Sunday, May 11, 2014

Frigates – Build To The Immediate Threat

Many people greeted the announced truncation of the LCS build as the advent of a true frigate.  ComNavOps has already gone on record as stating that the Navy won’t build a frigate but will simply build an upgunned version of the LCS – watch, though, they may designate it a “frigate” as a PR move to placate Congress and the LCS critics.  That said, what if the Navy did actually build a frigate?  Well, here’s a thought on the subject.

Frigates are smaller and lighter built vessels which are, theoretically, cheaper than their full featured, larger cousins such as destroyers and cruisers.  As such, they aren’t expected to last as long.  A 20-25 year life would be typical as opposed to a 40 year life for a larger ship.  This imparts a potentially valuable characteristic to a frigate:  it doesn’t need to be built with the long term in mind.  Properly recognized and utilized, this characteristic offers the basis for significant cost savings, speed of construction, and flexibility.

If we’re not building for far future threats that we can only barely imagine right now, we can, instead, focus on the immediate threats that are clearly defined.  Those threats can be dealt with using currently available technology and existing, proven weapons and systems.  In other words, the threats won’t change significantly enough over the life of the frigate to warrant investment in non-existent, what-if technology that will escalate costs, delay construction, and provide only portions of the promised or hoped-for performance.

Frigates - Inherently Adaptable?

For example, consider AAW.  A frigate, by definition, is not an area AAW platform.  It only needs to defend itself and a few nearby ships it might be escorting.  While future ballistic missile defense concerns might suggest a need to invest in sophisticated BMD radars and missiles, that threat does not yet exist and won’t for many years.  We don’t need to invest in imaginary technology to defeat a non-existent threat for a ship whose lifetime won’t see the threat.  We can limit ourselves to existing threats and existing solutions – a much cheaper approach.

Or, consider the current darlings of naval development:  lasers and railguns.  Oooh my …  I got a tingle just typing that!  Despite the Navy’s public relations announcements, these weapons are many years, probably decades, away from full functioning versions.  For a frigate with a 20-25 year lifespan, there’s no need to build in enormous electrical capacity, cooling capacity, and whatever other structural or utility support they might need.  We can save all that money and effort and in 20 years, if the weapons have panned out, we can build new frigates that are designed to support the systems.  Plus, we’ll know by then what’s actually needed instead of building in guessed-at capacities that may or may not meet the needs.

We see, then, that the shorter lifespan of a frigate actually offers the potential for greater flexibility and adaptability than a larger warship.  If the lifespan is around half that of a larger warship (say 20 years versus 40 years, to illustrate) we can build an entirely new frigate halfway through the lifespan of a larger ship and the new version can be completely adapted to the threats that exist at that time. 

If executed correctly, the more limited lifespan of the frigate offers some advantages.  The build can be cheaper since we don’t have to worry about far future, non-existent threats and can use off-the-shelf weapons and systems.  The ships, as a class, offer a larger degree of flexibility thanks to their shorter lifespans.  The use of existing technology should allow a much quicker design to construction timeframe instead of the usual R&D concurrency delays so prevalent today.

Of course, this is all predicated on being able to build a “cheap” frigate with a focused mission and specific, limited capabilities.  If we try to build a frigate with all the capabilities of a Burke then it won’t be cheap and it won’t be on-time and we won’t be able to afford to retire them at 20-25 years. 

The Navy has an opportunity, now, to adjust the fleet’s size and composition in a more useful and effective direction.  Will they?  History suggests not.  We’ll see.


  1. A frigate makes sense for the US Navy. They can be in places where a Burke can and can do the Missions where a Burke is an overkill. A Frigate can be on station anywhere in the world and can have the ability to do ASW, ASUW, limited AAW for self defense and limited Land attack.

    Which is why I think the US Navy should take the lessons from Germany, Spain and France, when it comes to Frigate designs. The Frigates being built right now in Europe have the capability to be far away from home and deployed half way around the world. At the same time, they have the capabilities up to the level of a Burke or a Type 45 destroyer.

    1. Nicky, other countries build mini-Burkes or near-Burkes and call them frigates. It's debatable whether they really are frigates at that point or, more properly, destroyers. Nonetheless, they do so because those are their capital ships, generally for budgetary reasons. The US has plenty of full fledged Burkes. We don't need mini-Burkes or near-Burkes especially if they cost near-Burke. What we may have a need for (I stress the word "may") is a much less capable, much truer frigate for low end work and specialized ASW/escort roles. I know you're fascinated by foreign frigate designs but the USN just doesn't have that need. A $1.5B near-Burke doesn't make sense when we already have plenty of $2.0B Burkes.

    2. So what would happen if the US Navy builds a Frigate based on the Álvaro de Bazán-class frigate, FREMM Frigate in the french version or the Fridtjof Nansen-class frigate design. What if the US Navy took the lessons of the Iver Huitfeldt-class frigate and build a frigate based on the lessons from the Iver Huitfeldt-class frigate.

    3. Nicky, I'm sorry, I'm not familiar with those designs. What lessons do you see in them that would be applicable to USN operations and ship designs? Think Pacific Pivot, Middle East, and Africa. Thanks!

    4. What about a frigate based on the designs and lessons from the Fridtjof Nansen-class frigate, Iver Huitfeldt-class frigate, Álvaro de Bazán-class frigate, Sachsen-class frigate and the FREMM multipurpose frigate. Maybe the US Navy can ask the UK if we can get in on the TYPE 26 GCS

  2. A US Navy Frigate does not have to serve as the core of an action group. As such they do not need, and should not have, the same kind of armament and sensors as an European, Russian or Chinese Frigate.

