Thursday, May 1, 2014

Replacement LCS – How Do We Get There From Here?

We’ve discussed how the Navy’s supposed new “frigate” that will replace the LCS is just going to be a slightly upgunned LCS.  We also noted that the Navy will do this backwards by forcing requirements to conform to the ship rather than designing the ship to fit the requirements.  No sense beating that horse any more.  Instead, let’s look at what the Navy can do and needs to do to make the replacement LCS (RLCS) even marginally useful.

The first and most important change is not additional weapons or sensors …  Ah …  Hang on.  Several people who were looking over my shoulder while I typed that sentence passed out in panic and disbelief and one ran off wailing and gnashing his teeth.  I’ll be back in a minute…            OK, I’m back.  I gave them smelling salts and a picture of a foreign frigate to hold tight.  They’ve calmed down and they’re happy now.

As I said, the most important change is not weapons or sensors;  it’s endurance.  The Navy envisions the RLCS as a key actor in the Pacific Pivot.  In order to make that work, the RLCS needs much greater endurance.  Currently, the LCS has around 14 days endurance due to food storage limitations.  With anticipated increases in crew size coming, that endurance is going to be further reduced.  To be effective, the replacement RLCS needs a much greater endurance.  We need to greatly increase food and water storage so that the RLCS can spend more than a couple of days on station and doesn’t need to have a replenishment ship tethered to it.

Unfortunately, additional storage space will eat into the internal volume available for new weapons, sensors, and additional crew.

The second and next most important change, closely related to endurance, is range.  For Pacific operations with limited basing options we need as much endurance as we can reasonably get.  The WWII Fletcher class destroyer had a range of 5500 nm at 15 kts.  By comparison, the LCS has a range of 3500 nm at 18 kts.  We need to add range in the form of bunkerage and whatever engine modifications are needed to at least get to the 5500 nm ballpark. 

Unfortunately, additional bunkerage will eat into the internal volume available for new weapons, sensors, and additional crew.

The third change is survivability.  There’s no point to fielding a vessel around the size of a WWII destroyer only to have it susceptible to one-hit kills or even near miss kills.  We need to add armor to the level of a WWII Fletcher, as I’ve opined in previous posts.  However, the Navy isn’t going to do that.  So, at the very least we need to add additional compartmentation and shock hardening of installed equipment.  Further, since the gun (of whatever caliber) is going to be considered an important part of anti-small craft defense, we need to mount the gun in an armored enclosure similar to the Navy’s 5” guns of WWII.  Those armored mounts consisted of 1”-2” steel and were proof against shrapnel and cheap kills.  If we’re going to have only one gun on the ship we need to at least protect it to the extent possible. 

Unfortunately, additional compartmentation and armor will eat into the weight margins and internal volume available for new weapons, sensors, and additional crew.

The fourth change is crew size.  We’ve already seen that the LCS is badly undermanned.  If we increase the range and endurance and add weapons and sensors the ship will be at sea for much longer periods of time.  The current model of doing no maintenance on board ship will not work.  The ship will need to perform onboard maintenance just like any other ship and that means a much larger crew.  We also need more crew for combat and damage control.  Of course, a larger crew means additional berthing, heads, laundry, galley space, food storage, water storage, etc.

Unfortunately, additional crew comforts and support will eat into the internal volume and weight available for new weapons, sensors, and additional crew.  Are you seeing a trend, here?

Lastly, and everyone’s favorite, we need to add better weapons and sensors.  I won’t discuss this further because it’s been beaten to death.  I will remind everyone that by the time the first four needs are met there won’t be all that much weight and space left to go sprinkling weapons and sensors all over the ship as so many want to do.  It’s just the reality of ship design.  It may be fun to talk about the whiz-bang technology of weapons but it’s the other aspects that will determine whether the design is ultimately successful.

