Monday, November 20, 2017

ASW Corvette

Well, the frigate debate is on!  Observers are weighing in with their favorite candidates for the Navy’s frigate competition.  Here’s a couple relevant thoughts.

-          ComNavOps is on record as saying that the Navy will go with the Freedom LCS frigate which would be the worst possible decision in every sense.

-          ComNavOps is also on record as stating that the Navy does not need a frigate – it needs a small, cheap, expendable ASW corvette.

However, observers are all enthusiastically promoting large, powerful frigates which are just mini-Burkes.  I’ll say it again, we don’t need mini-Burkes because we have plenty of full size Burkes!  Instead, observers and, sadly, the Navy are focused on how many VLS cells they can squeeze in and how powerful a radar they can mount.  In essence, they’re trying to see how close they can get to a Burke.  Hey, if you want a Burke, build a Burke.  A “frigate” that is nearly the match for a Burke is going to have a cost that is nearly a match for a Burke.

Here’s an example of what we really need: the Indian Kamorta class corvette

The Kamorta is a stealthy shaped ship that is small (358 ft) and ASW focused with

  • single ASW helo/hangar/flight deck
  • RBU-6000 anti-submarine rocket launcher
  • 4x heavyweight torpedo tubes
  • towed array
  • bow mounted sonar
  • sound isolating, raft mounted machinery

Additional armament is defensive

  • 76 mm gun
  • 2x CIWS

The radar is a reasonable medium range 3D planar array.

Add an 8-cell VLS for 32 ESSM and you have the basis of a nice, small ASW corvette which would be immensely useful to the Navy as opposed to mini-Burkes.

Kamorta Class ASW Corvette

Being slightly smaller than the Freedom class LCS and without the expensive focus on high speed, hopefully the construction cost would be a good bit less than the LCS.  If costs were too high, though, I’d drop the helo/hangar/flight deck since a single helo doesn’t contribute all that much to ASW simply due to its very limited availability.

This kind of ship can perform the peacetime “show the flag” and patrol duties that are currently using up our Burkes and preventing their proper maintenance and crew training.  In war, these ships can provide the numbers and expendability we need for shallow water ASW, peripheral patrol duties, can augment task forces, and can perform convoy escort duties.

This is what we need, not mini-Burkes.


  1. I like it. ASW worries me a lot and the absence of extra kit might also mean the crew has to focus on it more.

    I wonder, too, how good the Burkes are for ASW. They have torpedoes, two helos, and the ASW kit but I don't think they are sound deadened, and from what I've read they don't practice it much.

    1. I read somewhere that the Navy wants the frigate to be able to keep up with the battle group. Here's a Wikipedia link to a description of this Kamorta-class corvette.

      Navy Detroyers and hybrid electric drive to improve fuel efficiency. Could this be adapted for this ASW corvette ?

    2. I have no idea whether a hybrid electric drive could be used on a corvette. However, there's a larger point and that is whether a more complicated machinery plant is a good idea on a warship. We've seen in the LCS that the crew can't operate the propulsion plant and can't repair it when it breaks. Is that really what we want in a warship that is subject to battle damage? Maybe this is a case where simpler is better for combat. It's something to think about.

    3. HED drive is unlikely to be useful in a smaller ship since it is likely to be either CODAD or CODAG instead of COGAG like the burkes due to significantly reduced propulsion requirements. When operating at lower spd, CODAD or CODAG can just use the diesel engines.

      Burke HED really is just an attempt to bring it in line with the Zumwalt's capability to use any of its 4 gen sets (2 MT30s at 35MW and 2 RR4500 at 4MW) to power the ship via the IPS. The Burke only has 4 20MW LM2500s capable of powering the ship. The HED retrofit is to enable the 3 Allison AG9140 gen sets to power the boat when the power of the LM2500s isn't required to maintain spd.

      Gas Turbines are significantly more efficient than diesels at high power output both in Fuel and in volume but suffer worse efficiency when dialed back to lower power outputs. This is basically down to the IPT (integrated power turbine) being designed and scaled to operate at higher air velocities/thrust. At lower thrust the IPT are oversized, overweight, and not optimized aerodynamically. AKA diesels operate on roughly a linear efficiency curve while turbines operate on an exponential curve.

    4. I'm not sure that HED's are inherently more complex. They've been used for years.

  2. Why is this corvette better than say a FREMM class vessel for the Navy?

    1. Because the FREMM is a bad Burke and we have a LOT of Burkes. We don't need another Burke OR Burke-light.

    2. The Navy needs ASW vessels, not Burkes or mini-Burkes. Right now, our only ASW capable vessel is the $2B Burke. Does it make sense to risk a $2B ship playing tag with subs? Of course not. The same applies to $1B frigates (mini-Burkes). The Navy needs cheap, expendable ASW vessels to play tag with submarines that have all the inherent advantages.

    3. It's almost re-creating the idea of the Destroyer Escort. Lightly armed against surface competition, designed for ASW.

      The reason we did it back in the day was to get a lot of cheap units out there to fight subs.

      We should do it now.

    4. Of course you just need to add *my* pet idea of an 8" gun, large magazine, and multiple drone launcher for.... ;-)

  3. CNO, we would probably want to add at least some AShM to the thing, 1-2 4 shot box launchers.

    1. NO! No! no! noooooo. That's how you end up with multi-billion dollar ships. People keep adding functions beyond the mission requirements. Sure, you say, a few anti-ship missiles won't add much cost. And maybe a few more VLS cells. And some Standard missiles since we have VLS. And a better radar to control the Standards. And Tomahawk missiles. And bigger engines for a bit more speed. And ... Everyone wants to add their pet function and no one ever says no. By the end of the design, the $200M corvette has become a billion dollar mini-Burke. We have Burkes, subs, carriers, and an Air Force, among other assets, that can perform the anti-ship function. Besides, once you add other functions you start subtracting training time from the main function.

      Worst case, our corvette has a one-on-one encounter with an enemy ship and is sunk. We don't really care because we kept the cost low and we can build replacements quickly and cheaply. Plus, the enemy gave away his location by sinking our corvette (flaming datum) and one of our other assets probably sank him and we come out ahead.

    2. Here's the reality of adding a couple of rack launchers. The corvette doesn't really have the deck space so we have to add 8 ft of length to the ship. We also need some ship's electrical power so we need the next size up in generators. The racks, missiles, and generators add weight so we need slightly bigger engines to maintain our desired speed. Bigger engines need more fuel so we need bigger fuel tanks - hmm, might have to add a few more feet to the ship length to fit all this in. The missiles will need an extra couple of crewman to maintain, target, and operate them. We may need an extra crewman for the bigger generators and engines. Extra crew means more berthing space, a slightly bigger galley, more food and water storage. All that means more weight so we'll need even bigger engines. And so on ...

      People think that adding a rack of weapons is simple but it's not. There's a domino cascade effect of changes that accompany any equipment addition to a ship. It's why ship's continually grow over the course of their design phase.

      Rather than add everything we can fit into a ship design, we need to add the MINIMUM that can accomplish the mission. In this case, it's ASW and only ASW.

    3. An asset that can't defend itself against a simple missile boat is a useless asset. Even ASW ships need to present some deterrent against things like a Type 22. A box launcher or two of NSM isn't going to break the bank and at least provides some deterrence against the 200-400 million dollar ship getting whacked by a 10 million dollar missile boat which faces no threat.

