Friday, September 13, 2019

Hunter-Killer ASW Groups

In WWII, with the exception of a few very fast transports that traveled alone, protected by their speed, most supply ships made the Atlantic crossing in convoys.  Protection was provided by escort ships.  Threats to the convoys included air attacks, notably from Focke-Wulf FW 200 Condor long range bombers, surface ship attacks, though this was more of a potential threat than actual, and U-boats which nearly choked off supplies to Britain and, later, Russia.

While the convoys had ASW-capable escorts, they were only marginally effective.  The major problem was that they were tied to the convoy.  They could not detach from convoy to conduct long, drawn out ASW engagements.  After a brief counterattack against a submarine, the escorts had to quickly return to their place in the escort screen.  Unfortunately, effective ASW generally involved patience and time that the escorts didn’t have.  The role of the escort ships was to hinder submarine attacks by their presence rather than kill submarines.

One of the solutions to this inability to engage submarines on a protracted basis was the formation of dedicated anti-submarine (ASW) hunter-killer (H-K) groups.  These groups were formed around smaller escort carriers along with several destroyers, frigates, destroyer escorts, corvettes, and sloops.  Not being tied to a convoy, the H-K groups were able to move independently, hunt for submarines rather than just react to an attack, and take the time necessary to prosecute contacts.

The H-K escort ships were, by and large, lower capability or second line vessels such as Black Swan class corvettes, River class frigates, Wickes and Clemson class 4-stack destroyers, and the like.  ASW, at the time, did not require state of art ships because the ASW sensors were small in size and the weapons were common.  The main requirement – the main ‘weapon’ - for effective ASW was persistent presence – the ability to patiently search and remain engaged as long as necessary, using the submarine’s limited underwater time against it. 

The most successful US ASW escort carrier was USS Bogue (CVE-9) whose aircraft and escorts sank 11 German and 2 Japanese submarines.  The carrier’s aircraft were Grumman Avengers and Wildcats which used depth charges, rockets, and Mk24 FIDO acoustic homing torpedoes.

USS Bogue with TBM/F Avengers on Deck

This also raises the issue of weapons.  The major difficulty in WWII ASW was the lack of weapons that could effectively engage a submarine.  Even with the nascent sonar systems of the time, detection was relatively easy.  The problem was that the weapons of the time were very inaccurate and largely ineffective.  It required many weapon launches to achieve a kill and many submarines got away despite the profligate expenditure of weapons.  Depth charges, the main weapon of the time, were marginally effective, at best.

When WWII ended, the US Navy continued to operate H-K groups culminating in the Cold War ASW skirmishes with the Soviet Union submarine fleet.  Due to the larger size of the ASW aircraft, larger carriers were required and the Navy converted WWII Essex class carriers to dedicated ASW carriers.  Surface ships employed ASW weapons such as Weapon Alpha, hedgehogs, torpedoes, and the unmanned DASH helicopter.  Groups consisted of a carrier and 8 destroyer escorts.

USS Essex, CVS-9, with S2F Trackers on Deck, 1965

Eventually, as the ASW Essex carriers retired without replacement and long range land based ASW patrol aircraft came on line, the H-K concept died out.  ASW efforts became centered on the S-3 Viking fixed wing ASW aircraft operated from carriers, land based ASW P-3 Orions and the like, and SSN submarines.

Of course, the S-3 Viking has been retired without replacement.  Land based ASW aircraft require a permissive environment to operate and that is an unlikely scenario in a peer war.  Submarines, while effective in the ASW role, will be tasked with many missions and their ASW efforts will be somewhat sporadic.  Worse, they will be unable to operate near friendly units due to the inability of those units to distinguish friend from enemy.

Thus, the Navy currently has no H-K groups and little in the way of persistent, dedicated, effective ASW capability.  Ironically and dangerously, while our ASW capability is withering we are simultaneously seeing the rise of peer Chinese and Russia submarine fleets.  While neither yet presents an overwhelming threat, the trend in both numbers and quality of submarines is improving and it is only a matter of time until the submarine threats become substantial.  Further, many smaller countries are investing in quiet, deadly, conventionally powered submarines (SSK) which present a major threat to our nearer-shore naval operations.

What conclusions and lessons can we draw from the history of H-K groups?
  • Combating submarines at the convoy is a losing proposition due to the escort’s inability to take the time necessary to successfully prosecute a contact.
  • Aircraft are extremely useful and effective ASW platforms.
  • Persistence and patience are the key attributes of ASW
  • Land based, ASW patrol planes do not have the persistence necessary for truly effective ASW engagements.
  • State of the art ships are not necessary.  The ASW gear must be reasonably modern but the ships themselves do not need to be front line vessels.

So, what does all this tell us about potential modern H-K groups?

Need - Having noted that the convoy is not the place to attempt ASW and that convoy escorts make ineffective submarine killers, it is clear that modern H-K groups, acting independently, are required.

Aircraft – While a fixed wing aircraft would be ideal for a H-K group, the reality is that rotary wing (helo) aircraft are the better choice in terms of simplicity and ease of operations and budget.  An S-3 Viking type aircraft would require a carrier with catapults, arresting gear, advanced maintenance support, etc.  In contrast, helos can operate from any flat surface which lends itself to modified commercial vessels similar to the simplistic escort carriers of WWII. 

Ships – As was found in WWII, the best combination of ships for an H-K group is a carrier and several low end ASW corvette/destroyer escort type vessels.  ASW does not require state of the art ships with advanced radars, stealth, etc.  A basic, cheap ship that can carry sonars, arrays, and anti-submarine weapons is all that is needed.  The baseness and cheapness of such ships allows them to be procured in numbers and put at risk.  Does anyone really think we’re going to risk $2.5B Burkes playing tag with submarines?  Heck, it would be foolish to put the Navy’s new $1.5B frigates at risk.  After all, ASW is a high risk business and the submarine has most of the advantages.

Regarding the carrier, a modified commercial cargo/tanker vessel would be suitable.  Add a flight deck with enough room to operate around 10 MH-60R helos and a covered hangar for maintenance and call it a day.  Simple, cheap, expendable.

What we absolutely can’t do is what the Navy always does: build a gold plated, do-everything ship.  An ASW carrier is, by definition and requirement, a low end ship in a high risk job.  That calls for a cheap, expendable (another way of saying cheap) ship that we’re willing to send into harm’s way.

Weapons – We now have ASW weapons (torpedoes) that we believe are effective – at least, that’s what we tell ourselves.  However, to the best of my knowledge, they have never been tested under realistic conditions.  As DOT&E has noted many times, the Navy’s submarine threat surrogates are unrealistic and unrepresentative in the extreme and testing has not occurred under operationally realistic conditions.  We need to fire actual torpedoes (warheads removed, of course) at real submarines that are trying their best to survive and see what happens.  Yes, we may dent some propellers and cause some superficial damage to the submarines (assuming we can hit them!) but that is well worth the cost to find out how effective our weapons and tactics really are.

I’ve stated repeatedly that we need a Soviet RBU-ish type of rocket depth charge launcher (see, "The Modern Hedgehog").  This is even more important for H-K corvettes that will go toe-to-toe with submarines.

The US Navy has all but abandoned ASW in any persistent, dedicated, effective form and we need to regain that capability.  We need to bring back a fixed wing carrier ASW aircraft, ASW corvettes, and dedicated ASW Hunter-Killer groups.


