Transverse frame calculation

That is indeed a load of BS!

Designing a structure that is able to withstand running aground at hullspeed isn't the hardest thing to do. How come such an expert like you who seems to know more about materials and structure than anybody else couldn't do it?

 

This has been a rather interesting read to a complete novice. I own a 46' steel yacht hard chine with lots of frames (traditional Dutch build). I do feel I could drive this right through most of the French plastic in my home port no problems.

Brent's view seems intuitively sensible, whilst I cannot really adequately assess the veracity of the engineering claims.

At this stage (page 17 of one of many debates on origami/frames) the discussion has declined to the "BS this BS that" level.

As a scientist, I know there's reasonable proof for certain things, and I see no need to call BS when I'm discussing the existence of HIV with some conspiracy theorist. Seeing the local engineering faction getting so worked up about this seems revealing - if there was mathematical proof you could just move on.

I think we all agree that - frames or no frames - Gringo would not have survived if made of plastic or wood, any steel design is inherently stronger. Indeed a lot of the traditionalists on here seem to agree that frameless build is perfectly fine up to a certain size, bringing about huge efficiency gains. So the argument seems to be about the relative merit of frames in potentially making a strong steel hull stronger, or the necessity thereof from a certain size upwards?

Since both Brent's method of arguing from experience (anecdotes only go ever so far) and the engineer's traditional models seem to fall short here (I only see computer graphics of frames, none of compressed steel shapes), there must be some physical testing to scale that could be done to establish once and for all whether curved steel under tension (compression?) or framed steel is stronger.

I wouldn't put up my boat against one of Brent's designs by the way (I've only got one, and he might be right ).

 

Hereschoff, after doing all the calculations, often did tests to destruction, as the final word in the breaking strength of boats and their components, and to check the accuracy of his calculations. This is often done where extreme reliability is required, destructive tests being the ultimate definition of reliability, far beyond simple calculations.
Herreschoff also points out the difference between practical people and "Exhibitionists" who's motivation is to impress you with their numbers and show off and confuse you into reverence, rather than inform. If I find the quote, I'll post it here.
It may be in "The Common Sense of Yacht Design " or Sensible Cruising designs"
Convincing people of the need to pay huge sums of money for shop time to do totally irrelevant things, is the biggest scam in boat building and the main reason so many boat building and cruising plans fail.
There would be little difference in the outcome of a demolition derby between a framed steel boat and an origami boat , unless the framed boat has lighter plating to make up for the weight of frames, which is commonly done. Then the framed boat would be far more likely to be holed.
The claim that 16mm plate without frames is no stronger nor more resistant to holing than a 3.2mmm hull with frames ,is totally ludicrous.
Claiming weld cracks are 'Inevitable" is total ********.
There are 100 times as many people in my clientele, who don't have super deep pockets, as there are in the elitist camp. If I clutter up the anchorages of the 'bourgeois" with working stiffs who actually get their hands dirty building affordable boats , and actually do an honest days work,then that is something I'm proud of. I don't believe cruising should be the exclusive domain of the rich, and I'm proud of having enabled many to enjoy the cruising dream quickly and affordably ,by drastically simplifying the building process, and improving the results.

 

Please state where I, or Mike or Lydon have said this?

Again, ignoring the voluminous amount of evidence to the contrary (not just form that which I have already posted). But this “accepted” evidence is from Professional Institutions world wide and working professionals and those who adhere to correct procedures and standards. Clearly you do not.

For those that wish to look past the smoke and daggers put up by Brent and learn about welding and what can occur when procedures and standards are not followed, I refer you to the TWI circular attached. Entitled, “why do welds crack”.

“…Fabrication cracks in welded joints in either the weld metal or the heat affected zone of the parent plate can occur during welding, or occasionally up to several days or longer after welding has been completed. This type of cracking is associated directly with the welding procedure and is quite distinct from service cracks such as fatigue or brittle fracture which may occur at any time during the life of a structure if conditions are appropriate…”

How many of your welds are X-rayed…and are they examined against existing known standards of compliance?

Hmmm…let me see:

Yes, I see what you mean….quoting numbers does tend to blind people into thinking you know what you’re talking about.

OK, since you are the expert (with your own hull/designs), can you please provide the following:

1) Structure:
Total structure all the raw material cost to build. Total amount of man hours to build the structure.

2) Machinery
Total cost of all the mechanical equipment. Total amount of man hours spent installing all this equipment.

3) Electrical
Total costs of all the electrical equipment onboard, gennys, wiring etc. Total amount of hours spent installing all this equipment.

4) Communications
Total cost of all the Radios, lights etc. Total amount of hours spent installing all this equipment.

