Announced today:

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The Navy announced today it will down select between the two Littoral Combat Ship (LCS) designs in fiscal 2010. The current LCS seaframe construction solicitation will be cancelled and a new solicitation will be issued. At down select, a single prime contractor and shipyard will be awarded a fixed price incentive contract for up to 10 ships with two ships in fiscal 2010 and options through fiscal 2014. This decision was reached after careful review of the fiscal 2010 industry bids, consideration of total program costs, and ongoing discussions with Congress.

“This change to increase competition is required so we can build the LCS at an affordable price,” said Ray Mabus, secretary of the Navy. “LCS is vital to our Navy’s future. It must succeed.”

“Both ships meet our operational requirements and we need LCS now to meet the warfighters’ needs,” said Adm. Gary Roughead, chief of naval operations. “Down selecting now will improve affordability and will allow us to build LCS at a realistic cost and not compromise critical warfighting capabilities.”

The Navy cancelled the solicitation to procure up to three LCS Flight 0+ ships in fiscal 2010 due to affordability. Based on proposals received this summer, it was not possible to execute the LCS program under the current acquisition strategy and given the expectation of constrained budgets. The new LCS acquisition strategy improves affordability by competitively awarding a larger number of ships across several years to one source. The Navy will accomplish this goal by issuing a new fixed price incentive solicitation for a down select to one of the two designs beginning in fiscal 2010.

Both industry teams will have the opportunity to submit proposals for the fiscal 2010 ships under the new solicitation. The selected industry team will deliver a quality technical data package, allowing the Navy to open competition for a second source for the selected design beginning in fiscal 2012. The winner of the down select will be awarded a contract for up to 10 ships from fiscal 2010 through fiscal 2014, and also provide combat systems for up to five additional ships provided by a second source. Delivery of LCS 2, along with construction of LCS 3 and LCS 4 will not be affected by the decision. This plan ensures the best value for the Navy, continues to fill critical warfighting gaps, reduces program ownership costs, and meets the spirit and intent of the Weapons System Acquisition Reform Act of 2009.

LCS is a fast, agile and modular warship designed to complement the Navy’s multi-mission platforms with warfighting capabilities from littoral irregular warfare to mine, anti-submarine and surface warfare. There are two different LCS hull forms: a semi-planing monohull and an aluminum trimaran. The seaframes are designed and built by two industry teams led by Lockheed Martin and General Dynamics. Of the planned 55-ship program, LCS 1 is commissioned, LCS 2 is undergoing sea trials, and construction has started for LCS 3 and LCS 4.

The Navy remains committed to the LCS program and the requirement for 55 of these ships to provide combatant commanders with the capability to defeat anti-access threats in the littorals, including fast surface craft, quiet submarines and various types of mines. The Navy’s acquisition strategy will be guided by cost and performance of the respective designs as well as options for sustaining competition throughout the life of the program.

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What does this scurvy band of cutthroats (and others who dare venture here) think? Which did we see as the wiser choice? Advantages and disadvantages in comparison? What say you?




Posted by UltimaRatioReg in Navy


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  • Chuck Hill

    Looks like it will be the LCS-1 design, it’s got to be the cheapest to build, although looks to me the LCS-2 is the best design, with truly revolutionary characteristics, more economical cruise and larger flight deck.

    Hope they are looking at life cycle costs.

  • sid

    Sticking with either of the current hull designs will prove to be an egregious mistake…One day.

    But,in the meantime,the band plays on

    Whats needed is a “downselect” of the LCS concept itself. The whole show needs to be reset at the beginning.

  • http://cdrsalamander.blogspot.com CDR Salamander

    More cowbell!!!

  • Byron

    SINK LCS.

    SLEP THE FIGS

    BUY A EURO-DESIGN.

  • http://newwars.wordpress.com Mike Burleson

    What Byron said.

  • http://cdrsalamander.blogspot.com CDR Salamander

    Chuck used the “R” word in vain. Someone go get Sid to spank him – my swing’n arm is all sore’d up.

  • Chuck Hill

    I think you know where my sympathies lie, but they are going ahead anyway and if anything good comes out of this it will be through the LCS-2 design, LCS-1 is old tech.

    Re Aluminum: see the article in Navy times on the random cracking in the cruisers for which there is no design fix.

  • sid

    Re Aluminum: see the article in Navy times on the random cracking in the cruisers for which there is no design fix.

    Aluminum superstructure USN ships have been suffering cracking problems since the 1950’s. During storms, I’ve watched those cracks open and close like they were breathing as the ship worked.

    So now you want to commit to building 53 ships…the bulk of the surface Combatant fleet…with a strong likely of suffering cracking problems?

    Not to mention the problems of blast and splinter effects when some unlcky memebers of the class find themselves on the recieving end of angry ordnance….