  1. It certainly seems as if ASW is going the way of MCM. I understand that usually a CVBG has an SSN attatched,but is there a doctrinal change to shift the ASW role more to subs? Possibly a larger contingent attatched to surface groups, used in a more defensive than traditionally offensive hunter posturing?? I dont think pulling subs back from their penetrating offensive roles is a good move, but it would follow along with the surface fleets continuing spiral down into defensive tasking. Maybe this is non-public info but was curious if that was the case, or if the withering of ASW has gone unnoticed by the sub community.

    1. A sub cannot perform an ASW role for a surface group, at least not in a near location. The surface group would not be able to reliably distinguish a subsurface contact as friend or foe. A sub could sanitize a route well in advance, though.

      As far as current doctrine regarding subs escorting surface groups, I have no idea.

  2. I fully expect (just like MCM) that USN will say their new unmanned ships will take care of ASW and its going to be awesome in 3, 2, 1....

  3. I've heard often how wonderful submarines are for antisubmarine warfare, but I've only been able to find a single example of a sub on sub kill, HMS Venturer in WWII. I can think of a lot of problems with using subs for ASW. The communication problem prevents the tag team effect that makes ASW work so well. Subs big advantage is stealth, so if you kick up speed to catch up to a distant target, then flow noise will announce your presence.

    1. After 50+ years of exercises and training subs are very good at hunting other subs. There haven't been any more kills because there haven't been any wars where its been possible.

    2. There have been many sub on sub sinkings. The US Navy history site lists at least 17 in the Pacific theater in WWII (see, Sub on Sub History)

      By all accounts, US submarines routinely tailed most/all? Russian subs during the Cold War while remaining undetected. In a shooting war, those would have all been kills.

      The Japanese subs sank some of our subs in WWII although I don't have an immediate accounting or number. I assume German subs sank some subs, as well. And so on.

    3. But just the one while both ships were submerged. Venturer is the only one.

    4. "But just the one while both ships were submerged."

      Well, come on, now. That' kind of like saying there were no air to air missile kills in WWI. The technology just didn't exist. WWII submarines didn't have the technology to conduct effective submerged-submerged kills.

      If you're trying to draw some conclusion because you can't find an example of either a technology that didn't exist during war or a war that didn't exist during the technology, you're trying to make a very flawed conclusion.

      As I pointed out, the Cold War pretty well demonstrated the potential for submarine ASW.

    5. I think its a pretty important clarification to what your statement implied. Aside from that, I'm in the best sonar is best camp and would prefer to also have the most. In terms of ASW I worry about helos when subs have SAMs. I look at S-3s in the boneyard as an untapped resource even if land based or unmanned. If not S-3s, then an ASW UAV. For surface platforms, they are testing the ASW mission module for the LCS off the back of a fast supply vessel. Manned or unmanned, its a cheap way to get a sonar in the water. Plenty can be had on the cheap right now as the offshore business is in a slump.

    6. "For surface platforms, they are testing the ASW mission module for the LCS off the back of a fast supply vessel."

      If you're suggesting conducting ASW via modules on any old ship that happens to be available, you really need to come up to speed on ASW. While we can easily place a towed array or variable depth sonar on any ship via a module, without the ship itself being ASW-integrated it would have a very short lifespan!

      For a partial discussion of what an ASW-designed ship entails, you can read "Electronic Greyhounds" which describes the design of the Spruance class ASW destroyer.

      If a ship is going to get close enough to detect an enemy submarine with an onboard sonar/towed array then the enemy sub is, by definition, also within weapon range of the ship and unless the ship has been totally optimized for ASW, it will be detected and sunk long before it can detect the sub.

      An optimized ASW ship needs to be built from the first rivet for quiet operation. That means acoustically isolated machinery, rafted engines, minimal self-noise to prevent detection and self-interference, Prairie/Masker perhaps, etc.

      "Manned or unmanned, its a cheap way to get a sonar in the water."

      No, it's a suicidal way to get a sonar in the water. At best, it's a totally ineffective way. Potential targets will hear the ship coming long before they can be detected and will have plenty of time to sink the ship or evade at leisure.

    7. Well, the 2 Overlord USVs are (already)fast supply / crewboats as will be the first 2 LUSVs. I mean its not like their propulsion is any different from the fast ferry and yacht the LCSs are built on.

    8. Page 30

      page 13

    9. ???? What's your point? You've completely lost me.

    10. First, the ship you say isn't a thing has long sense sailed. It's not like an ASW helo is quiet. The Israeli USV uses the same dipping sonar as a helo. There is no reason the ship couldn't function more like a helo than a ship. Plus you can get FSVs used for around 4-8 million. You could put the MFTA and LWT from the LCS mission package on one of these for about the price of the platform. If the sub wants to cook off a 2 million dollar torpedo or missile at one of these highly maneuverable targets and give away its position to the other half dozen or so we can afford to put in the ame area, go ahead. Assuming we go USV. Not quite that simple, but....

    11. "the ship you say isn't a thing has long sense sailed."

      ???? What ship did I say didn't exist?

      There's nothing wrong with using unmanned ships for ASW although the control aspect is extremely problematic.

      You seem to be arguing about something but I have no idea what!

    12. Just saying I don't think a platform need be built from the bottom up for ASW. You yourself describe a cheap ASW carrier. The closest thing I can think of for that are the ESBs although too slow for my preference.

    13. "I don't think a platform need be built from the bottom up for ASW. You yourself describe a cheap ASW carrier. "

      You're confusing two different concepts and platforms. A ship that will conduct up close ASW, like a corvette or destroyer, MUST be built from the start with every item optimized for ASW in order to have any chance. That means acoustic quieting and isolation must be built into machinery and hull design, among other requirements.

      An ASW platform that will operate from significant standoff distance doesn't need to be acoustically optimized. Thus, a ASW helo carrier can be any modified commercial hull. The helos and escorts will keep the subs at arm's length.

      Do you see the difference, now?

    14. I understand, but what I interpret from that is you are thinking the LCS doesn't stand a chance.

    15. "you are thinking the LCS doesn't stand a chance."

      Well, let's think about it. The LCS machinery is not acoustically isolated. The waterjet propulsion is so loud as to be an acoustic beacon for many miles around. The LCS does not have a hull mounted sonar due to the ship's self-noise. The LCS towed array cannot be used in shallow water. The LCS has no anti-sub weapon like torpedoes or ASROC. The LCS self-noise not only prevents the installation of a hull sonar but drowns out passive sonar noise. The LCS is only structurally rated for a single MH-60 type helo which limits its ASW helo capability to just a few hours a day. Stop me when you think you've got the gist of my opinion about the LCS as a ASW platform.

  4. There's little doubt that US should be able to handle Russian and Chinese subs (we hope!) my worry is do we have enough of them? It's not like the entire US fleet of subs will be able to deploy against China all at once, some will still be in other theaters, down for maintenance or we have enough of them to face China fleet and Chinese subs? That's where having a dedicated ASW ship or better yet, some H-K group would come in handy, could be a force multiplier for our subs if you can have them work to together or some good way to communicate....

  5. …(again as civilian, I hesitate to comment), But:
    The converted helo carrier is a multipurpose vessel. It could also employ assault helos and landing forces.
    Escorts would be for close-in contact.
    Noise works both ways - target one of the group and you WILL be sunk (an analogy in WW2 was that a German U-Boat broke off an attack on a convoy when sighting an escort carrier inside the screen).
    The helo aircraft can cover a lot of territory - perhaps they could they lay patterns of long-floating passive detectors.
    And finally, add a tame hunter-killer sub as part of the task group - the helos should add hundreds of miles to her sensor range.

