Origami steel yacht construction

Discussion in 'Metal Boat Building' started by origamiboats, Nov 30, 2001.

Thread Status:
Not open for further replies.
  1. Ad Hoc
    Joined: Oct 2008
    Posts: 6,751
    Likes: 718, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Again, with respect, you are reading more into this than there is.

    This is no pissing contest, never has been. That conclusion can only be arrived at by those assuming that there is an agenda and an emotive form of attack. There is none. There is no emotion in an engineering statement of fact...only in the minds of those reading it.

    I really do not understand the logic of “pissing contest” when debating engineering facts.

    A claim has been made. This claim is being called into question. It is a simple as that. A purely factual response is required to support said claim. Whether the claim is easy or hard is irrelevant.

    Claim = Proof required

    Unless you support the faith based realm of science and engineering? Every time anyone replies supporting Brent’s ‘claims’ you provide him with a “get out of jail free card”..because he twists and turns and does not answer the question.

    This is all I and others have been doing…but after 40 pages of polemic, on the other thread, still no reply. Because Brent doesn’t reply, you think the claims are not false?

    But, if you wish to support someone making claims without evidence (ie placed on faith/trust only) then you are only fooling yourself. Perhaps then every time you walk into a show room…the salesman sees the big red flashing neon sign above your head…and smiles to himself….Christmas has come early! As you believe what you are told without question?...(surely not?)

    Precisely… proof…not words.

    That is all “we” have been asking for…and still waiting…
  2. MikeJohns
    Joined: Aug 2004
    Posts: 3,192
    Likes: 207, Points: 63, Legacy Rep: 2054
    Location: Australia

    MikeJohns Senior Member

    Leaping from the small reasoned errors to the grand fallacy! The usual diatribe against sensible knowledgeable design. And the rabbit pulled out of the hat is one and only one design and it's yours!

    Ignorance is bliss. But when people who actually know tell you your design is poor and unnecessarily weak your response is to try and rubbish the whole engineering process with Titanic type arguments.

    The Titanic was 100 years ago and I doubt you were privy to the mathematics and what it predicted. Instead you have picked the marketing line of 'unsinkability' and you are hanging your accumen on that !
    In the past you used the space shuttle as 'proof' that marine structural engineering is unreliable !

    Your arguments are very poor Brent.

    Its all about structure and your complete misuderstanding of structural design and analysis.

    You've had some serious deficiencies pointed out and they are not the only ones present in your designs.

    Why is your response is always to post this sort of rubbish rather than discussing the problem properly?

    Yes You've blown my cover. I'm probably Ad Hoc and Apex1 and LyndonJ and Bearflag and Welder-fitter and the queen of Holland....maybe I'm Brent Swain ( bugger ! ).

    I live in Hobart Tasmania Australia (Southern half of the world near New Zealand ....you've been there), Welder fitter lives in BC Canada which is why he knows you and your dealings. It would be a hard act to be both. Don't you think you are being a little paranoid just because we are both called Mike ?

    And you do things to the truth that most mothers would disapprove of. That's clear by now. You also dive into this stinking swamp of BS and distortion whenever the argument gets technical, why is that? Why can't you actually discuss something sensibly without red herrings ? Instead you are as slippery as a frightened eel.

    So would you like to talk structures, were not restricted to transverse frames here we can have a good time.

    What miscomprehension would you like to discuss?
  3. pdwiley
    Joined: Jun 2008
    Posts: 1,002
    Likes: 86, Points: 48, Legacy Rep: 933
    Location: Hobart

    pdwiley Senior Member

    I've got correspondence from both people and this Mike lives 10 minutes from where I do, not in Canada.

    Of course, in the matrix where physics is what Brent says it is, perhaps I'm just another internet sock puppet too.


    On flat bar frames and flexibility, sure, when they're not attached to anything, they flex nicely. So what?

    When Brent's angle iron longitudinals aren't attached to the hull plate, they flex nicely too. So does the hull plate. In fact it still flexes with the longs attached.