    For instance, a US frigate can do without a long range volume search radar -- a SPY-1, SPY-4 or AMDR-S is not really necessary. If the ship is operating as a member of a carrier group there will be an E-2 in the skies above and plenty of AEGIS assets around to derive co-operative engagement tracks from. If it is operating alone escorting merchant ships, against pirates or doing blockade enforcement, then it doesn't need to see stuff in the air 400km away. Frigates on the lesser navies on the other hand pack SMART-L or similar sensors because they are it when it comes to power projection.

    A similar thing can be said of weapons. Competing frigates pack long range SAMs like the Aster 30/45 or HHQ-9 because they are in essence serving as the primary air defense asset of an action group. For a US Frigate, the SM-2/SM-6 is not really necessary. A 40~50km missile for horizon range defense against AShMs is enough. Given the expenses associated with sensors and weapons systems packed onto competing frigates it is easy to then decide to carry more rounds of the said weapons. In a US Frigate the number of VLS cells can be somewhat smaller.

    As far as propulsion goes though, US Frigates need to go faster than most competing designs. Apart from their typical low/medium intensity roles a USN Frigate should be able to serve in a carrier strike group. This means going 30 knots. Competing Frigates do not typically operate with big fast ships, so about 25 knots is sufficient and sometimes all that is provided for.

    The problem is that the LCS is none of that. It is not capable of defending itself or it’s charges from anything but pirates in inflatables. It has no ability to engage Frigates or Corvettes of even 3rd world navies. It goes much faster than necessary but doesn’t have range to keep up with fleet operations. If it’s $100M that’s fine, but it’s 5 times that.

    Honestly, I believe that the US should build about 60 frigates on the following paradigm... This is more important than anything else in the Navy at this moment. And, honestly, it's worth sacrificing one Carrier and reducing the number of CVNs from 10 to 9 if that's what it takes.

    ● 5000 tons / 150 m / 100 Complement (Sailors + Officers)
    ● Gas-Diesel-Podded_Electric propulsion*
    ● 1 x 57mm Gun
    ● 24 x Mk 57 VLS cells (Typically 32 ESSM + 8 LRASM + 8 ASROC)
    ● 4~6 x 324mm torpedo tubes
    ● SPY-3 or AMDR-X radar (only)
    ● 1 x Helicopter
    ● Built to commercial standards / $900 Million cost cap

    *1 x 40MW turbine + 2 x 7.5MW diesels + 2 x 25MW Azipods -- 30 knots

    1. Dwight, the first part of your comment is spot on. See my comment in reply to Nicky. I said the same thing although you probably said it better. Excellent! Well said!

      The second part of your comment proposes a nice frigate design (I would take issue with the Mk57 since there is no missile existing or on the drawing board that requires that size but that's a small point). Where I hesitate to totally agree with you is in the need for a frigate of any design. Everyone just assumes the Navy needs a frigate. To be fair, that's quite likely a reasonable assumption. However, no one seems to tie the frigate to actual USN needs. People just fall back on listing generic frigate tasks without examining whether the USN actually needs those tasks and, if needed, whether a frigate is the best platform to accomplish them. Understand, I'm not arguing against a frigate. I'm just noting that leaping into the frigate buying arena without first conducting a USN-specific analysis of needs and having a specific CONOPS is foolish. The failure to do so is what led to an LCS that has little usefulness.

      Such an analysis would also tell us how many frigates, if any, we need. You suggest around 60. Why not 20? Or 90? I'm not criticizing your number and I don't expect you or anyone outside the planning levels of the Navy to have an actual answer. I'm just pointing out that without an analytical foundation, the choice of ship, design, and quantity are just baseless guesses.

      Having said all of that, your suggestion would probably turn out to be about right, I suspect!

      Good comment!

    2. The 60 number comes from two things...

      (1) The US Navy currently has 62 Burkes. It has awarded contracts for another 7 and plans for at least a total of 75. In the days where the Perry served as a frigate the US Navy has about 130~150 surface combatants that are not flatops, amphibians or auxiliaries. If you assume that at least 2~3 is needed per CVN and LHA/LHD in the fleet you have 38~57 so committed. You also need Burkes for the ABM mission whenever NK or Iran or somebody acts up in this regard. That's about 8 you need available to have 4 to send anywhere on demand. No wonder there isn't any hulls to go around when things like escorting ships through the St of Hormuz or of the coast or Somalia or look for a missing airliner or things like that. Finally, the current focus on big, expensive, ships leaves the CVSGs without and outer ring of pickets like they had in the 80s -- and outer ring which were normally Knoxes and Perries. 60 will allow you the Burkes to be left to do what they are most needed for. 60 will also give the USN about 3 addiitonal escorts in the outer ring per flattop if a "major" war ever happens.