      Quite honestly, I would delete the 76mm gun in favor of a rack or two of AShM. The gun is going to be generally useless against anything that is an actual threat at range and suicide boats can just as easily be dealt with using either CIWS or a 30/35mm cannon.

    4. Basically any Navy vessel without AShM is going to require escort in any peer or near peer action. Therefore, AShM should be a minimum equipment requirement for all ships that are expect to engage in combat.

      In the actual event that the ASW ships are actually hunting enemy subs, all the subs have to do is lead the ASW ships near an area with missile boats and they are in the free and clear because the missile boats will win if they can loiter 20-30km outside of the ASW ship and fire a salvo of AShM without issue.

      We know that for instance China has several hundred <500 ton AShM equipped boats that will flood the islands in the SCS. Combined with their corvette force, you are looking at roughly 400+ small (100-2000 ton) AShM boats/ships. If they can attack without risk, then the ASW ships don't stand a chance.

    5. These PLAN missile boats do not have CWIS or AAW. If PRC places their missile boats in a forward position, these boats will be vulnerable to air attack. Also, the missile boats will have to rely on other assets for targeting and will need communications to mass and coordinate an attack. Small missile boats make sense for blufor to use to defend the first island chain if PLAN missile strikes will take out airbases or A2AD pushes CVBG's too far back.

    6. "An asset that can't defend itself against a simple missile boat is a useless asset. Even ASW ships need to present some deterrent against things like a Type 22."

      No. That's the kind of thinking that leads the Navy to try to make every ship a do-everything and win-the-war-singlehanded ship.

      Let's try an analogy. Soldiers may encounter enemy artillery. Should every soldier have their own individual artillery piece so they can counterfire? I'm pretty sure you'd say no, that would be impractical. Besides, there's artillery battalions whose job it is to do that.

      Well, the same holds true for ships. We can't afford to make every ship a fully armed ship. Besides, we have other assets whose job it is to sink enemy ships.

      The ASW corvette either isn't going to be in likely ASuW combat scenarios or, if it is, it will be escorted by, or in company with, Burkes or carriers.

    7. The analogy doesn't work. AShM are effectively the rifle of surface combatants these days. Even EOD trains with and carries a rifle.

    8. This is a great conversation. It is the crux of all arguments of ship type.
      As I see it, the problems are, what do I need in peace time and how will I use that in war time?
      We need about twenty hulls to fly the flag. We are losing the south china sea, not because china built a few reef missiles but because we are absent to our partners, allies and their neighbors(potential partners).
      During most of the cold war that probably was a need for a gray USCG cutter.
      Now that cutter needs to be up armed. Not as a mini burke but as a, "I don't want to be the next Cole, Stark or UAE melt down."
      Does every patrol craft need AshM? No, because in peace time the threat of retaliation goes a long way to keeping other countries nice and as of yet proliferation of warships to rebels is very low compared to missiles.
      But what to have on a small frigate/patrol boat that makes it useful in war without breaking the peace time bank?

    9. "The analogy doesn't work. AShM are effectively the rifle of surface combatants these days."

      You just countered your own argument! AShM's ARE the rifle of surface combatants. BUT ... wait for it ... The ASW corvette is NOT a surface combatant!!!! It's a specialized tool with a single purpose. Its "rifle" is its sonar suite.

      We don't give individual soldiers their own artillery piece because that's not their job. We don't give ASW corvettes anti-ship missiles because that's not their job. If we're going to take the approach of weaponizing the corvette against all possible threats than we need to add a flight deck, 16" guns, MCM equipment, etc.

  4. The list of requirements for the FFG X is interesting as there are many possible solutions already in service around the world, some of which have been mentioned by commenter’s in other posts. I was fortunate to be involved in the construction of the ANZAC class in the late 1990’s and the FFG X requirements read almost exactly like the features of the ANZAC. Based on the MEKO 200 the ANZACs have a 5” gun, 8 x SSM, space and weight allowances for 2 x 8 cell mk 41 VLS (only 1 fitted), 2 x mk 32 torp launchers, 1 x MH60R helo and CIWS. All this in a 3500 ton hull.

    They carry a reasonable sensor fit and are fitted for but not with VDS. I cannot speak to the electronics currently fitted, but the MEKO designs were created to be easily updated through containerisation and other design features. Coupled with a 6000 nm range at 18 kts they provide ASuW, ASW and self protection AAW. IIRC the price was about $150M AUD for each ship in the late 90’s so $3-400M today would be a reasonable price estimate.

    The point I want to make is that there are many existing designs already available and in-service which could meet the FFG X requirements with minimal modification. If the pentagon and congress can resist the “not invented here” or worse "not transformational" syndromes a winning design could be selected within 12-18 months, allow 24 months for detailed engineering then series production (build to print) could commence at multiple yards.

    They would not be able to enter a contested sea by themselves, but would be a useful addition to any battle group. They would also be able to replace the AB in most peace time duties as well as escort and patrol duties in lower risk areas during war. Building them at a rate of 3 or 4 for every AB would provide the USN with a strong ASW fleet operating under the cover of one of the best AAW ships in the world.

    1. ANZAC frigates are slow for carrier battle groups. I saw a show where the HMAS Toowoomba was struggling to keep up with a CVN. An Australian SWO looked pretty embarrassed regarding how slow his ship was compared to the carrier.

    2. newsflash, the only US ships that can actually keep up with a carrier are nuclear submarines. US carriers are capable of simply outrunning every other USN ship. US carriers operate at slower than max speed so that USN ships running flat out can keep up with them. Carriers have basic hydrodynamic advantages for speed over all other military ships and also have a massive power advantage over all other ships.

      The whole reason the US looked into nuclear powered cruisers and destroyers was so that they could keep up with nuclear carriers.

    3. Replying to Anonymous November 20, 2017 at 9:45 PM.

      The reason ANZACs are so slow is we deleted the 2nd LM2500 Gas Turbine (like other nations kept in their MEKO 200s - such as Greece and Turkey). theoretical max speed is about 27kts. With both GTs it was about 31kts.

      It was a stupid cost saving decision based on flawed assumptions. Flawed for operational redundancy reasons if nothing else.

  5. You make a lot of valid points about the advantages of the Indian ASW corvette. A few points though.

    1) The corvette is a bit short on range- which matters since that's one of the weaknesses of the LCS- range is too short for escort duties or proper patrolling.

    2) Only has one helicopter. The more helicopters, the better, since they can be up in the air for longer.

    3) If they have to choose a LCS "frigate", the independence class would be better, at least on paper and looking at the model. At least it has a towed array and some VLS which can take some ESSW for self defence and RUM-139 VL-ASROC.

    Perhaps a FREMM with a less powerful sensor system like sea giraffe, and only 16 VLS, might work. Lighter, range over 7000nm (esp with lighter sensors and less missiles and VLS) might be a suitable alternative?


    1. FREMM is simply far too much ship. Anything really over about 4000mt is going to cost far too much.

      While people like to say that metal is cheap and air is free, that doesn't bear out in reality. Extra mt requires more propulsion which requires bigger engines which require more fuel etc. Realistically, the Navy needs the smallest ship possible that can do ASW and have reasonable self defense with the required endurance.

