Sunday, August 3, 2014

Fat, Drunk, And Stupid Is No Way To Go Through Life

From the movie Animal House, "Fat, drunk, and stupid is no way to go through life ...".

While the LCS certainly seems to have been designed by drunk and stupid people, it now appears that the LCS is fat, also.

Weight growth margins have long been a known deficiency of the LCS.  While fairly well documented in the Freedom variant, the magnitude of the problem in the Independence variant has been less clear and many observers have assumed that the Independence variant had little or no weight problem.  Freedom, you may recall, had to have "water wings" (buoyancy tanks) welded on to the stern and they have been incorporated into subsequent ships of the class. 

Stability has also been a known problem for the Freedom class.  Module swap tests revealed that simply shifting normal container weights caused the ship to reach its allowable incline limits.

A new GAO report now sheds some light on the weight situation and provides some actual data (1).

The report notes that the ships have exceeded their expected weights with resulting impacts on performance.

"Weight growth occurred on the first four LCS seaframes, which affected the capabilities of both Freedom and Independence variant seaframes. This situation has led the Navy to accept lower than minimum requirements on two delivered seaframes (LCS 1 and 2) in endurance and sprint speeds, respectively."

From the report, affected performance parameters include,

• range
• sprint speed
• navigational draft
• service life allowance for weight
• stability

The report notes that range has already been significantly reduced,

"In 2009, the Navy received authorization from the Joint Requirements Oversight Council to reduce LCS’s original endurance requirement, which was a 4,300-nautical-mile range when operated at a speed of 16 knots, to the current endurance requirement. [ed: 3,500 nm at 14 kts]"

The report states that the service life allowance (SLA) weight is specified as 50 tons.  This is the required weight growth margin for future equipment additions to the ship.  Only two of the first six ships have met their specifications and the rest have missed by a substantial margin.  Listed below are the individual ships, their target SLA (tons) and their actual margin (tons).

LCS-1  50  26
LCS-3  50 156
LCS-5  50  67

LCS-2  50 -16
LCS-4  50  16
LCS-6  50  31

Only LCS-3 and -5 have met their SLA margins.  The rest have missed by a substantial amount.  Interestingly, the Independence variant seems to be significantly worse than the Freedom, contrary to what most people thought.

The report also provides data on the ship's full load weights (crew, stores, module) compared to their naval architectural limits (max allowable weight).  Full load weights that exceed the naval architectural limit risk damaging the ship due to excessive strains and stresses imposed by the excess weight.  Here are the full load weights as a percentage of the naval architectural limits.  The closer the ship is to 100%, the more the strain and stress.  Values over 100% risk damage.

LCS-1  99%
LCS-3  96%
LCS-5  98%

LCS-2 101%
LCS-4  99%
LCS-6  99%

None of the ships have any significant operational weight margins and LCS-2 actually exceeds the allowable limit. 

The report indicates that the Navy will operate LCS-2 at reduced fuel loads so as to reduce the weight to acceptable levels.  As equipment or additional crew (remember that the Navy has increased the core crew from 40 to 50 and will probably add more) is added, the remaining ships may also have to be operated at reduced fuel loads.

Further, the Navy is addressing weight concerns in the Independence variant by designing reductions in fuel capacity (hence, range) in future ships of the class,

"... the Navy is developing design modifications for Independence variant seaframes to reduce fuel capacity—estimated to total over 100 metric tons—in order to restore service life allowances."

The report notes that various ships have failed to meet their range and speed requirements due to excess weight.  This, after the range spec was already substantially reduced!

The specification for sprint speed is 40 kts but the report notes,

"LCS 2 contractor officials told us that the calculated speed in the full load condition LCS 2 is 36.5 knots."

Thus, the shining characteristic of the LCS, speed, which negatively impacts so much of he ship's design, is not even being met.  Yikes!  That's a double hit.

As if all this isn't bad enough, the service life allowances not only aren't being met but it turns out that the allowances aren't even up to industry standard.  As stated in the report,

"Complicating the weight growth on early LCS seaframes is the fact that LCS requirements for service life allowances already fall short of the growth margins called for under Navy and industry recommended practice."

Standards for other ship classes range from a low of 5% margin for amphibious ships to 10% for surface combatants.  The LCS target margin is only 1.5% to begin with.  So, in addition to not meeting the margin, the margin was ridiculously low to begin with.