      (2) The second reason for 60 is simply economics. The USA has been a non-player in international commercial ship building since subsidies ended in 1981. Today, we are left with three big shipyards -- New Port News, Bath and Pascagoula. Four if you count the submarine only Electric Boat @ Groton. All of which are man-of-war yards with essentially one customer -- Uncle Sam. The USN has made a concious decision that this is the minimum industrial base and will keep these in business no matter what. In essence, these have become "public" shipyards run by private companies. We are building 0.2 CVN, 2 Burkes, 0.5 LHA, 1 Virginia and 1 auxiliary or so a year. But no matter how few ships we build, you are going to pay to keep the yards open. This is in part responsible for the escalation of hull costs the post war decades. 60 Frigates over 20 years allow you to stuff the shipyards with 3 additional hulls a year. That's a lot more economical and more inline with the minimum capacity. The alternative is to still pay for the retention of the facilities and skilled labor while getting fewer ships. You may pay a little less -- less the raw materials and variable costs. But you are still stuck with the fixed costs which at this point is the majority cost.

    3. As far as the Mk57 goes, it is simply a good idea to put the VLS on the perimeter rather than the center of the ship. On a Frigate, it's not so much for survivability as it is for reclaiming useful interior volume; about getting rid of that 8m long VLS assembly penetrating three decks right in the middle. For example, on the aft deck using the 57 will allow the helicopter to traverse the middle of the deck from a hangar to a flight deck. Using a Mk41 means that the VLS has to be to either side of the hangar or the VLS has to be exiled forward of the super structure. Since we already made the effort to develop a 25" VLS, build it and deploy it, let's build every new ship using this architecture instead of relying on the Mk41 forever.

    4. Will a long MK57 VLS really fit on the outside of a frigate hull? The DDG 1000 gets away with it by virtue of its size and tumblehome design.

      MK57 weighs twice as much per cell as Mk41, which is another limiting factor on a smaller frigate.

    5. Dwight, if you haven't seen it already, you might want to check out this previous post, Shipbuilding Costs - Impact of Low Volume and this one, Save The Industrial Base?

    6. The Mk57 is NOT tangibly longer than the Mk41 in strike length. It's just somewhat fatter per cell. The Mk57 is 7.9 m the Mk41 is 7.7m long. The difference is about the height of the top of the seat cushion of in a passenger car. The Mk57 is not currently offered in chopped down versions that are incapable of operating the Tomahawk or SM-6. But, in the interest of flexibility and given that any 5000 ton frigate will be more than 8m from keel to the flush deck -- anything less than at least 6~7m from waterline to the deck with 4~7 m of draft (10~14 m total) will be impractical for seaworthiness reasons if not anything else.

      It is a heavier system -- about 15 tons per 4-cells vs 14.5 tons for 8-cells. Most of that has to do with segregation; every 4-cells is compartmentalized in its own a blast/fire proof compartment. The Mk41 is NOT designed that way. Compartmentalization is a good idea and honestly, weight is a relatively minor factor. We are talking about 90 tons of launcher hardware on a 5000 ton ship -- 1.8% of the displacement. Frigates are not carriers, but they are not corvettes either.

    7. This comment has been removed by the author.

    8. According to Raytheon, a single 4-cell Mk57 module requires 75.8m3. Therefore, six of them (24 cells) requires 454m3.

      On the other hand, a single 64-cell Mk41 VLS only requires 424m3.

      That's 2 2/3rds more cells in a smaller volume! Of course the Mk41 volume is right in the middle of the ship, which is prime real estate. And a 64-cell Mk41 VLS weighs even more (119 tonnes empty).

      But I'd still prefer to have more shots for a given volume and weight.

    9. I don't think a USN Frigate needs more shots if you accept the ESSM as the primary air-defense weapon. Arguably you could have gotten by with 16-cells. That's 32 ESSMs, 4 ASROC and 4 LRASM. A little stingy but sufficient in a pinch. If you carry the Standard then you need that 400km radar, AEGIS combat system and other fittings like a Burke. Do that and you are going to cost almost as much as a Burke. If you are going to cost as much as a Burke, why not just build extra Burkes?

      I think a Frigate ought to be first and foremost a low-intensity warfare focused ship that is affordable to buy and operate, but which is not totally useless in a major war against a major world power.

    10. "Where I hesitate to totally agree with you is in the need for a frigate of any design"

      Okay. I may regret this, but I'll bite.

      The USN's job as I see it, were I the Navy Secretary, is twofold. A) Control the sealanes and B) land attack to influence events on land.

      In order to do A), which I consider its primary mission, it has to be able to sail on the ocean freely itself, and be able to engage and defeat threats to itself. This mission isn't going to be a zero cost mission. For B) I see it as being able to do this in a non near-peer environment with relatively low cost. For a near peer threat, if we decide the need is great enough, the cost is potentially very great. The decision point there has to be are we willing to pay the cost.

      The way I see our Navy now, in our Pacific Pivot the PRC is the greatest threat right now. Its not a blue water threat yet, but they are working on pushing out their zone of exclusion as much as they can. They are working on missiles, subs, CV's, and surface combatants all with a good weapons load.

      In facing a near peer blue water threat we have huge gaps right now that could be exploited, IMHO.

      The ASW mission as far as I can tell has atrophied. The Perry's are going, the LSC can't replace them, the Vikings are gone, and there is nothing to replace them. The anti-surface mission isn't what it used to be as well.

      In facing a lower threat land strike mission, we still have gaps. We only have Burkes. So when we want to patrol in the Persian gulf, and Syria erupts, we have a potential gap in resources. Again, I personally don't think the LSC is suited to that mission. It might do okay off Somalia, but that's about its threat level limit.

      Finally, in a real war situation, we might want to have some sort of DE type ship to escort merchant shipping, so the bigger boys can go fight the other guys big boys.