5) Auxiliary Systems
Total cost of all the piping, and systems on board. Total amount of hours spent installing all this equipment.

6) Outfitting.
Total cost of all the outfitting, such as: seats, bunks, anchors, mast, sails etc. Total amount of hours spent installing all this equipment.

Once you have provided this, since a boat is more than just bits of pulled together steel, it has to be finished, then we can see how much money and how many hours one of your gems takes to build. And what great svaings can be made.

Without these facts, your claim is meaningless.

 

I saw the pictures of the boat of your clients, Ho boy, they HAVE deep pocket. All sheathered in wood, countless electronic, winches galore.
You don't fool any body by being the hero for the poor sailor, your clients they have money and they spend it at Brent's design, like every where else.
By the way Herreshoff was a millionaire, he had a castle, a Merc Gull Wing 300SL (the most beautiful car ever built) and a Ferrari and read his books, they are very deceptive. Always the best of the best.
No Brent, boat are not cheap as you try to tell, they cost money and you know that. Be accurate, because the pictures worth a thousand words.
Frames or not, origamush or not, they cost.
I think the only one who succeded in doing cheap ocean cruiser was George Buehler. But you are not George by a great lenght. He is funny, he don't preach, he do not tell afabulation, and don't tell he is the Hero of the poor sailor. As I said he is funny, and you need to take some lesson on this field.
Daniel

 

I too am a amatuer in the design of boats and the building of boats but I know enough to know that Brents claims of conspiracy to inflate prices, billing unecessary steps and bamboozaling clients is not the truth in the industry. The industry is very competative and such practices could not exist for long.

Instead I think what is here is what I have seen in other industries through the years. You have a person who comes up with a niche product and rather than marketing it as such attacks some faction of the mainstream in order to elevate their product to seem mainstream instead of a niche product. The attack is often successful in convincing those who want to believe the conspiracy to begin with. The target is usually some faction who's traditional roll is poorly understood by the public. In this case it's Naval Architects and Boat Builders. Its understandable that the untrue attacks get the NA's and builders all worked up. That is what is revealed here.

I know enough to know that the right NA can be worth their take and then some when it comes to the overall cost of a boat project. That holds true whether the build is back yard or not. The folks that I have talked to who think that NA's are a waste of money seem to be people who do not value their time like they should. No matter how you cut it boats are complicated expensive time consuming things to build.

I have learned that when something seems to good to be true, it usually is.

 

I can give you the pressure required to collapse the hull, I can show you how its likely to collapse and what the effect of a point load would be too. That's not an issue. The problem is that unless Brent front's up with his actual shape then it's not going to convince him because he will then argue that his boat shape has magic properties. It's become apparent that he doesn't have either lines or offsets or a 3D CAD model. But Alex might?

The failure analysis of the shape as asked for by Rick a page or so back should indicate how easily a shape collapses while exhibiting very low initial stress.
As the boat gets bigger the loads and stresses tend to scale with displacement, so they go up relative to the ratios of the lengths cubed or thereabouts. So scale from a 36 footer to a 40 footer and the structure should be around 40% stronger. Scale from 36 to 60 feet and it needs to be around 4.6 times stronger, stiffer and more robustly framed.

Brent based his structural arguments on misunderstanding he is quite ignorant of the real failure modes of something like a boat hull. He needs to work with a professional. People have offered many times to help him for free but his response is to always show hostility and contempt for qualified assistance. Why he does this should now be clear to anyone reading this thread.

Brent's boat structures evolve as failures occur, that's quite clear. Keels get knocked into the hull in a grounding ....add a frame. Any of us would say why the ***** wasn't that frame there in the first place?

The clients are Brents concept testers in this trail he thinks he's blazing, but how do you test the one in a lifetime storm. That's where the scantling rules apply. Class societies (insurers and guarantors) observed the failures of tens of thousands of craft over the years and adjusted the design, strength and stability requirements until their rules produce a safe reliable boat that can take the events at the outer ends of the bell curve. A client can test a boat for 100 lifetimes and still never hit those conditions. But we should design an ocean class vessel for the ocean, not for a lake or coastal hopping.

Many of Brents boats have had full framing added by more knowledgeable builders. They unfortunately confuse the issue because Brent lumps all anecdotes and all boat tales into the thick sweet syrup of marketing dished up on a plate of dishonest representation of the merits of his method and the pitfalls of the robust building method.

We can keep this clear and crystal and analyse the hull very effectively with computer simulations of the structure. I do it for a living. But I want Brent's hull shape to make it worthwhile. Simple really, that will illustrate everything.

But some people don't actually want to know. That's the real problem. All the diatribe is making smoke that a BS origami hull can be sailed into to hide from the clarity that is on offer. I can't do much more than that if Brent won't assist.

