Tuesday, August 19, 2014

Undisputed and Unaccepted

There are certain enduring naval debates such as large carriers versus small carriers.  One of these debates is the value of small missile boats versus large multi-function vessels.  The leading proponent of the missile boat is Captain Wayne Hughes Jr., USN(Ret.).  He has literally written the book on the subject.

To summarize, his contention is that naval combat power is better distributed among many small vessels (the missile boat) than concentrated in fewer and larger vessels (Burkes, for example).  A mathematical model has been developed which factors in the various characteristics of naval warfare such as offensive power, defensive power, damage resistance, numbers of vessels, etc.  The model clearly shows that the single most valuable characteristic of a naval fleet is numbers.

It is a major irony that Capt. Hughes theories are simultaneously undisputed and unaccepted.  The model results are what they are.  There’s no disputing them.  What can be disputed, however, are the underlying assumptions that go into the model.  To repeat a saying as old as computers, “Garbage In, Garbage Out”.  If the data or assumptions are flawed then the results will also be flawed even if they are mathematically correct.

Chinese Houbei Missile Boat - Distributed Power

Is the Hughes model flawed?  I believe so.  For starters, the model is based on the assumption of fleet versus fleet.  It only loosely takes into account air power, for example.  Consider the contention of distributed power (small boats) versus centralized (Burkes).  While the salvo model reasonably models the surface versus surface action and associated factors, it does not really account for air power.  The lowly helo, or any other form of air power, would be essentially 100% effective against any number of missile boats since they have no AAW capability.  In contrast, a Burke would offer a significant defensive capability against air power.  So, the model suggests that missile boats are the preferred force structure but a consideration of air power suggests the opposite.

Or, consider the effect of scouting.  The model considers scouting but in a generic way.  As such, the model predicts the value of numbers and dispersion when evaluated against a generic scouting factor.  However, the model does not consider the impact of modern satellite systems, over-the-horizon radars, ESM dectection, and other scouting methods on the pre-combat scenario.  If the missile boats can be tracked before they ever get into the area of operations then they are just another drone target exercise for the defenders.

One of the central implications of Hughes’ model is that the enemy who faces a distributed fleet (missile boats) faces a dilemma – does the enemy radiate to find the distributed forces and thereby reveal his own location or does he remain silent and risk detection and destruction by the distributed force.  What is not considered is the third option which is to remain silent and let air, space, or subsurface assets do the detecting.

Another example…  The model does not really take into account the impact of an area AAW capable ship which can extend and provide its level of defense to the ships around it.  Further, CEC (cooperative engagement) effects are not accounted for.

One more …  Electronic warfare is not factored except in a generic way such as an improved defensive “rating”.  Things like deception and misdirection via decoys and false signals can have a huge impact on the conduct of a battle and yet are unaccounted for.  Small craft have little or no capabilities to wage this type of combat. 

Finally, the model deals only with the actual combat portion of the force structure issue.  It does not address seakeeping, range, endurance, support requirements, refueling, supply, or any other issues that strongly influence ship type selection.  The small missile boats are just “there” at the start of the battle in the model.  How they got there, or even whether they’re capable of getting there over vast distances and through heavy weather, is not addressed.  The combat model may suggest that small vessels are useful but the logistics and other issues may (or may not) preclude their use and this is not addressed.

Study of Hughes’ model quickly reveals that the model is very simplistic which is ideal for grasping basics or performing quick and dirty analyses, however, it falls well short of simulating actual combat involving the full range of combat assets and effects.  The model is equivalent to an introductory exposure to modeling and tactics.  It’s a good starting point for further, in-depth study but is not the end point.  To be fair, Hughes makes no claim that his model is a full featured simulation.  It is his supporters that have taken the model’s results and run with them beyond the model’s capabilities.

So, what is the takeaway form this discussion?  Hughes model is too simplistic to be an authoritative answer to any question of force structure.  Thus, the conclusion that distributed forces are the preferred force structure is a suspect conclusion.  The model offers suggestive conclusions that merit further investigation but far more factors need to be accounted for.  We have, therefore, a model which is undisputed but, because of the limitations, unaccepted and rightfully so.  A more distributed force structure may well be desirable but the model does not prove it.


  1. Hughes is right in the wrong way

    Replace missile boat with Missile Aircraft, and it gets really confusing.
    A Carrier in the pinnacle of concentrated power, yet it operates as a swarm of distributed platforms, some times.

    The same goes for ASuW helicopters and destroyers.