      To me, all this spells 'Frigate' as I know the term. Its:

      A) Cheap, so can be built in numbers
      B) versatile within limits. With a proper VLS cell it could have some LRASM, ESSM, and Tomahawks. That allows it to defend itself, have limited anti surface, and do land attack in low threat environments.
      C) It will have range. We'll still be talking about a Perry sized vessel.
      D) It will be an attrition unit in a big war. We could risk it more readily.
      E) It could do the ASW mission we are lacking now
      F) It could be the right fit for surface escort if we needed it.

      So that said, I generally like Dwight's model. The only 3 things I'd have issue with are:

      1) the radar (I don't think it needs a SPY or SPY equivalent, and I don't think we can afford it for a ship built in numbers
      2) the gun. Is the 57mm enough? Would the 76mm be better? To me that point is debateable.
      3) The VLS. I'd go with whatever is cheaper, honestly. The Mk. 57 has advantages, but we are talking a low end ship. If accepting more risk, risk we accept now with the Burkes and Tico's, means more hulls with the same capability, I'd do that.

      Okay. Its on paper now. Go ahead and pick me apart. :-) Keep in mind that I'm just writing off the cuff, so be gentle.

    11. But for less volume and weight you could have a 32-cell Mk41 with 32 ESSM, 8 VLA, 8 LRASM and still have 8 cells for something else.

      Hunting subs could eat ASROCs quickly, so 16 VLAs might be nice.

      Or if you pull the SPS-49s off of the retiring Perry's to use with SPY-3 and fire SM-2/6. Eight SM-6s might not sound like much, but it would give the frigate a credible long ranged, anti-MPA capability.

      Or carry TLAM to shoot at Al Qaeda targets-of-opportunity.

      You can never have enough shots.

    12. Jim, I would quibble a little bit with the way you expressed the Navy's purpose. Remember the principle, "The Seat of Purpose is on the Land". A Navy exists to influence events on land. It does this by controlling the seas, as one means. It may attack the land directly (Tomahawks), as another. It may escort cargo to facilitate land actions. And so on. Thus, the Navy must influence events on land regardless of the threat level. Of course, how to do that efficiently for a given threat level is what tactics is all about.

      That said, you've identified at least one specific possible frigate use for the USN and that is ASW. Of course, that leads one to ask what type of ASW (blue water or green) and under what circumstances. It's conceivable that what we need is not a frigate but a dedicated, single function, shallow water ASW vessel akin to a corvette of WWII to complement the Burkes. I'm not saying this is what we need, just pointing out that the mere fact that a frigate might be able to do this task doesn't mean that it's necessarily the right vessel for the job.

      Consider, do we really have a need for a frigate in an all-out war? It's possible we may not. It might be that the type of war we envision with China (what type do we envision? - there's that lack of strategy again) doesn't require frigates. Or maybe it does. Only if we have a specific strategy and various war plans can we actually determine our frigate needs, if any. Outside of that approach, we're just building generic ships and hoping we can find something useful for them to do which is exactly the situation the LCS finds itself in.

      We've been divesting ourselves of frigates (the Perrys) for some time now. That would suggest that the Navy, at least, doesn't see a need for frigates. Of course, that would also be crediting the Navy with a level of wisdom that their demonstrated actions don't support!

      This is what I mean when I say that no one has demonstrated an actual need for frigates. Instead, we've all leapt straight into the discussion of weapons fit. To be fair, it's very difficult for anyone outside the higher levels of the Navy to be able to analytically justify (or not) the need for frigates (or any other type of ship or plane for that matter).

      My personal take on it is that we have a need for a relatively small number of frigates, say 30 rather than the more common 50-100 that so many would like to see. Instead of large numbers of frigates I'd concentrate on larger numbers of small, dedicated ASW vessels and lots of Avenger-ish MCM platforms, among other pressing needs.

      Hope some of that makes sense.

    13. What does it take to do ASW?

      Traditional thinking is a task group consisting of 4-8 surface combatants with tails/VDS, and 6-10 or more helicopters. Possibly add one or more SSNs and long-ranged, fixed-wing MPAs.

      This may still a good composition for open ocean ASW. For shallow water ASW, a larger number of ships may be preferable.

      Helicopters are necessary for both.

      The USN exclusively uses the H-60 for ASW, so sufficient hangar and flight deck space in the task force must be accounted for.

      The USN has chosen the CAPTAS-4 VDS to go with our MFTA towed array on the LCS. It makes sense to consider this pair the open ocean baseline for ASW surface combatants. Hull mounted sonars are also important, IMHO. They may not have the capability of the VDS and towed array, but they are always available. VDS and towed arrays take time to unreel and reach their operating depth.

      CAPTAS-4 requires a ship of at least 3,000 tons, according to the marketing material. IMHO, if you are going to build a 3,000+ ton ship, you might as well give it ASCMs and at least point air defense or local area air defense.

      Shallow water ASW combatants may need different, smaller sensors (e.g. CAPTAS-2, CAPTAS Nano).

      One wild card is the use of UUVs and USVs. The Darpa ACTUV is particularly interesting. If it proves successful, it could take over the dangerous shallow-water ASW mission from small, manned combatants.

      So there are many ways to slice it, but, IMHO, the task force needs 4-8 tails and 6-10 or more helicopters to have a robust ASW capability.

      The USN splits helicopters between combatants and the CVN in a CVBG. Unfortunately, we continue to shrink the number of combatants accompanying task forces.

      I think this is a prime niche for a frigate. It can bulk up the number of tails and helicopters in a task force.