Excessive weight also affects stability as demonstrated with the Freedom module swap tests.  Other ship classes have stability margins (distance the vertical center of gravity can shift in response to weight growth before stability is compromised) of 0.3 m for amphibious ships to 0.8 m for carriers.  The LCS stability margin is 0.15 m - again, a very low value compared to other classes.

Note that the current weights are with the very stripped down version of modules currently being procured.  As the modules gear up to their target requirements, the module weights will increase and this is already impacting module design and will get worse with time.  As noted,

"According to Navy officials, future additions to mission packages ... will be offset by removing existing systems ..."

Module weight limits may result in modules being developed in variations.  For example, the MCM module may not have all its equipment in a single module.  Instead, it may have to field variations of the module which have subsets of MCM equipment to meet weight limits.

What does all of this mean?  Well, beyond the obvious conclusion that the LCS design is a poor one, one of the major selling points of the LCS was that it would represent the ultimate in flexibility and adaptability over its service life.  This would be the ship that could be adapted and modified to accommodate future needs, thus keeping it relevant over its entire life.  Unfortunately, the reality is that the ship is severely constrained by weight issues and has little or no room for growth.  Module improvements - and let's be honest, improvements always mean bigger and heavier - will have to be severely restricted by weight limits.  Anything added to the ship will have to compensated by the removal of an equivalent amount.  This pretty much eliminates flexibility as a characteristic of this class.

Amazingly, the Navy is about to embark on this same weight limited path with the Burke Flt III.  Talk about an inability to learn a lesson!


(1) Governement Accountability Office, "LITTORAL COMBAT SHIP - Additional Testing and Improved Weight Management Needed Prior to Further Investments", GAO-14-749, July 2014

21 comments:

  1. Warship traveling at sustained 40 knots is a pipe dream. Changing the requirement to 30 knots standard would had made things easier.

    The savings in using standard GE2500 engines might give it more simplicity to maintain and save cost over lifetime.

    The rest of the cost would had been better spent on a true steel hull and some facility to degauss it on a biannual basis.

    ReplyDelete
    Replies
    1. The Independence-class already used standard LM2500 engines. The Freedom-class uses RR MT30 which is basically a Trent 800. Both of these engines are used all over the world and have over 2 decades of maintenance experience.

      Delete
  2. Totally off topic, there is a resource I think you might be interested in at the Defense Science Board website. It has reports on all kinds of military subjects. In particular there is a report on sea-basing that you should read, although it is a few years old.

    Randall Rapp

    ReplyDelete
    Replies
    1. Randall, thanks! I'll check it out.

      Delete
  3. I can't say it surprising that the LCS Flight 0 turn out to have weight problems, as with prototypes such problems are guarantee to occur. The surprising thing is that no one made allowance for it. I am not just writing about the lack of margins in the original prototypes design, but the assumption made by senior Navy when they move to quick to put the LCS into production. Testing had hardly started when they put out their FRP to produce the LCSs, pressured by congress and OSD to backup their claim of a lower price per ship when series production began. In fact I personally believe the weigh issue became a major problem, not because it existed, but because there were no time allowed to correct such problems.

    There is little that can be done legally to correct the weight issues on those units already order. In might be necessary that they be used only as Anti-ship
    vessels as that would not require the addition weight of ASW and mine warfare modules. After that I suggest the Navy allows the builders to make those major design changes needed to increase the LCS's reserves, to the point were heavier modules, increase fuel supplies and additional modification. This will most like require enlarging the current LCS designs, and accepting a slower maximum sprint speed. But such changes, forced by real world experience, are common in any R&D program working on the edge as the LCS program has been doing.

    The only real question then become is will the bureaucrats and politicians in Washington realize that the problems are solvable, or will they pull another ass protection cut and run, and leave the Navy without ships the Fleet desperately need.

    ReplyDelete
    Replies
    1. But what can be salvaged? If the weight margins are as thin as they say, then the mission modules themselves are going to put them dangerously close or over. The only way to fix that is do something goofy (IIRC the torpedo bulges gave the old Standard BB's extra displacement and weight margin that helped offset the increase in topweight when they were refit) or redesign the bloody hull.

