a clean sheet design specifically built for good growth margins.

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    1. I should also note, the addition of the SPY-6 is certainly worth it. The SPY-1 needs to be upgraded eventually anyways. As for the number of them, I think you’re mistaking the reduced RMA count of the Flt II for the count on the Flt III, though there may be some material about the Flt III I haven’t read which states that they wanted more RMAs for it.

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    2. "I believe you’ve mistaken the Flt III for the DDGX program."

      No, I meant exactly what I said. The Flt III is the replacement for the cancelled CG(X) and the Navy looked at no other options despite the inherent limitations.

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    3. "I think you’re mistaking the reduced RMA count of the Flt II"

      Again, I meant exactly what I said. The requirement for the Burke Flt III AMDR was a 22 ft radar and due to inherent limitations of the parent Burke, they had to settle for a 14 ft radar. From the Burke Wiki,

      "An AMDR with a mid-diameter of 22 feet (6.7 m) had been proposed for CG(X), while the DDG-51 Flight III design could carry an AMDR with a mid-diameter of only 14 feet (4.3 m). The Government Accountability Office (GAO) found that the design would be "at best marginally effective" because of the "now-shrunken radar"."

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    4. "The requirement for the Burke Flt III AMDR was a 22 ft radar and due to inherent limitations of the parent Burke, they had to settle for a 14 ft radar."

      Here's a question that's occurred to me that I haven't heard addressed. Suppose we backed off the requirements for the Burke Flight 3 to make it just an air and missile warfare destroyer. That is, delete the helicopters, hanger, and flight support crews and support for them. Would this buy enough additional weight margin to make the radars bigger?

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    5. When the Navy ordered the Raytheon AN/SPY-6 new gen AESA/GaN radar it was estimated it would be 30 times more sensitive than its predecessor, the SPY-1, but and a big but after testing Raytheon claimed SPY-6 was 100 times more sensitive.

      How this offsets the size reduction of the array from 20' /22' to the Burke Flight III's 14 ' unknown, Navy has said that radar sensitivity scales as a cube of the size of the radar aperture, and while improvements can be made to the T/R modules said this is a linear not cubic relationship and only adds marginal capability on the order of +1 or 2 dB. Smaller arrays create diffraction-limited beamwidth and insufficient to provide engagement quality tracks at longer ranges, size matters whether the radar is AESA or not.

      Would note the Japanese picked the Lockheed SPY-7 in preference to the Raytheon SPY-6 for their ASEV ~17,000 ton BMD/HGV cruisers.

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    6. "delete the ... Would this buy enough additional weight margin to make the radars bigger?"

      Without an itemized listing of weights we can't know for sure but I would think it would. Even that partial list you cited is a LOT of weight. However, weight is not the only constraint on the Flt III radar size. They are also constrained in supporting utilities (power, cooling, etc.) and superstructure area. Additional power generators and coolers, among other things, would have to be fit into an already overcrowded internal ship's volume. Would deleting the items you cite free up enough space? I would think so.

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    7. "estimated it would be 30 times ... testing Raytheon claimed"

      As they used to say, a manufacturer's claim and a dime will get you a cup of coffee (betraying my age with that reference!). As you know, claims are essentially works of fiction. Most claims are based not on testing but on theoretical calculations under perfect conditions and have no applicability to real world scenarios such as detecting stealth objects.

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