    I did two posts on thi a while back that I've dug up

    I even prompted D&F to join in :)

    And Ive just noticed you prompted my first post!

    I appear to have overworked my tiny brain today :)

  2. The model shows that numbers matter in force-on-force situations. What's interesting about it is it shows that numbers matter more than improvements in offensive, defensive or staying power.

    There are variations that capture the contributions of mutual support between ships in a task force.

    I agree, though, that the papers and books I've read on the subject treat airpower in the abstract, as essentially another version of a pulsed salvo. This may under represent its contribution.

    Small missile craft can have effective EW systems, especially those that couple decoys and deceptive techniques with low observable technology. They can also carry point defense and local area defense missile systems.

    If you look over Hughes' & Co.'s New Navy Fighting Machine, you'll note the small missile combatants only comprise a small portion of their overall fleet structure.

    Inexpensive combatants can be very valuable for screening and tripwire duties.

    One thing that i somewhat disagree with in their writings is equating "numerous" with "small". We can build larger ships inexpensively. Numbers is what matters, not size. Numbers are driven by cost. Size is only one factor in the cost equation.

    1. As you recognize, the problem is not with Hughes' model. It is what it is. The problem is with people who have taken the results and run to the extreme with them. There are those who use the model to argue for an almost all small boat navy. As you point out, the model addresses salvos between fleets. It does not address the many other factors that determine the "fit" of a small combatant.

      Ah, while I agree with your last statement that we can build larger ships inexpensively in theory, I'm not sure the USN has demonstrated any such capability! Not disagreeing, just making a wry observation!

      As I mentioned in the post, one of the major shortcomings of the model is that the small combatants are simply assumed to be present where needed at the start of a battle. There is no accounting for how they get there, their observability, their support needs, etc. To be fair, that's not the purpose of the model!

  3. Is Hughes asking the wrong question?

    While small vs large is always a good debate topic, probably good for selling books. I would have thought a better, more relevant question is probably what is the ideal mix of large and small combatants?

    No Navy is ever going to 100% large or 100% small, but how to you get the mix right?

    A maths model is never going to give you the correct answer, just to many unknowns. Different situations, different threats would also affect your answer.


    1. Mark,

      Take a look at the New Navy Fighting Machine.


      They go into considerable detail about the mix they want.

      The breakdown is 10% of SCN budget for a "green water" navy, including these small coastal combatants.

      10% for strategic deterrence (SSBNs and ABM ships).

      And 80% for more traditional, blue water ships.

    2. Thank you,

      a very interesting read, he covers a lot of territory.

      He argues you can experiment with the operation of smaller ships, but if you build ten times as many, is ten small experiments less risky than one big one, I am not convinced this assumption is valid.

      He assumes that SSK's can be built at a much lower cost than SSN's, Australia's experience with our Collins class subs appears to argue that your SSK is only cheap if it built to a lower standard. Similar to what you see with UAV's, A reaper is cheap only because it is built to a lower standard, not because it is unmanned. While our Subs have enjoyed some success in naval exercises, they were unable to get to the exercise area undetected, in a real war, they would have been destroyed in transit. My point is cheap is not always effective in combat.

      That said I do see small combatants having an important role, especially in the green water environment.

      If you look at surface combat in WW2, more than 10% happened in the green water environment. This is the environment where US PT boats inflected heavy losses on the Japanese navy in WW2. If an engagement with Chinese forces were to occur, I suspect a large portion would occur in the green water environment. The US navy has not had this kind of capability for quite some time. Are we really ready for this? I would argue this is what China is getting ready for.

      The other role I see for the small combatant, is that of remote sensor node. We do this with aircraft (E-2), but it is expensive, you need a carrier in your combat group for example, ASW helicopters are good, but if you want 24/7 persistence you need a few and need an expensive platform to operate the from. My idea is a tiny, corvette sized ship, unmanned and unarmed. Equipped with a quality radar and towed sonar array which is all networked to a DDG or CG. My thinking being that a DDG can today effectively engage targets hundreds of miles away, but a number of small, cheap assets located at the limits of the DDG's sensor would enable to make full use of its long range weapons.


    3. Mark: "That said I do see small combatants having an important role, especially in the green water environment."

      That's an oft repeated statement. As a notional concept, it's fine. My problem with it is what specific green water locations do we anticipate operating small combatants in? I can see police type operations off the coast of African nations but I have a hard time seeing much in the way of green water combat ops anywhere. I suppose you could call the MidEast waters "green" but any combat ops there will be decidedly "blue" in nature.