So, there you have it.  That’s what the Navy could reasonably do to get from the current LCS to the RLCS.  Of course, that’s not what I’d do but given the Navy’s near certain selection of the existing LCS as the basis for the new small surface combatant and the ass backwards “design” process they appear to be embarked on, this is the logical way to get from here to there and wind up with even a minimally useful vessel.  Quite sad but this is what it’s come to.

32 comments:

  1. Good Top Level Operational Requirements. A shame the Navy won't adopt them because of their inability to admit they missed it on the current LCS Designs.

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  2. I think your high level requirements are good. I'd add signature management, specifically acoustic signature.

    However, I have a more fundamental question: What is the CONOPS for the RLCS? Is it a fleet escort (ala frigate)? Is it a big Streetfighter? Is it a truck for modules? All of the above?

    To go along with this, how does it fit in the fleet architecture? Do we need to rethink how we put the fleet together? A bigger, more expensive RLCS will cut into other program funding, which will jeopardize the current plan.



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    1. B.Smitty, you undoubtedly read the "LCS Replacement Process" article a few posts back. In it, I raised the exact questions you're asking. Unfortunately, the Navy seems determined to repeat the original LCS failings in terms of the design process, or lack thereof. There will be no analysis of alternatives or CONOPS or definition of roles and missions. I hope you understood that I'm not advocating this approach. I'm just suggesting that this is what the Navy could do to squeeze at least a little bit of usefulness out of the next LCS given the completely flawed approach they're pursuing.

      Your point about acoustic signature is excellent, however, that would require a larger redesign of the base LCS than I think the Navy will do. That kind of quieting needs to be built in from the tiniest rivet on up. For reasons that totally escape me, given the proliferation of small, quiet diesel subs, the Navy seems not to consider that level of ASW capability to be worth the effort.

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    2. Yep. I had read it, of course. It was so perfect, I did not feel the need to comment on it at the time. ;)

      My main point above is that all of these Navy (and Joint) systems needs to fit together to form a whole. We can't look at the requirements of the RLCS in isolation.

      Maybe we can come up with a better fleet architecture that dispenses with multiple, existing programs in favor of a new set.

      I think we are on the same page here. Just reiterating what has been said before.

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    3. I'd still love to see a CNO Navy Fighting Machine fleet architecture as a counterpoint to the New Navy Fighting Machine. ;)

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  3. As long as you're on the topic of what the Navy will do, as opposed to should do, I'll opine that they'll simply lengthen the hull(s) of the LCS and call it good. I mean, more room for UAVs and modules and all that good stuff.

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    1. Yep thats what they will do, proberbly just with LCS1 I would imagin, for fun shall we take a guess , a sweep stake if you will, as to how much extra ?

      Ill go first : 100ft


      Big exasperated sigh.

      Beno

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  4. I would contend the your RLCS is really about finding a platform to do all the things the LCS has no chance of doing for a price less than what it cost to field and operate a DDG. IMO, the two missions in question are ASW and ASuW.

    As you stated, there is no way to accomplish these mission within the current LCS hull forms. As such my hope beyond hope (though there has been extreme resistance to the idea from Big Navy) is that the next FFG is militarized version of the National Security Cutter.

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  5. "What is the CONOPS for the RLCS? Is it a fleet escort (ala frigate)?"

    At this point I'm wondering 'What is the fleet's CONOPS'?'

    To me it appears that we have a fleet designed mainly for striking lower tier powers, and defending theaters/ships from limited ballistic missile threats.

    The surface fleet has Hornets and some aged Harpoons that it can use to strike ships, but given the age of the Harpoons and their capabilities it seems a real question as to whethery they can get through near peer defenses. The newer build ships (sans CVN's) have little to no ASuW capability. They don't practice ASW from what I've read, and are losing the platforms designed to prosecute that mission.. And their weapons loadout is for bombing nations with Tomahawks or shooting down ALCM's.

    Subs have the ability to attack surface ships, and this, IMHO, is our strength. But the Virginia's are still having a problem with their outer coating, and the latest flight has been made less hydrodynamic in the interest of carrying more SLCM's.