    1. "(again as civilian, I hesitate to comment)"

      Don't hesitate to comment! Good ideas can come from anyone. Hey, it's not like our military leaders are making great decisions and coming up with great ideas.

      "The converted helo carrier is a multipurpose vessel. It could also employ assault helos and landing forces."

      A little bit yes and a lot no. For example, we can make a fairly small ASW helo carrier but if you want it to also be an assault helo carrier (an LHA/LHD, essentially) then you have to greatly upsize it to include berthing for, presumably, hundreds of troops, storage for their gear and vehicles, additional galley space, more food storage, more fuel storage, additional munitions magazines, command and control facilities for land combat, etc.

      On the other hand, an ASW carrier could probably flex to an MCM mothership role without much additional space, equipment, effort.

      "add a tame hunter-killer sub as part of the task group"

      This is an appealing idea but it doesn't work in practice. The friendly forces can't readily distinguish between a friendly sub and an enemy sub and no ship commander is going to be willing to wait to see if a detected sub is friendly! With no friendly subs in the area, ships/aircraft can freely attack any contact they find. With a friendly sub in the area, they have to wait while they try to determine whether the contact is friend or foe and that's a good way to get your ship sunk!

      Do you understand the concept and does that make sense to you?

    2. ...ComnNavOps. first point was that I meant no increase in size -the CVE would take the same helo load but just a different mission. For berthing, the Marines could sleep on the deck for a week like my Dad did in WW2.
      The second point is with the "tame" nuclear sub. I meant it was close and known to the escorts - maybe right under the carrier. Kind of like a super torpedo with a distant contact, requiring close coordination between air, surface, and sub. (yes I remember how old Seawolf came to the end of her trail -sunk by an overeager DE in a 'safe zone'...Don McCollor

    3. " "tame" nuclear sub. I meant it was close and known to the escorts "

      There's no such thing as 'close and known' for a submarine. They are so quiet and hard to track that unless they are intentionally making noise the surface ships won't be able to track it. Once having lost track of it, any new contact will be treated as hostile. No ship captain is going to wait to see if a close sub contact is friendly or not!

      You may not be appreciating how spread out a surface group, especially a carrier group, is. The group covers a 50 mile diameter or so. Having a sub 'under the carrier' would render the sub useless as any enemy sub would likely be attacking from many miles away. Also, the noise of the carrier would render the friendly sub deaf.

      The best use for an escort sub is to range far, far ahead of the group's path, sanitizing the route or the eventual destination but staying far away from the vicinity of the escorts.

    4. apologies - it is a knotty problem. A question is what detection assets could an ASW group provide to a sub? Also do subs operate alone? - it would seem the problem would apply more to them...

    5. A surface group can't provide any useful detection information to a sub because they can't communicate with them - at least not in anything approaching real time.

      Yes, subs operate best when alone. That way, anything the sub detects it can safely classify as enemy.

  6. Doenitz’s vision of naval warfare being dominated by submarines is a reality, at least for high end peer-peer warfare.

    - The U-boote war in the North Atlantic was largely decided by long-range, fixed-wing aircraft like the B-24/PB4Y-2 Privateer. Ultra, bombing or mining U-boote bases, eliminating the German maritime search/surveillance network, bombing shipyards and supporting infrastructure, were all significant contributors.

    - Modern submarines are completely different beast compared to WWII submarines and the lessons learned are limited.

    - By the late 1950s, surface ships were already technologically inferior to submarines in both the critical sensor and weapons ranges. Essentially, the problem is that the surface ship cannot employ its sensors optimally, but a submarine can. The issues are ambient/self-generated noise, and presence of thermoclines, which VDS and towed array systems do not completely solve; besides submarines also possess towed array sonar systems. Thus, submarines can not only out-detect surface ships, that can also deliver effective weapons strikes first – this is a fundamental imperative of war at sea. Dr Freidman cites several quotes from admirals in his text on USN destroyer designs that support this position.

    - SSNs now enjoy operational movement/speed advantages over surface ships, particularly in bad weather, which is prevalent in the North Atlantic and Northern Pacific. Worse, bad weather is highly correlated, meaning that there will be periods of 2/3-days out of every ten in winter months where the sea states will be so bad that the surface fleet will have *severely degraded* sonar detection ranges, flight decks will be closed, helicopters will be “grounded.” The ancient ASROC and the anemic Mark 54 torpedo will not provide solutions to these recurring periods of near absolute vulnerability.

    - Surface ships held a vital advantage communications advantage over submarines, but submarines are now able to take full advantage of high-speed data networks while submerged making coordinated wolf-pack action by submarines a reality.

    - The *acquisition* cost difference between a modern ASW ship like a DDG-51 (or equivalent) and an SSN like the Virginia is a wash. The acquisition cost deference between an AIP submarine like the Types 212A - 371 million euros ($394 million) through Type 218 and a modern ASW destroyer is profound. The *life cycle * costs of an AIP submarine versus an ASW destroyer are significantly lower, largely due to the tiny crews on the submarines.

    Given the realities of modern naval warfare cited above, I would buy as many submarines as I could, and fill out the fleet with surface ships, mostly as a hedge that some future sensor technology could reverse the considerable submarine advantage.


    1. A more "pure" ASW ship should be at least several times cheaper than an SSN. Even the FFG is supposed to be under a billion each past the first few. Three for the price of one Virginia SSN.

    2. "ASW ship should be at least several times cheaper than an SSN."

      You make a good point about relative cost. The sub has most of the advantages so we can expect to lose a few to several ships for each sub sunk, hence, I assume, your cost comment.

      Just a couple of cost related notes:

      1. The cost of the Navy's frigate is going to be around $1-$1.5B. No one except the Navy believes it will be under $1B.

      2. The more common enemy sub type will be diesel SSKs which are much, much cheaper than SSNs. Thus, the cost differential is a problem. We'll be sending $1B-$3B Burkes and frigates up against SSKs costing $300-$500M or so. Not only will our ASW ships not be several times cheaper than the subs they're fighting but they'll be several times more expensive. This is one of the reasons I consistently call for cheap, simple ASW corvettes.

    3. We will have to wait and see on the cost of the FFG. The Navy's FY20 budget submission expects them to cost around $900M after the first one. The Navy thinks they can go even cheaper. I haven't seen any $1.5B estimates.

      I can see the case for a cheaper ship. The British Type 31 frigate is supposed to only cost £250M ($313M). It is closer to a low-end ASW ship. However they are no better at meeting their cost targets than we are.

    4. What you guys are missing is the submarine holds the sensor and weapons advantage - it isn't the surface ships that will be hunting the submarines, it is the submarines that will be hunting the surface ships!


    5. GAB
      Shouldn't the surface noise caused by weather drown out a subs sonar just as easily as a surface ship's sonar.

  7. One thing missing about the ASW assets that traveled with a convoy was the British bulk cargo ships with flight decks added known as merchant aircraft carriers or MAC ships. They were a mix of grain carriers and crude oil tankers and totaled around 20 conversions all up. The aircraft were either 3 or 4 Swordfish which could be stowed below the flight deck in a small hangar for the grain ships only. The flight decks were 410ft for the grain ship and 462 ft for the tanker. On occasions they were used to ferry US fighters to the US on the flight deck , as was many of the escort carriers.
    Their speed meant they could only travel with the rest of the convoy any A/S work was done by the Swordfish.
    The Black Swan class were first rate anti submarine ships for the time, being around frigate size ( they were termed 'sloops' a pre war term before the frigate designation came along). They didnt need the high speeds of destroyers nor the heavier surface warfare guns and torpedoes.
    After the war the surviving MAC ships were reconverted to their normal cargo role.