      What do you think?

    4. Mark, your question is good and the answer is straightforward. Or, at least the methodology to answer it is. It starts with a coherent geopolitical strategy. After that, it's a simple matter of wargaming out the military required military strategies to support the geopolitical.

      Of course, it all starts with the geopolitical which we are badly lacking today!

    5. When I was thinking green Water, I was thinking in terms if the large Archipelagos of the pacific, namely Indonesia/Malaysia and the Philippines. Too big and open to be called Brown and not Blue either. If my definition is wrong, let me know.

      It is in these restrictive waterways that I see small powerful craft would seek out and hunt larger vessels that venture into these more restrictive environments. This is exactly the role US Navy PT boats did so well in WW2. In this environment ship losses are inevitable in my opinion.

      My thinking is there are two ways to dominate a green water environment like this. One is through the use of air power, based on Carriers which can project power in from afar, or you deploy surface units to dominate up close.

      Unfortunately in area as large as the Pacific you will never have enough carriers to cover the entire battle space. Current budget limitations only add the shortfall. Obviously your carrier battle groups will be deployed to areas of primary interest, but what you you deploy to cover the gaps? My answer is small cheap, relatively well armed ship which you can afford to deploy in large numbers. Now such a ship will not win a battle on its own against an enemy carrier battle group, but that is not is job. Its job survive long enough to report its location so other more suitable assets can then do that job.

      If you give this boat say a 3 inch gun, and a missile like Hell fire, you can engage other small combatants and offer fire support for small operations, without the need to bring high value assets like a Burke.

      I do not see these ships as coming out into a Blue water environment to challenge a blue water navy. My thinking is that once you get into a blue water environment, your large high end assets would come into there own and would dominate a force made up of these small combatants.

      I hope this makes sense.


    6. Mark,

      I think the Aussie Collins class experience has a few aspects to it. Australia had virtually no submarine shipbuilding industry and was relying on Kokums and the US for significant expertise. They had to create production facilities from scratch. And after all this, they only built six boats.

      If the US were to enter the SSK business in a significant way, we could overcome these early startup issues with a larger production run, as well as leveraging our considerable SSN experience.

      I agree in part with your concept for small ship usage in green water, however one often neglected drawback is that small ships require ports too. These ports are subject to attack, where ships tied to the pier are easy targets.

      I think the PT boat isn't a good example. It's too small and short ranged. I'd rather see us build a "combat-ish" OPV. Anything from an enlaged Sentinel class with small AShMs, to a low-cost L'Adroit OPV that could carry a medium helo, to a larger ship like the USCG OPC. Obviously the bigger you go, the more expensive they'll be.

      L'Adroit is an interesting compromise. It was designed with the idea that small patrol vessels like the Sentinel really aren't all that cost effective. Going up a size notch doesn't cost THAT much more. The engines on L'Adroit are only modestly more powerful than the ones on Sentinel (2 x 5.6MW vs 2 x 4.3MW). Yet you gain a much more seaworthy vessel, with greater range and endurance, and the ability to carry a helicopter.

      L'Adroit has plenty of deck space to mount weapons, if needed. Of course everything you add adds to the price.

    7. B.Smitty,

      What I was thinking of was an up gunned Armidale class OPV, which is about 300 Tonnes. It could easily be up sized to 500T at low cost.

      Small crew (21) would grow to 30, the unit cost from $35M to $50M

      I do like your idea re a LÁdroit size ship, I see where you are going, this ship could to easily carry more firepower.


  4. Well I think you conclusively sank that theory.

    And I would have to agree with you, Faced with a Full Spectrum Carrier Battle group, with the flexibility of top range modern naval assets, small fleet missile boats will be at a significant disadvantage.
    You simply cannot equip small boats with the full range of systems due to power and space requirements, and hence the advanced force will have the overriding choice of attack tactics, playing to their strength and the small boats weaknesses.
    Recon range, weapons reach and speed \ endurance is all going to favour the larger ship, and in terms of simple positioning and attack these are definitive in naval battles. This was established WAAAAAAAAY back and unless the laws of physics just massively changed or you have an absolute idiot commander the small boat is going to lose.
    There is no reason at all ( unless you’re the a for mentioned idiot commander ) that you can’t ensure that your engagements don’t favour numbers, With extended sensor range you would always ensure an engagement is as near as 1 to 1 as you could manage. ( preferably, massively in your favour )
    Admittedly close to shore, “green water” navy’s have some advantages that allow them to punch over their weight, but contrary to current popular opinion they have some massive disadvantages too. And with the right tactics, in a battle for naval dominance they are screwed.