    Against that we have new Chinese vessels and Russian vessels all with lots of supersonic AShM's, and the Dong Feng 1. Neither of which we are sure the Aegis can protect the CVN's against.

    If that's all we want, then maybe a bigger LCS is fine. Because we aren't looking at matching near peers on the ocean.

    As it stands, if the Chinese decided to invade Taiwan, and we decided to do something about it, I think our surface fleet has to sit it out. The Hornets might have a tough time fighting some of the latest Chinese fighters. And you don't want to get the ships within range of the latest cruise missiles or ballistic missiles.

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    1. Jim, your comments are valid. I've stated repeatedly that we lack a geopolitical strategy and associated military strategy (the CONOPS, in your statement).

      An important point to keep in mind is that all the problems I describe in my posts exist in other countries navies and militaries and probably to a large degree. China's missiles, aircraft, and ships won't perform anywhere near as well as their listed capabilities suggest. Without this awareness, you may get the impression from this blog that we are falling apart, militarily, and every other country is getting stronger. I discuss the issues the USN faces. What I don't discuss to any great extent are the issues that other countries face. Consider the history of Soviet weapon systems. They sound formidable on paper but every time they've faced US forces they've performed quite poorly. Be cautious about ascribing perfect performance to enemy's weapons while recognizing all of our own shortcomings. Be sure to assess both side's systems realistically. For example, the dreaded DF-21 is deadly on paper but is borderline useless in practice due to the targeting issue.

      The problem is the trends. China is trending upward and ever more capable. We're trending downward and ever more hollow. If we do nothing to change our path, eventually the two trends will cross and we will truly have an inferior military. Trying to describe this path and its consequences is a large part of why I write this blog.

      Your comment about changing the hydrodynamics of Virginias is intriguing. I've not heard anything about that. Do you have some references I can investigate?

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    2. Good comments.

      The DF-21 is less than useless at the moment. To my knowledge it as only been tested against land targets. We've had IRBMs that can hit an unmoving, carrier-sized area for many decades.

      The large number of Chinese fighters is a different question. Much of their actual capability will depend on training, maintenance, and integrated C4ISR, but fighting in their back yard means they can mass numbers that we may have difficulty dealing with.

      But as CNO says, the trends are what's important.

      There are a couple good, topical articles in the latest Proceedings,

      "Rethinking the Future Fleet"
      http://www.usni.org/magazines/proceedings/2014-05/rethinking-future-fleet

      "Sea Power in the Precision Missile Age"
      http://www.usni.org/magazines/proceedings/2014-05/sea-power-precision-missile-age

      My bigger worry about the Virginias is the VPM section may add $3-400 million per boat. This means, for the construction budget needed to buy 45 $2.8 billion, non-VPM Virginias, we can only buy 39 $3.2 billion, VPM Virginias.

      As we've said time and again, numbers matter.

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  6. CNO: I was wrong, its not the very next, but the Block V.

    https://medium.com/war-is-boring/6a2e251be29c

    Also, you bring up a good point. I do tend to being alot more skeptical of our stuff than the enemies stuff. Brahmos may be stunning. It also might have its own fatal flaws though. I suppose that I'm just alarmed at the trends, and, with the LCS and the F-35 our appalling inability to efficiently procure new weapons system. A fighter in development for 20 years?!?!?

    Thanks for the links, BSmitty. I will read them.

    As to the DF-21, my thinking was that in an open ocean environment, you are correct. But if we are to park a CVN within range of a nation we want to support (SK, Taiwan, Phillipines) their targeting solution becomes alot easier. I also thought that the DF-21 was capable of using individually retargetable MIRV's, which allows them to hit a wider swath of ocean for each missile. Am I wrong?

    Thanks!

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    1. DF-21D is designed to hit moving ocean targets, but to my knowledge, testing hasn't proceeded past static land targets.

      IIRC, MARVs are a possible future option, but not part of the initial capability.