      At that point, given most of the money for this has gone into the 'seaframe' from the get go, its practically a redesign. Then maybe the HI offering looks better if its not beset with weight issues just because its there.

      Delete
    2. G LofAugust 4, 2014 at 12:26 AM: "There is little that can be done legally to correct the weight issues on those units already order."

      zzzzzzzzzzzzzzzzzzzzzzzzzzzz

      This is incorrect, the Navy took a number of steps to modify the Freedom hulls, ultimately installing a stern extension on LCS-1 and a hull plug (lengthening) on LCS-3 on.

      GAB

      Delete
    3. GAB, I was talking about any major changes to the ships already in production, Yes ECO can be issued and small correction can be made, But nothing like lengthening the hull as suggested for the Freedom class as Lockheed Martin propose last month, or whatever corrected action Austal may propose for the Independence class can be made without a price increase.

      I thing the best outcome would ne to take advantage of Congress slowing the program, and turn the FY 15 LCSs into prototypes for next generation LCSs. Let Lockheed build there long hull LCS with room for the MK41s, maybe even long flight deck (3 extra meters.)

      I don't know what Austral can do with their design, as they seem not proposed any changes to the hull size, but maybe they can increase the draft or enlarge the outriggers.

      Delete
    4. GLof, you were referring to the fact that with the contracts already issued, the specifications are locked in for that batch, barring Change Orders. I understand that.

      I've already posted that the Navy will turn the "mandated frigate" into the LCS Flt II so your "best outcome" is almost assured to happen. I don't agree that it's the best outcome because the LCS design has such fundamental design flaws but that's another topic.

      You mention a somewhat larger flight deck for the LM version, if I understood you correctly. Variations of this theme have been proposed by many people whereby the LCS acts as a mini-helo mothership, lilypad, or somesuch. The problem with that is that the LCS is not structurally rated for anything more than a single -60 type helo. I've seen reports suggesting that the flight deck itself can handle up to two -60's but nothing more. The flight deck was designed to a lower structural standard as a weight and cost savings measure early in its development. Given the weight issues described in the post, we can see why.

      With all that said, what use do you see for a slightly lengthened flight deck? If part of the lengthening would also involve strengthening, that would come at a significant weight increase penalty on an already weight-challenged design. What are your thoughts?

      Delete
  4. There was an assumption that computer added design and construction would enable us to get it right the first time. No need for prototypes.

    While these design tools are clearly useful, it looks like they underestimated how hard was to build a model which reflected the complexity of reality.

    Although I suspect part of the people is when people adjust the model to reflect the assumptions of the decision maker.

    Telling people what they want to hear does make you popular in the short term, in the longer term it is always problematic.

    Mark

    ReplyDelete
    Replies
    1. Mark, good point about computer aided design. Unfortunately, the military is leaning ever more heavily on the practice as testing funds become scarcer.

      Delete
    2. Blaming CAD for the problems is fairly ignorant. There have been numerous designs done fully in computers and they have all come out within a couple % of computed results in basically all categories. This is true of ships, cars, planes, etc.

      They've done designs as large as the say a Boeing 777 or an Airbus 380 and all have basically come out to the exact result. The only times you run into bad results is generally gross human error or omission. They've also done the biggest ships in existence and the final finished designs are within 1% of computer estimates.

      And if anyone thinks that the either LCS is more complex than say a 777 or 787 or a350 then they are fooling themselves. I'm really not even sure if the LCS designs are really that more complex than the EEE ship designs. All these were designed completed within CADAM packages.

      So its probably instructive to look for blame/issues outside of the actual use of CADAM to design the vessels.

      Delete
    3. ats

      Please re read what I wrote, I am not blaming computer added design, but unrealistic expectations by decision makers from it.

      The concurrency decision with the f-35 is a classic example of a silly decision driven by an unrealistic assumption. I do not believe this decision was made by engineers, but program planners making bad assumptions.

      Mark

      Delete
    4. ats, just a reminder ... Please keep your discussion and criticism polite and respectful. Neither the commenter nor their views are ignorant.

      Regarding computer aided design (CAD), Mark noted that CAD was clearly useful but not the ultimate answer and that is a perfectly reasonable statement. I've read several reports that state that the CAD work did not completely eliminate construction problems due to mismatched locations, incorrect sizes, et.