    2. "Only has one helicopter."

      I'm dubious about even having one helo since it would only be sporadically available. The more I think about it, the more I'm inclined to leave it out. Remember, this ASW corvette is not (or should not!) be the only ASW asset we have. We should have P-8s, true destroyers (not Burkes) with helos, ASW helo carriers, and fixed wing ASW aircraft (S-3 Viking replacement). In such a balanced and mixed force, the job of the corvette is presence - to make the enemy subs stay in hiding or go out of their way. The corvette may find and engage shallow water subs on their own but their main job is to deter or locate subs and call in other assets for the kill. The corvette isn't going to be operating on its own, in a total vacuum. It will be part of a mixed force. Thus, a helo is not mandatory and if deleting the helo/hangar/flight deck allows us to build a significantly cheaper vessel in significantly greater numbers than the trade off is well worth it.

    3. " true destroyers (not Burkes)"

      That, and the statement someone else made about keeping up with the Carriers makes me mourn the loss of the Spruance's; and the idea behind them. A fleet nowadays of 40 Burkes and 20 Spruance would seem a lot more balanced.

      But we are where we are, and we can't do everything, so the ASW ship is a good start.

  6. ats,

    Saw this on tapatalk forum. ... e&_cview=1

    Some points of note:

    1) Basic hull target cost of $495MM (FY18). That's only ~15% over the cost of a basic LCS hull (~$430M) under the same conditions. (Note that this is "non-flyaway", i.e. excluding design, weapons, equipment & delivery costs). However price is the least important evaluation factor.

    2) Special emphasis on 5 technical requirements, with threshold/objective values: 1) Acoustic signature, 2) VLS capacity, 3) Range, 4) Service life allowance, 5) Accommodation.

    With these in mind, FREMM can still be the frigate the USN ends up with. Since price seems to less of a factor, and range is a criteria, the ASW corvette is not sufficient on this aspect alone.


    1. "the ASW corvette is not sufficient on this aspect alone."

      Don't get confused about what I'm calling for. I'm not calling for an ASW corvette as the candidate for the Navy's frigate wish. It's not a frigate. I'm calling for the Navy to drop the frigate and instead build a small ASW vessel. That would be a completely different program.

      To repeat, the ASW corvette is NOT a candidate for the Navy's frigate program.

    2. I think people get confused by the (admittedly confusing) terminology.

      We used to have Destroyer Escorts that did this job. Then they became 'Ocean Escorts', then in '75 Frigates.

      Granted, these later ships were up gunned from the example here (Garcia's had 2 5" guns, and I think even Knox could fire Harpoons) but they clearly weren't DDG's and had a focus on ASW.

      Nowadays the term 'Frigate' cover ships that are in many cases anti-air destroyers.

    3. Knox was a good asw updated one would be great. We used to carry a mix in the Asroc launcher. 4 Asroc and 4 harpoon.You also had 2x2 HWTT. Machinery was sound dampened plus the prairie masker.

    4. I have a soft spot for the Knox. It seems like a good ship devoted to one task. And with the launcher able to launch both ASROC and Harpoon pretty versatile.

      Avondale seemed pretty clever about how to build them too:

      "These ships were built on a production line, with prefabricated modules being assembled upside down, welded together and then rotated into an upright position.[4] They were originally commissioned as destroyer escorts (DEs) 1052–1097 in 1969–1974,[1] but were redesignated as frigates (FF) on 30 June 1975.[5]"

  7. One possibility for an ASW Corvette/light frigate would be a version of the new USCG OPC, 360 x 54 x 17 feet, ~ 4,000T, 8,500 nm range, 60 days endurance, max. continuous speed 22 knots being built by Eastern Shipbuilding FL. Contract price for basic hull $264.4M, including GFE budgeted at $421M, first ship to be delivered 2021.

    If you specify higher speed it will cost, rule of thumb for every increase of 4 knots you need to double the horsepower.

    OPC uses a Hybrid propulsion system, two 7,280 kW MAN 16V28/33D STC and two DRS 650 hp electric motors for speeds to ~ 9 knots, as when in ASW mode. Using propulsion diesel engines at slow speeds adds significant wear and tear on the engines and increases the potential for coking/wet stacking, by adding electric auxiliary propulsion system gain the advantage of reducing fuel and maintenance and lifecycle costs.

    Assuming OPC max. speed is 24 knots, to increase to 28 knots you would have to double horsepower, would need to lengthen ship to add new engine room for two new engine, more expensive MGR etc, etc.

    CNO "NO! No! no! noooooo. That's how you end up with multi-billion dollar ships"

    If Navy, totally unlikely, followed this option they could fund two to three ships for the price of a single specified FFG(X).

  8. Wonder what the price of this OPC/ ASW variant would be if:
    1)A version is designed with acoustic silencing.
    2)A version designed with proper armament for ASW and self defense.
    3)A version meeting navy standards( vs coast guard's).
    And finally, The navy wants a frigate able to keep up with a battle group. But we have Burkes to do that.

    1. Just to be clear, the ASW corvette I've proposed is not suitable for the Navy's frigate desire. The ASW corvette would be a complete replacement program.

      Related to pricing, are you aware that half the OPC's length is devoted to the helo in the form of the flight deck and hangar? That's a lot of room and money to be able to operate a single helo! A single helo is appropriate for CG but not for a small, cheap ASW corvette.

      Regarding costs, they would certainly go up as you add equipment and capabilities but not by all that much. The equipment that would need to be added (towed array, sonar, ASW torpedoes, etc.) is relatively cheap compared to, say, Aegis radar/combat suites.

    2. The HI ships and the OPC are intriguing to me, but a lot of study (IMHO) would have to be done. Suppose you wanted to make the OPC an ASW corvette. Could you eliminate the Helo and just use the space for (something, whatever) else without spiking cost?

      My biggest concern is the quieting. I think quieting absolutely positively is a must for any ASW ship.

      Can you take a previous design and effectively 'quiet' it in an economically feasible manner? Or does it make more sense to design a quieted ship from the keel up?

    3. This is such a great thread. I wish it was happening in the Naval War College.

    4. One slightly off topic, CNO (or anyone)... the Corvette you list has a 3" gun. I see more and more American designs using the 57mm....

      The 57mm seems like a crappy gun. Why has that become the default weapon for small combatants? Is there a good reason? Or is it just cheaper?

    5. One more slightly off topic: One reason for a small surface combatant used by the Navy is for 'presence' and anti drug missions.

      Why is the Navy doing anti drug missions in the gulf? Isn't that the Coast Guards job?

    6. "The 57mm seems like a crappy gun. Why has that become the default weapon for small combatants? "

      I have no idea. Good marketing on the part of the manufacturer?

      The underlying question is what do we want a gun on a small vessel to do? What do you think it should do? Answer that and you'll know what kind of gun you need (hey, maybe a 57 mm is the right gun?).

      Let me know what you think.

    7. "Why is the Navy doing anti drug missions in the gulf? Isn't that the Coast Guards job?"

      Bit of a gray area as to whose responsibility it is. The reality, though, is that the CG simply doesn't have the resources - that makes it a Navy job or it doesn't get done.

