Realistic scantilings

Rule of Thumb Design

DanishBagger,
It's an odd day when I find myself taking a stance more in support of the Brent than against! But I need to remark about the Origami method and boats at least in passing. My remarks are more about the idea of origami than it's practice by the Brent.

First, these boats are strong and not flexible or flimsy and next their hulls do go together quickly almost regardless of your metal working skills. Not that makes much difference in the time to build a finished yacht.

So:

This idea is not fully founded, its not wrong to be cautious and the Brent isn't very articulate in regards logical discourse so you'd be hard pressed to find out why that statement isn't as accurate as possible.

These boats have an "analyisis and calculation" more in the traditional [wooden] tradesman's/boatbuilder's sense than on paper. The tradesman of old had Rules of Thumb and without bothering to submit them to an engineering examination the Brent has developed his own set of RoT; but only refers to them in obtusely stated arguments which I think cover the value of these lessons learned.

In other words, having studied the Origami method and specfically the Brent's scantlings individually; I find there are good design and structural features that may be covered from other's view and honest examination by the Brent's poorly worded rants about his "metalmessiahship".

The hulls are 3/16" or heavier (as far as I know) and that, for a <40' boat begins to approach the StrongAll method wherein the interior structure is reduced in favor of heavier hull materials. What has not happened (by the Brent as far as he has published) is a formal structural analysis of the boats; BUTTTTTTT!!!

With all that said, there are no instances of hull failure or even fatigue to call to question the method or the particular scantlings - design of framing of the existing hulls. It is embarrassing that the Brent refuses to find a more graceful means of making such a simple point- but there is the full history (perhaps archaic history of marine design) of boatbuilding to support concept that "tried and true" is valuable information.

I am not saying, as does the Brent in any venue he seems to attend, there is no room for improvement, no reason not to analyze or that these designs are the final word in metal marine forms. All I want to point out is that we need to look closely at what is really being built - and not be distracted because one of the builders of this method is rude to a fault.

So, while I can't agree with the bombast and noise that passes for discussion with the Brent, there is validity to building boats that are guided by rules of thumb- especially if you're building the same one over and over.

Am I discounting what MikeJohns has said? Not in the least, in fact I read those posts daily for a week being more informed each time I read. [I'd put MikeJohns in the Dave Gerr category of being an articulate and insightful engineering mind who's turn of phrase has helped me more in a few paragraphs than anything I've read in a decade.]

What I'm saying is that we shouldn't allow some grumbly, inarticulate and argumentative online presence to encourage us to ignore the fact that empirical experimentation as a part of layman's designs is a valid means of evolving a metal boat.

As regards the scantlings of the larger hulls, to my knowledge they are scaled- where a 30' is 3/16" a 50' is 3/8" or something to that effect.

I agree that the egg shell idea will fail if the impact is experienced in such a way as to overcome (as MikeJohns has explained I thought rather elegantly) the combination of local panel rigidity and shape stiffeness. What the Brent seems to miss, or choose to ignore, is that simply because this combination of momentum and collision has not yet resulted in much damage, that is little reason to believe in CANNOT happen.

Finally, back to building method as defining the hull form, the origami method severely limits the shapes of the waterplane and I still hope to hear from a practicing designer their impression of the performance aspects of this legacy form?

Cheers,

 

The Dix 65 ft boat I had built, used 4mm plate across the WHOLE hull with 3mm deck.... This boat was built in 1991 and have sailed ever since across the globe and it shows how light a hull can be with proper scanting rules used wisely. This is the 65 Dix uses in his website.

 

I'm not sure how much we disagree in the following, but I think I have to "expand" a bit.

Nope, it sure doesnt. I'm not saying (I hope not, anyways), that these boats are "flimsy". With the thickness mentioned, it better not be, but more about that later.

Well, the thing is, that in order for a flat panel to have rigidity, you either have to support it, or use a thick enough material to resist the flexing. Later in this post you mention 3/16" steel plate or heavier, which, no matter how you put it, is rather thick (and heavy), all in an effort to resist flexing. You seem to say, that because it's thick, it cannot flex or be fatigued? I think of that as overbuilding, simply because you could use much thinner plates, if you used "old-school methods", yet have at least as good rigidity. To me, that translates into "amateur job" (says the amateur).

I'm not sure I understand the last part in that paragraph. However, with regards to the rules of thumb of boatbuilders of yore: Even "modern" boatbuilders have that. Wood-epoxy boatbuilders have that, as developed from the initial years of trial and error. Scantlings included.