    1. Interestingly, Wiki also cites 4000 sorties from 19 MACs, a dozen attacks by Swordfish, and no U-boat kills. Of course, mere presence could have had a deterrent effect - we have no way of knowing. Still, on the face of it, the record was zero success.

    2. Yes. With limited capacity the chance to sink submarines was remote but that was more the hunter killer groups job to spend the time and effort to get a kill.
      However success in this context would hopefully be no ships sunk in the convoy they traveled in and being able to free up escort carriers from having to travel with the convoy.

    3. "no ships sunk in the convoy they traveled in"

      It is noted in Wiki and elsewhere that ships were torpedoed in MAC escorted convoys. Not particularly surprising since the MAC concept was a very marginal ASW weapon system.

      With just 3-4 aircraft, a convoy would be lucky to have a single aircraft aloft at any given moment. That's hardly an effective ASW effort given that the aircraft's only detection sensor was the Mk1 eyeball.

      Were some U-boat attacks deterred? I'd like to believe so but We'll never know. Regardless, it was a reasonable effort for the time.

    4. Not zero success, since every merchant vessel that got through was a success.

      Sinking u-boats was the least important part of the war in the Atlantic. It was getting the merchant ships through.

    5. "Not zero success, since every merchant vessel that got through was a success."

      Of course. However, we're talking about H-K groups whose job is to find an sink subs, not escort carriers.

      The MAC carriers achieved zero success at sub kills. Whether they had any beneficial effect as convoy escorts is unknowable. Hence, the statement,

      "on the face of it, the record was zero success."

  8. The US Navy already has great escorts carriers known as LHDs and LHAs. If war with a major naval power threatens, the first step is to offload the Marines from these deployed ships to protect "advanced naval bases" and airfields from enemy commandos and irate locals. No sane person thinks ARGs will sail around in war zones full of 2000 Marines with enemy subs lurking.

    1. It would be unwise in the extreme to use ships costing several billion dollars as ASW carriers. By definition, ASW carriers go where the submarine threat is greatest and risking multi-billion dollar carriers doing that would be poor asset management.

      Worse, if a LHA/LHD is sunk, we not only lose a multi-billion dollar ASW carrier but we lose one of our few and precious amphibious ships - a double loss!

      No, the solution is not to shoehorn expensive amphibs into the ASW role but to purpose build/convert commercial based ships as ASW carriers at a fraction of the cost and a fraction of the size.

  9. maybe something like the Jeanne D Arc or Moscow class ships. Could carry a half dozen or so ASW Helos as well as a good AAW fit for air defence of the HK group. add six or so Corvettes/FFs to round out the group.

  10. Perhaps there is a need for two styles of HK group.

    The first is an HK surveillance group consisting of a SURTASS-LFA-equipped vessel, with escorts. The SURTASS ship uses its sonar in active mode to provide wide area search and queuing for the second type of HK group, the pouncer group.

    The pouncer group is configured along the lines of the OP with a mini carrier and multiple combatants. Its job is to prosecute detections made by the surveillance group.

    With multiple surveillance and pouncer groups operating in overlapping regions, you can cover a larger area.

    1. I've wondered about SURTASS in combat. We would have used SOSUS arrays to detect Soviet subs in combat but I've never heard of any plan to use SURTASS. I don't know why. It's an open question in my mind.

    2. I don't think you can use SURTASS in combat any more than you can use AWACS in combat. They're both meant to stay behind forward forces and provide long-range detection. Hence the split between surveillance and pounce groups.

      I'm not aware of any other wide-area detection technology that has a chance against quiet subs.

      Another option might be to use a bunch of semi-disposable USVs like Sea Hunter towing variable depth active sonars in a line or wedge, sweeping the area in question, with a pouncer group waiting in the wings to jump on any detections (or flaming datum).

  11. I swear, half of the posts on this blog are of nifty ideas or concepts learned the hard way in ww2 and then employed through most of the cold war, and then completely dropped without replacement. Not a complaint, keep it coming.

    1. Hey, I've never claimed that these are original ideas of my own. What I claim is that I'm willing to study and learn the lessons that history offers for free! The Navy, for reasons I can't fathom, refuse to study their own history and learn their own lessons. Very sad.

      The only original thing I do is update the ideas and lessons to apply to today's setting.

      Stay tuned. Lots more coming!

  12. I have proposed a fleet to include eight Surface Action/HUK Groups (SAG/HUK). Each would consist of:

    1 Battlecarrier - 50,000 tons, like the US battlecarrier proposal back in the 1980s or something similar to a Russian Kirov front end (with big guns and VLSs instead of big missile tubes) and Kiev back end. I'm thinking something like 2x3 16" guns forward, 256 VLS (basically cover the superstructure with cells), and a Kiev-type flight deck with ski jump that would handle 12 Harrier/F-35B and 16 helos (based on Kiev capacity) plus drones. The guns would provide significant surface power in the open ocean and could also be brought in for pre-assault NGFS. The air component should be sufficient for group air defense out in open ocean, and could also help in the attack role to support an assault.

    1 ASW cruiser - something like the Japanese Hyuga, roughly 20,000 tons carrying 10-12 ASW helos, plus drones, with some VLS and basic air search and sonar. This would be the primary ASW asset.

    1 multi-purpose cruiser, 20,000 tons, Des Moines class hull, AEGIS or successor plus bow sonar, 192 VLS cells, 2x3 8" guns (fore and aft), section between stacks and rear gun a helo/drone flight deck with hangar underneath.

    2 Burkes or successors for air defense.

    3 mini-Burkes.

    4 ASW frigates, something like a Perry with 76mm gun, VLS cells including ASROC, 2 helos, and 2 ASW rocket launchers like Soiviet RBU-6000.

    ASW corvettes and auxiliaries as needed.

  13. Meh. Helos are far too short-legged to be much use against a submarine attacking with cruise missiles.

    It's simple math. Sub launched cruise missiles have ranges of several hundred miles. An ASW helo can really only operate about 50-100 nm from the ship.

    1. Helos are also far too short-legged to be much use against a ballistic missile launch site located in inland China! Fortunately, both the ballistic missile site and the submarine have the same weakness which is an inability to target a ship several hundred or a thousand plus miles away.

      Submarines, even cruise missile subs, are almost zero threat several hundred miles away. They have no targeting ability over that range. There is a very remote possibility that they could obtain targeting data from some other sensor but, at that point, the issue for the surface ship is not ASW, it's simple missile defense.

      I'm sorry but your comment is completely irrelevant and meaningless due to the inability to target over those distances. This is why the dreaded DF-21 anti-ship ballistic missile is no theat whatsoever.

    2. The Russians seem to have from some time back used satellites to find naval targets using Elint etc.
      This would be the way to use wide area surveillance and provide local area target coordinates to a cruise missile submarines of which they invested a lot of effort into. They could tail a high value group as well but the USN would know you where there.