  9. CONOPS, CONOPS.... The ASW Corvette is proposed to deal with submerged threats to itself and others in both blue water and littoral environments.

    This should mean that it has the means to do ASW (helo, hangar, torps, hull sonar, towed sonar etc.) Anything else should only be there to ensure that the ship is able to do ASW. This will mean that it should have a reasonable local area air defence capability (medium range radar, some ESSM (not heaps), CIWS).

    It should have some capacity to deter surface threats from it's local area, BUT that only needs to be out to the ships own radar horizon (If the ship can't detect it, it doesn't need a means to shoot it). This means that an AShm with a range of 80km isn't helpful as the ship has no means of detecting a threat out that far.

    If a little ASW corvette is being sent to play tag with submarines on it's own in a hotly contested environment with multiple surface and air threats we should have sent a Burke (or multiple Burkes).

    It's very easy to take the thinking that we need our ships to be able to defend against everything to do their job to mean that they need EVERYTHING, hence you end up with a Burke.

    1. "If a little ASW corvette is being sent to play tag with submarines on it's own in a hotly contested environment with multiple surface and air threats we should have sent a Burke "

      You say that and yet you violate that concept by wanting to add helos and a short range anti-ship missile. Consider your own (correct!) statement. If we're asking the corvette to operate in a high threat environment there will be a Burke(s) there to provide all the anti-ship weaponry that's needed so the corvette doesn't need even a short range anti-ship weapon - that's not its job.

      Could there arise a rare occasion when an enemy ship somehow manages to penetrate to our supposedly low threat area of operation totally unseen by any surveillance asset and attack our corvettes? Sure, but that's unlikely and to increase the ship's cost and decrease numbers just to deal with an unlikely event is foolish. The escort carriers at Leyte were caught in just such an unlikely scenario. Does that mean we should have put 16" guns on all escort carriers to guard against a very unlikely case? No, we accept a little risk and gain a lot more numbers and lower price. Too many people want to design against every possible scenario instead of establish a CONOPS and design to that.

      Similarly, a Burke can provide helos for ASW and the corvette doesn't need them. For low threat environments, a helo would be nice (so would 16" guns, Tomahawk missiles, etc.) but is not mandatory. The corvette is not going to operate alone (CONOPS). It will operate in groups. A group of ASW corvettes is sufficient to suppress or prosecute a sub and it is quite likely that P-8 or helos will be available if needed.

      We need to begin designing around the BARE MINIMUM needed to accomplish the mission rather than the MAXIMUM or even the DESIRABLE. Only in that way can we achieve the bare minimum cost and maximum numbers.

      Consider the cost impact of a helo on the overall cost of a corvette. A flight deck and hangar will close to double the length of the vessel. We'll have to add machine shops, aviation fuel tanks, helo munitions magazines, helo spare parts storage, around 15 extra berths for the aviation detachment, extra food/water storage, bigger engines for the larger hull ... you see where this is going, right? The single helo has an enormous impact on the ship's cost.

      Sure, a helo is desirable but not at the expense of increased prices and decreased numbers. Our CONOPS has already identified that we can get helos from Burkes or elsewhere much/most of the time so let's skip the helo, save lots of money, and build more corvettes!

    2. You say that and yet you violate that concept by wanting to add helos and a short range anti-ship missile.

      NO, I said I did NOT want an anti-ship missile, what is the point it doesn't need it. The ship only needs the capacity to defend itself enough to do it's ASW mission. A medium calibre gun is fine.

      Some anti-air defence is required for this ship to defend itself. RAM might be enough, but a few ESSM is probably beter so that this ship can protect itself enough to continue the long slow work that effective ASW is. Having no ESSM ends up back at LCS levels of protection from air threats which is insufficient.

      The helo is where I disagree with you at a fundamental level. For ASW work localising a contact requires triangulation. To achieve triangulation multiple detectors in different places are required, preferably within a limited timeframe.

      There are a number of ways of having multiple detectors to localise a submerged contact. We could have a single ship with a helo or helos, we could have multiple ships with attached sonar, we could have sonar buoys dropped out to detect in different places (which could be launched from a single ship). Not having a helo organic to the ship doing ASW limits the capacity of that vessel to triangulate a contact. In blue water ops this is a problem, relying on P8 or other vessels may well present the issue where the corvette knows there is a contact out there, but has great difficulty in locaising it well enough to launch a weapon at it.

      I understand the design compromises that come with operating a helo, the ASW mission compromises of not having a helo are rather dramatic. NOTE: A Helo could be a UAV for dropping sonar buoys which send signals back to the ship, but having no means to widen your detection to achieve triangulation is a major limitation

    3. I've just read more of the comments elsewhere through the thread. I realise that I am still envisaging a more escort role for the corvette where it will be operating to localise and prosecute submerged targets and needs the capacity to do that entire chain.

      If this is an asset that is operating as part of a larger group where wide area air defence is already taken care of, and other assets are providing the helos then this becomes a very focussed ASW ship.

      RAM, a medium calibre gun and a few 0.50 cal HMG is enough in this role. Everything else the ship has is for ASW purposes.

      This is likely to mean that this corvette stays small, with a smaller, ASW focussed crew.

      I'm in the land of Oz, so I'm much more used to the idea that our navy ships may well be a bit more isolated from other supporting assets and will need to be able to look after themselves.

    4. I agree about the helo, for now it will be necessary if working away from the other assets. One of the things that is going to change asw, IMO is the sea hunter. Now people talk about this thing roaming the oceans alone and following subs. Maybe it will. But a better and more practical use would be teamed with a smaller ship such as the asw corvette. With this ability we now can find the sub without air assets.
      The navy will continue to want a helo/uav hanger even if I'm correct about the sea hunter. The reason is that during the time of war we will talk more and more about persistent surveillance. But that's a whole other article that would lead us back to putting that AshM on the deck.

  10. Re: Kamorta. I would have to give it a resounding meh.

    The cruising range (3,500 nm) is far too short. We need 4,500 nm at least.

    It can only carry one helo. Two helos spots at a minimum are needed for near-continuous ASW coverage.

    1. Helos are not necessary. Read my other comments to see where the ASW corvette falls in the overall ASW scheme.

    2. I read it. It just doesn't make sense.

      There's another name for an ASW surface combatant without a helo. A target.

    3. You're welcome to your opinion!

  11. I was thinking in a different approach to the specialized asw corvette: if you want to fight a submarine, than you have to be a “surface submarine”.

    How? Three requirements: 1) a stealthy platform, 2) a Combat Management System and sensors equal to the ones embarked on submarines, and 3) the right weapon system.

    Stealthy platform:

    First of all, you have to be as quiet as a diesel-electric boat. How? Just being a diesel-electric boat!

    Take the hull of an OPV (german Fassmer 80 or Nz Protector class), i.e. a hull length about 260-280 feet. Add a diesel-electric propulsion plant (yes, running on batteries and reloading with a diesel engine every 1 or 2 days, or running only on diesels for transits).


    Embark a Combat Management System powerful enough for processing all the information collected by a towed array sonar (TAS), an active-TAS or a VDS, plus a hull mounted sonar, and a 3D radar system and an ESM system.


    Main weapons would be 4 single tubes for heavy weight torpedoes (without reloads) and some kind of ASW rocket, like Bofors 375 ASW rocket system or RBU-6000.

