Transverse frame calculation

Cool down mate, and don´t pee in your pants.

For the sake of keeping this platform out of risks, the worthless sketches have been deleted.

But you will find no judge in Europe to even think about a lawsuit when plans which endanger the life of people at sea, are discussed on a open Forum like this one!
Feel free to try, but be aware it might most probably fall on your feet when safety aspects become part of the drama.

 

But wait, there is more…

You cannot even define what you are trying to say, you confuse yourself, 1st it is a bullet …armour plating perhaps…now, it is resistance to holing. Since unless you are sailing around the Somali waters, this bullet holing rules out 99.99% of the sailing fraternity. What you are trying to say, is bending, as you eluded to this with your reference to lots of framing.

So, since you like lots and lots of numbers to go with your lots and lots of words. Let us examine that premise.

I’ll keep your imperial numbers, but convert them into metric, much easier to calculate. Imperial units are for Americans and old people.

If I take your 3/8th that is 9.525mm, lets say over a 3foot span (91.44cm). So a bit of 3ft by 3/8th inch steel.

What is the equivalent size of Douglas Fir wood?

This is, as I mentioned here:
http://www.boatdesign.net/forums/classification/transverse-frame-calculation-32584-9.html#post368481

is all about equivalent stiffness, EI.

So, we need to find the equivalent stiffness of the 3/8th steel, and according to Brent it is greater than 23inches thick (58.42cm).

So an area of 3/8th steel over 3foot is 87.0966cm. If we keep the width the same, 3ft, what thickness of Douglas Fir is required to be the same? This is the ratio of the Young’s Modulus, thus:

Douglas Fir ~ 10MPa
Steel ~ 208MPa

8709.66 x 208/10 = 1811.61

But to be the same width, what is the thickness?

Thickness = area/width = 1811.61/ 58.42 = 31cm.

Now, in my book 31cm => 12.2inches. So just 12.2inches of Doulas Fir is required to be the same as the steel, is this greater or less than 23 inches, since, you said:

Wrong, again!

Yet again, you do not know what you’re talking about.

 

I have dealt with legal bullies like you a hundred times.

The fact is, you have no case. Legal threats are the last refuge of people who have a poor understanding of the law. If you want to waste a whole pile of money in an international copyright case, be my guest. Hhave an attorney issue Cease and Desist letters... If that doesn't work, feel free to have your attorney file a claim in your local court. Unless you can (in a very unlikely event) get a judge to issue an injunction, and then have the foreign countries issue reciprocal injunctions, you are basically wasting your time... even if you had a case. Which you don't. I am sure the "offending parties" on the board would welcome a challenge.

 

No.

That is according to Archimedes theorem.

And not “SHOULD BE”, they are ALWAYS inline.

How on earth do you know?

What is the weight of the engine that XXX has bough from the scrap heap??

What is the weight of the prop that XXX has bough from the scrap heap??

What is the weight of the extra frames , outfitting, piping etc that XXX has put in their boat because you do not control nor care what they put in??....etc etc.

When you buy cheap, CHEAP = HEAVY!!!!!

In other words, you have no idea where their final LCG and VCG is….gross negligence when peoples lives are at risk!

 

WRONG!

As the designer you tell the client what they can or cannot do to your design. You inform them what are the consequences of changing the design. If the client ignores you and your advice, then that is their fault. And thus, when the bad things happen, you can walk away from a court of law saying I told them so, and have the paper work to prove it and the paper work to demonstrate why I said to the client they should not do it and hence, it is no longer my responsibility and no longer MY DESIGN.

Which also means, you cannot claim ANY credit for any success they may have, since it is no longer YOUR design. You relinquished that role by letting them do what they like.

But you cannot advise, because you have no calculations no supporting evidence to say whether doing XX or YY is better or worse. Thus, you simply don’t care. You just want them to employ you to build it...

Changes affect cost and/or performance. It is grossly negligent to suggest that because it is their project you wash your hands of it. It is their project, to build, but it is YOUR design and YOUR design they are building and THEIR LIVES they are placing in YOUR hands!

 

A good thread if it was not marred by narrow minded snobs and failed commercial vendors going for Brent’s jugular. To discredit someone just because the person is successful, by saying that his design are unsafe, will do nothing to promote other designers or boating but will just scare people away.

Is this a new way of promoting quality work?

I like to see frames like this in a 36 footer.

Sorry, this demonstrates to me that you have no clues at all.
This thread definitely proves that you can always find an expert who disagrees with another expert.
Come on boys pull up your socks, you are a disgrace to your trade.

Brent, keep up the good work, you do more for boating than that bunch of detractors.

Mala

 

The term succesful is quite subjective term and the reason to this whole thread is the question if his designs are safe or not. So far Brent has failed to answer to the questions what lies behind the engineering except "stands hammering" and "can be shot with 306" which are hardly valid in this regard. So the question of the safety of BS origamiboats is still at best questionable..
Everybody seemingly "against" him her would be very happy if he, instead of being so stubborn, would take some advice and pay attention to some of the obvious faults pointed out in this thread.
Like it's said here before he's method would be allmost perfect for a backyard boatbuilder if there weren't some flaws and lacks in the design, drawings and calcs.

 

And who are you? You have been asked several times about your background, but you haven't answered yet!
This demonstrates to me that you have no clue at all!