 

So this leads to the 'demolition derby'

This illustrates the willful ignorance dished up endlessly. Understand that today I'd (metaphorical I )be working for Nathaniel on a powerful computer using an expensive and accurate structural simulation package so that he could get on with designing rather than breaking things.

We broke things, we fine tuned the structural simulations (verification), it works brilliantly for isotropic materials like steel and alloy.

That's why we don't need to damage anything.

 

I keep reading this puncture resistance argument again and again...enough to make neophytes worry about there hull thickness and aiming for some 30 footers with 1/4 inch shell.
My understanding of steel hull structures is that puncture resistance is not so much of an issue on a pleasure boat of the league size we are discussing here. As far as I know, puncture is not a common failure on a (healthy) steel boat...even a 36 footer built as it should be of 10 gage steel. Any punctures in steel boats I have seen were result from corrosion problems, ie maintenance issue not from under sized shell. Weld failures and fatigue are much more to fear, arguing on puncture resistance is irrelevant. A small defect in a weld has much less chance to fail if the plate is supported by a frame than if it is completely relying on itself. ...But Brent doesn't worry about weld failure and fatigue, he just keeps coming back with the puncture resistance argument.
Any comments on this puncture resistance deal?

Over confidence is dangerous. In engineering there is something called reliability (http://en.wikipedia.org/wiki/Reliability_(engineering)), over estimating reliability is not a good design practice....

There has been some interesting exchanges about structures of steel boat threw those Brent Swain ranting threads and thanks for all the constructive input, I really enjoy reading those discussions. Even though you won't change stubborn minds you are instructing those who like to learn.Thanks guys.

Murielle

 

Hello Murielle
Way to many verables, case stenarios.emagination. to say one way or another is supirior when it come to gettng the hull holed.
I guess it's because of welding all these years and seeing metal shreaded holed and ripped.
I can sorta see the aurgument that a frameless wont hole as easy because the whole panel will flex in more vs the framed version but then with bulkheads, tanks and whatnot it wouldn't be much different.
Safest bet is dont hit solid sharp objects LOL
Tom

 