  • UltimaRatioReg

    Sid,

    Angry ordnance? Pish posh. The LCS sensors and speed will keep it far from anyone wanting to do it harm….

  • sid

    Oh yeah.

    How are those “warfare” modules coming along?

  • Larry Schumacher

    Agree totally on SLEPing the Figs Byron, but would rather see a modified Berthhoff put into production while developing FFGX

  • http://xbradtc.wordpress.com XBradTC

    Well. One seaframe down. One to go.

  • CWO3/7441/USN(RETIRED)

    I for one believe the LCS program is a waste of money and has nothing to do with enhancing our maritime doctrine. The best LCS so far is a Coast Guard Cutter on the surface and a submarine below. The first combat mission will require a reconfiguration of the LCS because they weren’t configured properly and the first casualties will disable the LCS’s operational capability. Manning a ship is also based on potential casualties in combat. I would rather see mobile weapons loaded on an LCAC, now that’s a littoral combat ship.

  • John

    There is no way the LCS program will ever be able to stand on it’s own in the real world. We need to think about another class of Frigates in the next 10 years.

  • Scott B.

    At this stage, I believe it’s worth quoting a couple of paragraph from an entry Galrahn [Raymond Pritchett] posted on his blog on June 15, 2009 :

    (bold emphasis added)

    ——————————————————————
    Defense Daily is reporting on the LCS cost cap.

    “The Seapower panel during its markup recommended restructuring the Littoral Combat Ship’s (LCS) $460 million-per ship cost cap so that it adjusts for inflation and no longer counts non-procurement government costs for oversight and lifecycle management. Seapower subcommittee Chairman Gene Taylor (D-Miss.) also included in the mark, as expected, language saying if the two LCS contractors–General Dynamics [GD] and Lockheed Martin [LMT]–cannot build each FY ’10 ship under the cost cap the Navy must take steps to allow additional companies to bid on the program.”

    In case you don’t know, those costs will remove about 14% of the LCS cost from the SCN budget, or around $62 million. Basically the Navy pays for those costs out of a different budget. That will likely be enough to get the LCS below the $460 million cap in multiyear.
    ——————————————————————

  • Scott B.

    One of the things it says in the Navy announcement is this :

    “The Navy cancelled the solicitation to procure up to three LCS Flight 0+ ships in fiscal 2010 due to affordability. Based on proposals received this summer, it was not possible to execute the LCS program under the current acquisition strategy and given the expectation of constrained budgets.”

    What this means is that none of the industry teams was able to meet the $460M cost cap for the FY2010 ships, even after non-procurement government costs for oversight and lifecycle management are excluded and inflation is accounted for.

    In other words, once you re-inject these government costs into the equation, which represent about 15% of the total, this means that none of the industry teams is able to offer the FY2010 LCS for less than $540M. That’s just for the seaframe.

    Now, if you inject one module into the equation (at the average cost of $60M), what you get is essentially a high-speed one-trick poney costing at least $600M per unit.

    Multiply that by 55 hulls, and you get a grand total of at least $33 billion dollars. (and it gets worse if LCS gets built indefinitely as Bob Work suggested not too long ago !).

    Compare that with what LCS was initially supposed to cost (threshold of $220M for the seaframe plus $150M for 2/3 modules, i.e. $370M in total), and you quickly realize that the LCS program is going to drain at least an excess $12.5 billion away from the shipbuilding budget.

    For all intents and purposes, what this means is that the “LO” component of the “HI-LO” mix envisioned in the failed SC-21 vision effectively kills the “HI” component.

  • Scott B.

    Scott B. said : “For all intents and purposes, what this means is that the “LO” component of the “HI-LO” mix envisioned in the failed SC-21 vision effectively kills the “HI” component.”

    The Navy leadership has probably been aware of this situation for some time now.

    Since the “LO” component was going to kill the “HI” component because of its prohibitive cost, the solution envisioned by the Navy was to turn the “LO” component into the “HI” component of the “HILO” mix, as explained by RADM Goddard in June 2007 article published in AFJ : (bold emphasis added)

    “For example, to maximize re-use of existing designs to reduce nonrecurring engineering and take advantage of the learning curve, a potential strategy for surface combatants is to derive the planned CG(X) cruiser from DDG 1000 and the DDG 51 Arleigh Burke-class destroyer replacement from LCS. Upgrading the radar on DDG 1000, and replacing the Advanced Gun System with additional vertical launch cells to create CG(X) would be similar to how the CG-47 Ticonderoga-class Aegis cruiser was derived from the DD 963 Spruance-class destroyer. Similarly, installing the multifunction radar on one of the LCS variants and retaining the modular mission packages would provide a replacement for DDG 51s.

    That’s indeed what the future might look like if nobody stops that train wreck called LCS as quickly as possible.