      "2004 May 28: Russia launched a classified military payload to monitor foreign Navy activities. According to the Russian Space Forces, KVR, a Tsyklon-2 rocket carrying a Kosmos-series satellite blasted off from Baikonur Cosmodrome at 10:00 Moscow Time. Four minutes later, the spacecraft separated from the upper stage of the launch vehicle. The payload was identified as Kosmos-2405.

      Tsyklon-2 routinely delivers US-PM electronic intelligence, ELINT, spacecraft designed to detect sea vessels by intercepting their radio signals. The information from the satellites reportedly can be used to navigate Russian cruise missiles toward their targets.

    3. @CNO

      Submarines were capable of tracking and making long-ranged attacks against surface ships many decades ago.

      Sound refracts and reflects through multiple convergence zones.

      High speed data networks (not slow ELF) make it possible for submarines to share targeting data over unlimited distances while submerged.

      Surface ships are not the hunters, they are the prey...


    4. " Plenty of open source info on how that kill-chain might work."

      Comment was deleted for impoliteness. You can make your point respectfully or not at all. You might also add a reference link if you think there's information that might be of value.

    5. "Sound refracts and reflects through multiple convergence zones."

      It does - under the right circumstances. However, that's a haphazard and reliable method and does not produce a range, only a bearing. The sound could come from any of the convergence zones, hence the unknown range. If someone has figured out how to determine range from passive/convergence zone detections, I'm unaware of it.

      "High speed data networks (not slow ELF) make it possible for submarines to share targeting data over unlimited distances while submerged."

      I'm unaware of this. Do you have a reference? I'd like to learn about this.

      "Surface ships are not the hunters, they are the prey..."

      Always have been! However, that doesn't mean that surface ships should not have any ASW capability. It's all about doctrine and tactics. Yes, the sub has most (not all) of the advantages but proper doctrine and tactics can change the equation. The surface force has the advantage of multi-domain capability, meaning it can use fixed wing aircraft and helos which the sub has no practical defense against (reports of sail mounted SAMs notwithstanding). This also gives the speed advantage to the surface force.

      Ships also have a potential cost/mission advantage although modern navies don't take advantage of it. A simple, basic, $50M-$100M ASW corvette, for example, is likely not going to be a viable target for a sub because the gain is not worth revealing the sub's position. Thus, the corvette enjoys, to an extent, 'immunity' from a sub and can work at detection and presence which forces the sub to hide/evade (mission kill).

      On paper, the Wildcat and Sherman, among other examples, may have been inferior to their opponents but numbers and tactics allowed them to succeed. So, too, with surface ships and subs. That's not to say that subs are easy prey - quite the opposite! It says that surface ships can have a chance, if properly used.

      It would also help if we actually trained for ASW rather than one brief, annual, scripted exercise prior to deployment. Take a ASW corvette (or build a dedicated ASW destroyer/destroyer escort) and have it train for nothing but ASW, both individually and as a coordinated group with other ships and aircraft. Develop tactics for the modern ASW battlefield and change the equation, at least somewhat.

      In WWII, German U-boats wreaked havoc but ultimately lost to an extensive, multi-faceted ASW effort by the Allies. In contrast, American subs wreaked havoc on Japanese shipping and were not stopped because the Japanese never put the kind of effort into ASW that the Allies did.

    6. I think one of the dangers of the mini Burke or even new FFX, I dont bother bringing up LCS, is ASW (and I would add MCM) need constant training and working at. It's a perishable skill, we need ships and H-K group that constantly trains and thinks ASW. It should be there primary (70-80%) of their mission. Don't load them up with AEGIS and other expensive systems, just raises the cost and increases the distractions to ASW. Bringing back an H-K group in any shape or form would bring back capability and well needed training.

    7. "I am sure you will delete this,"

      Then why did you write it? I deleted your comment for being disrespectful, not because you disagreed with me. Rewrite the comment respectfully, leaving out the personal attack, and it will stand. Respect and politeness - it's a simple concept. Argue the idea, not the person.

      If you really want to be helpful, offer a reference rather than vague, unsupported statements.

    8. CNO: “It does - under the right circumstances. However, that's a haphazard and reliable method and does not produce a range, only a bearing.”

      1. Not haphazard, and far more reliable than ASW surface ships, which will be statistically mission ineffective due to weather about 15-20% of the time in the winter months in the North Atlantic and Pacific.
      2. Bearing only ASCM launches were tactically viable for passive RGM-84 shots decades ago; surely Russian COs would consider 3M54T or 3M45 missile salvo.
      3. War waged by a competent enemy is a team affair: two or more submarines can generate multiple bearings for a position fix if needed.

      CNO: “Ships also have a potential cost/mission advantage although modern navies don't take advantage of it. A simple, basic, $50M-$100M ASW corvette, for example, is likely not going to be a viable target for a sub because the gain is not worth revealing the sub's position.”

      1. Doubtful. There is zero evidence that any western navy can procure an effective escort for anything like 5x that, much less $100M, at least not with a hull mounted sonar equivalent to the AN/SQS 53, an equivalent to TACTAS, masker systems, isolated propulsion plant, an effective standoff ASW weapon, a CIWS, and a local air defense missile.

      2. Point one above does not address the procurement of ASW helicopters, which are necessary for surface ASW; nor does it address the life cycle costs associated with surface ships and helicopters.


    9. GAB,

      I've got to disagree with you about the reliability of convergence zones. Their existence is dependent on a variety of water conditions: sound channels, thermoclines, surface conditions, bottom depth, etc. Having the right combination of conditions to produce convergence zones is a haphazard occurrence.

      When CVs exist, they provide bearing only. Theoretically, multiple subs could share data and triangulate to obtain range but I'm unaware of any viable underwater data sharing transmission capability. Yes, multiple subs could extend/float antennae but that would kind of assume that they already knew where and when the target was and just needed to momentarily communicate to finalize range. Realistically, I'm unaware of any way a sub could 'call' another sub and ask for a cross bearing. If you know of viable underwater data networks, let me know!

      Yes, bearing-only launches are feasible although just as likely to waste missiles as find a target. The dilemma is, do you shoot semi-blind and risk wasting your inventory or wait and risk missing an opportunity? Also, unless we have been hugely oversold on the effectiveness of surface ship AAW (Aegis, for example), the weapon load of missiles from a single sub is only a moderate threat, at least as compared to torpedoes for which we have almost no defense.

      Regarding ship cost, I'm referring to a corvette size ships (analogous to the WWII Flower class) with the bare minimum of ASW equipment - essentially what you've listed minus any helo, hangar, or flight deck. If we can't build such a ship for $50M-$100M (and you're correct that no Western navy has demonstrated such capability!) then we're doing something badly wrong in our ship design and construction programs. We can build very large commercial tankers for $100M and, while acknowledging the differences between commercial and navy ships, it boggles the mind that building a ship a fraction of the size with some specialized equipment added would increase the cost to what we see today. The Cyclone class PC was built for $15M-$20M (then year dollars) and a corvette wouldn't be all that much bigger or more complex.

      Some data points:

      The DDG-1000 SCN budget doc lists a cost of around $45M for the combined bow sonar array, towed array, torpedo countermeasures, and unspecified software.

      The Burke SCN lists the SLQ-25 Nixie as $1.5M

      Other specific ASW equipment is not listed. May be GFE?

      As far as life cycle costs, those apply equally to surface ships and submarines. I don't know which is greater but they are, presumably, crudely equivalent.

    10. @CNO

      The DoN FY2020 budget justification book will dissuade any hope of a “cheap” ASW corvette; a ship type that was *never effective*at deterring or sinking u-bootes and the threat has not just evolved, it is a completely different beast.