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  7. Oh, one other thought I had that might act as a possible deterrence to possible Chinese aggression in the short term... it doesn't involve, but could help, the Navy... (sorry, I know its a bit off topic...)

    Could we buy the latest block of Harpoon (Block II, I think?) and mate them up with the BONE? Or maybe LRASM if that comes on line? The BONE can carry 24 JASSM's, off which the LRASM is based. And if we could agree to let Japan and the Phillipines let us base the jets out of there, it provides a whole new threat environment to the Chinese Navy.

    The BONE itself was designed as a low level high speed, long range penetrating bomber, so the chances of it getting to within shooting range, especially with LRASM, seem pretty good. And it might be fast enough (almost as fast as the F-35! ;-) ) to shoot and get out too.

    We have 60 odd BONE's.. If we could dedicate 20 of them to the Pacific pivot, that would be an ability to dump 480 missiles (theoretically. If we could buy that many) into a kill basket that might hold a Taiwanese invasion fleet.

    Its not a long term solution, but it would provide a heck of a day one punch.

    Just a thought.

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    1. Yes, I think the USAF is already interested in LRASM for the B-1.

      They can fly from Guam to hit potential Chinese Naval targets.

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    2. Jim, your thought about the B-1 is fine except that you've considered it in isolation. Do you think it's more likely that the Chinese will simply accept the massive hit to their Taiwan invasion fleet or that they will attempt to wipe out Guam, Japan, or the Philippine bases that the B-1s would be stationed at? Those few bases are fixed, easy targets. I'm not saying that your idea is not worthwhile. I'm just suggesting that you take the line of thought all the way through.

      You've got an idea. What will China do to counter it? How would you counter their counter? And so on. At the end of the analysis, is it still a good idea?

      All of us have the tendency to consider our ideas in isolation and that produces some pretty flawed notions.

      You have a potentially good idea. Think it all the way through and then tell me what you conclude.

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    3. I didn't write out my idea clearly. I was wondering if it was a feasible maritme weapons system. From what I've read it is. I wasn't thinking of it just slaying the dragon alone.

      In the game of Naval chess that we play its just a piece. I wasn't intending that it would act in isolation any more than the Tico's or CVN's would act in isolation against the Soviet Navy.

      I'm guessing that the Chinese would put all sorts of political pressure to bear first on the other nations (other than guam) to not house the bombers. After that, they'd try to eliminate the threat.

      I see a couple of options for them to do this:

      A) An initial, first strike to get the bases before the bombers go on alert status

      and

      B) some sort of airborne means of trying to shoot down the bombers.


      Each is a threat to us, but each also poses a problem for them.

      I believe they have to have a first strike against the bomber bases because if they don't the bombers could loiter in the air on an alert status (these are cold war era bombers after all, it wouldn't be their first time) refueling as needed and within range of friendly air cover. A first strike is a real problem for them politically if they couch this as just trying to 'regain a piece of China'. Especially if they use something like a ballistic missile.

      As to B) its certainly a threat. But to find a fast, low level bomber that can launch missiles from 500 miles away at a target box is going to be a problem that ties up valuable jets and draws them out of their comfort zone. Then they get closer to our CVN's and their airwings.

      Now, they could flood the area with civilian shipping. But frankly that is a fairly thin ruse if they are invading.

      Finally, even if the whole bloody thing doesn't work, it forces them to use resources that otherwise might be dedicated towards our CVN's/SSN's/SSGN's. It draws their forces out from the comfort of being close to the homeland, where they have alot more support.

      Just my opinions. :-)

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  8. Assuming that the replacement ship will be based on the LCS, here are my thoughts which will, I hope, address all of the issues.