    14. B. Smitty,

      No surface ship today typically carries 16 VLA, and the VLA inventory is so limited that its not likely that ships would deploy with that kind of a load.

      If the thought is to reduce size/weight while still maintaining some amount of point self defense, an option would be to go with the MK 48 VLS that could be installed along the outside of a hull to provide ESSM capability. For ASW, the Compact Rapid Attack Weapon (CRAW) could be matured and integrated with a small booster (use the ESSM booster?) to provide a mini VLA capability that would increase ASW load-out. Actually, both concepts could likely be considered for inclusion with LCS.


    15. None currently do, no. But we haven't fought an ASW war since WWII.

      We may find munition usage far higher than anticipated, if the British experience in the Falkland is any guide.

      The point is, having cells beyond the bare minimum provides options.

    16. Having cells beyond the bare minimum provides cost. - a tricky balance.

      You have a tendency to want to provide more of everything on a given ship. That's fine as long as you append the phrase, "... which means we won't be able to afford as many ships."

      It's a debatable point, to be sure. Personally, I'd rather have two ships with fewer weapons than one ship with more (yes, I know the incremental cost of a "few" more cells doesn't equal the cost of a ship - I'm illustrating a concept).

      An excellent point about munitions usage. Every conflict ever fought has demonstrated hugely greater munitions usage than anticipated.

    17. Interested Party, I love the concept of the Mk48 VLS for smaller vessels, especially the bulkhead mounted versions. A row of those along the Perry's hangar walls would have been quite beneficial.

      I wonder if they can be mounted at an angle on the sloped sides of superstructures or if they have to be absolutely vertical?

      Good comment!

    18. CNO,

      The original thrust of this side-discussion was whether to use Mk57 with fewer cells or Mk41 with more, assuming a given volume and weight.

      I recognize cost factors heavily into this. I don't know how much they cost, individually.

    19. For a frigate or other medium-to-large warship, I am in favor of exceeding minimum thresholds, where it can be done economically. VLS cells aren't that expensive. Design margins should be relatively high.

      We try to skimp here, but it ends up hurting us. Routing and placement of systems is harder. Ship classes face more expensive upgrades. Future flights are more constrained.

    20. B.Smitty, you and I have a fundamental difference of opinion about what a frigate is, I'm afraid. While it's tempting to buy into the "few more" argument when considered in isolation, the reality is that by the time we add a few more cells, and a little bigger radar, and slightly more complex combat software suite, and a little bigger hangar to accomodate a couple UAVs, and little bigger gun and magazine, and so on ..., not to mention the few more crew needed to operate and maintain the equipment plus a little more berthing, heads, galley space, food and water storage, etc. to support the few more crew, we've worked our way up to a near-Burke at a near-Burke price tag.

      The main characteristic of a frigate should be affordability/numbers (the two are identical). The design approach to a frigate is to add only the bare minimum necessary to meet requirements and not a thing more. Let's face it, frigates are mostly a peacetime ship and in that regard, numbers matter far more than a few more weapons. If we really need a few more VLS cells (or whatever) then let's build more Burkes.

      A frigate's main jobs of patrol, escort, and ASW don't require the capability of more than one or two brief AAW engagements against a few missiles or planes, at most. More than that means we need a Burke. How many SAMs do we need for one or two limited engagements? Given the very short engagement window, probably 4-8 SAMs per engagement is all that's needed. The fight will be over, one way or the other, before a frigate can launch more than that. Fitting a frigate with more than that is just going to see ships sunk with larger amounts of unexpended ordnance.

    21. Absolutely correct regarding munition expenditure. VLA expenditures have been studied by OPNAV on multiple occasions, and the results seem to be driven by the level of classification of the target that the surface ship is authorized to launch on. Basically, if you have to wait for a contact to become a confirmed submarine target, then expenditures aren't nearly as high as if you are authorizing weapons release on possible submarine targets. No big surprise there. Frankly, if I'm the CO of a DDG, its weapons free since those VLAs are cheap compared to me, my crew, and my ship.

      Taking the MK 48 with ESSM further, its really intriguing to think about what could be done with a mini-VLA that could be packed similar to an ESSM and mounted on an LCS / FFG sized hull. Would provide a stand off ASW capability that complements an embarked helo without installing the larger MK 41 cells.


    22. CNO,

      Agreed, it is a slippery slope. One option is to "build for but not with". Meaning you size the ship to take a 32 cell VLS, but only install 8 cells to start. This way you have the margin to add cells if needed, without having to design a new ship.

      The term "frigate" spans a wide range of ships. Basically anything bigger than a corvette but smaller or less capable than a destroyer.

      You want a cheaper, less capable one. That's perfectly valid.

      I go back and forth. I don't think we can afford enough Burkes to cover the full air defense mission. So I'd prefer to go with a hi-lo arrangement. Let the Burke be the primary area AAW ship and make a frigate capable enough to augment Burkes in CVBGs/ESGs, but act as independent escorts when the threat is lower.

      You say 4-8 SAMs per engagement, but what type of SAM? Is it SM-6s to shoot down enemy aircraft? ESSMs to cover a sector from missile attack? Or RAMs to cover the frigate itself?

      Or do you need to have layered defenses with some combination of SM-6, ESSM and RAM?

      The FFG-7 class used to carry 40 missiles. Is this "too many" for your frigate?

    23. "for but not with" still costs money. We've already had the discussion about steel is cheap and air is free. Neither is true.