    1. Beno,

      In their defense, I don't think anyone is arguing in favor of an entire fleet of small combatants. Just that they form a component of the overall fleet.

      Take a look at the NNFM link i posted above.

    2. For some reason I can’t seem to get at it ? Possibly the Chinese are stealing it as it attempt to wend it was over the Atlantic to me, I’m not sure.
      But as ComNavOps our current distributed forces are often helicopter or fast jets, representing significant missile and torpedo boat functionality. One shouldn’t forget that RHIB’s and landing craft might also count, and we operate patrol boats and inshore craft already.
      So what you’re talking about here is a blue water fast attack craft or corvette, and I’m not seeing the utility? (Short of being cannon fodder) Although I apologise I can’t see the document properly. Could you maybe treat me to the salient points?

    3. Here it is on my Google Drive,


      They classify them as "green water" missile combatants.

      One purpose is to allow us to "be there" on the surface, without committing Burkes or other large, expensive surface combatants. Consider situations where tensions are escalating but hostilities haven't started. We may need ships to enforce a blockade or inspection regime that operate inside an enemy's A2/AD umbrella. The transition to war could happen in an instant. Do we really want Burkes and Ticos and CVBGs in the middle of that initial furball? The ROEs may force us to wait for the enemy to shoot before returning fire. A squadron of six Houbeis approaching a pair of Burkes enforcing a blockade location could light off 48 AShMs in an instant, before we have a chance to respond. Even with their formidable defensive capabilities, the Burkes would be hard pressed to survive the attack.

      OTOH, if we had a squadron of missile combatants performing the same duties, yes we may lose some, but some may survive due to sheer numbers and point defenses, and their loss is far less painful than losing a pair of Burkes.

      Hughes' notional missile combatant is a 500-600 tonne ship with 8 missiles, 30-35kt top speed and manning around 25.

    4. Hey, thanks ill give it a read now :)


    5. Thanks B.Smitty quite an interesting document. They really go to town on their explanation.
      I have to say thought they recommending a single combatant, but an integrated group of ships they seems to have designed, from VTOL small carriers right down to the kind of ships we are talking about.
      ( they are also recommending several hundred even smaller vessels )
      I understand the way they are slotting these together. And it does kind of work, but without any cog in this machine the whole thing kind of falls apart.
      It’s a massive outlay, 10% budget would still take years to design and build new classes. It’s basically a whole new SUB navy.
      Interesting document tho thanks.

    6. It would be a different Navy from what we have now.

      I'm not a huge fan of their reliance on STOVL carriers. They make a case for them, for sure, but putting all your eggs in the F-35B basket seems extremely risky. Plus STOVL carriers can't carry the force multipliers available to CTOL carriers.

      I don't get building a mere 12 fast ASW vessels. What good will 12 ships do? You might see 3 deployed at any one time. 12 NGFS ships also seems pretty limited, especially since they freeze all amphibious ship production. 12 MIW ships also would a rather small number to fill the need.

      The 160 OPVs they want are essentially USCG Sentinel class cutters. In conversations with Capt. Hughes, he's indicated he'd prefer to cut that number down to buy more missile corvettes. Maybe 60 of each.

      The 400 inshore patrol boats are a variety of small RHIBs.

      10% is a lot, but you do get 248 vessels out of it, not counting the small RHIBs. They can provide a significant chunk of day to day "Phase Zero" forward presence around the world.

      The missile combatants only account for around $150 million/year of SCN spending (about 1%). Most of the 10% is spent on OPVs and CVLs.

    7. Due to overwhelming demand (B.Smitty asked about it once), I'll be publishing a post on the NNFM in the near future.

  5. Also ;)
    I’m not going to run the model, BUT if you were to support a navy of small fast missile boats with the range, numbers and equipment to take on a modern advanced navy (LCS? lol) it’s going to cost you a lot more to run.
    Personnel, supply, training and maintenance will go through the roof. Nobody has tried it yet properly ( in my opinion ), but I would expect the initial build cost of each unit to be more expensive tonne for tonne too.
    Burkes might seem expensive, but they really aren’t when you stack them up against an equivalent capability.