    Try flexing the flat bar frames once the longs are even tack welded to them. You can't. The longs on my hull are 32x6 flat bar on 300mm centres from the bearding line. They form very nice curves in their own right and all their floppiness seems to vanish into the matrix.

    Then add the hull plate and weld it only to the longs. Stiffness increases.

    A bit of information from the Yahoo origami group that I found interesting: Brent's displacement calcs for the 36' hull say 17,280 lbs - it's in his book. 2 builders said the hook weight on the crane was near or just over 20,000 lbs. That's a fair sort of variation - 15% over design weight. Could be the amount of stuff the owners/builders put inside of course.

    My Colvin design has 2' more hull length, 6" less beam and the same draft as Brent's bilge keel design. It displaces 15,200 lbs.

    Yet a framed design is always going to be heavier than a Swain origami design, according to Brent.

    2 people like this.
  4. TeddyDiver
    Joined: Dec 2007
    Posts: 2,579
    Likes: 123, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

    You are welcome to take the cabin and wheelhouse in the calculation of stability.. I do.. just make sure they stand submerging without flooding..
  5. Wynand N
    Joined: Oct 2004
    Posts: 1,260
    Likes: 148, Points: 73, Legacy Rep: 1806
    Location: South Africa

    Wynand N Retired Steelboatbuilder

    Shame on you Mike; how can you forget that you are me too :confused:
    1 person likes this.
  6. Tad
    Joined: Mar 2002
    Posts: 2,306
    Likes: 191, Points: 73, Legacy Rep: 2281
    Location: Flattop Islands

    Tad Boat Designer

    Proven how? Transverse framing has been "proven....dead wrong, repeatedly"

    In what way has transverse framing been proven dead wrong? Please give several examples as you state "repeatedly".

    The second part of your statement...... "calculations, which have been proven wrong so many times" .......Which calculations? Please give examples of marine structural calculations currently in use which "have been proven wrong so many times". Please use something other than the sinking of the Titanic or the flight of bees.....

    Apparently your stability calculations consist of making a model and putting it in a pond upside down to see if it turns right side up? If this is so I can understand your ignorance of stability calculations and the work involved in doing a proper study. Sometimes deck structure is included, other times it is not. Not including the deck structure means there is an added safety factor (bump in the GZ curve) up high (as the house immerses).

    But any serious stability study requires a correct VCG, your model does not have that, and you do not have any idea where it might be unless you do an inclining experiment of the actual vessel. You might be surprised to find that some of the boats built to your designs will run out of stability at 80-90 degrees.....
    2 people like this.
  7. welder/fitter
    Joined: Jun 2008
    Posts: 407
    Likes: 32, Points: 0, Legacy Rep: 423
    Location: Vancouver

    welder/fitter Senior Member

    Well, maybe I've misjudged Brent, as no one else on these forums has ever given me the compliment of having Mike Johns' level of knowledge! Maybe because the other members recognize that, where my knowledge of metallurgy ends, Mike's goes on, and on, and on!(Besides, Mike Johns is much more polite than I)

    Despite Brent's assertion, I would suggest that he and Van de Stadt are not the only one's whom have brought innovation to steel boatbuilding in the past 100 years. Rather, Brent's innovation... what is Brent's innovation? Anyway, what about Ted Brewer's radiused hull? What about his "Brewer bite" which is of greatest value when the construction material is steel, as it allows for the benefits of the cutaway keel, skeg hung rudder, etc., while reducing weight?(in exactly that part of a boat where weight can so easily gather). I would expect that there are many other designers and engineers who have brought innovations to steel boatbuilding in the past 100 years. Riveted iron to welded steel? Aluminum & alloyed steel?

    A final note on the Alex's boat saga: Should I attach the e-mail where I offered Alex a $10,000 long term, no interest loan to finish his boat? Should I repost the origami post where I agreed that a bunch of us could give him a hand to finish the steelwork? How about the last advertisement in the Island Trader, where it's advertised for under $15,000(I'd have to dig out the issue to remember the final number, I came across it while in Comox), though this is the $17,000 hull so often mentioned? I've stayed away from Haidan's hull since he asked me to and wish him the best of luck with it. Rather than post photos, video and discussion to show more of Brent's BS on this topic, I look at it as a further distraction from the more pressing issues.