    Secondary weapons would be an Mk-46 30 mm gun and a Sea Ram. You would also need some kind of 3D radar, and – maybe – a couple .50 guns.


    This ship should be a modern day submarine-chaser (WW II PC-class), which general arrangement would be:
    - Hull mounted sonar
    - Mk-46 30 mm gun in “A” position
    - ASW rocket system in “B” position
    - TAS, A-TAS or VDS on the stern
    - 2 x 2 heavy weight torpedoes launcher firing over the stern
    - Sea Ram in “Y” position
    - 2 x RHIB / Unmanned surface vessels on davits on the mid-length, for sonobouys dropping
    - And all else available deck space would be dedicated to additional unmanned surface vessel or launching and recovery of unmanned aircraft vessel, for surveillance and radio relay between sonobouys and the ship
    - There would be no flight-deck and no hangar. Just a winching area for vertrep.

    Such a ship, could be built for about US$250 million each?

  12. An upgraded Turkish ADA class corvette like the new Istanbul class frigate might fit the bill?

  13. It requires 9 sorties to keep one MH-60R airborne constantly (high intensity, short duration), or 12 or more sorties per orbit for low intensity, sustained air operations.

    Assume each MH-60R can fly two sorties per day, on average.

    An independent task force with an ASW focus should plan on providing at least one MH-60R orbit plus some number of reactive sorties, depending on the false alarm rate, perceived threat, and acoustic conditions.

    Figure eight MH-60Rs, minimum, in the task force. That's 18 sorties per day, or enough for one persistent orbit plus 6-9 reactive sorties.

    In higher threat areas, areas with poor acoustics, or areas where simultaneous ASuW and ASW threats exist, this number could double or triple.

    Ships without aircraft obviously don't contribute to these numbers, so an independent task force would need a minimum of four Burkes to carry eight aircraft. The only way to scale up is to add DDGs or some other helo-capable vessel (LCS?).

    On the other hand, four helicopter-equipped, ASW corvettes plus two Burkes would have 8 aircraft.

    The later is a more reasonable, less expensive design, in my opinion.

    1. Interesting. I'm not sure where you get your figures nor am I sure exactly what you're saying. For instance, 9 sorties to keep one helo airborne - I assume you mean that in a 24 hour period it would require 9 separate flights, each flight providing 2.7 hours of coverage. Correct me if I'm misunderstanding you.

      You are focused on arithmetic rather than Concept of Operations (CONOPS) and you've made the implicit assumption that the corvette is the only ASW asset in the military since your "solution" is based only on corvettes (with a helo contribution from Burkes).

      That's not "correct" in that it ignores the total ASW force structure. To be fair to you, the post is only about the corvette, not about the total ASW force structure. Once you see the total ASW force structure and CONOPS you'll see that there are many other, better solutions than the single one you've calculated. That's the problem with writing a post - I'm limited to a short few paragraphs and can't present the total picture which would require book to properly describe. Let me try to briefly expound on the CONOPS and ASW force structure.

      I've presented what I feel is the glaring need for the Navy and that is a small, cheap, expendable ASW vessel - the corvette. What I left out (actually I've discussed it in other posts and comments) is that we also need a true destroyer (not a Burke) that has ASW as its focus but on a bigger scale which would include helos. We also need an ASW helo carrier to form the basis of ASW hunter-killer groups. We need a replacement for the S-3 Viking.

      Now that you see the total ASW force structure, let's consider CONOPS. Destroyers would provide the ASW escort for carrier, amphibious, and surface groups. Hunter-killer groups would be sent to areas of likely submarine activity. Corvettes would provide convoy escort, home harbor patrol, and peripheral, lower threat patrols. With that in mind, you can see that the corvette is not the ultimate ASW killing machine and does not need helos or anti-ship missiles. It just needs numbers and the ability to detect and ward off the occasional submarine. We're not going to ask the corvette to sail into the Chinese A2/AD zone alone and sink every sub in the Chinese navy. That's someone else's job. The corvette is the cop on the beat - patrolling and protecting convoys and peripheral areas and alerting other forces if a sub is detected.

      More specifically, the corvette would always operate in groups (say, a squadron of four). Thus, if a sub is found, four corvettes would team up to localize and attack it. That's more than enough capability. Between them they can saturate an area with sonar and torpedoes. Also, the small size of the corvette makes it an undesirable target for a sub. A sub is likely to pass on wasting a torpedo on a corvette and giving away its position. Thus, the small size confers a degree of "invulnerability" - but only a degree. We'll still lose some and that's why they need to be cheap.

      Hopefully, this makes it all clearer.

    2. CNO, pretty much agree here. I'm more favorably inclined toward helos, simply because of early 70s on a FRAM I in the Indian Ocean, working with Brit frigates who had helos when we didn't (after DASH cratered), and seeing the flexibility they had that we lacked.

      I like your CONOPS approach. I like something like a Japaneses Hyuga or Izumi for the HUK group. I would consider something like a battlecruiser with air, including VSTOL, based on maybe a combination of Russian Kirov front end (with big guns instead of some missiles) and Kiev back end to pair with the Hyuga/Izumo to form a surface/ASW action group. In the open ocean, away from shore-based air, that would be a very formidable force.

      For your destroyer type, I think we could adapt something from the Horizon/FREMM/F105/Hobart group, a mini-Burke around 6000 tons with beefed up ASW.

      For the corvette/frigate I agree with Andres as to the three priorities. I wonder if something like an updated Maestrale could work.

    3. "I'm more favorably inclined toward helos"

      Of course you are! Who isn't? I'm inclined toward them, too!

      However, when we start talking budgets, overall force structure, and fleet numbers then we have to start making decisions. Hard decisions. Decisions based on priorities.

      Of course you want helos - you're not paying for them. Now, when every helo equipped corvette, which doesn't really need a helo, costs you a half a destroyer, do you still want the helo? When the entire helo equipped corvette program causes the cancellation of the S-3 Viking replacement, do you still want the helo? When you can only afford half the number of corvettes do you still want the helo?

      Everybody is inclined towards helos.

      If "inclination" is all that matters then let's skip all the small stuff and just build a fleet of 355 Ford class supercarriers because I'm even more inclined towards them then I am towards a helo equipped corvette!

      When you have a fixed naval construction budget, it's a zero-sum game. Every capability to pay to add to the corvette is a capability that has to subtracted from somewhere else. Nothing's free.

      Think hard about this and if you still want a helo for every corvette then tell me what you're willing to give up to get it.

    4. Good question. My approach is to revive the Zumwalt high-low approach, where instead of making everything the most expensive platform, we build some high end and fill out the numbers with low end units. The Burkes could be high end and the ASW corvette the low end. Suppose hypothetically it costs $50 million to add a helo and another $50 million to operate it over the life cycle. If we build 40 corvettes, that's $4 billion. That's about the difference between the cost of a Ford and a Nimitz. So instead of building 10 Fords, build 6 Fords and 6 cheaper carriers, which would still be slam dunk winners over any potential enemy carrier and a match for most third world air forces. Pay for the helos by building low instead of high for numbers elsewhere. To do this requires that we have a well established CONOPS, and then build to support that.