And he never will post such a thing.
With regards to the first part, I'm not sure I quite get what you're saying. As I understand Brents "designs" and the method itself, is that the heavier material is used to GAIN interior space, not the recerse, as you can use much lighter materials, and much less material by supporting the "shell" - especially considering the flat "waterplane" as you guys call it. What's worse about Brent's claims in particular is that he's claiming that there's no problem to build something, say, 60ft. Now, with that flat waterplane, more or less unsupported, you will have to go even thicker to resist the flexing.

The problem is, that even though there has been no failure up until now on his boats, doesn't prove they're seaworthy, and certainly not "close to bulletproof" (he didn't use those words, but that seems to be what he wants to convey.

I, on the other hand, aren't saying the method sucks per definition, I'm saying that the method is limiting in all sorts of manners, and that it's ridiculous to caim this method to be superior to "old school" methods. Speaking of which, I find the primitive way of building, and using extraordinary heavyweight scantlings to overcome poor engineering (or no engineering, in Brent's case) primitive as hell. Much worse than the overbuilding of old-school wooden boatbuilding (yes, that one was for you, Brent, if you're still lurking backstage).

True. I only entered this discussion, because I grew annoyed with Brent's unfounded claims. I especially disliked his claims that his method was superior to anything out there, yet he utterly failed to show how that could possibly be. He only came orth with further - equally unfounded - claims to support the former. I am in no way, form or fashion trying to pass as an expert in these things (I'm not saying you're suggesting that - I just need to emphasise as much)

Yes, there are certainly validity in building by rules of thumbs, but so far, "the Brent" (as you call him consistently, ha ha) has not given any rules of thumbs, nor has he shown the basis for his rules of thumb.

I'm 100 percent with you.

Of course not. The problem is, that in order to develop rules of thumb, you have to have a lot of trial and error and a lot of thinking. Overbuilding by way of just using extremly much material is simply ridiculous in my eyes. Further, I doubt that a true layman (as in completely blank) would be able to build a seaworthy, safe, and lasting vessel without looking up things like scantlings (i.e. rules of thumb other people have derived from trial and error). Besides, in Brent's case, I would like to know things like vanishing stability and so on, since the things are build with such heavy scantlings I fear the worst, frankly.

Yes, in order to resist flex/lack of rigidity. The problem is, that by using flat panels over such a length, the panel _wants_ to flex.

Exactly. I have to make the point at this stage, that by his own argumentation, apparently my pseudo-sandbagger must be stronger and more seaworthy than his steel boats

Me too.

Ta (trying to sound british, lol).

 

Brent Swain

Tom McNaughton of the yacht design school is an enginer with a good grasp of marine engineering too. I noted that he wrote a fairly damming critique of your design justification. I'd be interested in your reply to this. Which I pulled of another website. I know a lot of people here who have considered your designs have been put off by these sorts of comments.

Thanks


Quote Tom MacNaughton

Periodically someone will just decide that the transverse framing is "not necessary. They always come up with great sounding verbal rationalizations but have never actually done the math.
The amount of weight you can save by tailoring construction to save the absolute maximum in weight, including custom spacing the transverse frames and other transverse members is so minimal and the mathematics necessary to properly predict where you can reduce transverse framing is so complex that I am certain that no one advocating the elimination of transverse framing has actually done the math.

They are just building cheap, weaker boats.

One North American advocate [Brent Swain] has written a book which he told me "proved" his case, yet on buying his book I found there was no real structural analysis in it and the one piece of math in the book which applied to reducing framing was wrong.

There have been recent attempts to reinvent the construction method. Any reduction of the scantlings simply produce a boat less strong than the other methods. Naturally a rationale for this cannot be put in engineering terms. There it would evaporate.

The overall rigidity of the boat is largely dependent upon the framing. This leads into another argument. This one says that you can eliminate the framing by increasing the thickness of the shell plating. While this would, in theory, and viewed in isolation be true. It does not really work out because stiffness usually comes from thin deep frame members with high section modulus for their weight. Thickening a thin relatively heavy plate to provide the lost strength from removing the frames is very inefficient. The net result is that if you eliminate framing you about double the weight of the hull shell.