  • sid

    a potential strategy for surface combatants is to derive the planned CG(X) cruiser from DDG 1000 and the DDG 51 Arleigh Burke-class destroyer replacement from LCS.

    Anyone who ignores the danger of this is whistling past the burials at sea that will come one day.

    Borrowing from Baron Brassey:

    An admiral having Freedoms or Independences in his fleet will be certain to put them in the line of battle, where their comparatively light protection will be at a disadvantage.

    Human nature -misguided Hubris in this case- never changes….

  • sid

    What I said on Feb 4 2004

    If a commander doesn’t have the requisite number of
    hulls available, then he will have to pick and choose which “focii” he needs carefully. Once on station he is stuck with what he’s got. No reconfiguring unless he sends his LCS’s off to some distant place to reconfigure. Thats if a distant place within range is available. LCS is an operationally inflexible concept-unless there are plenty of LCS hulls. Its doubtful that will happen in the best of circumstances, and really doubtful if the selection is a 400 ft ship that will be regarded as a major combatant.
    Also, no one seems to want to broach the significant chances of LCS hull losses. Maybe because that dirty little fact helped kill
    Streetfighter. You morph this into a frigate, then it will turn multimission just to protect the investment and things will be back at square one.
    The core missions are of the type that are conducted in either a
    completely benign environment or which require covering protection
    from other forces. In short, the LCS isn’t worth the money without its mission packages.

    Still stickin’ to it.

    So…Where are those mission modules anywho?

  • sid

    And the whole “Speed is Life” thing… It is an enduring myth.

    Cebrowski had it wrong.

    In fact, it took a complete change in operational doctrine and tactics, combined with maneuverability that could only be achieved at less than half the mach 2 design speed of that aircraft and others.

    Here is an account from Jim Bell, who had a chance to ponder the subject while on extended TAD in Hanoi:

    (excerpted from ‘The Heroes’ Wife’. changes to the orignal narrative and emphasis are mine)

    I was flying at 1200 to 1500 feet at a speed of 620 knots. The thinking at the time was there was no way a gunner could track such a fast moving target at a low altitude. I remember seeing alot of truck traffic on the coast highway, but not much else, and no one was firing at me. When I got within 15 miles of Hon Gay on my way out, my RHAW suddenly lit up. A few seconds later the anti-aircraft radar was locked on. I put my gear in jamming mode, but why I didn’t make a radical course change, I really don’t know. Like most carrier pilots, I’m sure I harbored some illusions of invincibility. Whatever my thinking process was, it was faulty because a few seconds later I was in trouble.

    “Speed is Life” didn’t work for the Royal Navy. “Speed is Life” didn’t work for Naval Aviation in the 1960’s. “Speed is Life” will not work for SWOs currently on watch who think its somehow different today….

  • Bill

    LCS-1 is grossly overweight and requires significant redesign to ‘fix’ everything affected by that factor alone. LCS-2 is little more than an enigma at this point. So how on earth does one leap from there to the assertion that “both ships meet our operational requirements”??

  • Grandpa Bluewater

    I labored to produce a masterpiece of sarcasm re: “It must succeed” and the computer ate it. Just as well.

    Why are we cursed with flag officers and a SECNAV who don’t know orders to the universe to change the laws of physics don’t work. It’s a failure. Face it. Deal with it. It’s your job. Do it.

    Oh, that’s right, they aren’t listening, much less paying attention.

    Side bets anyone? Popcorn? Program? Watch the train wreck, it’s exciting.

  • sid

    In fact, it took a complete change in operational doctrine and tactics, combined with maneuverability that could only be achieved at less than half the mach 2 design speed of that aircraft and others.

    The dramatic decrease in aircraft losses since then (’83 really),
    took has been the result of the creation of an entirely new design discipline.

    Note to Blackshoes. It applies to you too.

  • sid

    Does this mean that LCS-2 is DOA?

    Haven’t heard much ballyhoo from Mobile.

    And haven’t seen any spiffy commercials from General Dynamics touting their Really Cool Ship like we’ve seen from LochMart….

  • Mark Toomey

    I believe that U.S. Coast Guard “National Security Cutter Class” would be a much more cost effective LCS design with a greater range (albeit less speed) and with configurable modules could meet the same operational requirements!
    >>>>http://www.uscg.mil/acquisition/NSC/features.asp
    Mark Toomey CWO2,USCG Retired

  • sid

    Over at Galrahn’s place, pitcrew brought up Tim Colton’s prescient take.

    Then, you have this little blurb from Navy Times:

    Lockheed Martin spokeswoman Jen Allen said the Navy’s approach will make it possible to cut costs even further on the ship program. A spokesman for General Dynamics was not immediately available to comment Wednesday evening.

    Hmmmm….

  • Scott B.