      Bare bones weapons, sensors and comms for an ASW ship will cost ~$333.4M - look closely at line 11, 2128 FFG-Frigate, particularly PDF pages 199-201

      Ordnance - $ 43.4M [32-cell VLS, SeaRam CIWS, and 57mm gun]
      Electronics - $279.7M [minimal radars, TACAN, EW, AN/SQQ-89 ASW Combat System]
      Flight deck - $ 10.3M [RAST, lighting]

      Note that the VDS, arguably the most important componet of the ship will be GFE (Government Furnished Equipment) at added cost. Note that a hull mounted sonar is not included.

      There is no hope for a cheap, effective ocean-going hull - the U.S. ship building industry has collapsed.

      The Maritime Administration last bothered to publish statistics (Report on Survey of U.S. Shipbuilding and Repair Facilities) in 2004. In 2018 DOT reported just 5 ocean going container vessels under construction and 4 on order, and 2 planned.

      If we want to win a war at sea, bomb the enemy shipyard, mine their harbors, and build as many submarines as possible.


    11. It sounds like someone has a very definite vision of future ASW, worthy of an article.?! Just saying ...

  14. I read in many of the comments about how effective yet cheap modern ssk can be. Could a ssk not form the basis for a design of cheap ASW corvette. Similar equipment fit but cheaper as not submersible. Maintaining the ultra quiet propulsion and fitted with basic surface warfare equipment, 57mm and seaRAM. I don't know maybe its a dumb idea.

    1. Mike, a submarine gets it's quietness from being submerged (no wave noise and the pressure suppresses propeller cavitation) and from the streamlined, teardrop shaped hull. None of that would apply to a surface version of a submarine.

      The concept may not be viable but I like that you're thinking outside the box! Keep it up.

    2. Ok, I assumed engine noise was the main source of noise. Always happy to learn more, cheers.

    3. One of the major sources of noise is turbulence and eddies caused by irregular shapes and openings in and of the hull. Hence, the streamlined shape of the sub hull.

      Early on, it was found that flow noise (turbulence/eddies) over the ballast tank openings was causing noise and those openings had to be designed to minimize the noise. This is similar to flow noise from water movement over rocks on the sea floor.

      Yes, noise comes from many sources other than engine noise!

  15. Another possibility to replace or supplement the ASW carrier with a ship that launch its own sonobouys using rockets, missiles or other projector. Use a UAV to relay the signals. When you need to attack use ASROC's. Not as useful in a hostile EW environment, but subs that surface to jam are meat.

  16. One of the interesting things about the effectiveness of these HK groups was that they were contingent on aircraft, primarily long range, land based bombers, and of course their own carrier based aircraft.
    These aircraft were pretty good at sinking or damaging U-boats on the surface. If the boat dived before the aircraft could hit them, they would circle the area until ASW craft could arrive.

    This was possible because the airspace was largely uncontested. It was also predicated on long range, fixed wing aircraft.

    Some of these principles are likely to still apply.
    i.e. Large numbers of long range, fixed wing aircraft that can cover thousands of square miles of ocean are required for oceanic ASW to be effective.

    Small scale, ASW carriers, able to be built quickly and cheaply are required in fairly large numbers - remember that the allies ended up producing literally hundreds of escort carriers to cover the many convoy routes across the world's oceans.

    Large numbers of cheaply built ASW corvettes/frigates are required to both hunt submerged subs that have escaped the attentions of the aircraft (aircraft have limited time over target, limited munitions and limited sensor capability), and to provide ASW escorts to the carriers.

    But more importantly, this particular historical method is only really going to be possible if the airspace is mostly uncontested. Equally, these hunter killer groups would not really be feasible if there are significant enemy surface forces lurking.

    The only real threat these HK groups faced were U-boats. The surface fleet threat was long gone, there was only limited threat from long range Axis fighters and bombers flying out of the French Atlantic coast.

    So they were a good solution for the Atlantic.
    They were not used in the same way in the Pacific.
    They did come into play very late in the Pacific theatre, after much of Japan's naval and air assets had been expended or pushed back. Even then, they operated as part of much larger fleets, including large numbers of fleet carriers, cruisers, battleships etc.

    I guess my final point is that the HK groups work for ASW, if that's all they have to deal with.
    It made sense against the Soviets for the same reason.

    Against China in the Pacific? I'm not so sure.

    1. "Large numbers of long range, fixed wing aircraft that can cover thousands of square miles of ocean are required for oceanic ASW to be effective."

      That's a dubious proposition. Recall that the reason fixed wing aircraft were effective ASW assets in WWII was because submarines were still, essentially, surface ships that only submerged as needed. Thus, aircraft could spot surfaced subs. Today, subs would rarely/never surface in combat and fixed wing aircraft would be useless for observational detection. Yes, they can still use sonobuoys but those are far from wide area sensors. For a fixed wing aircraft to be effective, it either needs to already know or suspect the location of a sub (detected by other means or monitoring a known likely location like a navigational chokepoint).

      "only really going to be possible if the airspace is mostly uncontested."

      True and a good observation.

      "Against China in the Pacific? I'm not so sure."

      Recall that the Atlantic convoys were not generally within range of land based Axis air. It was mainly the U-boat threat. Similarly, convoys from the US west coast to Pearl Harbor and then to Guam will not generally be within land based air range but will be subject to Chinese sub threats. I see no reason to believe that the convoy system and the threats will much different from the WWII Atlantic scenario and we'll need similar, low end ASW escorts.

    2. While sonobuoys are not large area sensors, they are the best available tool.
      Surface ships simply can't cover the required area for large scale oceanic sub hunting.

      In fact, to be completely historically accurste, the most importsnt factor to the utility of HK groups during the Battle of the Atlantic was probably the success of allied codebreakers.
      Without the enigma data, it would have been a much more difficult prospect, bordering on wasteful in tetms of return on the enourmous investment in ships, aircraft and men.

      As you are no doubt aware it's incredibly difficult to find submarines in the vastness of an ocean. It was possible in large measure because the allies knew a hell of a lot about the disposition and activity of Donitz's U-boats.

    3. "enigma data,"

      An important factor, without a doubt. Good reminder.

      "incredibly difficult to find submarines in the vastness of an ocean."

      It is! Fortunately, we didn't/don't have to! Submarines are not evenly and randomly distributed across the entire ocean. If they were, they'd be almost impossible to find. Of course, if they were, they'd represent almost no threat.

      The operational reality is that subs will congregate where the targets are: convoys routes, navigational chokepoints, and the like. Thus, the search area for subs is much narrowed. We only need to search near the target areas and along known sub transit routes. In a very real sense, we don't need to go looking for the subs, the subs will come to us!

  17. Looking from the outside I would have a helicopter carrier as the core of the HK group plus several small corvettes/frigates/sloops.. These would have the ship born sub killer weapons e.g. asroc/depth charge or what ever is deemed best.
    On the basis aircraft drop sonar buoys which "die" when the battery dies, why not fit a buoy to unmanned vessels that can be sent out away from the fleet, stop and listen. When stopped they are quiet, when power/fuel is low they can return to the fleet to be refuelled. These un manned vessel do not need to be large and could even be submersible so they can work in all sea states. They don't have to supper fancy. If you make them small and cheap you can have loads of them and it doesn't matter if you loose some. After all they are is powered sonar buoys that in the long term will be cheaper than the "throwaway" aircraft ones.