In an actual calculation comparing a normal hull framed both longitudinally and transversely with one that eliminated the framing the increase in weight of the metal structure of the vessel was 96%. Even disregarding the consequences for plate forming operations and welding operations of going to thicker plate, it should be easy to see that the large weight penalty is not acceptable because the performance of the boat will suffer terribly.
Do we really believe that these people are making the shell plating as thick as necessary to gain back the strength lost by eliminating the framing, given this weight penalty? I think it highly unlikely in view of their claim that they can reduce costs. Therefore should a metal boat be promoted as “frameless” you can essentially say that something is wrong.

A North American advocate [Brent Swain] has written a book which in one place compares the stiffness increase obtainable by using a thicker plate versus a thinner using an erroneous prediction of the relationship of thickness to stiffness. Presumably his entire system advocating reduced framing is justified by basing it on this erroneous calculation. There appears to be another interesting reason for this intense desire to justify reduced framing. We have noticed that all the structural members whose removal is advocated are the ones whose shapes are difficult to predict if you do not understand how to design the vessel with developed surfaces and produce patterns and plate expansions graphically such that every piece of the boat can be precut and can be set up and welded into a predictable shape.

Instead of this fully predictive system these boats seem to start out as scale hull plate patterns created by trial and error by cutting shapes and “folding” them until a shape is derived which looks good. Then the full sized patterns for the plates are scaled up for various sized vessels. However this trial and error system leaves no way to predict the shapes of transverse frames, watertight bulkheads, floor timbers that follow the shape of the hull and keel, etc. Interestingly enough it is these same members whose shape cannot be predicted using these methods that suddenly are declared “unnecessary”. At best this seems an exercise in self-delusion.
One final argument made for “reduced framing” is that if boats are composed of curved surfaces and that curved surfaces are stiffer and therefore don’t need framing. Let’s get real, even to figure the deflection on a simple curved beam of constant radius gets you into calculus. When you get into anything as complex as a boat hull with varying curvature in all directions, not to mention chines, deck edges, varying loads from ballast keels, large engines or rigs, the math pretty much goes off the charts. I just simply don’t believe that the folks I’ve seen advocating this as a reason to reduce framing have done these calculations.
Even with today’s computers and some pretty fancy and expensive software achieving any significant weight savings given the normal complexities of hull shape is quite unlikely even without considering some of the other factors which tend to make it difficult to save weight in real world hulls. Among these are the fact that without frames to stiffen the structures all the stress simply runs to stress concentration points where the hull may be reversing direction of curvature, be flat for hydrodynamic reasons, have some sort of chine or other corner around which the stress will not carry without some support.
Given all this the prediction of stress levels to sufficient accuracy in any given area to allow the reduction of scantlings on the basic of curvature becomes unrewarding and in practice is never done. My experience is that the people asserting that they can make such scantlings reductions, although speaking with great confidence and often with much disparagement of those who question them have not in fact done the analysis necessary to develop rational scantlings and are in fact just deciding to believe what they want to believe. One common characteristic of these promotions seems to be little or no space devoted to any real structural analysis of the relationships between methods. There seems to be a lot of space devoted to circular arguments saying that no proof is needed because only very stupid people living in the past could possibly not see the superiority of this new method. The evidence that these people are stupid is that they ask for the proof! These are “religious” arguments in that we are asked to “have faith” and those who doubt are castigated as lacking in the vision of the “true believer”. You will find us always on the side of “doubt” rather than faith.
We are always worried that we have made a mistake, have failed to see a possible failure mode, are using a model that is not as predictive as it might be possible to construct, etc. The “true believer” is unencumbered by doubt and therefore need never check for mistakes, worry about failure of imagination, etc.
We don’t buy into this and you shouldn’t either. In conclusion, do not be distracted from the lessons of real structural analysis by the promotional materials of these companies.

This is simply another repetition of the mistakes that builders have made over and over. I would suggest remembering an old principle of design: If structural analysis says a boat is strong enough it may be wrong, but if structural analysis says a boat isn’t strong enough it is probably correct.

End quote (Tom MacNaughton YDS)

 

Thank you Lyndon. Great find!

I couldn't help but laugh when I came to the part where he (too) were getting religious associations with regards to Brent's circular arguments.

 

Thanks guys
excellent reading:idea:

 

Flat surfaces? What flat surfaces? There are no flat surfaces on an origami sailing hull. This is where your mathematical theories fail ,as they are all based on flat surfaces. I've mentioned this many time in this debate.Re- read this until it sinks in.
Brent

 

A very large radius is in layman terms an "almost flat" surface. Instead of us continueing to reread your nonsense, how about you backed said nonsense up with real analysis, numbers and fact, and did the exact same with everything you say is crap. Up until now, you haven't even been able to provide anything asked.