    Anyone remember the statement made by Gene Taylor during the subcommittee mark-up of the FY2010 NDAA : (emphasis added) :

    “I am very concerned with the progress of cost reduction in the Littoral Combat Ship program. I will not go into detail here and the list of mistakes made in this program because we would be here for most of the day if I did. But this year is a ’take it or leave it ‘year for the LCS. I asked the Assistant Secretary of the Navy if $460 million was a fair price for the vessel with the current efficiencies of the two shipyards. He believed it was a fair price for the procurement costs of the ship, but that he had government costs for oversight and life-cycle management that would be hard to fit under the current cost cap.

    Therefore, this mark proposes to re-structure the cost cap to allow for a total procurement cost of $460 million per vessel. The contractor can take it or leave it. As Chairman, I will not propose one penny more. If the contractors take it, fine; we build ships and get the mine-hunting capability the CNO needs for the fleet.

    If the contractors do not take it, the proposal would direct the Secretary to use the funds authorized to compile a technical data design package that could be bid to other contractors who might take it. No more games on this program, no more promises. Build ships for a fair price or not, that is the deal on the table.

  • Chap

    Who’s looking a few moves ahead (Byron’s at least one move ahead with his proposal)? What’s the next decision after this one?

    And wouldn’t it be interesting to talk to the foreign navies who have been offered a variant of LCS to see what they think?

    Seems like a useful piece of journalism if someone asked a flag in one or two of those navies…

  • sid

    What’s the next decision after this one?

    Develop a coherent, comprehensive fleet plan…Not some staff work from FFC. Operational staffs are too consumed with the crisis dujour to really focus on such big picture items. The latest maritime strategy reflects this.

    Also, wrest control of strategic, operational, and tactical planning from the contractors. That the services subcontracted this role in the 90’s is why we are here.

    Instead, convene a no joke summit like those of a century ago, and fix the philosophy first.

    Then decide what and how to build according to that framework.

  • sid

    And wouldn’t it be interesting to talk to the foreign navies who have been offered a variant of LCS to see what they think?

    I’d bet that’s locked up in confidentiality agreements with the contractors with which they have held talks.

  • Cap’n Bill

    Alas, I put all my hope in the wrong bucket. This new generation of responsbile persons seem to be beyond redemption. One is forced to give up on today’s Lords of the Admiralty and trust in the smartz of the Congress. How could this be worse ?

  • Grandpa Bluewater

    Cap’n Bill:

    Re:”How could this be worse? ”

    Stick around. We’ll see soon enough.

    Popcorn?

  • Scott B.

    Chap said : “And wouldn’t it be interesting to talk to the foreign navies who have been offered a variant of LCS to see what they think?”

    A couple of months ago, the Israeli Navy decided to drop the LCS-1 derivative and go for a MEKO A-100 derivative instead :

    http://www.defensenews.com/story.php?i=4160683

    http://www.janes.com/news/defence/jni/jni090706_1_n.shtml

  • sid

    Instead, convene a no joke summit like those of a century ago, and fix the philosophy first.

    Here is a better example

  • doc75

    “Aluminum superstructure USN ships have been suffering cracking problems since the 1950’s. During storms, I’ve watched those cracks open and close like they were breathing as the ship worked.”

    sid, the funny thing is that I have flown many hours on aluminum aircraft and have never watched cracks open and close while in flight. Paper thin aluminum, too. Through a few storms and other events. Not quite wave slap but plenty of fatigue cycles more than a ship. And some of those platforms like the KC-135 or T-37 were designed in the 1950s.

    What this tells me is that the Navy has historical problem with design of aluminum structures. Probably cause the designers treated it like steel. One would hope the current designers did a better job than the earlier ones.

  • doc75

    Forget Berthoffs, SLEP FIGS or FFG(X). The default shipbuilding function in the USN is more DDG-51s.

  • sid

    sid, the funny thing is that I have flown many hours on aluminum aircraft and have never watched cracks open and close while in flight.

    Gee doc…You’ve never had that kind of fun? ;)

    As an A&P (pilot too, but only highwing/slowspeed/fixed gear), I will have to quibble with your analogy.

    The many tons and thousands of square feet of an aluminum superstructure sitting atop a differently behaving steel hull in a seaway is a way different animal than the relatively densely reinforced semi-monocoque fuselages you cite.

    But Byron is the one to wax eloquent on that score….

    As for the DDG-51 for everything argument. The one thing I agree with in the whole LCS morass is the need for relatively small ships to “get in close.”

    Sure is a travesty the USN decided to turn the LCS into ersatz Frigates.