    5. Now I get it, If you have an ASW focussed destroyer the ASW corvette just becomes a sonar carrier within the overall ASW structure. This would mean that it has just enough on it to do it's ASW role in that group. This could actually be quite small, with the minimum size actually being dictated by seakeeping needs in blue water, rather than weapons or crewing.

      The lack of a current ASW focussed destroyer becomes a problem in this construct.

    6. "The Burkes could be high end and the ASW corvette the low end."

      Well, if that's the extent of your force structure then, yes, you'd better give the corvette a helo (in fact, you ought to give them two) because that's the only ASW asset you have!

      I described my force structure and where the corvette fits into it.

      An analogy would be the Army. If the Army only had main battle tanks and jeeps then they'd better load every weapon they can on the jeeps. But, if they have tanks, and infantry fighting vehicles (Bradleys), and self-propelled artillery, and mobile rocket launchers, and so on, then they can let a jeep be a jeep. If we have a robust, logical, coherent ASW force structure then we can let a corvette be a simple, non-helo corvette. But, if we only have Burkes and corvettes then we'd better load the corvette up with everything we can think of!

    7. "Now I get it, If you have an ASW focussed destroyer the ASW corvette just becomes a sonar carrier within the overall ASW structure."

      You've basically got it! This actually goes back to a CONOPS and a force structure built to fit that CONOPS. If you don't have a coherent CONOPS then you wind up with random ship designs and, because you don't know what it's supposed to do, you try make every ship capable of everything.

      When you have an actual CONOPS and compare it to what the Navy is actually doing, you begin to see just how disjointed and incoherent the Navy's force structure is.

    8. I'm not saying the Burke's and the corvettes would be to only two. They would not, just the extremes. In fact, I mentioned at least one other platform, an escort of about 6000 tons, between the Burkes and the corvettes. I'd actually envision several platform levels. If you are saying that the corvette would simply function as a sensor for big brother destroyer, then that's a slightly different CONOPS from what I had in mind. My corvette would be capable of independent operations, and I think the help would be very valuable in that context.

      My experience was that the helo added so much additional capability and versatility that it was almost a must on any surface warfare vessel. You could certainly build a corvette or frigate without a help, but I just think there would be lots of times where you would be thinking, "Damn, if only I had a helo..."

      I agree that CONOPS has to come first. And as far as budgets, there are all sorts of highly cost effective measures--like mine warfare--that we are almost totally ignoring in our rush to spend money of shiny new things. We could reorient a lot of our spending. I'm just not inclined to believe that helos are the things to cut.

    9. At the end of the day, I am probably envisioning more a frigate for this mission. I would also have corvettes, but the would focus primarily on the littoral mission. I'd probably want something a little bigger doing open ocean ASW, for seakeeping purposes if nothing else. But CONOPS has to be the driver, and without nailing that down we are just spitballing.

    10. "At the end of the day, I am probably envisioning more a frigate for this mission"

      Yes, I think you are!

      I described my CONOPS (albeit briefly!) and where the helo-less corvette fits in. I suspect that you're describing desirable characteristics, in your mind, rather than a vessel that fits neatly into a CONOPS because, I suspect, you haven't thought it through to the point of having a CONOPS. You have a capability but not a CONOPS.

      Now, I don't mean this in a mean way, at all. Until I started this blog, no one thought about CONOPS, least of all the Navy! I know you've been following the blog for some time so I know you've seen me hammer on the need for CONOPS repeatedly. CONOPS is what drives a logical ship design and acquisition rather than just adding as much as we can to a ship and hoping it will do something useful somewhere down the road.

      Wandering farther afield, the lack of CONOPS is also why we (the Navy) don't practice tactics and operations. Without any CONOPS, we have no coherent tactics and operations. Any given commander can make up any tactic or operation they want and no one can point to anything better.

      Hopefully, you're seeing that CONOPS (and strategy, from which the CONOPS is derived!) is the key to everything!

    11. "But CONOPS has to be the driver, and without nailing that down we are just spitballing."

      Correct! With a proper CONOPS, we'd have no disagreement because the needs and methods would be pretty clear for all to see. Without it, everyone's idea is as good as anyone else's. Actually, I rate my ideas as better only because I'm at least deriving them from a consistent CONOPS basis. Of course, if you come up with a different CONOPS then your vision would be equally valid, even if different (assuming you also have a valid strategy in mind from which you derived your CONOPS).

      What is your strategy (I'm asking rhetorically)? Strategy dictates the force structure. For instance, a blockade strategy for a war with China would dictate a different force structure and force level than an A2/AD roll-back strategy. So, before you think through your CONOPS you need to have a strategy in mind.

      This is the kind of stuff that the professional Navy leadership should be thinking about but, sadly, I can find little evidence of strategic and operational thought and absolutely no evidence of any CONOPS. Very disappointing from our professional warriors. We may be putting more effort into this than the Navy!

    12. I've actually formed some pretty complete notions of CONOPS and resulting fleet structure, starting from an analysis of what threats we are likely to face. I've been trying to figure a way to condense it down to the size of a post here, and so far haven't been able to do it satisfactorily. I will try to post something of a response. Basically, a lot of my thinking goes back to your commentary a few months back about we don't need any more Burkes.

    13. As far as your proposed roles for the ASW corvette, I wonder exactly what you have in mind for the escort role. Is it going to be fast enough to stay up with a carrier? Or is it more designed for merchant ship/convoy escort? If the latter, can it function effectively just with a group of other corvettes, or are you going to need other assets to give the air and surface protection? And as far as your idea of four prosecuting a sub, if they do that from an escort role, then don't you leave a big area unprotected? It seems to me that it might work better to have a couple of helos instead of an extra corvette. Just trying to understand exactly how you see this thing working.

    14. From looking at your subsequent posts, perhaps what you have in mind is some sort of littoral corvette. If you use to escort from point to point along territory that you control, so you can cover it with ground-based air, then it makes sense. I have the same sort of ship in my proposed inventory for the same purpose.

      I guess where things got a little confused is that I agree wth your commentary that not everything needs to be a Burke. If anything, I think we have too many Burkes now. It seems to me that if a Burke is $1.8 billion, then we could get two mini-Burke destroyers, like a FREMM or F105, for $900 million each, or three escorts, something like a Nansen for $600 million each, or six frigates, something like a Singapore Formidable, for $300 million each, and some mix of those would give us a lot more versatility and capability than putting all our eggs in the Burke basket. As far as the Burkes themselves, I like another idea that you floated about upsizing to carry more reloads and possibly the Zumwalt gun or two of them. The idea is that the Burkes and other destroyers would be capable of all three--AAW, ASW, Suw--while the escorts would focus on two and the frigates on one.

      For what I see as our requirements, I'd like to see 12 carriers, 10 amphib groups with the capability to lift 5,000 troops each, and 8 of what I'll call surface action groups, your HUK group plus something like the proposed Iowa class with the back end converted to jump jets, or for those more familiar with Russian ships than with that, something like a Kirov front end (with big guns replacing some missiles) with a Kiev back end. That could also serve as your shore bombardment for the Marines and your drone farm. That's 30 task forces, to screen each one adequately, you'd need 6 or more ships. We sure as heck can't afford 180 Burkes, so maybe 60 Burkes (two per TF), 60 mini-Burkes (2 per TF), 60 escorts (2 per TF), and 90 frigates (3 per TF). That's 270 hulls for the price of 125 Burkes. Or if you don't need 270, you can downsize across the board and go cheaper.