    Basic Frame:
    Start with a stretched GD LCS layout. My reasoning is multifold and I will address these as they apply below. Expand the deckhouse sideways to get rid of the walkway on each side while leaving a pocket for an MG in the same what they do with the aft deck corners. Extend the deckhouse aft to recover about a third of the flight deck. The flick deck is quite massive and losing a third of it will not be detrimental to ops as it’s still bigger than the LM flight deck. The expansion of the deckhouse and extension of the basic frame should allow for the extra fuel, systems, crew, provision storage, and protection (added weight) that you brought up.

    Propulsion:
    Here is a simple solution to bring down weight and increase the endurance – Dump the Pump. Since 40kts is not a requirement then the waterjet pumps are a waste, especially in the area of efficiency. Switch the 4 pumps out for two Azipods. Not only are screw drives much more efficient than pumps, Azipods are also about 10% more efficient than traditional screw drives. In the end you gain efficiency and you save weight. By going with Azipods (which are electrically driven), you ensure that future EW weapons (railguns, lasers, and EM) will have enough electrical power.

    Survivability:
    Besides the areas that you outlined (armor, mountings, shock buffering, bulkheads, etc) the choice of the GD LCS provides a unique benefit in the area of survivability. Its core design of the trimaran creates “spaced” armor for over half the hull. This means that strikes against the back half of the ship have to go through three hull walls, and all the systems therein, before reaching the crew and engineering spaces located in the center hull of the ship. Also, being a trimaran makes it more stable ad less prone to listing and capsizing due to damage to the hull (especially of ballast tanks are used as counter weights). The choice of Azipods also improves survivability as a hit on one pod still allows the ship to maneuver with the other pod.

    Weapons:
    Let’s start from the front.
    1. If the 57mm does not fit the mission for the new ship, UpGun it to a 76mm.
    2. The forward mission bas should use VL Spike NLOS missiles (25km, fiber optic guidance).
    3. Behind the missile bay, but in front of the bridge (the same location as the “International Variant”), mount Harpoon or JSM missiles on deck but in LO housings (no below-deck space taken up)
    4. Remove the “pitiful” 30mm cannons and replace them with VL Hellfire/JAGM missiles
    5. On the rear corners of the hanger, mount a 35mm Millennium Gun to replace the 30mm cannons from #4 above. These serve as surface weapons and as CIWS support.
    6. Replace the 11-Round SeaRAM with the 21-round RIM-116
    7. Replace the four 50 cal MGs with Mk51 MAWS mounts. These not only can use the existing 50 cals, but can mount everything from a Javelin and an M240 up to a 30mm M230 (same gun as the Apache Helo). It can also mount non-lethal weapons as well.

    So far, none of the above weapons takes up any more internal space that the LCS uses now (excluding ammo). Here are some thoughts on weapons that will take up internal space.
    8. In the recovered “catwalk” areas mount the same VL missile tubes from the DDG-1000 project. This would allow larger “strike” sized weapons to be used.
    9. Aft of the hanger mount “Self-Defense” sized Mk41 VLS tubes along the edge that will house Advanced ESSM missiles or anything else deemed appropriate.

    Sensors and Systems:
    1. Get a proper radar. AESA based and 360 in coverage.
    2. 360 IR EODAS capability. Northrop is already developing them called “Silent Watch”
    3. AESA based jammers, possibly integrated into the radar.
    4. Active laser DIRCM capability. Upgrade to actual destructives lasers when available.
    5. The combat system should allow any weapon (including the Mk51 MAWS) to be used from any ship workstation.

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    1. SpudmanWP, nothing wrong with that! I'm intrigued by the EODAS but, at the moment, it's a developmental effort not a fully functional system. That's the trap the current LCS fell into - depending on non-existent technology. There's nothing wrong with developing the EODAS but it should not be counted on. I note that you have conventional radar so you're not dependent on EODAS. That's fine. Install it if and when it's ready.

      I assume you mean the Mk57 PVLS from the DDG-1000? I'm doubtful that those can fit in the LCS-2 design but I don't know. I note that they are no missiles existing or under development that require those large VLS cells. Maybe just stick with the conventional Mk41 VLS?