Hell, you haven't even been able to put forth even a somewhat coherent argument in a discussion with an idjit like me. I mean, I expect someone who sells boatplans for "real" boats (as oppose to small dinghies) to have done at least _some_ homework, but you, you haven't even seen the books.

Now you try with your shift of focus, by pretending that all our arguments are flawed, since it's not entirely flat, the surfaces we speak of - In reality making yet another strawman argument, where you pretend that our arguments were solely based on that. Which, as in any strawman aren't even close to the truth.

Could you please pull yourself together and provide at least a few of the numbers of which we ask? Where are the calculations? Where is the analysis? And no, I'm not buying your book, since I have no intention of aiding in the financing of projects like yours.

 

Following Brent's lame and disappointing reply to the comments of Tom MacNaughton I think DanishBagger has basically said it. It's all starting to sound like a load of BS.

Structural engineering known only to Brent, a massive number of completed boats known only to Brent , Numerous collisions scrapes storms and reef encounters known only to Brent. Dished up with circular arguments and some very dubious financial reasoning.

It’s just a faith system justified by ‘The book’ sound familiar?
You believe it or not because there are never real facts there’s just the book and the Prophet .

The Prophet appears to be concerned about giving away too much information because he may well damn himself. Like Kmorin having to say that the longs are welded to the plate before it is pulled into position and hence the compression argument , but Brent appears to have wanted to keep that as an argument in reserve, to get money from people . If they had heard the engineers comments he could then say….“well in fact they don’t know that we actually put the longs into compression” but once this knowledge is out the engineers say that is not significant and he loses another magic bullet for slaying engineers. This curved surface argument is just his last grip on any anyone taking his arguments seriously but it has been shown to be mostly baloney. Starts to sound feeble in the face of the knowledge here.

I think he should now either post the full details and slug it out with the engineers or accept that his bigger designs may be VERY WEAK for their size, Any other approach now stinks of dishonesty.

Tom bought the book and found that the only structural analysis in it was simply wrong. I accept Tom’s professional educated view on this over Brent’s assertions. But it is apparent that Brent can only appeal to the ignorant with his arguments. There is very little he says in justification that anyone agrees with.

A broker friend in Seattle thinks that Brent's numbers are a great beat-up. He reckons Brent's '200 boats' is a great exaggeration for finished vessels. He says from the Canadian mandatory Pleasure Craft registry details he would estimate a fraction of the number of finished boats in Canada. With perhaps a hand-full in the US and perhaps one or two overseas. Brent could counter this with some real details.

I would also like to know which vessels collided with all those icebergs reefs and hurricanes unscathed??? Which design since this is very significant and please what was the vessel name ? Otherwise this sounds like more marketing BS and maybe some of the un-built ones on journeys yet to happen ?

All this sounds a little unfair. I think its justified considering that so much praise of these boats comes from the person who makes money from them. This guy also is not shy in being rude about other designers and professionals .

Would I advise anyone to build one of his designs……. I’d take the study plans, scantlings, numbers, stability curves and ratios to a consulting NA/ME and ask them what they thought for a couple of hundred dollars. Or send them to Tom MacNaughton and ask him make it a class effort at the YDS.

If Brent will not provide this info then I’d run not walk to someone with a more honest approach and more knowledge like Mr Wynand.

 