  6. In a lot of ways I see this as a rehash of a very old argument, that started with the introduction of the torpedo, with the threat of an unfavorable exchange rate. If a singe missile kills either a cruiser or a corvette, it makes more sense to lose a corvette per missile. This is the base of the argument. However as stated above, there are many other factors that are important to any navy (range, versatility, sensor range).

    Randall Rapp

    Did you ever check out that study on seabasing I recommended, CNO?

    1. Randall, I did read it. What particular aspect did you want to call to my attention?

    2. Just the differences between what was originally planned for the MPF(F) and what was actually built, and the HSV fast shuttling transport concept that led to the JHSV.

    3. Possibly older
      Juan Ecolle was before the self propelled torpedo I believe
      Originally the word applied to what we now call mines.

  7. Perhaps a useful exercise would be to find an example of small ships beating big ones?

    1. There are numerous examples of torpedo boats sinking or damaging large warships.

      Egyptian Osas vs the Israeli destroyer Eilat.

      Pakistani destroyers Khaibar and Badr hit by Indian missile boats.

      USS Cole.

      However none of this is really relevant. The small combatants espoused by Hughes & Co. aren't really meant to beat larger enemy warships by themselves. They are meant to complicate the enemy's targeting picture and cause them to divert time and resources away from attacking the battle fleet. They are also meant to act in traditional screen and tripwire roles.

    2. Just to clarify, Hughes small combatants absolutely are meant to threaten and beat larger warships. If not, they wouldn't be a threat and wouldn't complicate the enemy's targeting.

    3. Threaten, yes. But they don't have to beat large warships by themselves. They are meant to fight as part of the "battle network".

    4. More examples from the German E-boat Wikipedia page,

      "During World War II, E-boats sank 101 merchant ships totalling 214,728 tons.[6] In addition, they sank 12 destroyers, 11 minesweepers, eight landing ships, six MTBs, a torpedo boat, a minelayer, one submarine and a number of small merchant craft. They also damaged two cruisers, five destroyers, three landing ships, a repair ship, a naval tug and numerous merchant vessels. Sea mines laid by the E-boats were responsible for the loss of 37 merchant ships totalling 148,535 tons, a destroyer, two minesweepers and four landing ships.[6]"


    5. B.Smitty: "Threaten, yes. But they don't have to beat large warships by themselves. They are meant to fight as part of the "battle network"."

      It's been a while since I've reread Hughes book in detail but I don't recall him suggesting that small combatants would operate as part of a network. I don't recall that he specifically ruled that out but networking was never a mandatory condition of small combatants.
      My recollection is that the small combatants were self-contained fighting units which would provide their own sensing though nothing about the model would preclude networking.

      Am I recalling that incorrectly? I may be.

    6. From the New Navy Fighting Machine,

      " Coastal combatants are heavily armed, but small enough to accept affordable losses. They should operate in tactical formations of two, four, eight, or twelve vessels. They carry no surveillance aircraft, so depend on CVLs or shore-based reconnaissance.
      They have small crews in combat and when put out of action the crew is expected to abandon, rather than try to save, the ship, and to be rescued by other vessels. They might team with friendly forces in constricted waters where the large blue water ships should
      not be put at risk, for example, operating from Turkey or Romania in the Black Sea, from Sweden or Denmark in the Baltic, from Saudi Arabia or Kuwait in the Arabian Gulf, from the west coast of South Korea in the Yellow Sea, or Colombia or Panama in the Caribbean.
      They can serve as an advance force to screen blue water ships conducting amphibious operations, or protecting MSC (Military Sealift Command) or MARAD ships delivering men and materials that might be attacked while entering a friendly port. "

      So they definitely see the small combatants acting as part of a larger system.

    7. B.Smitty, my apologies. I thought you were referring to Hughes' work as presented in his book. From the book, I don't recall any reference, direct or indirect, to networking as a characteristic of small combatants.

      For the NNFM, you're quite right that a degree of networking is implied.

      This is one of the potential weaknesses of both the NNFM and the current Navy. As I've stated in multiple posts, I'm dubious that we will be allowed to maintain the degree of networking that we assume we'll enjoy. Given that the Navy (and military in general) refuse to conduct exercises under conditions of maximum electronic warfare, we'll have to wait to find out (probably the hard way!) how robust our networking will prove to be.

      The problem with building an entire force based on networking, CEC, shared data pictures, Link XX, etc. is that if the desired communications prove unachievable, we'll be totally unprepared.