  • Cap’n Bill

    Sure now there are some very smart former Navy types working on Capital Hill. They know the score about propulsion required for semi-displacement hulls. One only has to count to TWO to understand the beauties of diesel power for ships of the type the USN needs. How long will the Congress play games with erratic naval leadership ? I can’t understand how it is that SECDEF has permitted this game to continue on its drunken path.
    I’ll buy some popcorn but longevity won’t permit a large purchse.
    Better yet, I’ll start to rub the old brass Budda.

  • Grandpa Bluewater

    Cap’n Bill:

    Popcorn optional. Have a seat in the bleachers next to me.

    Contemplate the stresses on an aluminum hull trimaran, with long swells abeam, doing snap rolls when the horizontal separation from peak to trough is the same as the hull centerline to hull centerline transverse distance. Flex, compress, flex, compress with the force vector the same as the outboard hull wt., not to mention the vertical V squared in 20 foot swells running peak to peak in 30 seconds or less. Rock and roll. Port hull in the air, center in the peak, stbd in the trough, reverse. Wheee! Crack!

  • Byron

    Doc,to answer the question, let me ask you a question: How many hours will an airframe have on it before it begins to exhibit stress fractures? The F-15 should be a good place to look. Keep in mind that an aircraft is flexed ONLY when it’s in the air; on the ground, the frame is essentially in stasis. A ship on the other hand, is being flexed constantly, even while in port. And an aircraft can make it across the Atlantic in 5 hours…how long will the ship be in the water going across the Pond?

  • UltimaRatioReg

    Capn Bill,

    “I can’t understand how it is that SECDEF has permitted this game to continue on its drunken path.”

    ‘Fraid this one goes back several administrations, as does the deterioration of our Navy. Gonna take a long time and major mindset shift to fix. Methinks we won’t see that any time soon.

  • Bill

    Doc said: “What this tells me is that the Navy has historical problem with design of aluminum structures. Probably cause the designers treated it like steel. One would hope the current designers did a better job than the earlier ones.”

    This is a topic near and dear. Suffice to say, the problems with fatigue cracking of aluminum hulls is not at all a USN problem; we’ve beaten that issue to death over the years with all of the fast ferry’s and other non-USN builds. It’s something in which both ABS and, to an even greater extent, DnV, have spent untold thousands of man-hours trying to get a grip on. The upshot is that, for high-stress areas with fully-reversing high-cycle loads, we find ourselves in the virtual design toilet when it comes to allowables stress levels (with the issue of what ARE the design loads also still a constant headache and oft gotten wrong..still). For a 500o-series marine grade aluminum alloy, the allowable can be as low as 8 ksi, as-welded, for a material that otherwise has a yield strenght of 6 to 8 times that number!

    And therein lies an intersting conundrum for the design/construction of high-speed vessels: What benefit really derives from the use of lighter aluminum alloy as the hull material when one can safely only allow less than 20% of tensile stress levels in so many critical load areas?

    Historically, most ALL of the aluminum high-speed ferry and naval vessels suffer chronic (in some cases, severe) structural cracking. The original Incat 74m tha won the Riband trophy was such a structural wreck after that record-making voyage that the ‘practically new’ vessel was spirited off to a yard in Holland and very quietly rebuilt from the ground up. We’ve all learned a few things since then..but one of those lessons is the incredibly low allowable stress levels that we must design with..and live with..in an aluminum ship structure.

  • doc75

    Byron, I’m quite familiar with the F-15 and fatigue on that airframe. A key difference is the aircraft goes through cycles more rapidly than a ship. In the course of a flight hour, the number of cycles is far more rapid — higher frequency spectrum — than a ship. Having said that, Bill points out one of the true problems: no one knows what the loads are for ships. Considering how many centuries we have been sailing ships, aircraft designers have a better idea of load spectra on an F-15 wing spar than ship designers have on a stiffened panel — as a result, we have better design efficiencies and damage tolerance on that F-15 wing spar. I like the fact that the USCG is instrumenting their NSCs although because of the low number of sensors the data is extremely sparse. Going to composites aren’t going to help much if you don’t understand the loads! In case you didn’t know, they fatigue, too, (just ask Boeing on that topic for the 787). When using aluminum, marine designers should consider some of the selective reinforcement and damage tolerant approaches in aerospace.

  • Byron

    Doc, how many times in that hour will the ship rise and fall across the wave crests? What sort of loading does making a course in a quartering heavy sea put on the structure? Add to that the liquid volume in the tanks that is moving (though mitigated by baffles, it’s still moving)? And ACM NEVER lasts more than a few minutes; the rest of the time the aircraft is subjected to relatively benign loads.

  • Grandpa Bluewater

    Byron:

    Don’t forget shock loading (slamming), torque loading (seas off bow or quarter), bending moment and elastic release from same (bury bow on the down pitch – wave goes aft and stern drops, then bow breaks free…).

    Every thing gets much more complicated in catamaran and trimaran designs.