    I've probably missed something obvious, please let me know if I have.

    1. One obvious drawback is the very slow speed of the unmanned vessel, relative to a helo, which means response time is poor to the point of detrimental. You get a 'sniff' of a sub 20 miles away and it will take 1-2 hours to get one of these unmanned craft to the area. By then the sub is long gone.

      Another drawback is the need for constant two-way comms. Each unmanned craft has to be controlled and data has to be continuously transmitted. That's a lot of comm activity which means greater potential for giving away one's own position. It's one thing for a sonobuoy to transmit one-way, low powered, over a very short distance to the overhead helo and another to transmit high power, two-way, over 10-50 miles.

      The need to control and monitor each individual unmanned craft would require a fairly substantial increase in control stations and personnel on board the host vessel.

      Considering that a helo might lay dozens of sonobuoys investigating possible contacts, you would need dozens of these craft to duplicate the capability. That would require a pretty substantial and specialized host vessel with some pretty robust small craft handling capability. We've seen that the LCS requires 30-60 minutes to launch or recover a single unmanned vehicle! Now, we're talking about launching/recovering dozens of such craft per hour!

    2. Sorry if I missed led you. My proposal was the un manned craft were part of the system. the corvettes would still be doing asw and so would the helicopters from the helicopter carrier. The un manned craft would just increase the search area. If they get a "ping" helicopters would be dispatched.

  18. @CNO

    The DoN FY2020 budget justification book will dissuade any hope of a “cheap” ASW corvette; a ship type that was *never effective*at deterring or sinking u-bootes and the threat has not just evolved, it is a completely different beast.

    Bare bones weapons, sensors and comms for an ASW ship will cost ~$333.4M - look closely at line 11, 2128 FFG-Frigate, particularly PDF pages 199-201

    Ordnance - $ 43.4M [32-cell VLS, SeaRam CIWS, and 57mm gun]
    Electronics - $279.7M [minimal radars, TACAN, EW, AN/SQQ-89 ASW Combat System]
    Flight deck - $ 10.3M [RAST, lighting]

    Note that the VDS, arguably the most important componet of the ship will be GFE (Government Furnished Equipment) at added cost. Note that a hull mounted sonar is not included.

    There is no hope for a cheap, effective ocean-going hull - the U.S. ship building industry has collapsed.

    The Maritime Administration last bothered to publish statistics (Report on Survey of U.S. Shipbuilding and Repair Facilities) in 2004. In 2018 DOT reported just 5 ocean going container vessels under construction and 4 on order, and 2 planned.

    If we want to win a war at sea, bomb the enemy shipyard, mine their harbors, and build as many submarines as possible.


    1. " dissuade any hope of a “cheap” ASW corvette"

      You've gone WAY beyond my vision for a ASW corvette. My corvette would have no helo, flight deck, hangar, TACAN, EW/SEWIP, VLS, SQQ-89, RAST, or lighting.

      It would have ONLY a towed array, hull sonar, Russian RBU-ish, SeaRAM, very low end radar (essentially just navigation), and a trainable ASROC box launcher. Nothing else. None of that is terribly expensive.

      You may be confusing my concept for a ASW corvette with a fully functional, fully capable ASW vessel. This is not the case. The ASW corvette I'm proposing is analogous to the WWII Flower class. It is intended to provide presence (forcing subs to divert, hide, move away) and some MINIMAL ASW capability in the escort or patrol role. This is NOT a vessel intended to go one-on-one hunting for subs.

      With a towed array (MFTA) and hull sonar, it is a mobile, enhanced sonobuoy. It is intended to escort and operate in groups. Its strength lies in numbers.

      "If we want to win a war at sea, bomb the enemy shipyard, mine their harbors, and build as many submarines as possible."

      No argument there! We will, however, still need low end ASW corvettes for harbor patrol, chokepoint monitoring, convoy escort, and the like.

    2. Why not use an unmanned vessel like Sea Hunter for this? Maybe also have a manned, "command" vessel that controls multiple Sea Hunters.

    3. For certain, very limited functions, yes.

    4. Like a mobile, enhanced sonobuoy?

    5. @CNO: “The ASW corvette I'm proposing is analogous to the WWII Flower class. It is intended to provide presence (forcing subs to divert, hide, move away) and some MINIMAL ASW capability in the escort or patrol role.”

      Fair enough, but what does “minimal ASW capability” really mean, and how does the opportunity cost of your proposal compare to alternative options like submarine based ASW? Might the money be better spent on multi-purpose destroyers, a fixed sonar system, or even bombers to strike the submarine bases? Not only does the concept have to work, it has to be “better” than other options (cost, use of manpower, production, effectiveness, etc.).

      Not embarking helicopters is one thing; but not being able to control helicopters, share/process data, or refuel and rearm them is another. And you still need a hull mounted sonar of some type as self-protection when sea states go above 5, as well as CIWS, and a ‘local’ air defense (torpedoes are not necessarily the primary weapon of submarines).

      I think the “Frigate” requested by the Navy has the minimal capability required, deleting the helicopters will save acquisition hosts for the frigate program, but will not impact the requirement for ASW helicopters, and hence not save much money to the fleet as a whole.

      This is the cost of not having a much longer ranged/more effective alternative to VLS ASROC – helicopters are your only ranged attack weapon, and those helicopters come at a premium (costs, payload limit, weather limits on flight operations, on station limitations, operational availability limitations…).


    6. "Not only does the concept have to work, it has to be “better” than other options"

      No. It has to COMPLEMENT other options. Sure, a multi-purpose destroyer is a better option (a Burke, I guess, at $2B+) but does it make sense to assign a highly capable, very expensive Burke to patrol or escort duty where the likelihood of sub threat is fairly low? Surely, there's better things for a Burke to do!

      A point of confusion may be if you're thinking that I'm suggesting that a small, helo-less, ASW corvette is the ONLY ASW asset that's needed. Not so!!! Take a look at the Force Structure page on this blog and you'll see what I'm proposing for overall force structure, overall ASW structure, and where the ASW corvette fits into the scheme.

      I get the impression that you think I'm looking at an ASW corvette as the front line, main ASW asset. NO!!!!

      As with the Flowers, the job of the ASW corvette is patrol/control of the lower threat areas, convoy escort (lower threat), harbor patrol, navigational chokepoint monitoring, and the like. Its job is to detect a sub and call in more capable assets while still having the ability to put up a bit of a fight. It's the ASW speed bump of the sea.

      An individual corvette is only marginally capable but it becomes effective through numbers. No enemy sub is going to risk trying to penetrate a squadron of corvettes - so, mission kill or delay which means at least temporary success.

      "you still need a hull mounted sonar of some type as self-protection when sea states go above 5, as well as CIWS, and a ‘local’ air defense"

      I specified exactly that!

      "not being able to control helicopters, share/process data, or refuel and rearm them is another. "

      These are not front line ASW assets. They are CHEAP assets whose strength lies in numbers. If helos are available then the platform/base that launched them can service them.

      "how does the opportunity cost of your proposal compare to alternative options"

      The economic concept is that a small, basic, no-frills ASW corvette is not competing with Fords or Burkes for funding to any significant extent. Further, such a corvette allows us to utilize other, smaller shipyards which allows us to field larger numbers of vessels. The WWII Navy had 6000 ships but only a few of them were carriers or even Fletchers. The vast majority were smaller less capable ships that patrolled the periphery, provide harbor defense, scouted low threat areas, escorted low threat convoys, etc.