      Interesting that you've picked the LCS-2 version to further develop. I suspect that the Navy will go with the LCS-1 but not necessarily for any good reason.

      Good thoughts!

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    2. I have always thought that an EODAS-like system would be a good fit for ships. Imagine my surprise when NG announced that they had adapted EODAS to ships and have even tested them at sea.

      http://www.northropgrumman.com/Capabilities/SilentWatchEODAS/Pages/default.aspx

      That being said, yes you are correct that it is still in development and should not hold up the rest of the project. The way I see it, there is no downside to leaving space for them and putting them on later.

      On the VLS issue, yes Mk41s would be fine. I was just trying to "future proof" the concept.

      On my choice of LCS-2 over LCS-1, the LM design has already shown that it has very LITTLE growth room, if any. Remember the "Reserve Buoyancy" issues that it had. They had to lengthen the hull below the waterline just to get it to spec.

      LCS-2 did not have that problem and since all the things that we were talking about will increase weight, "Reserve Buoyancy" will be a (if not "the") deciding factor.

      However, I can see this going the way of the YF-22/23 contest where apprehension about new technology and design philosophies (and the inherent risk involved) played a big part in the decision making process.

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  9. I think that is self-evident that the first step is lower the high-speed requeriment. The huge propulsion eat a lot of internal space and weight. From my point of view a maximun speed of 30 knots is more than enough for keep up with the rest of the fleet. The LCS Flight II idea of make a larger LCS sounds dumb, because the extra weight is going to make it a slower ship anyway, just more expensive.

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  10. Lipstick on a pig.
    Halt the program now.
    How do you uparmor aluminum?
    Pitiful..

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  11. I think the best replacement for the LCS is to look towards Europe, Asia and the Middle east to draw design ideas and experiences from. That would mean looking at the current Frigates that are out their in Europe, middle east and Asia to see what worked for them and what didn't. I do think a Frigate for the US Navy should be somewhere between an ANZAC class frigate and a Spanish F-100 Frigate.

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    1. Nicky, if the USN needed some ocean escort vessels, then I am sure the Navy would build some more, but since all our surface combatants currently are ocean escort vessels, I don't see any reason for them to add more ocean escort to the fleet while other types are short have gapping wholes.

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  12. Actually, it's not that complicated...

    Let's have

    ● A 5000 ton / 460 feet (29 knots hull speed) reduced observability hull
    ● Power it with half the Zumwalt's generator/propulsion system
    ● Put a 57mm gun, 24 VLS cells (25% of Burke) and a helicopter on it
    ● Put the SPY-3 X-band radar on it as the ONLY radar
    ● Use the same power / computing architecture as the Zumwalt
    ● Man it with about 100 crew members (33% of Burke)
    ● Keep it at around $900 million (50% of Burke)
    ● Buy 60 of them, sell off all LCS already built, cancel all remaining 24 LCS, reduce Burke buy by 12 ships, retire all Perrys, retire all Tocons, retire all Flight I Burkes, reduce CVNs in fleet to 9 ships, retire 1 LHA without replacement

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  13. I did something similar here... http://www.shipbucket.com/forums/viewtopic.php?f=15&t=5104#p116614

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  14. Replacement LCS

    On the assumption that new ship will be based on one of the two current designs due to the claimed time constraints, proposals to be submitted before the end of this month, in reality to save the 'face' of the Navy command from the cock-up of the current LCS ships.

    Lockheed and Austal will dust off the plans based on the previous export proposals that turn the LCS speed boats into warships, but found no takers as yet due to their high price.

    So as to meet ComNavOps requirements of increased endurance, range, survivability and crew size, and one requirement you did not mention was a reduction in cost,what are the options.

    1) The LCS-1 Freedom is based on a semi-planing hull for the claimed 47 knots (54 mph), they do this by using its massive power to generate lift to get over the hump of the bow wave, the wave drag reduces significantly thereafter, it is a one trick pony. When operating in the displacement mode the hull is inefficient and figures have been quoted of maximum range of 3500nm @ 14 knots.