      When I discuss frigate AAW, I'm talking about ESSM for self and near defense. RAM/CIWS backup is a given. There's no need for a frigate to perform area air defense. If we need area air defense, we need a Burke (too bad the Ticos were retired!). Perry's had Standards because that was the only option at the time. The 40 "round" magazine also included Harpoons and it fit roughly in the volume of an 8-cell Mk41 VLS. Nothing wrong with fitting more in the same space, to a reasonable extent!

    24. Interested Party, the idea of a dual or quad packed mini-VLA is interesting. What torpedo would be used with that? Currently, the VL-ASROC uses Mk46/54, IIRC. Would a significantly smaller torpedo still be lethal towards a submarine? They have pretty strong hulls!

    25. The torpedo for a mini-VLA would have to be a new weapon since the MK 46/54 are too big, both in diameter and weight. But it doesn't have to be a completely new weapon. The Compact Rapid Attack Weapon (CRAW) is an offensive variant of the Anti-Torpedo Torpedo (ATT) that was recently deployed on the USS BUSH. It's not quite ready for prime time (still at the ONR FNC level) but close enough to start thinking about potential applications for a smaller, lighter torpedo. As for lethality, it's really a question of what your target threat is and what type of warhead you might use for achieving either a mission abort or hull rupture. The MK 46/54 both use the same MK 103 bulk charge warhead; the ATT uses a bulk charge warhead for the ATT mission, but a shaped charge warhead could be fitted to the CRAW for increased lethality in some/most scenarios.


    26. CNO,

      The Mk13 Mod 4 magazine on the Perry takes up at least as much room as a 32-cell tactical length Mk41, probably more. The full system weighs as much as a 32-cell Mk41 as well.

      So to get an idea of what the CNO frigate looks like, we have roughly the following parameters:

      - 3000t or larger (to support CAPTAS-4)
      - One or two H-60 helicopters (or more UAVs)
      - 8-32 VLS cells (at least 16 ESSMs to support 2-4 "engagements", plus at least 4 VLA for ASW)
      - 1-2 RAM/SeaRAM
      - CAPTAS-4
      - MFTA
      - Hull sonar?
      - Radar suite?
      - EO suite
      - EW suite? Active component?
      - 57/76/127mm gun

      What else? How fast? What kind of radar fit to support ESSM? Does it have any modular space?

      Radar systems that support ESSM can range anywhere from Sea Giraffe AMB with Ceros 200 fire control illuminators, up through CEAFAR/CEAMOUNT, and on to SPY-1F/SPG-62 or SPY-3.

      SPY-3 and CEAFAR/CEAMOUNT are probably the most capable of dealing with saturation attacks and high-speed missiles. SPY-3 also can do multiple other modes simultaneously (e.g. surface search, periscope detection). SPY-1F/SPG-62 has greater range and commonality with AEGIS warships.

      Sea Giraffe AMB and Ceros 200 is the cheapest, but least capable.

    27. B.Smitty, so you're designing ships for me now? :)

      Do you have dimensions of the Mk13 magazine? I've never seen that.

      I don't know that I'm in favor of any VDS. I don't know that I'm not. I've never read any report of the effectiveness of a VDS either in general terms or relative to a towed array. The USN doesn't generally use VDS although I have no idea why not. The Soviets were big on VDS for what that's worth. The short story is I don't have an opinion on VDS. I have stated that a helo type dipping sonar might prove useful.

    28. Of course! ;) I just want to understand what you are looking for here. There are numerous trade offs that will greatly impact price and capability.

      The LCS ASW module includes the Thales CAPTAS-4 VDS as an active/passive component. It also includes the TB-37/U MFTA as a purely passive component.

      Most high-end Euro ASW frigates use some variant of CAPTAS as well.

      I don't have the full dimensions, but eyeballing the design it looks like it's at least six SM-1s in diameter. I'll try to get some better estimates.

  3. Designed service life is an interesting topic. There are merits to both short and long service lives. You can buy more ship for the same yearly SCN budget if you intend to run them longer.

    OTOH, you will have to spend more on mid-life updates, and technology may pass them by to the point where they are uneconomical to operate.

    If you average out the cost to build a ship over its service life, it costs the same amount to buy one $400 million, 20-year ship as it does to buy one $800 million, 40-year ship.

    So are less capable ships that are completely replaced every 20 years better than a significantly more capable ship that has to be updated and preserved for 40? I don't know.

    Can we build a useful $400 million frigate? I'm not so sure. The USCG OPC may cost close to that and it's "just" a cutter. A frigate variant might add $100 million or more worth of sensors and armament. The LCSes cost more than $400 million each as well.

    I'm more confident that we could build an $800 million frigate.

    1. B.Smitty, there's another, far more important, factor to consider when weighing short life versus long life builds and that is the Navy's demonstrated tendency to early retire ships. Other than the occasional carrier, like Enterprise, it's been very rare for any ship class to reach its design lifespan. The Ticos aren't even coming close. The Tarawa class didn't make it. And so on.

      If we aren't going to allow the ships to meet their lifespans then we may as well consciously design for shorter lives that perhaps we can meet.

      You also recognize that I'm not debating long or short lives for larger ships, only for a new build frigate? And, it only makes sense if the ship can be built cheaply enough which is a major question given the Navy's demonstrated inability to control costs!

    2. The shorter-than-expected service lives can be partially attributed to the ongoing, post Cold War peace dividend draw-downs and budget cuts, IMHO.