      The interesting point is that we're fully and blindly commited to networking while simultaneously recognizing its fragility by insisting on alternatives to GPS in new guided weapons and pushing for autonomy in long range UAVs. I give credit for recognizing the potential limitations but give equal blame for not (yet) recognizing the same limitations in fleet networking and failing to exercise and train accordingly.

      Thus, the networking is both a cornerstone and a potential weakness. I suspect China and others are devoting a great deal of effort to disrupting our networking and I suspect that the routine Chinese hacking of our military and industrial networks is, partially, practice for electronic attacks on our ships and aircraft come combat.

    8. Sorry CNO, I used the dreaded "battle network" buzzword.

      In this instance, I meant to simply say it is a "component of a larger suite of complementary systems". Rather than to say it is a node in a communications network.

      We have used smaller ships in these roles well before the advent of modern digital data networks. So I don't think networking is a prerequisite.

  8. Here is a PowerPoint slide presentation which the advocates of the New Navy Fighting Machine used in December 2013 to describe their vision for a revised USN fleet architecture:


    Their NNFM philosophy concerns fleet architecture concepts operating at a higher conceptual plane, it is not strictly concerned with the future role of their notional small surface combatants.

    There are some number of NNFM opponents who take the position that very little of the battlespace modeling work done by the NNFM advocates can be relied upon, saying that the modeling results are contrary to what has been learned through many years of real world experience.

    Who is right, and who is wrong? Or is there any kind of clear answer to that question?

    1. Real world experience engaged with whose navy, Japan's? That is the last time I can think of that we were engaged in significant fleet actions.

    2. Anon, I neither defend nor attack the NNFM but there are many examples of naval combat since WWII that can be examined for lessons: Falklands, India-Pakistan, Israel, Praying Mantis, Cold War US-Soviet, etc. Even small incidents offer a chance to learn. For example, the recent buzzing of the US ship by a Russian aircraft should offer some insight to the relative employment of aircraft versus ships in confined areas. We can learn from the maneuverings of ships and aircraft even if they don't result in the actual pulling of the trigger. The rival maneuvering, surveillance, intelligence, tactics, etc. are all relevant.

      As I say, plenty of lessons to be learned. The challenge, of course, is to obtain unfiltered data and accounts of the actions - no small feat!

  9. 'Just to clarify, Hughes small combatants absolutely are meant to threaten and beat larger warships. If not, they wouldn't be a threat and wouldn't complicate the enemy's targeting'.
    In a scenario whereby small ships are patrolling home waters, each individual craft that is able to locate hostile vessels and provide targetting information to land based missles is a threat. Wouldn't a large number of civillian craft (speed boats, fishing vessels etc) all provide a potential threat that would be very time consuming to counter ie check or destroy.
    You have your network of sensors and as a tripwire, maybe a few coast guard vessels.
    Cheap and effective. Wasn't a navy/marine task force defeated in a simulated assault because of info provided by 'hostiles' on fishing vessels?
    Dave P

    1. Hughes' small combatants are not visualized as defensive in nature but, rather, as forward deployed offensive platforms. Am I misunderstanding your point?

  10. Another craft that needs to be added is these small combatants submersible variant, the minisub. With modern technology, much harder to locate, and easily as dangerous, but more expensive to build & operate, and requiring higher trained crews.

    Randall Rapp

    1. Randall,

      IMHO, you have hit on a Streetfighter concept that would be interesting.

      The Hughes/Cebrowski Streetfighter is a 5-600 ton ship, with 8 anti-ship weapons, and minimal anti-air capability. For defense, it relies on low signatures, supporting resources, and limited point defenses.

      Now look back to WWII.

      The German Type VII U-boat is a 5-800 ton ship, with up to 14 anti-ship weapons, and minimal anti-air. It too relies on low signatures, supporting resources and limited point defenses.

      Note, the Type VII was not a true submarine. It was a submersible ship that spent most of its life on the surface.

      This distinction gives us potential for cost optimizations vs a true submarine. It does not have to have the same level of submerged performance. In this role, it also does not need extensive ASW sensors. It is primarily an ASuW vessel.

      The distinction also, potentially, allows us to rectify one issue with all modern SSKs: slow deployment speeds. A submersible could be optimized for surface performance and could be built to reach and sustain higher surface speeds.