    2) The LCS-2 Independence which has trimaran hull which gives a low hydrodynamic drag and though capable of a sustainable 44 knots (51 mph) can achieve 4300nm @ 20 knots +, with MTU documents claiming Austral trimarans capable of 28 knots with just 2 x MTU8000 20V @ 9100kW.

    So to me the LCS-2 is the obvious choice to go forward with plus the radical suggestion to delete the gas turbines and accept the limitation of a maximum speed of 28 knots, The gain from this is first cost, it has been said that the current propulsion system diesels, gas turbines, complicated gearing and the noisy and inefficient at lower speed waterjets cost add a cool $100 million per ship.

    The other obvious gain is in space saved in taking out the 2 X GT and the intake and exhaust trunking to give room for additional bunkerage, crew and storage, though the LCS-2 has never been short of space, just the design layout priorities. Survivability is a much more difficult requirement to meet as ship is 100% aluminium, starting from scratch you would use steel but that is not where it is. The design with the outer hulls give limited protection to the central hull from missile hits, and priority the re-design to ameliorate the effects of shells and missiles.

    The above the RLCS would be an effective ASW frigate, an expensive MCM and a borderline ASuW ship if appropriate missiles installed, but for the PEO in charge the most important word in his vocabulary would be NO after re-design frozen. The aim must be to keep the cost down and numbers up.

    The Navy could sell this design to Congress in the name of cost savings to meet the sequestration budget and save face at the same time as just a mod to LCS, very unlikely though.

    Nick

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    1. Nick, very interesting comment.

      I've wondered about the claim that the outer hull provides protection for the inner. Is that true or would a missile pass right through the outer and impact the inner? None of us know; I'm just wondering.

      Also, if the outer hull is holed and flooded would it then act as a sea anchor with the drag causing the ship to want to go in circles? In other words, could relatively minor damage and flooding in the outer hull cause problems all out of proportion to the actual damage. I wonder how compartmented the outer hull is? Is it actually one big tank and any flooding will fill the entire thing? Again, just wondering.

      You say the RLCS as you've described it would make an effective ASW frigate. How so, given that it wouldn't be optimized (quieted) for ASW. I'm not disagreeing, just interested in understanding how you see it.

      Your comments about cost are valid, however, the Navy has absolutely no ability to control costs so this will be an expensive design no matter what they do!

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  15. ComNavOps Thanks for your response

    “I've wondered about the claim that the outer hull provides protection for the inner. Is that true or would a missile pass right through the outer and impact the inner? None of us know; I'm just wondering.”

    As you say a lot of unknowns, speed of missile and the kinetic energy remaining, sensitivity of fuze, the point of impact may be on outer hull, main hull or superstructure, size of warhead and the amount of propellant in missile on impact which may cause as much damage if not more than the warhead. Best if anti-missile and decoy / jamming work.

    I am not a naval architect qualified to answer your query on damage to the outer hull and its effects and there have been so few trimaran ships to look back on for empirical data, though trimaran boats have lost an outer hull and made it back to port. Build in explosive charges to detach damaged outer hull on command, sensible or idiotic, in the days of sail if a mast was broken and partially over the side they would cut it free.

    Re the RLCS ASW frigate I'm sure I have seen on the MTU web site that they have engine rafts specifically designed to abate their noise and vibrations, perhaps making foolish assumption that rafts would be specified for the new engine room, and would they go diesel electric to allow the flexibility of single engine operation of two low noise propeller / azipods.
    (The Koreans who are definitely in the first division of ship design and manufacture have for the similar size new FFX Batch 2 frigates chosen hybrid electric drive system( DRS http://www.drs.com/news/20140319.aspx ) as have the RN with the Type 26, a ship twice the size at 6000 tons.