      The Tarawas averaged 31.2 years in service, which is only a few short of their planned 35 year service lives.

      The Perrys that weren't sold averaged 27.8 years, which again is only a couple short of their planned 30 year service lives.

      OTOH, the Austin class LPDs did hit their design life of 40 years.

      The Spruances were the worst. They only averaged 23.5 years in service.

      I agree that this is a concern. However there's nothing that says the Navy will keep a class with a shorter designed service life for the full time either, though perhaps it is more likely.

    3. As ComNavOps has pointed out, the Navy retires ships early to justify new construction. Well, if we admit that this sad reality is not going away, then short life-span ships just might be the way to go because they'd require continuous construction.

  4. For the interest of putting things in pictures, here's my concept of a 5000 ton frigate rendered in 3D and with accurate to scale equipment and features. Check it out and let me know what you think...

    1. I've always been a fan of that design. Sorry to hear you lost all of the models.

    2. Dwight, that's a fascinating design. Well thought out and nicely presented!

      I am not a naval architect so bear that in mind for the rest of the comment. I have doubts about the viability of a tumblehome hull form especially in the frigate role. The hull reportedly has stability issues in certain seas. In addition, the hull's horizontal cross sectional area decreases as the hull submerges which means that the ship's buoyancy decreases as the hull sinks unlike a conventional hull which is the opposite - note, I'm on shaky ground, here, and I could well be wrong. If I'm right, that's an undesirable characteristic from a damage control point of view. Finally, the stealthiness of the hull is suspect - I'm not radar/stealth expert, either! - in that the hull is a giant, solid reflective surface if viewed from the perpendicular angle. I suspect that the Zumwalt was designed the way it was to reflect land based radar which would be incident parallel to the sea/land surface. However, in an at-sea role which a frigate would have, the more common radar source would be planes which would have the incident radar approximately perpendicular to the sides of the ship. That would create an immense radar reflection. Again, I may well be wrong about this.

      Just out of curiosity, how does the ship conduct UNREP and refueling?

      I thoroughly enjoyed studying the design! Thanks for sharing.

    3. CNO,

      I know Dwight modified his original design to have a more traditional, non-tumblehome bow, to address the seakeeping concerns. But I'm not a naval architect either, so i can't evaluate its effectiveness.

      Aircraft radar emissions would only be perpendicular to the deck house and hull at specific range, altitude and bearing bands around the ship. All other locations should see a far smaller RCS. That's how stealth shaping typically works.

      Now whether the angles Dwight chose are optimal for evading aircraft emissions is open to question. That'd take some significant modeling.

      Even if it wasn't, a clever commander could run his ship in a jigsaw pattern to limit exposure to specific threat locations.

      Lastly, even if his stealth shaping is not optimal for aircraft detection, it still is very valuable for defense against active radar homing, sea-skimming missiles.

    4. B.Smitty: "Even if it wasn't, a clever commander could run his ship in a jigsaw pattern to limit exposure to specific threat locations."

      Presumably, there would be equally clever pilots who would fly at varying altitudes and bearings. It only takes one hit on radar to start the process of localization.

      While not an expert on radar/stealth, it's clear to me that stealth is a multi-faceted exercise that can, and should, include platform shaping/coating, tactics, electronic support, geography and climate utilization, etc. This, then, leads to the conclusion that placing too much emphasis on only one of the various stealth factors may quickly become counterproductive as well as prohibitively expensive. That, in turn, leads to the F-22/F-35. Are we trying too hard to achieve stealth via only one means (platform shaping)? Could we achieve more effective stealth by somewhat (not totally!) de-emphasizing platform characteristics and, instead, emphasizing the other factors? For example, the AF has abandoned dedicated electronic warfare aircraft. Would they be better to have a slightly less stealthy aircraft that is supported by readily available electronic warfare planes that have the speed and maneuverability to participate in the various missions?

      Trying to get all the stealth out of only one facet leads to the F-22 which was hideously expensive for its time (how quickly that perspective changes!). Would it have been better and cheaper to build a half as stealthy F-22 plus F-22 "Prowlers"?

      Should we build a max stealth Zumwalt type ship or should we accept half that stealth and spend the savings on enhanced ECM?

      I know enough to ask the questions but nowhere near enough to answer them!

    5. I don't think we should confuse aircraft stealth with ship based "stealth". Realistically, ship "stealth" doesn't have the same operational impact as VLO stealth does with aircraft.

      The only truly VLO ships are submarines.

      That being said, I agree that stealth, and ship survivability in general, is a multi-faceted exercise.

    6. B.Smitty, now that raises a great question. What operational impact does ship stealth have? I've never read anything that even remotely discusses the issue. Ship stealth may be the most effective thing ever developed or it may be largely useless. I have no idea. The only data point is the inference that comes from the fact that the Navy has continued to pursue ship stealth with each new design being further along the stealth path. That suggests that the Navy sees value in spending significant sums of money on stealth. Beyond that, I've got nothing! Let me know if you ever find anything even remotely definitive.

    7. CNO,

      Here are a couple links,

      The first has some estimates for RCS of the CG-47, DDG-51 and DDG-1000 classes, along with a discussion about the merits of RCS reduction. They start with the assertion that each successive generation of ship types listed above show around a 50-fold decrease in RCS.