      Thinking about a modern Type VII in the same size range, we could use a modern-designed submersible hull form and a modern diesel-electric plus battery power plant. Notional specs,

      Displacement: ~700tonnes
      LOA: ~70m
      L (pressure hull): ~50m
      BOA: 6.2m
      B (pressure hull): 4.7m
      Draft: 4.7m

      2 x 6-7MW diesels
      1 x electric motor
      1 x prop/propulsor

      25+ kts surfaced
      10-18 kts submerged

      Max Depth:

      8000nm surfaced
      ? submerged

      Endurance: 3+ weeks surfaced
      Complement: 15-30

      4 x 533mm torpedo tubes (14 weapons. e.g. TLAM, MK48, SLMM, LRMS, LRASM/NSM or more LWTs)
      14-28 IDAS missiles in 2-4 VLS clusters
      1-2 x 30mm RMK-30 retractable cannons

      3D radar
      Surface search radar
      Modest sonar suite

      Sail storage for a single RHIB for VBSS, or mine hunting ROV.

      Unit cost:
      ? (It would have to be far less than existing SSK designs and not THAT much more than a pure surface Streetfighter to be worthwhile.)

    2. Another thing I've wondered if any navy has experimented with is underwater recharging. Think aerial refueling but a nuclear sub recharging a diesel's batteries (could also probably resupply oxygen too).

      Randall Rapp

    3. I don't know man. How likely would this be to survive? And a new build SS, with a modernized hull that can make 25kts on the surface and 18kts underwater? That seems like alot of development. And if you try to lean out the price by reducing things like quieting it seems like you've just created a Romeo that's really fast on the surface.

      I think you might be able to get better cheaper by building your own SSK or buying one of the German SSK's.

    4. I do like what it brought to mind though. A new GuPPY!

    5. Randall, an interesting concept! B.Smitty, fascinating design!

      One of the challenges would be to fit sufficient fire control sensors in/on a very minimal superstructure.

      An operating depth of 300m is quite substantial. Another challenge would be proofing the sensors, VLS, and other external fittings against that kind of water pressure/exposure.

      What would be the combat advantage of such a submersible over an actual sub, if any? You mention transit speed but that alone seems insufficient. Presumably, cost would be the major advantage? As you point out the cost would have to be substantially less than a true SSK.

    6. Randall, underwater refueling? Another interesting idea! Presumably, the challenge of communication would be the problem. How to find the two vessels and communicate during the refueling operation. I don't know the extent of underwater comms possible today. The question is whether the operation could be conducted without giving away the position.

      I also assume that the refueling would only be in a far-forward combat zone. If not, there would be no need for submerged refueling - it could take place on the surface, at leisure.

    7. How likely is it to survive compared to what? Remember, the CONOPs is not for independent submarine operations. It is to fill the small combatant Streetfighter role.

      It would be FAR more survivable than a Visby, LCS or Sea Lance.

      All it has to do is dive and it renders all ASuW systems ineffective.

      Operating on batteries, it shouldn't be hard to make it rather quiet. So even specialized ASW systems may still have to work to kill it.

      The German Type XXI submarine could hit 17kts submerged and nearly 16kts surfaced. The US Balao class could go over 20kts surfaced. I'm confident a modern hull design and propulsion system could easily exceed these speeds.

      I don't see any need for deep diving performance. 2-400ft operating depth is fine for this role. So this vessel could be made from less expensive mild steel (like the Gato class) or high strength steel. It wouldn't need more expensive HY-80 or H-100.

    8. B.Smitty, you suggest a minimal ASW/sonar suite. Of course, once the vessel submerges it will be blind other than active/passive sonar. I would think a moderately capable passive sonar suite would be desirable? Otherwise, while it might be substantially protected from surface attack, it would also be blind.

      Once it submerges it becomes just another sub from the surface vessel's perspective. Without substantial quieting and a comprehensive sonar suite, would it be too easy a target when submerged? Can a submersible with the amount of external equipment envisioned be made quiet enough to be survivable?

      Also, one of the assumptions of the Streetfighter-type concept is that squadrons would act in a co-ordinated fashion. That implies a large degree of communications and data sharing (back to our network!). Submerged vessels don't communicate well. Trying to operate squadrons of submersibles that aren't communicating may give rise to more blue-on-blue issues.

      I'll have to think about this concept more!

    9. CNO,

      Cost, in theory, is a big advantage over a regular SSK. Mild steel, smaller size, less need for advanced sonar or quieting. Surface speed would let it get to/from its operating area faster, and be able to intercept shipping or escort them. SSKs are way too slow for this.

      It would have far less submerged performance and endurance. It would submerge primarily to evade threats or to stealthily approach targets - just like a WWII sub.