    It appears at long last the Navy are sorting out the ASW and MCM systems, ASuW seems work in progress. If the Navy could restrain themselves and specify the bare minimum equipment and no gold plating, no VLS, expensive radar and large gun etc. they could end up with an effective ASW and MCN warships.
    Nick

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  16. IMHO, neither of the LCS hulls are optimal. A conventional displacement hull or a mini-Zumwalt at abut 5000 tons is a better option. Hulls are not expensive to design or produce. It is the systems going into them that cost money and time in buckets.

    For a Frigate to be useful in both littoral/low intensity escort duties as well as blue water ASW operations in support of carrier groups they don't need to go 47 knots, but they should be able to go 30 knots (or as fast as the Burkes and he rest of the CVSG). This is neither difficult nor costly. The most effective and efficient way to make a ship go fast is not to try to get it on plane or give it prodigious amounts of power. The easiest and most efficient way is to simply make the ship longer. If you want to go 30 knots make the ship 500 feet (152m) long and you'll go 30 knots with about 5 hp per displacement ton. For a 5000 ton frigate that's just 25,000 shp to an efficient props. Trying to go 32 knots at that length will require about 100,000 shp so let's don't even try!
    Also, for a Frigate to be useful in LCS type roles while also able to be pressed into traditional fleet and mercantile escort duties it has to be able to defend itself and ships in it's vicinity effectively. It doesn't have to be able to do it in the face of saturation attacks, but it should be able to handle a half dozen or so incoming missiles, a flight of aircrafts or an enemy surface combatant or two. To do this it needs an air search or multi-function radar, about 16~32 full caliber VLS cells and 4 times as many ESSM rounds as the primary AAW weapon. The SPY-3 is an existing sensor so we should use it and forget a long range sensor like the VSR or AMDR-S. Any deficiency in range won't matter against low intensity threats in solo operations... not with the 50km range of the primary weapon. In a strike group the frigate pulling picket dutires will get AWAC and/or VSR feeds from other ships in the formation. 24 tubes may not sound like a lot, but it is adequate. 24 tubes allow for 8 tubes to be stuffed with a total of 32 ESSMs and leaves 16 full caliber tubes for the LRASM and ASROC. If and when we need a cruise missile barge you can also stuff it with 24 TLAMs and just keep it out of harm's range. That is enough -- not generous, but enough.

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  17. Finally, from a propulsion standpoint the USN should really start thinking of Diesel-Gas-Electric propulsion. Gas turbines get about 40% thermal efficiency at full load compared to about 55% for reciprocating diesels. That's not bad considering their power density. But at part load efficiency falls to about 20~25% or so which stinks. That is exactly the operating condition most Perry's spend most of their time in -- 12~20 knots with one of the of the two turbines running and operating at about 50% to 25% the 20,000 shp rating. Using a single large turbine like the 40MW LM6000 and a pair of 7.6 MW diesels like the Catepillar MaK VM32 will essentially double the operational fuel efficiency of the Frigate. Also, the Navy may want to consider accepting off-the-shelf commercial propulsion advancements instead of sticking to rather obsolete paradigms. Forget one shaft or two shafts. Just buy and install a pair of 20 or 25MW ABB Azipods, or 1 Azipod and one coaxial fixed prop in a contra-rotating arrangement. That's 8~12% more efficient than traditional shafted props. This is important not so much because of fuel costs (which is not a the biggest cost of operating a warship) but because of logistics costs. If you only need to supply it half as often or it can go twice as far without bunkering, then you don't need as many tenders and auxiliaries and you don't need as many allied ports along the way. This is huge given that either are kinda scarce at the moment.

    A 5000 ton / 30 knot ship with SPY-3, 24 VLS tubes, a 57mm gun spotting a turbine and two diesels with one or two Azipods can be built for about $900M (Half the price of a Burke). With automation similar to the Zumwalt's you can crew it with about 100 officers and sailors. That's a good deal and it's completely achievable within the next 3~4 years -- About 1~2 years to design it and about 2 years to build the first hull -- given that NOTHING on the ship is nor an existing system or technology.

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