      For littoral work, I'd go for something a lot smaller than our LCS. Maybe something down to Visby size, that actually looks like a pretty good model for me.

      Anyway, that's a little more of my thinking.

  14. What is wrong with a modern day version of the Flower class corvette of WW 2 fame? They were very cheap to build and easy to operate. They were designed as anti submarine escorts and were very effective. I'm not suggesting anything as basic, but what would be needed for an anti submarine ship that had the capability to defend itself. The idea of KISS does apply, especially if you expect to lose a lot. German tactics evolved to kill the escorts and then take out the merchantmen. Does anyone really expect that in a peer to peer conflict that an enemy would follow different tactics?

  15. The issues I see being repeated here are price and removing helicopters. Yes I see the reasons for removing the helicopters- cost and taking up valuable warship real estate.

    However, i haven't seen any evidence put forward about which equipment is best for detecting and destroying subs. If you want a good anti sub ship, you need to know this. Using my high end google skills, the only article which seems to directly address this is

    I actually asked Pete, author of "submarine matters" blog from Australia, about what the outcomes of wargames are- do subs win more often, or do ships, and he said that info was mostly classified.

    So given the one up to date link I can find, removing helicopters isn't an option if you really want an effective Anti Sub warship.

    It would really help if there was information comparing various options eg x3 anti sub frigates with x2 helicopters each, vs x6-10 smaller ships which were acoustically quieter, with sonar and towed array.

    Otherwise we're all making guesses about what is really needed.


    1. You're partly right and partly wrong.

      You're right that knowledge about the specific performance characteristics of all the individual ASW equipment is necessary to design any particular ASW platform.

      You're right and wrong about the availability of information. You're right that there isn't very much but you're wrong that there isn't any. I've amassed a large body of ASW writings (okay, several papers and dozens of article snippets). I have a few that deal directly with shallow water ASW but the majority are scientific papers indirectly describing aspects of ASW, for example, sonar performance and sound propagation in shallow, brackish waters. So, again, you're right that there are few papers which say, here is exactly how to conduct ASW and what equipment you need - that would be too easy! One has to read all the papers, assemble an overview from the bits and pieces, and draw conclusions about applied ASW. The naval war college and postgraduate schools are good sources of thesis papers on ASW, by the way.

      So, I've got about as good a documented understanding of ASW and ASW equipment as is possible to have from public domain information. This is information I've found, assembled, and analyzed over the years. You'd be hard pressed to sit down one morning and find it all.

      You're right that wargame results are either classified or not for public consumption (FOUO). What we hear about are just snippets trumpeted by someone with an agenda. For example, the infamous picture of a carrier through the sub's periscope is published by someone wanting to push some particular pro-submarine or anti-carrier agenda. What they didn't mention was all the times during the course of the exercise that the sub was found and "sunk".

      Finally, you're wrong about the need to compare specific options. Any option can work. It's all about tactics. Consider the WWII example of the Japanese Zero and the US Wildcat at the start of the war. On paper, the Zero was the hands down winner and all pre-war analyses would have stated that. However, the reality was that the US pilots managed to develop a set of tactics that offset the Zero's advantages enough to at least produce a draw in combat, if not an actual "win" for the Wildcat.

      Thus, the presence or absence of a helo does not determine whether we can conduct effective ASW. Rather, the tactics we use, with or without helos, will determine our success and either way can work. I've got a post coming about small vessel ASW tactics, by the way.

      With all of that said, I've taken my vast knowledge of ASW (okay, slightly better than the average observer) and concluded that helos, while nice to have, are not mandatory, especially in shallow water, and, given the significant impact they have on ship size and cost, are not worth having on this particular vessel. I also, in other posts and comments, have called for a true destroyer that would have ASW helos so it's not as if I'm saying that helos have no place in ASW - just no justifiable place on a corvette!

      You're wrong that we're all making guesses. Most readers are but I'm not. If one puts the time and effort into it, as I have, one can make ASW assessments that are substantially better than guesses. When I write this blog and offer comments, I'm offering readers the benefit of my research and analysis. In other words, for the most part, I've put far more thought into these topics than the readers have and I'm offering them the benefit of that effort. Despite that, some readers/commenters believe that they know better. A very, very, very few do. Most just have an unfounded and unsupported belief that they've picked up somewhere (like the infamous backbreaking torpedo myth). That's fine. I'm here to inform and entertain those who are open to learning and I'm willing to let the others make their comments and move on.

      Does all that make sense?

  16. CNO,

    Thanks for your detailed reply. I understand the reasoning for your preferences and it makes sense. Taking out the helo saves money, opens up the real estate, and start developing tactics.

    Sadly, all this healthy discussion and debate may be for nothing. At this USNI site, the FFG(X) minimum criteria listed on page 10 and 19-23 show that the frigate is supposed to do AAW,ASW,AsubW and show the flag. Minimum equipment includes sonar and towed array, but no torpedoes or missile launched torpedoes.

    There is a bright spot- at least they're moving beyond the LCS now.


    1. "Sadly, all this healthy discussion and debate may be for nothing."

      Possibly. On the other hand, I'm contacted by lots of active duty personnel at all levels who follow this blog so I know that the information is getting to the Navy to at least some small degree. Whether it's enough to change anything is something we'll likely never know. At least I can go to bed at night knowing that I've tried!

  17. If a small cheap ASW corvette is the objective, I suggest something similar to the South Korean Pohang class. The Pohang class comes in a forms, an ASuW and ASW variant.

    The Pohang class is nearly 290 feet long and displace 1,300 short tons. The ASW variant has a hull mounted sonar, 2 x 76-mm guns, 2 Mark 32 triple torpedo tubes and drop depth charges. She can make 32 knots.

    I suggest something little bigger, maybe another 40 feet and another 400 tons. Keep the 76-mm gun and torpedo tubes and add a 16 cell VLS for 32 ESSM and 8 VL-ASROC and add a CWIS or SeaRAM and a couple of small caliber guns.

    Whatever the configuration, the ship should be designed to stay at see for more than a few weeks at a time, 60 to 90 days should be the minimum.

    1. Nothing wrong with that vessel as the basis for an ASW corvette. However, stretching it and adding weapons is missing the main function which is ASW. From your description, what the vessel needs, and any ASW vessel needs, is ASW detection capability. Thus, it needs a short/moderate length towed array, hull mounted sonar, possibly side mounted sonar arrays (like the Virginia class sub - don't know if those can be adapted to surface ships or not?), a simple helo-type dipping sonar, extensive acoustic quieting, and maybe a VDS.

      After fitting all that, then we need ASW weapons: Mk54/32 torpedoes, ASROC (not necessarily VL-ASROC!), RBU-6000.

      Last, it needs a short range self-defense of SeaRAM and CIWS.

      If there's still room and budget, a 76 mm gun.

      VLS, which everyone wants to add to every vessel, is a waste. It adds weight and complexity in the form of a larger, heavier, more complex weapons control software suite and associated more powerful radar, more technicians to operate and maintain the systems, larger engines (or decreased range) to deal with the added weight, and so on. All for a small, cheap ASW corvette. It won't be small or cheap after that!