scantlings

Winston Bushnell did the northwest passage in a 26 ft origami boat to my design. BC artist Godfrey Stephens T-boned a steel barge doing hull speed, a log boom doing 14 knots and spent 16 days pounding in 8 ft surf on the west coast of Baja , all with no serious dammage. BC architect Cesar Caflish was aboard when he T-boned the barge, Norman Abbey helped get him of the Baja beack.Don Shore pounded across 300 yards of Fijian coral reef , with no dammage, as boatyard owners in Suva will attest to, and collided with a freighter in Gibralter with no serious dammage, as Gibralter boatyard owners will attest to. Don's book "Arround the World on Viski" is for sale at Harbour Chandlers in Nanaimo, as are books on Winston's northwest passage . So don't take my word for it, read what others have written.
It's been suggested here that such experiences don't consitute as good an analysis as someone, sitting on their ***, with zero experience , doing some calculations on a computer ,and when the two dissagree , the computer outweighs real experience. ********!!
Until recently, the most advanced mathematical calculations stated clearly that it is absolutely impossible for a bee to fly. It's a good thing no one told the bees. I'm sure ,according to all modern aero dynamic theories , all bees in the world would have instantly fallen to the ground and stayed there until the math declared it possible. Surely the bees couldn't have been right and the mathematicians wrong!
McNaughton was an interesting case . I've been told he tells all his students "Don't read Brent's book." Nothing I could ever say could sell more books that that. If he is trying to discourage people from buying my book, by saying things like that , then his judgement, and intelligence are very questionable.
In so far as what I've been doing makes much of his form of knowledge largely irrellevant , and less sellable , it's understandable that he would try to discourage the growth of a form of boatbuilding that threatens to make him irrelevant. It's hard to charge high fees for teaching something that is really quite simple. The more complicated you can make it , the more money you get paid to teach it. Just another boat design version of a livery stable owner at the dawn of the automobile ?
This reminds me of a story about a substitute teacher in New York teaching kids how to tell the time in Spanish. The principle dragged him down to his office and gave him ****, saying "You just blew our entire curiculum for the entire month in one hour." He was supposed to make it last a month.
I suggest that you read Hereshoffs book "The Common Sense of Yacht Design" in which he talks of exhibitionists who try to make things appear a lot more complicated that they really are in order to put themselves and their knowledge on a pedestal. This is what motivates captain Bligh skippers with young female crew.
Any one who has worked with steel will have seen clearly how putting a curve in a piece of plate increases it's stiffness exponentially.Even a slight curve makes it a totally different animal from a flat plate, especialy when this curve is supported by angle longitudinals under compression. The bow and stern of an origami boat are far more than slight curves. I couldn't crank it back with a 12 ton hydraulic jack. So which is more accurate , the jack or your theories? Sure bees can't fly!
If one spends foolishly , it is entirely possible to spend so much on a boat that the hull consitutute 5 % or less of the total. If one uses a bit of resourcefullness, the percentage of the total that the hull represents becomes a much bigger portion of the total. We are awash in used marine grear that is as functional as the day it was new. A new sail for my boat that costs $2500 , costs around $350 used, in almost new condition. Blocks that cost $40 each take a few minutes to build and under $1 worth of materials, and the homemade ones are better blocks. The 540 gallon per day watermaker I describe in my book costs under$1,000 but costs over $10,000 new from west marine. My arco 40 sheet winches cost me $150 each at a dock sale , yet are as functional as new ones at many times that price. Etc Etc.
My hull and decks worked out to 65% of the cost of getting sailing.
The 5% figure assumes that one is abysmally foolish enough to buy everything brand new at retail prices. Such an assumption is an insult to most amateur boatbuilders I know.
When amateur boatbuilders ,who had been using traditional methods, first saw the Origami Boatbuilding video, they said" Man I'll never build another frame."
I couldn't get the ballasted models for my boats to stay inverted, even in flat calm water. The air captured in the wheelhouse of my boat consitututes as much righting moment as adding 3500 lbs to the keel. They have positive righting moment to well beyond 170 degrees.
It is well known what causes ultimate stability problems . Excessive beam and flat decks. My boats have neither.
Take a beachball and give it 5% ballast on one side and it has perfect righting moment. Take a raft and give it 70% ballast ratio and, when inverted it will stay inverted. Thus the more a boat's midship section resembles the beachball.( High cambered cabin top, trunk cabin instead of flush decks , wheelhouse ,avoiding excess beam) the better it's ultimate stability. The more it resembles a raft ( flat flush decks , excesive beam etc) the less it's ultimate stability. It doesn't take a rocket scientist to figure that out.( Oops I just put a bunch more mathematical snake oil salesmen out of work)
Brent

 

Brent Swain origami boats

Brent

Apart from all the innuendo contempt and rudeness you are prone to a model of argument which could be called leaping to the grand fallacy from the smaller reasoned errors.

It appears that you have a penchant for twisting information past the point of dishonesty to prop up this ad-hoc faith based approach to boat design.

Your distrust of engineers, calculations and computer models makes it very hard to convince you of anything. Your arguments are skewed towards an almost lunatic fringe approach which denies any reasonable discourse.

All this is a huge shame because you had a relatively novel approach to a niche market producing smaller boats that work. By scaling your designs up to 55 feet you are in dangerous territory.
Are you even aware that vessel loads do not scale linearly with size ? Do you know how they scale? There's a teeny little bit of math in this.