 

Hubris

I agree, I think i even said it, and then promptly got negative reputation.

I applaud Brent wholeheartedly for what he is trying to do. I even disagree with some others that salvaging is not smart for a home builder, I mean, i am not saying use junk parts, but certainly everything doens't need to be factory new.

Brent's method and attitude (not his personal attitude, but the spirit of self accomplishment) is classic sailor can-do attitude. Has some definite advantages.

I like the idea of using large monolithic plates for simple fairing. The isotropic mechanical properties of steel make it ideally suited for it, above say the Kelsall method (in that GRP is fundamentally anisotropic and so may flex unpredictably.

I like how in his book he has some simple things and diy bits that can really help a sailor who doesn't mind doing the work himself.

But before you think i am scratching his back, and don't dare quote what I said without the caveat.

That is where it ends.

Brent has shown gross ignorance and/or negligence in addressing the fundamental mechanics, engineering and physics problems in his design. None of these issues couldn't be EASILY resolved if he wasn't so vain. Brent's woeful amounts of hubris is preventing him from being a truly top notch boat designer in the economical and home builder market. Instead he puts his own pride ahead of the safety of his customers.

Near everyone on this thread if you actually read it in its entirety have said quite a few good things about brent, amongst the critical bits. They aren't trying to scare him out of business or get his customers. If anything I think they want to see him succeed. But they also don't want to see boat owners loose the money they invested, get hurt, or worse.

Lets be further clear, in case I minced my words. Brents designs as it stands, may have gotten his boats so far. This is a great thing. These boats may even have some great advantages in some scenarios. But it is clear, even at a glance, and even more so upon educated and thorough inspection that his design has critical flaws.

What really pisses me off is that instead of having an academic and professional discussing with Brent, is that it has devolved into people being called liars, libel, slander, and legal threats. How does that serve you Brent?

On this board we have engineers, architects, boat builders, physicists, and others who each are quite skilled regardless of Mala's suggestion that we are all boobs. Brent himself is not unaccomplished. The guy has sailed more and built more boats likely than I ever will.

Brent and Mala, please understand that our criticism is because many of us are experts in our field, we expect that since the designs are out of the orthodoxy, the design should be justified in an empirical manner. To do this requires some rigor. I am not saying one has to be a NE, NA, or mathematician, it sure helps though, but you should be able to bring your design to one and bounce the ideas off of them, and get a good idea of mechanics and forces involved.

When I look at your design, I can see various "hot spots" that scream out to me. These come from my education and experience, others make their own criticisms, however once again you interpret this professional advice as a personal attack to your vanity, which if you were to look at it correctly it is really a professional courtesy.

Your boat design has made a contribution to the development of small steel boats, don't sully it, by failing to heed the advice of your peers. To do so would be a shame, irresponsible, unethical, and possibly criminal.

</rant>

 

Name calling in lieu of valid argument?

There's enough to argue about. Brent's been shown to be completely ignorant on any engineering basics. Pick one, any one of many of the complete misunderstandings he holds and go into bat for him. Not able to? then listen and learn.

Brent endangers both vessels built to his plans and the lives of those on board totally unnecessarily . Because he won't ever admit he's wrong, and he is wrong on just about every structural and material property that he's touched. The list is so long now it's mind boggling anyone can be so dumb in the face of constant education.


Remember Brent brought this on himself, right from the start, he's always been the aggressor, just this time everyone finally got sick of it. He's driven this debate by his replies, and they are not discussions, just the law according to Brent.

It's the emperors new clothes......... Mommy if it has no frames and is poorly designed and the designer has no idea about materials, no lines no weights and moments then how come he says it's it's safer and stronger:?: :?: :?:

As Brent always says "Judge his advice on what it does for the adviser" Brent makes a good income building the boats for clients that are supposed to be so easy to build.

 

While appreciating "keeping this platform out of risks", it's a pity those sketches were withdrawn; they said a lot of the BS nonsense. This discussion is covering a serious safety issue with consequenses for the public, non-professional consumer. With this background, no European court would touch a lawsuit against the publication of them. I would be happy to stand by your side if such a case came up, Apex1.

I have been silently following this thread and I want to express my gratitude to those of you, who have kept meeting the BS bs with engineering facts, in spite of the attitude of the guru. He is putting lives at risk with his complete lack of engineering competence and responsibility. The efforts from our "structural department" here will probably open the eyes for would-be customers so they can avoid charlatans like BS. In the end that will save lives, which will be your reward, Ad Hoc, LyndonJ, Sören, Apex1 and all the rest!!!!

 

I wonder what Jacques is saying to all this?
Remember Jacques? He's the guy who started this thread with a question about the calculation of frames according to ABS and ISO.

 

Going back to the beginning sure is enlightening, I wonder if Brent would stick to this. Knowing what he must know now (but likely wouldn't admit).

 

Well on the subject of posting plans, I dont know all the legal mumbo jumbo on it but it sure don't seem right to me. From what I seen on the ones posted even though the drawings were distorted from the original shape the measurements were still there and readable, enough so to build the hull and transom.
Thanks for pulling them off Richard
Tom

 

No mate, sorry,

there is NO way to build a structure using these sketches. (and there would have been no way to build a boat using the originals as well)...