      CG-47 - 154,670m2
      DDG-51 - 3,093m2
      DDG-1000 - 61.86m2

      "By Combining RCS reduction and jamming techniques, an increase in platform survivability is gained. If each of the range or power equations that have an RCS term is evaluated for the significance of decreasing
      RCS, a 50 percent RCS reduction translates to the following [5]:

      1. A self-screening or standoff jammer that only needs 50 percent of the power to obtain the same jamming effectiveness

      2. The burn-through range becomes 25 percent closer to the radar

      3. The radar's detection range is reduced by six and a quarter percent

      Exocet missile seeker performance vs each target is given as follows (km converted to nm):

      CG-47 - 33nm
      DDG-51 - 12.4nm
      DDG-1000 - 4.7nm

      As you can see, the missile has to be VERY close to the DDG-1000 to pick it up. Add in the effect of simple countermeasures and/or some low-powered jamming (say from SPY-3), and it may not even be a viable weapon vs the Zumwalt.

      From the second PDF we get the detection range for a representative MPA radar (APG-137 used on the P-3) of 68.6nm against an 800m2 RCS target.

      Using the formula:

      (New RCS/Old RCS)^0.25*Old Detection Range = New Detection Range

      We see that the APG-137 detection range vs each warship is roughly:

      CG-47 - 255nm
      DDG-51 - 96nm
      DDG-1000 - 36nm

      Now granted, this is a simplistic analysis. There are many other factors that play into detection. Wave height might reduce radar effectiveness. Wake recognition could improve its effectiveness.

      OTOH, RCS reduction opens up the possibility that the DDG-1000 could take an SM-2 shot at a searching MPA before it's detected (assuming it was so configured).

    8. Dwight,

      Did you consider adding a two-helicopter hangar? I'm not sure where the space would go, but having either two helicopters or one helo and some UAVs seems like the way the USN wants to go.

    9. B.Smitty, given the Navy's history of highly questionable decisions, I'm not sure "the way the USN wants to go" is necessarily the best design guide! heh,heh

      Some might think that the opposite of what the Navy wants would be a generally good guide to building an effective navy. heh, heh

    10. ;)

      In all seriousness though, this goes back to a point I was trying to make earlier. Ships performing ASW won't operate alone. There will be a task force, and that task force will need a number of surface combatants with tails and a number of helicopters to perform effective, round-the-clock operations and have capacity to prosecute one or more simultaneous contacts.

      Somewhere in the 6-10 ASW helicopter region, with some capacity for overloading in wartime would be preferable. That doesn't count UAVs desired for surveillance and recon.

      You need six FFG-500s to carry six helos, with no extra capacity.

      OTOH, six FFG-7s or LCSes could carry twice as many.

  5. I was going to do an update with basically the same hull, but with an Azipod XC propulsor arrangement rather than the ducted pumpjet. The Azipod XC combines one centerline tractor pod with a centerline fixed propeller in a contra-rotating arrangement. It allows for the maneuverability of a podded propulsor with the space and hydrodynamic efficiency of a single shaft design. The arrangement can be done with up to two 25MW (33,525 hp) motors for a combined output of 67,050 hp -- about right for a 5000 ton 30~32 knot frigate.

    ABB Azipods are the most widely used propulsor in commercial shipping. It hasn't been qualified for warships, but there is no reason a warship cannot use commercial components and practices. The Japanese and Koreans do just that for their AEGIS destroyers. And if there is any doubt on shock survivability, well ABB Azipods do not penetrate the hull like a prop shaft external self-contained motors mounted vertically below the rear transome. If anything it is more survivable as you can sheer the whole thing off and not flood the interior of the ship.

  6. An affordable frigate of 5000t. with 16 VLS for escort and patrol sealanes mainly for ASW. Well that sounds just like Japan's next 25DD class "destroyer" (keep in mind that the Japan call almost everything a "detroyer").

    "...25DD class destroyer (New 5,000-ton destroyer program first revealed in the MoD's FY2013 budget request, DD-119 [9] and a second in FY2014, DD-120.[10] Seemingly an ASW optimised development of the Akizuki class likely intended for Sea lines of communication duties rather than the escort of Ageis destroyers as in the case of the Akizuki. Planned to cost even less to operate and maintain than the already low cost Akizuki class, partly through the use of COGLAG [Combined Gas turbine Electric And Gas turbine] propulsion. ¥72.3 billion has been requested for the construction of the first unit in the class, and to respond to a reduction of Hatsuyuki-class destroyers)..."

  7. The Akizuki actually has a very nice domestic radar suite which combines two four faced AESA radars. A smaller one for horizon search and a bigger one for volume search.They are not waveform integrated like the US dual band efforts, but functions as two separate sensors. Performance wise it's in the same class as the APAR which is "enough" for the ESSM weapons system. It is also smack right on the budget at about $890M.

    On a US Frigate class the sensor closest to fitting the bill will be a SPY-3. Yes, it's currently a $200 radar system. But it won't be if we are not building 1 set every 2 years.

    Theoretically a good and affordable sensor would be to take one of those three SPY-3 arrays and mount it on a rotating pedestal which revolves as 30 rpm. This will allow you to scan the entire sky every 2 seconds. If and when called upon to perform fire control illumination or when operating in a task group the array can be "stopped" to cover a fixed 120 degree quadrant. Such a 200~250 KM X-band radar capable of volume search, horizon search and target illumination will be enough even if it can only see 120 degrees at any one time. But, given how expensive it is for us to do anything these days it might be better to simply spend the R&D dollars on buying the more expensive 3-pane SPY-3.