    2. I forgot about a variable depth sonar. One advantage using VLS is the flexibility in the weapons you can carry. And, in the case of VL-ASROC, greater range than using a box launcher.

      But, to minimize cost, let's go with a modernized Mk 16 8-cell box launcher instead which can also fire a Harpoon as well. If room permits for reloads, maybe a total load out of 16 ASROCs and 8 Harpoons.

      But, endurance is a key requirement and a capability that needs to be designed into the ship from the start. No going back to port every few weeks for maintenance. Maybe dedicated tenders for at-sea replenishment and maintenance are needed.

      In addition to a small ASW corvette, I think unmanned ASW platforms like the Navy's Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) program are worth pursuing. The Navy has been experimenting with Sea Hunter for about 18 months and is interested in procuring a second ship.

      In the near future, I can imagine the teaming of unmanned and manned ASW platforms to enhance our ASW capabilities. At a minimum, they would be deployed to protect naval bases and key port cities. Best case, they would be used to hunt and kill submarines in the open ocean.

  18. I've been toying around with this idea for a few days. I keep coming back to the simplicity, cheapness, and mass production of both the Knox Class and Perry Class.

    My proposed frigate with a lower case F:

    Single Screw

    Hull and towed sonar, 3rd radar, EOIR, a couple ECM mounts and a couple of multipurpose decoy launchers

    Flight Deck for MH-60
    Hangar would be a large garage the width of the ship with side doors w/ davits and a large rear door to the flight deck. Normal embarkation would be 2 UAvs and 2 RHIBS, although you could squeeze in whatever is needed: 2 MH-60s, some ISO containers with USV equipment.

    1x 5" gun - ability to easily reload 5" magazine from flight deck vertrep. My reasoning is that a cheap/small ship will get tasked for NGFS instead of a Burke or Tico.

    2x RAM 21 round launchers - I would possibly look into resurrecting the counter torpedo munition that was under development 10 or so years ago that was to be fired from the mount. This gives the ship 42 small missile cells for point defense and possibly further development for counter torpedo munitions as well as surface to surface rounds (see canceled griffin).

    Missile deck for 8-12x canister heavy missiles - any modern ASM canister could be mounted. I would do a low risk development of VL-ASROC out of a canister in port/starboard orientation. This would give flexibility in what types of munitions as you simply bolt on a canister based off of mission need. It is also lighter than the old ASROC box launcher and non-penetrating compared to a VLS allowing for an overall smaller/shorter hull. Avoiding a VLS also avoids mission creep in development to turn this into a mini-Burke.

    2x lightweight torpedo tubes. I would like the lightweight torpedoes to share rounds/magazine space for weapons also used by the UAVs or any MH-60s that the ship rearms.

    2x 25mm RWS possibly with add on Hellfire racks or Rocket pods - again to share rounds for stored UAV weaponry – the ship is carrying the rounds, might as well have something that can fire it.

    1. This seems like a very light frigate with no functional emphasis. With no VLS and only 8-12 cannisters, the offensive capability is extremely limited. Presumably, ASW would be somewhat of an emphasis which would mean around 8 cannister ASROC which would only leave a max of 4 cannisters for an anti-ship missile.

      The 2x RAM is a nice self-defense.

      So, what do you see as the primary function or role of this frigate and how does that tie in to the weapon/sensor fit?

    2. To resurrect an older term - ocean escort.

      Not much has changed in ASW warfare since the cold war. Most of those escorts had 8 ASROC, perhaps some reloads depending on class, and they had even less air defense capability.

      I think 8 ASROC plus 4 ASM or TLAM equivalents are more than sufficient for offensive action.

      This is basically an cheap escort first and foremost. It cant do area air defense, it cant to offensive anti-surface strikes, its not really rapidly modular or upgrade-able. It doesn't offer a lot of post retirement job opportunities for flag officers. Its a ship, that has bottom tier self defense abilities, sensors, and a dozen or less effective war shots - but could be built in enough numbers to be around when anything is better than nothing.

      Random bomb a terrorist camp with a TLAM or land attack ASM is there, ASROC is there for prosecuting ASW contacts in an escort role. If it is anticipated, in a MTW, it canl be a fire support ship - there are plenty of mid/small weight canister missile options to bolt to the deck to supplement the 5" for bombardment. Why? Its cheap enough/numerous enough to risk.

      The other issue is simply the Navy has a big problem with basic seamanship. One issue is we don't have large numbers of JO deck/command spots on a large batch of small ships to give them experience. This thing is cheap enough to build a lot of.

      Random thoughts - although if pressed to make a prediction - I think the Navy will continue to evolve/devolve, not by design, but by happenstance, into self escorting single platforms. CVNs sailing alone or with one escort, ARGs based off a single big deck phib.

  19. The Korean Daegu class is very close to what we are looking for. Check it out. We might want to put a RAM in place of the Phalanx, and 57mm in place of the 5" gun (or not), as well as use US versions of the Korean weapons. But for $500M (sources list it under $400M for the Koreans) we could contract manufacture an amazing escort.

    1. That's not a bad design but it's a little big at 400 ft. I still like the Indian Kamorta as a starting point.

    2. From what I read, the Daegu

      - needs less crewing (140 vs. 193)
      - is faster (30+ kts vs. 25+ kts)
      - has an all-electric drive to be quieter when needed for ASW
      - better range/endurance by 1,000 nautical miles
      - better weapons (added VLS and box AShM)
      - reliability of being evolved from a proven design

      And it appears to be cheaper, too. (Daegu is listed at under $300M, which I don't believe, but that's still FAR cheaper than any prices listed for the Kamorta). Why would we choose the Kamorta over the Daegu?

      Anything is better than an LCS, and neither the Daegu or Kamorta will replace the new FFGX, but we probably need something significantly under $1B focused on ASW too. I'd go with the Daegu before the Kamorta.

    3. "Why would we choose the Kamorta over the Daegu? "

      I hope you haven't misunderstood. I'm not proposing that we build/buy Kamortas. I'm saying it would be a good starting point for a USN ASW focused corvette.

      I like the Kamorta because it's smaller. The main characteristic of a ASW corvette is numbers which means low cost - like around $200M. In order to achieve that it would be necessary to eliminate the helo/flight deck/hangar and probably trim off another 50 ft or so. Then, we add just the equipment needed for ASW and self defense - nothing else.

      Crew size - smaller the better consistent with combat and damage control

      Speed - irrelevant in ASW work especially when discussing 5 kt differences; besides, we'd install our own propulsion system and I don't know what speed that would give us

      Electric drive - nice to have and that can be added to any design

      Weapons - we can add whatever weapons we want

      Reliability - that will be whatever our shipyards build into it!

      Again, I'm only looking at a starting point for a design. The closer the starting point is to what we want, the better. The Daegu looks to be almost a low end frigate in size and capability and that is not as good a starting point.

      What the Daegu might be is a good starting point for an open ocean ASW battle group escort. Something that can keep up with a carrier and has better range/endurance and has a helo/hangar. But, that's a completely different vessel than an ASW corvette.

      Review the WWII Flower class corvette history for an understanding of the role of a small ASW corvette.


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