    Then there are small dimensional differences in plate cutting and location of weld seams which are inherent in the fabrication process, combined with quality of fit up of plates and weld quality and consistency between different units of a class. Example: USNS Able had crack problems, USNS Indomitable didn’t.
    Identical steel ships, catamarans. Why? Dunno.

    Then there are day to day minute to minute changes in weight distribution in tanks due to adjustments for stability’s sake when fuel is burned, water consumed or distilled, etc, etc.

    It’s a bit of a black art. Oh, and then there is WEATHER…

  • Bill

    FWIW..

    Our Norwegian naval friends have developed and evolved a methodology for deriving accurate structural design loads that is a major departure, and very significant improvement, from the traditonal ‘rules based’ approach that is often supplanted by tank testing of grillage models (also a ‘black art’ fraught with uncertainties), used historically by USN and literally everyone else. Our own NRL was involved cooperatively with the testing and development/maturation of the Bragg strain measurement technologies that go along with the Norwegian approach to defining global hull design loads..that is, until that NRL groups funding was cut off.

    As a positive consequence of some ongoing joint USN-Norwegian development programs, the improved methodologies are slowly being ‘transferred/absorbed/understood’ and ABS is very much ‘in the loop’ with that technology transfer as well. So there is a reasonsable expectation that the age-old problem of adequately quantifying hull design loads is due for a significant step forward…not that either LCS has benefited from that, of course.

  • doc75

    Byron, this could go on for a while. What about wing loading harmonics from non-symmetric weapons load-out under the wings –even in level flight?

    Waves or turbulence, it doesn’t change the fact that ship designers could adopt aerospace fatigue and damage tolerance practices to eliminate some of the problems discussed. They haven’t.

  • Byron

    Granpa, understood all the above, and can even picture in my head the dynamic forces that caused the issues I’ve dealt with in the past. Doc, how many hours are the aircraft subjected to these stresses, vice a ship over a 20 year period? I’ll give you a benchmark: a ship in six months time (reasonable deployment) will spend 30K hours in a fluid medium and constantly under stress.

  • Bill

    Byron;

    You meant 3K..right?

  • Scott B.

    Bill said : “one of those lessons is the incredibly low allowable stress levels that we must design with..and live with..in an aluminum ship structure”

    Excellent post.

    If I may repost some of the comments I made back in June 2009 :

    ——————————————————————
    Another problem with LCS-1 is that interactions between the steel hull and the aluminium superstructure are not without major *challenges*, e.g. :

    1) Aluminium is difficult to join to steel structures (you need to use either explosion bonding or biweldable strips).

    2) Aluminium can lead to galvanic corrosion with steel.

    3) Aluminium has a coefficient of thermal expansion almost double to that of steel, which may cause distortions with temperature variations in service.

    These *challenges* are not just hypothetical : for instance, in 1991, when USS Princeton detonated an acoustic mine under the ship’s quarterdeck (the blast detonating another mine 300 yards off the starboard beam), a 6-inch crack opened in the Princeton’s aluminium superstructure running up one side and down the other, with more than 10% of the superstructure separating from the main deck.

  • Scott B.

    Another repost from June 2009 if I may :

    ******************************************************************

    Aluminum doesn’t burn, except in the form of finely divided powder or flaxe, in which case it will oxidize exothermically, much like other finely divided materials such as iron and titanium.

    However :

    a) aluminum alloys have a low resitance to temperature, with a softening point @ 200°C and a melting point @ 600°C, meaning aluminum structure will suffer structural collapse much faster than steel structures, ceteris paribus.

    b) aluminum alloys exhibit a high thermal conductivity (aluminum conducts heat 2.5 to 9 times faster than steel), meaning that once a fire has taken hold of a compartment, the bulkheads surrounding that compartment will heat faster when made of aluminum (again ceteris paribus), eventually igniting the contents of surrounding compartments by radiant heat.

    And that’s the crux of the matter : once a fire has taken hold, a ship is going to be in a world of hurt, and this is going to happen much faster when the ship is made of aluminum (again ceteris paribus).

  • Byron

    Mea Culpa: six months is 4300 hours…finger-itis. It’s still a lot of hours on a frame, and if you multiply that out 20 years..

  • Bill

    A practical anecdote to Scott’s post about the difficulties associated with the structural fire protection of aluminum: I was involved in a large SWATH build that was driven in to the ground (so to speak) by the weight of the structural fire protection required to achieve the USCG cert for that particular sized vessel..the largest of a series that had yet been produced by the yard involved. With the benfit of hindsight, steel would have been the better (i.e. lighter) choice of construction material in that case. And of course..the vessel suffered later from the usual problems with nuisance cracking of the aluminum structure…aggravated no doubt by the imposition of unplanned additional weight for the structural fire protection.