      Consider the F-35 which was found to suffer from cracked bulkheads despite, I presume, extensive stress analysis modeling.

      Consider the LCS which suffered extensive hull and superstructure cracking despite, I presume, extensive stress analysis modeling.

      Consider the LCS and other ships which have undergone job function analysis to determine manning levels and yet have been shown by experience to be severely undermanned.

      Consider the LCS which has been demonstrated to have severe weight and stability problems despite extensive CAD and mathematical modeling. These problems were a surprise to all involved and the numbers were far from the predicted values.

      Consider that the Navy still performs wind tunnel tests, shock tests, acceptance trials, electronic signature tests, flight tests, etc., all despite the various platforms having been extensively modeled and CAD-built.

      Consider the extensive litany of DOT&E reports citing design deficiencies in various platforms despite extensive modeling.

      Consider the extensive litany of DOT&E criticisms of Navy performance models used for simulations.

      I can go on endlessly but you get the idea. CAD and the various modeling methods used to support it are, as Mark stated, a useful tool but hardly a guarantee of success. If it were, we wouldn't bother building prototypes.

      Delete
    5. CNO,

      The biggest issue with the design is that the Navy kept changing it!

      You have focused on this many times, but no design tool can save you from crappy requirements, that are in perpetual flux.

      Frankly, it is a miracle that LCS turn out as well as it has, things could be much, much worse...

      GAB

      Delete
    6. CNO, I meant no disrespect in my reply. ignorant was meant to imply lack of knowledge or understanding, not as a slander. AKA, unless there is some fundamental bug in the CADAM software, the CAD or use of CAD cannot be at fault cause it only does what it is told and exactly what it is told. The issue lies in project management and in procedures, something that is entirely independent of using CAD.

      Most of you points about extensive modeling and analysis are off base. If there was extensive analysis and modeling, it would of caught these issues as it has in numerous projects in the past. It is likely that instead of doing extensive modeling and analysis that they took significant shortcuts.

      Certainly if the weights and stability didn't match they took significant shortcuts in modelling the design.

      And by your own assertion, the DOT&E found that there were major issues in the performance simulations. This occurs when you don't actually model the design and take significant shortcuts.

      You build prototypes to find unknown unknowns. The vast majority of the issues with the LCS designs should never of been unknown unknowns if the Navy and the contractors were following standard industry best practices/known best methods to model the designs.

      I mean really, if weights were not matching as severely as has been reported, it can only be because the Navy/Contractors were taking massive shortcuts on the designing of the ships with the CADAM packages they were using. When used properly, the packages give results for things as basic as weight within a couple of percent (basically within the margin for error in manufacturing generally).

      The CAD/CADAM is not the issue, the gross negligence in the use of it is the issue. There are too many commercial CAD/CADAM based projects that come out basically exactly where the simulations say they should for the CAD to be the actual issue.

      Delete
  5. One question I have from the article:

    LCS-1 50 26
    LCS-3 50 156
    LCS-5 50 67

    LCS-2 50 -16

    How on earth to LCS 3 and 5 rate so much better than their sisters? Did they forget to put in the engines?

    ReplyDelete
    Replies
    1. Jim, you'll recall that buoyancy tanks were added to LCS-1 and then incorporated into subsequent ships of the class in the form of a lengthened hull. Perhaps that's the reason? Just specualtion on my part.

      Delete
  6. One of the biggest justifications for the LCS was the ability to operate at very high speeds. When the LCS program was first started, they were advertised as being able to make 50 knots. As time went on, this was revised down to 45 knots and then 40 knots. The USN now admits that at their designed full load displacement, they will be able to make no better than 36.5 knots, which is the same as a Fletcher or Gearing class DD at its designed full load displacement.

    Why not just scrap this ridiculous, overpriced farce of a program and replace the LCS with an updated version of the Fletcher or Gearing class with the same hull and updated weapons and electronics? Hell, even a Fletcher or Gearing with the original World War II weapons fit would be far superior to the LCS for the missions the LCS was intended to carry out and much more survivable in combat. What a waste!

    ReplyDelete
  7. This comment has been removed by the author.

    ReplyDelete
    Replies
    1. USMC, I read the article. Was there a particular point you wanted me to take note of?

      Delete