Lets look at your embellished Bumble bee logic for dismissing established and verified analysis.

This argument is baloney, it often surfaces when people have a conflict with scientific or technology. The irony of this beat-up is that in reality it completely vindicated aerodynamic analysis.

At an aerodynamics conference decades ago an academic presented a paper showing that the presumed wing beat of a Bumble bee would produce more drag than lift in other words it wouldn’t be able to fly. His humorous tongue in check conclusion was a throw-away line that “Apparently bees can’t fly”. The real message was that the biologist’s presumptions were incorrect.
Prompted by this very shortly afterwards, using high speed video frame technology and detailed dissection of musculature and joints biologists showed that the insect beats and feathers its wings in an elliptical pattern not up and down and showed where the main power stroke occurred and estimated the muscle power available.
The aerodynamics study was then reworked and fitted the model very well, if I remember correctly it also showed that the Bumble bee would be unable to hover and requires foreword movement for stable flight both of which fit the observations for this animal.

The initial newspaper beat-up from a bored designated ‘science’ reporter covering the conference material ran the story “Science proves that bees can’t fly” completely misrepresenting the issue as newspapers tend to do.
This appealed to fundamentalist religious groups at odds with science who took up this argument with vigor. It has passed into urban mythology to be repeated ad nauseum by people who really should know better. Like much urban myth it proves to continually rise from the ashes.

The final follow-up mathematical model was a triumph being very accurate and predictive; unfortunately being a scientific study without a media grabbing headline it never made the news except for the synopsis in science and engineering journals.

The myth is often used as a justification for the dismissal of any science that is inconveniently in conflict with some personally held belief system.

End Bumble bees.



Also I’m looking for arguments that you can relate to, Consider this:

We have been building curved steel hulls for over 100 years now, the stock flat plating is often pulled into the frame and fixed in a stressed condition. (As we did for timber planking. ) Similarly for flat bar longitudinals they are usually pulled in and allowed to self fair under their own developed stresses as they ‘flow’ around the transverse frames . The sum total is not so different to your methods and yet other boats are fully formed (no fixed in stress) and there is no noticeable difference in durability or stiffness for either method .

 

The arguement seems to be that a fibreglass boat that meets all the rules and can't stand 16 days pounding in 8 ft surf is strong enough, yet a steel boat that can is not strong enough.
Ran out of time again.1 minute left .
Brent

 

What a load of crap. Noone is arguing that. Did you really think that strawman argument would fly (or float, as it were)?

Edit: Oh and this time, please try reading (and understand), what people are saying. If we were saying what you're suggesting, we'd have written that.
There's a reason several people have dissected your argumentation - and it sure as hell isn't about proving a GRP boat is stronger. What a load of milly's willy.

 