    I’m certainly not ‘anti aluminum’ across the board and know how to work with that hull material. There have certainly been many a successful yacht, ferry and the occasional naval hull built with aluminum. But the tradeoffs need to be conducted with real-world knowledge..just saying.

  • Byron

    Scott, don’t forget the wonderful affect that high velocity salt air (rushing through various ventilation inlets) has on aluminum.

    And I bet that crack was just aft of the main mast, or just forward of it…

  • doc75

    Scott B., think fire barriers. Bill, yes you have to consider fire barriers. The ones today are pretty light.

    “I’m certainly not ‘anti aluminum’ across the board and know how to work with that hull material. There have certainly been many a successful yacht, ferry and the occasional naval hull built with aluminum. But the tradeoffs need to be conducted with real-world knowledge..just saying.”

    Bill, bingo. Reflexive anti-aluminum talk doesn’t help build ships that are effective or affordable.

  • Byron

    Doc, given what I do for a living, which is ship repair/construction, I will tell you that the life cycle cost for aluminum is much higher than steel. Period. Dot. End of sentence.

  • Bill

    “Bill, bingo. Reflexive anti-aluminum talk doesn’t help build ships that are effective or affordable”

    Reflexive, I’m not. Point of reference only, not trying to puff: I’ve been directly involved in the construction of more than 100 aluminum vessels, high-speed types and/or advanced hull form stuff like SWATH’s and a couple tri’s,.Cats, SES’, monohulls.from 23m LOA to 120m LOA, ..and that does not include the LCACs in the count..which would practically double that number. I personally comissioned over 50 of those…and some LCACs to boot.

    I know a ‘little’ about how aluminum works in practice…just saying. I’m no structural expert, but the hands-on experience with that many vessels has given me a certain perspective, having also built many such in steel and a very large number in composite as well, particularly in Norway and Sweden. Each material clearly has its palce and good use.

  • Byron

    Doc, do you have any idea as to what it costs to work with aluminum? The special restrictions applied by NAVSEA quality assurance? NDT requirments?

    Here we go:

    In the “critical zones” (which are the areas most affected by stress in a ship, the mid-body), these restrictions take affect. In the fitting process, plasma arc is not allowed for cutting purposes with respect to the final cut…which means if you plasma cut (the most efficient means, and also the most common)you have to cut off a further one inch of material…with a saw of some sort. You are not allowed to use any sort of lubricant on the blade, as this will affect the NDT process. There are restrictions on other tools, including the welding processes, the brushes you can use, the methods of contouring and beveling the weld joints. A NAVSEA check point for fit up also has to take place, and the weld joint must be “floated”, with no tack welds in the weld joint. That means a LOT of temporary attachment welds, which by the way also have to have NDT. The weld site has to have weather and wind tight containment. The weld gas must be tested twice a day to insure proper dew point. Once all of this is done, welding can now take place.

    Now the hard part starts. Every inch of every pass must stay completely free of any sort of debris, so there’s a lot of cleaning that goes on during the weld operation. Once the weld process is complete, the weld must then be further contoured so that at no point in the weld joint can any dye penetrant be trapped. If you can imagine the places on the underside where all manner of structural elements are in place, you also have to apply the same weld restrictions. Think LOTS of grinding…lots. And all with tools that are anything but high production. To further add to the welders misery, he has to contend with the existing conditions in the parent metal.

    Now that the weld is ready to present to QA and NAVSEA, the really ugly part starts. Every inch of weld gets dye penetrant tested…every inch. Butt welds (where two plates come together) are also tested with ultrasound to detect interior porosity. No matter how good the welder is, this process has never in my experience passed the first time. There’s always repairs.

    Now steel? The same insert will get a visual inspection and one or two UT shots. Now you know why aluminum is so damn expensive to work with.

  • Bill

    Byron said: “To further add to the welders misery, he has to contend with the existing conditions in the parent metal.”

    And very few ..very, very few..realize what the colloquial term ‘rotten aluminum’ means. The ‘experts’ will tell you there is no such thing. Ive got a fiver on Byron knowing exactly what I mean.

  • Byron

    When you talk about aluminum, keep in your mind that it’s a damn sponge. Most metals are porous, but aluminum is a sponge. Oil, salt, hydraulic fluid, any of the different things you find on a ship will get impregnated into the parent metal.

    Bottom line is that the damn stuff is way more expensive that working with steel…especially when all you can buy is ASTM-B-928 (take a guess how many mills make this material AND will supply a certificate of compliance to the buyer?).

  • Scott B.

    doc75 said : “Scott B., think fire barriers. Bill, yes you have to consider fire barriers. The ones today are pretty light.”

    Approved fire resistant for aluminum deck & bulkhead (N-30 rating) per MIL-STD-X129 (aka Fire Resistance of U.S. Naval Ships) is the FireMaster X607 Marine Blanket.