    No, all of this is just more attempts to distract people from focusing on whether or not Brent can answer the question which they ask; "Does the snake oil salesman really know what is in the snake oil?"

    Welcome to the Brent Swain cul de sac! On the road of knowledge of designing and constructing steel sailboats, you have taken a wrong turn - you can't get there(further along the path of knowledge) from here. Feel free to go around in circles, but please keep in mind that everything enters & exits through the same hole. :eek:

    Mike Graham(not Johns)
  8. Brent Swain
    Joined: Mar 2002
    Posts: 951
    Likes: 35, Points: 0, Legacy Rep: -12
    Location: British Columbia

    Brent Swain Member

  9. Brent Swain
    Joined: Mar 2002
    Posts: 951
    Likes: 35, Points: 0, Legacy Rep: -12
    Location: British Columbia

    Brent Swain Member

    A hull and the sea which pounds on it is a far more complex situation than any computer analysis can calculate. Pounding on a Baja lee shore in 8 to 12 foot surf, pounding across 300 yards of Fijian coral , T boning a steel barge at hull speed, pounding on a rocky shore in the med for six days , 30 years of ocean cruising in all conditions without a single structural failure at sea is a far more relevant structural analysis than any computer can do.
    Clive, with the 47 foot origami junk in Europe has asked who he can a contact for the demolition derby challenge in the Med. Does the guy with the epoxy woodie have an email contact I can foreward to Clive?
    Or has he chickened out?
  10. bearflag
    Joined: May 2010
    Posts: 227
    Likes: 17, Points: 0, Legacy Rep: 195
    Location: Thousand Oaks, California

    bearflag Inventor/Fabricator


    Brent, on an unrelated issue. Could you please take a moment and realize you are cutting off the second half of the QUOTE tag, and make reading of your posts very difficult.

    This isn't a criticism, it would just help the forum immensely if you could spend a few moments and get that resolved.


  11. bearflag
    Joined: May 2010
    Posts: 227
    Likes: 17, Points: 0, Legacy Rep: 195
    Location: Thousand Oaks, California

    bearflag Inventor/Fabricator

    Computer analysis, and other engineering methods are a starting position.

    The main benefit of say Finite Element Analysis is that you can see where the actual stresses and their relative magnitudes are. So while these forces aren't exactly like what would be experienced in nature they are fairly predictive. Moreover unlike actual models or full scale structures, you can see where the weak spots are without having to cut apart the whole structure and examine the material for molecular scale deformation or fracturing.

    Computer models are not a panacea, that is sure. But what they do allow us to do is design structures that take advantage of the material properties of that structure in order to maximize its strength, and minimize the weight if that is something you are interested in doing. Say if the analysis indicates a stress beyond the optimum levels at a particular bulkhead you would know you should reinforce that area, or alternatively if the area is unstressed it could be lightened. Incidentally on a boat, reducing weight is one of the best things you can do to increase a structure's strength.

    Of course any FEA engineer worth his paycheck knows that the best computer model can't replace intuition, academics, and experience, but there is no reason it should. When something is properly engineered it is a holistic design that incorporates all the design aspects in a symbiotic best-fit methodology.
  12. Brent Swain
    Joined: Mar 2002
    Posts: 951
    Likes: 35, Points: 0, Legacy Rep: -12
    Location: British Columbia

    Brent Swain Member

    Similarly, at 30 feet the boat may "feel rigid enough" but Brent has no engineering to back it up. At 60 feet though, even the bow to stern flexion is going to star acting more like a rubber hose than a solid pipe without the internal frames to prevent the deformation of the skin (think like a hose starting to crimp where the inside edge bows inward and the sides are forced out).

    Your cabinsides act like huge fore and aft beams on edge, their bottoms held in place by the side decks and the tops by the cabin top. The cabinsides are prevented from getting any closer to the chines by the pipes supporting the mast from the chines and two more similar pipes further aft, along with the mast support web.