      The ASW corvette is not competing with anything. It is complementing the high end capabilities. It takes up the duties that are low threat but still vital.


      The frigate program is a mistake but that's another topic!

    7. @CNO

      We are talking past each other.

      I am an OR, and I believe in numbers [more properly the high-low force mix], but ships *must* be effective both individually, and as a force.

      It is difficult to believe that ships lacking communications, data links, and ineffective sensors will be somehow able to operate effectively as a group.

      Smaller ships are, on a unit basis, more expensive for less capability than larger ships – a large force of *cheap ships* is anything but cheap, and does very much compete with larger platforms for funding. Numbers can be justified *if* the force is more effective, but there is also a reason that the last effective cold war ASW ship (DD963) approached the size of a WWII light cruiser.

      Force size is dictated to a very large extent by life-cycle costs (what it cost to buy, crew, operate, maintain, and dispose of a weapon system), not simply acquisition cost (purchase costs), and certainly not by the cost of steel, which is by far the cheapest element of ships since the development of the integrated circuit. DOD CAPE guidance on life-cycle costs repeatedly emphasized that manpower accounts for about 40 percent of the ship’s total O&M costs.

      Submarines, particularly SSKs, are particularly efficient, bot as weapons platforms, and in manpower.

      WWII corvettes were *ineffective* - both individually, and in mass.


  19. In the 1950's and 60's, the Navy operated many Essex-class carriers as ASW carriers. Normally, they carried 2 squadrons of S-2 Trackers, a squadron of helicopters, a few E-1's, and a flight of A-4s for local defense. This totalled about 45 aircraft.

    Your concept is good in low-threat environments where contact with enemy ships and aircraft is unlikely. But, helicopters only provide local ASW defense and, as you mentioned, the Navy needs a fixed-wing ASW platform. And, any ASW H-K group operating in the open ocean should have them too.

    I submit a larger platform is needed, something that could carry 30 to 35 aircraft and helos. I'd also modify the E-2 into a ASW platform. It's in service and the modifications shouldn't be too difficult. And, I would include at least a frigate for local air defense.

    1. How about an Antisub variant of the V-22 operating off of a modified ESB?

    2. The Navy examined this possibility and rejected it. I don't know why.

  20. "the Navy needs a fixed-wing ASW platform."

    Yes, they do. However, we run into a few problems with this. The main issue is that the Navy can't build an aircraft for under $100M and a low volume, specialized aircraft like this would probably run closer to $200M. That just won't allow us to procure sufficient numbers of fixed wing ASW aircraft to fill ASW carriers.

    What we need is the modern equivalent to the WWII TBM Avenger: cheap, easy to produce, and basic. We need a sonobuoy and torpedo 'dropper' with no sophisticated electronics.

    With a very expensive aircraft, we'd only be able to equip the Nimitz/Ford air wings, not ASW carriers.

    "I submit a larger platform is needed, something that could carry 30 to 35 aircraft and helos."

    That will cost $6B-$8B and is utterly unaffordable. The comparison data point is the America class LHA which can operate around 20 F-35s or a mix of around 25 F-35s and helos. To go even larger like your 30-35 aircraft and needing cats and arresting gear would push the cost into the $6B-$8B range.

    That's a huge overkill. Why would you ever need 30-35 aircraft? What mission would a ASW carrier execute that requires that many aircraft? I suspect you're envisioning all kinds of sea control or some such missions which means you've fallen prey to the modern military tendency to make very platform a multi-function, do-everything miracle worker whose main characteristic is, of course, that it's unaffordable.

    1. "The main issue is that the Navy can't build an aircraft for under $100M and a low volume, specialized aircraft like this would probably run closer to $200M."

      Building off an existing platform, like the E-2, will help to lower costs. You could put all the electronics from your TBM Avenger with room for sonobouys and torpedoes.

      "That will cost $6B-$8B and is utterly unaffordable."

      It would be a multi-billion dollar platform, but I don't think anywhere near $6B-$8B. The Rand Corporation looked at 4 carrier options a couple of years ago. The procurement cost for their 20,000 ton EX carrier was $2.5B. The procurement cost for their larger 40,000 ton LX carrier was $4.2B.

      A larger carrier than the one you envision offers more capability, sea control being one of them, but it also provides room for MCM helicopters. And, additional aircraft provide for greater and more persistent coverage as well.

      Multi-mission isn't necessarily a bad concept, but it has to be well managed. We've been quite successful with aircraft. The S-3 started off as a anti-submarine platform and was later used as a tanker, a cargo transport, and for electronic support.

    2. "The procurement cost for their larger 40,000 ton LX carrier was $4.2B."

      Exactly!!!! The 40,000 ton America class LHA can operate around 25 aircraft and does not have cat/trap capability and costs $4B. You're proposing a larger carrier (30-35 aircraft) WITH CAT/TRAP capability (more cost). THAT'S GOING TO COST A GOOD DEAL MORE! Hence, $6B-$8B. Plus, when was the last time the Navy built a ship that didn't run hugely overbudget? Heck, $6B-$8B might be underestimating!

    3. @fighting Irish: I recall reading that the JMSDF was studying an ASW variant of the V-22. Worth keeping an eye on that to see what comes of it. I can understand the appeal the concept has for the Japanese - the ASW V-22 would bring them closer to the ASW capability the S-3 offered, while not needing cats or traps.

    4. "Exactly!!!! The 40,000 ton America class LHA can operate around 25 aircraft and does not have cat/trap capability . . ."

      The LX concept does lack cats and traps, something I missed, but they don't cost $2B to $4B either. CVN-77 cost $6.2B, which would be $7.5B today.

    5. The America class LHA is too slow to support ASW, lacks sound isolation systems to limit self-noise, and of course lacks the weapons/sensors/data systems to do ASW even as a secondary mission.

      Most commercial hulls are rated for *sustained speeds* of 22-kts or higher, making them faster than many 30-knot warships in sea state 4+.


  21. It looks like coordinated submarine comms are heading in the direction of a buoyant cable streamed from the sub.

    The cable acts as an antenna and uses UHF to talk to a low orbit satellite. Sam tech as a sat phone. You can use it to coordinate an attack and talk to higher and other surface or aerial assets in real time.

    Using modern materials that cable can be very small diameter so loss of stealth is not an issue.

    Interesting idea. Most of the data I found is from 2011 or so, so its likely someone somewhere has it in use today. Probably those fiendish Chinese if I had to hazard a guess.

  22. Late to the party, but I have a question related to this, in regards to the Ford class.

    With the Ford being heavily reliant on electronic magnetic (EM) for most of its key systems, is it possible for a sensor to detect those EM signatures will mounted on a sub?

    1. Yes, CNO Greenert acknowledged that the Ford's EMALS was an electromagnetic beacon for all to see.

    2. I'm aware that the ford class produces a large, detectable EM signature that can be tracked, probably even by EMF satellites.

      My question is more tailored to whether a submerged submarine could. If yes, what's to prevent China from developing submarine specific weapons platforms to can track/ exploit that EM signature?

    3. Submarines have electromagnetic sensors, so yes. Of course, they have to stick a mast up to use them and they don't like to do that.

      China already has plenty of cruise missiles and I'm sure they have lots of radiation-homing missiles as well. I'm not sure what you have in mind beyond what they already have?

    4. I have nothing in mind, I'm just kind of ignorant on the subject.


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