      For example, it could transit from bases in Europe on the surface at 15-20kts, submerge to periscope depth when within sight of the Syrian or Lebanese coast and monitor shipping and small boat activity. It would be effectively immune to shore based anti-ship missiles, since i doubt many could target a periscope.

      It could then submerge, close towards the coast, and fire IDAS at land targets up to 20km away, or perform covert MIW using an ROV or LMRS.

      If it had to intercept a suspicious boat, it could surface and make a 25kt dash. Clearly that's not fast enough to catch a go-fast. But it is fast enough to catch a fishing trawler, or small cargo vessel.

      Sensors would include radar, ESM, optics on the periscope(s), and sonar. These are standard on all submarines. What more would a small combatant like Visby have?

    10. CNO,

      Coordination can happen while surfaced or at periscope depth.

      In service tethered or disposable communications buoys can allow communications while submerged.

      In the future, blue-green lasers could allow subs to communicate directly at short distances.

      The submerged ship might be an easier target than a true sub, but only for ASW-equipped forces. Chinese Houbeis and other missile boats would be at a loss. If our ship can get a bearing on the enemy ASW ship, it could fire a Mk48 at it. If the ASW ship sends a helo, we can fire an IDAS at it. So it's not completely defenseless.

      As to the level of sonar needed, I'm not sure. It is not designed to hunt other submarines. A hull mounted sonar might be enough. If a towed array isn't that much more expensive, then sure, go for it.

      Also, if it raises a tethered comm buoy, it can receive offboard targeting. A distant P8 or Triton could send it targeting vectors for surface ships in the area, and it could launch based on those.

    11. B.Smitty, it's an interesting concept and well worth evaluation. In fact, it's exactly the kind of thing that I would hope the Navy simulates and games out on a regular basis. Unfortunately, I'm unaware that the Navy does that. The only gaming that seems to occur is when the Navy sees a need to defend a pet project and then I suspect the games are skewed to produce the desired result. Unlike pre-WWII where we extensively gamed out hundreds of scenarios, I fear we've abandoned this avenue of technical and tactical evaluation.

      I hope I'm wrong and that the Navy is actively and extensively looking at this kind of thing but, if so, they're keeping the activity quite secret. That may be the case but I doubt it since they have no problem trumpeting simulations involving the LCS, for example.

    12. A variant armed with a lighter 324mm torpedo armament and the VLS system replaced with a airlock and additional living space would be great as a Seal delivery vehicle.

      Randall Rapp

  11. No. I was thinking of the utility of small vessels to a county like Taiwan. As for offensive small combatants, maybe CB-90 like boats with the ability to bombard the shore with mortar fire and/or able to fire hell fire missles.
    As for the Hughes model specifically, I dont think it's suited to the US navy way of doing things. It would be another LCS like risk.

  12. Always enjoy reading these posts. Your concluding paragraph is exactly the sort of reasoned and informative discussion I wish I could see more often. 'The idea as a whole may well have merit, and shouldn't be dismissed out of hand, but your methods of arriving at that conclusion are flawed'.

    1. Shock, I'm intrigued! How are my methods flawed? I describe aspects of the model, analyze them, and draw conclusions. You may disagree with the analysis and conclusions but the method is quite logical. Tell me more! What different methods would you use?

  13. Why does a small littoral boat have to be helpless against helicopters? I don't know where that assumption comes from. The Hughes proposal calls for 500-600 ton combatants. You cannot fit a SeaRAM on that vessel that will outrange helo-launched Hellfires, rockets, and guns? Or do these helos have Harpoon missiles, and if so, how do they acquire their littoral targets before firing?

    1. The small missile boat discussed in the post does not have room or weight allowance for RAM launchers. Of course, once we move up to corvette size vessels the matchup against helos begins to change.

      Regarding helos/Hellfire versus RAM, the ranges of the two missiles are identical (5 miles). However, the helo has the advantage of being able to "mask" its approach by flying literally wavetop, popping up, firing, and disappearing back into the waves.

      Similarly, the helo/2.75" rocket outranges RAM by a mile or two.

      Presumably, various enemy helo weapon systems have similar range advantages.

      You also indirectly raise an interesting question: how small a vessel can SeaRAM be mounted on? The Ambassador MkIII is a 500t ship with Phalanx CIWS. SeaRAM is 2-3 tons heavier. Could it be mounted on the Ambassador? I don't know. I suspect it couldn't be mounted on anything much smaller.


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