realistic scantlings

Yes there is an upper limit on how big you can go without transverse frames, but frameles 57 footers have been built and cruised enough miles year round on the north coast of BC , in all weathers ,to go around the world, proving their structural reliabilty beyond any reasonable doubt. You suggest that pounding on a lee shore in 8 ft swells, pounding across 300 yards of Fijian coral reef , surviving hurricane force winds, colliding with a freighter, and a quarter century of successful cruising with no structural failures , etc is not a structural analysis? ********! Now that is self delusion!
Don Shore wrote a book called "Around the world in Viski, " an excellent book and a hard one to put down.I can highly recommend it. It's available at Harbour Chandlery in Nanaimo. He did a circumnavigation in one of my 36 footers. His son was aboard when he pounded across the Fijian Coral reef. He had family members join him at various points in his circumnavigation. You claim that he is a liar and that all the people who joined him are liars, or self delusional and only imagined it? You claim that the tug boat operators in Suva who pulled him off and told him that had the boat been anything else, including aluminium, it would have broken up quicky, are all liars, or only imagined it?
When Winston Bushnell did his single season passage thru the Northwest Passage on Dove 3 , he had two crew members aboard , Len Sherman, and George Hone who works for West Marine in Nanaimo. Both George and Len wrote books about the trip. You suggest that they are liars ,or only imagined the trip? You suggest that the coastguard members they met along the way are either liars, or only imagined that they met them? You suggest that the people in Pond Inlet who looked after the boat were all liars , or only imagined it? When Mungo spent 16 days aground on the west coast of Baja , pounding in 8 ft surf,and was winched off thru 8 ft surf, with no major damage , you suggest the skipper, Godfrey Stephens was lying ,as was Norman Abbey and Rudy Butula, who helped winch the boat off the beach,or that they were all delusional and only imagined it? You suggest that Patrick Cameron, who delivered the boat back to BC was a liar , or delusional and only imagined it? You suggest that Bill Mottershead on Roan , who encountered Hurricane force winds while returning to BC from Hawaii a couple of years ago was a liar, or only imagined it?
No vessel in Canada under 20 tons or 10 hp requires any documentation, and none under 20 tons requires registry. Registry was once simple and thus common, but recently the bureaucratic personal empire builders have made it so complex that fewer and fewer pleasure boaters bother with it.
I've sent plans all over the world , from Malaysia to Hungary to Argentina, etc etc. Now that the Spanish version of my book is out, more will be built in Spanish speaking countries ( and Portugese, etc) .
You suggest that Canadian federal registry is mandatory for all boats built in both Canada and around the world? You suggest that any boats built anywhere in the world to my designs which are not on the Canadian registry don't exist?
You have a serious credibility problem, and appear to be in need of phsychiatric help.
There is still the option of building bigger vessels using origami techniques , then putting in whatever interior structural members it takes to make you feel comfortable , saving huge amounts of time and avoiding much potential distortion in the proccess.
Any existing design for a hard chine or radiused boat can be built using origami methods, so it is no more limiting as to shape than any hard chine or radiused chine construction. I hear no one here complaining about the shape limits of their construction.
I have never suggested that the proccess can't be improved . Improvements that I couldn't imagine 20 boats ago seem so obvious now. That will continue to happen. It is an admission that you have lost the arguement when you have to put words in someones mouth in order to have something to argue against.
What others seem to suggest here is that methods derived 50 years ago cannot possibly be improved upon.
The math shows that the best approach ,according to mathematical theory, is the thinest possible plate with the maximum amount of framing. The math doesn't take into account the much lower forgiveness of thinner plate when it comes to distortion ,corrosion, etc. It assumes an even pressure on the hull, not the point loading of a sharp rock, in which case thicker pating is the only defense, and transverse framing with lighter plate reduces the chances of survival and resistance to holing drastically, unless the sharp rock only hits directly on a frame and not next to it. Now that is self delusion.
With a material that has the same strength in all directions, and as high as 60,000 psi, any amount of curve drastically increases the rigidity.
To make it simple , go to a locker, take out a rectangular tupperware container. Take the lid off and twist it. It twists easily. Put the lid on and twist it again. Not so easy. Transverse frames would make little difference, far less than the lid. This becomes crystal clear in an steel hull. Try twist an origami or framed hull without the decks on. The degree of floppyness is the same , frames or no frames. Put the decks on and it becomes as stiff as a brick, frames or no frames. Try to twist the hull with the decks on ,with a hydralic jack on a post. You can't do it , frames or no frames. This completely proves the fallacy in McNaughton's theory about frames providing overall structural stiffness. So how much more of his bull do you still believe? It's possible to be quite naive until you have built a steel boat or two with your own hands.
My boats have outsailed Benteaus , Coopers etc, proving that they suffer no performance disadvantage. Their passage times have been as good as ,or better than most other cruising boats.
How does the ocean know when a boat of a given weight has 4,000 lbs in framing , like a steel tahiti ketch, or the same weight in plating , and no framing, before knowing how much resistance to put up?
Friends cruising the BC coast have told me . "Geeze Brent , it seems like almost every anchorage I go to has one or more of your boats in it. They seem to out number other steel boats by about three to one." I've yet to see or hear of a McNaughton boat being seen here or anywhere else. I think the ease of construction , the cost saved, the fairness of the hull and their unblemished reputation for strength and reliability have a lot to do with it. If that were not the case , there would be far fewer of them.
I don't see McNaughton giving the figures for their designs here, nor Mike giving the figures for his designs. How many of his steel boat designs had McNaughton himself sailed across oceans, or built with is own hands, or maintained for over ten years. You learn a lot when you do, knowledge you could never gain doing calculations while sitting at a computer without getting your hands dirty.( I've cruised 11 months a year since 1976 and crossed the Pacific singlehanded 9 times in my boats, and built with my own hands over 3 dozen, all for happy cruisers, most of whom wouldn't want any other design.) You don't learn much about steel without getting your hands dirty.
I give my clients all the structural materials list , detail materials list , loftings, rig, mast details, interior tankage , self steering, inside steering , etc . everything that matters, then answer their few remaining questions by email.
Where has the "50 years out of date "steel boatbuilding methods got cruisers? Deeply in debt, and taking years to do what I enable them to accomplish in a few days, with far more distortion , maintenance problems and bondo work.
There are few more effective ways to make a total fool out of oneself that to proclaim that that which as worked well for over a quarter century and endured many extreme torture tests, and tens of thousands of miles of ocean cruising in all conditions,"Won't work"
I can imagine fewer more foolish comments than to claim that a boat that has endured pounding on lee shores in huge surf for 16 days , a pounding across 300 yards of coral reef in huge swells , a collision with a freighter and a passage thru the NW passage ,etc etc , is "not strong enough."
For every one cruiser who believes the mathematical snake oil salesmen, there are about a dozen who see the sheer folly of their arguements and decide that the" Be reasonable and do it the hard way " advocates are a millstone around their necks in achieving their dream of going cruising in a sound , seaworthy metal boat, without too much of lifes limited time slipping away. They leave the more gullible to toil on the treadmill , following the self serving advice to " Do it in a way that fills my pockets first" , while they get their asses out cruising, quickly , affordably and safely.If you want advice on how to get out on the cruising grounds quickly , cheaply and safely, and be able to stay cruising and off the treadmill for decades, get your advice from someone who has accomplished that, not from someone who hasn't.
Colvin estimates the time for a hull and deck construction at 1,000 hours, a job I tack together in 100 hours. My origami 36 has 1/7th the amount of chine cutting , and welding that there is in a Van de Stadt design. The total welding time on a 36, to painting ,is 350 hours.
Tanton yachts and Graeme Shanon are both designing in Origami now. Strongall boats are still going strong, and are well proven, as are frameles boats designed by Roberts over the last few decades( or do you also claim that they and their owners are lying or imagining it?)
If I were trying to fill my pockets, I'd be charging a lot more that $350 for a set of plans for a 36, or a lot more than $20 for my book. What I am trying to do is debunk the elitist myth that in order to enjoy the cruising life, you have to spend many years on the treadmill , paying snake oil salesment for the latest trend in boat technology( often recycled from decades past) or you will sink for sure. It's sad to see people who belong in the cruising life discouraged by the demands of snake oil salesment convincing them that they need far more money than they have, before they can go cruising. The number of boats built quickly and affordably to my designs , often by people who could never have afforded to go cruising had they followed the advice of the self serving snake oil salesment, who try convince them that the most convoluted, expensive and time consuming way is the only one available, suggest that I have been successful. Their cruising yarns are a constant reward, long after the money has been spent. Besides, while I am living aboard full time, more money than It takes to live and cruise is quite irellevant to me anyway. Getting them free and off the treadmill gives me a far greater sense of accomplishment than money in the bank and the numbers on some banker's computer.
Many of my responses to your questions have had a habit of being mysteriously deleted till now. Hope these make it.
Brent