    Transverse frames are not a bad thing, nor a good thing, just structurally irrelevant in smaller sailing hulls.
    In larger hulls, it is far better to first pull the hull together then add them later.

    re, you could say... but what if I increased the thickness of the walls. Well unfortunately your weight is going to go up like a fat pig in a pile of slop because the internal volume goes up as the the cube if you assume you maintain the boats proportions). Unfortunately the cross-section only goes up as the square. So if you doubled the length, you would need 4 times the metal to maintain the same dimensions, but you would only have half of the strength.

    There is a point where the law of mechanical simlitude cuts in. The disagreement is where that point is. Small sailing hulls are so grossly over strength that they obviously don't have to be built with the same structure as a tanker, and adding such framing is totally irrelevant, and a waste of time and money, as they will never incure the loads which would make them relevant, given the relatively small amount of weight and inertia we are dealing with..

    You can continue this sort of math ad-nauseam, double the length, keep the same beam, double the metal thickness, and now you lose the dimensional rigidity do to a smaller cross-section. So now you are about half as stiff as you were before bow to stern.

    Half as stiff is still stiffer than anything you can move with a 20 ton hydraulic jack. Any stiffer is irrelevant, and doesn't justify a ten fold increase in money and time.
  13. Ad Hoc
    Joined: Oct 2008
    Posts: 6,751
    Likes: 718, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Exactly, not rocket science.

    And Brent’s reply to the ‘obviously can defend’ simple question is…????

    Do you understand now?
  14. LyndonJ
    Joined: May 2008
    Posts: 295
    Likes: 19, Points: 0, Legacy Rep: 233
    Location: Australia

    LyndonJ Senior Member

    That really is the pot calling the kettle black. BS methods are to bad mouth everyone as much as possible so to avoid actually discussing anything.

    I'm a structural engineer(civil) and an FEA jocky. Only total ignorance could ever lead to the conclusion that a few tall tales from a total tall tale artist can replace the engineering process.

    You have victims not clients. So full of lies it's unbelevable.

    Eg ...you have the hull lines and did proper stab calcs from those sections :rolleyes: but you don't have the lines or the 3d model or the weights and moments. Not even offsets.:rolleyes:

    You are desperate to be viewed as a proper designer but you've backed yourself into a stinking cave/swamp whatever full of BS.

    So you just threw a model in the water and rolled it around without even knowing where the COG was and announced it had 180 deg stability.:rolleyes:

    A dangerous designer totally ignorant of sensible design. Not able to see where you are going wrong and worse..................not wanting to know....ever.........period.
    You'd rather a client came to grief than modify your very poor structure detail. While tellin gthem they are so lucky to have avoided proper designers.

    Suckering people into a big scam based on deceit. Deceit like none of my hulls have ever suffered damage. Then it turns out they have rotated keels ripped welds and started sinking. So then you say it's the revised design that doesn't sink............until the next problem sinks the boat, then you'll revise that and say ..................none of my boats have any problem.:!:

    You said your hulls could be scaled to 60 feet without transverse frames:rolleyes: Ignorance and a total lack of concern for clients. Just a total ego trip in a world of your own.

    Attack everyone by badmouthing them and making even more stupid mistakes. Arguments that work on the mark who's going to lose his $$.

    The deception continues on, you won't even pull socks up when shown you made a total design blunder. (The same design you imply can pass survey).

    Man you are a mess. You've had every dumb argument demolished and now all you have is the anecdotes. And you don't identify the boats the sizes who built them or what framing was in them. And a lot of your boats have transverse frames and better detailing added by builders who know better than you.

  15. LyndonJ
    Joined: May 2008
    Posts: 295
    Likes: 19, Points: 0, Legacy Rep: 233
    Location: Australia

    LyndonJ Senior Member

    The regulatory bods give you the loads, they derive those from both calculation and from statistics from thousands of vessels.

    The rest is easy, stress paths, srength, fatigue are where FEA comes in.
    Brent tells his mark$ that it's all to make profit for builders and cons people into weak designs. He uses 3 or 4 tall tales as his statistical evidence that his engineering is superior.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.
Thread Status:
Not open for further replies.