    Two layers of 1.5 inch each on fire side are required for deck (i.e. total = 3.0 inch), and two layers of 1.5 inch each on both sides are required for bulkhead (i.e. total = 6.0 inch).

    Firemaster X607 blanket, an amorphous alkaline earth
    silicate fibre which is incombustible, does not create smoke nor contribute fuel during a fire has a Melting Point of 1200+° C and density 128kg/m³.

    IOW, to protect 1 m², you need :

    deck : 1 m² x 0.0762 m (i.e. 3 inch) x 128 kg/m³ = 9.75 kg

    bulkhead : 1 m² x 0.1524 m (i.e. 3 inch) x 128 kg/m³ = 19.50 kg

    OTOH, a 1 m² aluminum plate with a thickness of 7.9 mm (5/16″) has a weight of 21 kg.

    The added weight is not as insignificant as you seem to believe.

  • Scott B.

    Now, just to further complicate the issue :

    1) The high thermal conductivity of aluminium means that fire boundary needs to be contained by boundary cooling, otherwise fire will propagate throughout the ship.

    2) Boundary cooling traditionally requires fairly large fire fighting teams, which makes it vulnerable to temporary / permanent loss of personnel.

    3) How is this supposed to work with the skeletic manning currently envisioned on both LCS designs ? Automatic fire suppression ? Mmmhhhh….

  • Byron

    And lets not forget all those pesky wireway MCTs….

  • Scott B.

    Next problem with aluminium is one that, strangely, doesn’t receive as much attention as fire-resistance : aluminum tends to produce splinters when hit.

    Again, the problem is not just hypothetical, as Norman Friedman explained in his description of the USS Worden incident (hit by a Shrike missile off Vietnam in 1972) :

    “Her aluminium superstructure acted to multiply the fragments produced by the missile; every pellet from the missile produced two or more in the superstructure, so that instead of a shield it became a deadly instrument in its own right”

    (Norman Friedman, Modern Warship Design and Development, page 168).

    You could off course somewhat mitigate the problem with anti-fragment materials, but then again, the impact in terms of weight and cost is not insignificant.

  • Scott B.

    Finally, here is another passage from Friedman’s Modern Warship (page 169) which remains remarkably valid up to this day :

    “Writing in 1974, K. Purvis, who had been responsible for all of those ships [i.e. the British postwar frigate program], noted that ‘a visit to the wreck of the Graf Spee in 1940 firmly convinced the author that the risk inherent with aluminium was only justified by its weight saving in minor bulkheads in the superstructure.

    The corrosion and modulus of elasticity problems combined with the complication of construction are so costly that they do not justify the weight saving achieved, which is far less than would be anticipated at first sight if the aluminium is extended to more important structural items’.”

    Ken Purvis, together with Lt Kilroy, did board the wreck of Admiral Graf Spee in 1940, to conduct a survey and remove artefacts.

  • UltimaRatioReg

    Scott B.,

    Great observation. Spall created by a projectile impact on aluminum alloy is very deadly indeed. Much worse than steel. So, it would cut into people, hoses, hydraulics, computers, sensors, all sorts of stuff.

    Pointing again to a possibility of a mission kill with a hit from even light ordnance.

  • Grandpa Bluewater

    Summary:
    Aluminum might be dandy for yachts and maybe even a small ferry.

    A warship? Unsuitable, see above.

  • Grandpa Bluewater

    “aluminum alloys have a low resitance to temperature, with a softening point @ 200°C and a melting point @ 600°C, meaning aluminum structure will suffer structural collapse much faster than steel structures, ceteris paribus.”

    Let’s put that in sailor terms. It means that the all aluminum bulkheads transmit the heat to the ladders, WTD hinges, hatch covers and decks very efficiently, so they “soften” well before the compartment ambient temp reaches 200- 250 degrees. This happens very quickly and relatively far from the site of the fire.
    Decks sag under the weight of equipment resting on it,bulkheads sag and rupture, spilling flammable liquids, ladders lengthen, sag, burn flesh touching them and give way at loads well below the weight of a man. Water tight door hinges sag and give way under the weight of the door and are no longer gas or water tight.
    Flammables touching bulkead or decks flash into fires distant from the original one.

    Deathtrap.

  • Old Guard

    I love Gene Taylor’s “take it or leave” sataement. His concern is getting work into Pascgoula. Then we can small fast ships with the same bad quality work Northrop Grumman is pushing out of all it’s shipyards.

    LCS is the mangled step-child of traditional Navy types trying to design to Adm Cebrowski’s “gun-slinger” concept. The idea was to have a small, fast vessel with modular weapon payload capability. Crewing was to be 5 or less and the key element would be a very high speed escape capsule. Cebrowski even used the “E” word for gun-slinger (expendible), which should have cost about $20M a copy before the warfare modules.

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