 

But but but....stammering

This is all very emotional and a very impassioned
.
But I think the issue was that your small boats are probably compliant with the scantling rules anyway. So all they are doing is saying the rules are ok.

The next serious point made was that you cannot scale the structure a 30 footer to 55 working on a linear relationship. You might sail around the world fine then get dumped on by a giant wave one day and find your boat implodes. The main loads for a boat design are operational loads and pressure heads not grounding loads. This point was made before to you.

A good expose of your arguments...a bit like your continual slamming of fibreglass light weight performance boats, but there are millions of them out there sailing around the coasts and oceans without problems but .001% of them fall apart or their keels fall off. But they get washed across reefs and get pounded on lee shore beaches too.
The argument is as Danish keeps pointing out so frustratedly a load of cobblers. You can pound on a lee shore for a week and still be OK but the sistership disappears without trace in a big storm. This is where the rules are at. This is what you seem to be blissfully unaware of in your phobia of the NA's analyzing your designs.

Why on earth don't you come clean from the start and have a meaningfull dialogue with them ? Your attitude seems very suspect. I wouldn't trust you with my life with your attitude problem... but I would trust them.

You would make a good newspaperman you beat everthing up into a fantastical story that sounds good but means nothing. The credibility problem is plain to see fo anyone reading these posts. You'd be much more wholesome if you could be more open and honest.