1
Steel costs
The steel for a 36 shell is around $8,000 There are about 300 lbs of welding rod in the finished steel work. Man hours to put a 36 hull decks ,cabin, cockpit , wheelhouse keel rudder and skeg together is around 90 hours. One client who used a portable, engine driven welder with an hour meter on it, took 350 hours total for all the metal work, detail included, including the time the welder was idling ,while he did fitting and grinding, all with the welder as the only power source.
One 36 I did and detailed cost around $17,000 for almost all the steel work.
2 Mechanical equipment .
Some will buy a used vehicle with a diesel in it for under $1,000 and install it themselves, others will buy a new one at retail prices, and pay someone to put it in. The cost thus varies drastically. I have no control over the spending habits and resourcefulness, or lack of it in my clients. I recently heard of one asking about some super expensive blocks, when the ones I advocate in my book cost under $2 each and are as strong and reliable as any commercially produced.
I have no way of immunizing anyone against such foolishness.
3 Electrics
My current boat is the first one I have ever owned with an electrical system. I cruised for many years and several pacific crossings without an electrical system, as has been done for thousands of years .I advocate putting in conduit thruout the boat before foaming ,then going cruising while letting your electrics evolve according to need. That costs under $20 initially.
4 Communications
I cruised for many years and several Pacific crossings before buying my first VHF, as many before me have done. I have the toys now, but never put off cruising before having them..
5 Auxilliary systems
Piping?To get cruising, I have 2 feet of plastic pipe to my sink drain, about 6 feet for my bilge pump. My composter head has about 9 feet of aluminium pipe which I bought in a scrap yard for about $2, and 4 ft of 2 inc black poly,around $10.The rest I salvaged. About a day to hook it all up.Thru hulls were stainless pipe nipples and ball valves from the scrapyard, which cost $1 a pound.
Composter head cost me around $30 for materials. My book tells you how to make one. Had a bucket for the first 10 years. Did the job.
Stainless sink cost me $1 a pound in the scrapyard.
6 Outfitting
I just retired the mainsail I paid $100 for in 1980. Got many Pacific crossings out of that one. Got my moneys worth. What does that work out to in dollars per gallon? Genoa cost me $350, the going rate for a used genoa in good shape. New main cost me the same, also the going rate.
For bunks I spent around $5 for used carpet, far easier on my back than any foam I've yet found. Covered it with Sampson, a polyester 3 oz loose weave saturated with PVC, $14 yard in 5 ft width, Two meters does both my settee bunks. Plywood bottoms means simply stapling them on . An hours work.
Three of us got together in an anchor building bee, one on the torch , one on the grinder and me welding. We built ten delta type anchors in two days two 55 pounders each and one 35 pounder, we sold one 55 pounder to pay for the steel , rod and gas. Built my anchor winch for $25 worth of stainless, and rod. My book shows you how.
Arco 40 sheet winches cost me $150 each at a swap meet. Friends gave me halyard winches. Furler for the genoa cost me $80 to build . My book shows to you how.
Mast I traded for a set of plans . Cost the guy who traded it $75 for a 40 ft piece of air dried sitka spruce with three knots the size of you little finger nail, in the entire 40 ft length.
Rigging wire cost me $20 in a scrapyard. Turnbuckles cost me $26 each 26 years ago. Now they cost $22. Got sail track given to me.
Plywood was from a firm testing BC plywood by putting pressure on it til it cracked, then checking the pressure gauge, and throwing it out, A freebee. Paneling my dad paid $1.50 each for4X8 sheets . One client paid $5 each for 4X8 sheets of 3/4 fir. Another watched a movie set fill a dumpster with G1S 3/4 inch fir plywood. There is plenty around. Some I salvaged off beaches. Well tested, unlike new stuff . Wont delaminate..
Took me two days to rough my interior in. Then it was livable . The rest was hobby , at my leisure, as materials were found for free. Meanwhile, there was swimmin , hunting and cruising to be done. Life is short. Have the desert first.
From the time my steel arrived to launching was one month. I did take a couple of days off during that month.
Then I ran her north and borrowed a friend's welder to finish the detailing on the beach, ten days work. Then another ten days of painting, one day of foaming then put the interior in. Six weeks rest, then time to rig her, a weeks work.
During that time I pulled together 2 more 36 footers to keep the cash up. I had $4,000 when I started the hull and ordered the steel ,and by the time I launched I had $40.
Tools ?
Cutting torch, propane tank, rent a n oxygen bottle ,225 amp buzzbox, 5 inch Makita angle grinder, 2 cheap comealongs , rent a bigger chain one for two days. 3- 3/4 inch pipe clamps. 8 ton hydraulic jack , sledgehammer, Helmet , chipping hammer, bal peen hammer , vise grips, and that's about it for the steel work.
Woodwork? hand saw, jig saw, plane, hammer screwdriver, square, level . That's about it.
Painting
Paint brush, rollers ,free paint from the recycling depot, and $25 a gallon epoxy from the surplus ; mask, and 24 feet of cheap plastic hose $7 , and that's about it.
Total time ? May 12thg to mid october,1984, including puling together 2 additional 36 ft shells in that time.. Then sailing and moving aboard.
Yes even rich people are now building my designs , not to save money, but for their excellent track record of toughness, and survivability , extremely well balanced sailing finger light helm on most conditions, and extreme fairness and beauty, being indistinguishable from round bilged boats in the water, with out the need for a single drop of fairing compound.
Structural failures are almost unheard of in small sailing craft, with the rare exception of Roberts skegs. When a 36 is 50 times overstrength, if scaling it up to 40 ft makes it only40 times overstrength, who cares?
How does your less than perfect weld compare in strength with a copper fastening in red cedar every six inches ,which as been holding ships together for thousands of years , or even a deck fibreglassed to a hull with polyester? They"approve" that. So copper fastenings and polyester must be stronger than welding? Duuhhh!!

 

The inside edge of the deck is prevented from buckling upwards or downwards by that super strong , fully welded beam on edge, called a cabinside, supported by pipes from the inside deck edge to the chines. That is stopped from buckling either way by being fully welded to that super strong bulkhead called a cabintop, That is stopped from going anywhere by it's camber,and being fully welded to parts on the opposite side of the boat.
It's this stubborn determination to look at each part in isolation,as if it is unattached to anything, which is the cause of the inability of many here to comprehend the structure as a whole, but stubbornly insist each component has to stand alone. It doesn't!

 

Try it with a can made out of 3/16th or 1/4 inch plate. Then try a wooden nail on steel . Then try a steel nail on wood.

 

Here is your post comparing 5mm,with 18mm, saying the difference is slight.

 

Your logic remind me this story:
A guy go to the car dealer and ask what is the safest car on the lot.
The dealer answered: this brand.
And the guy said: and if I go head to head at 60 miles against a eighteen wheeler?
The dealer answered: buy a locomotive.

It means your train (funny )of thought is quite enfantile. Read what you wrote, then take a history book, and you will see the light.Duuhh!
By the way, not cooper, treenail and iron and not cedar, long leaf yellow pine.
As for the Viking, Norvegian pine, on sewing. The english and Dutch used extensively oak for the planking also.
Cooper was reserved for small open boat, and for the interior cabinetery. And the sheathing of course.
Agency "Aprouve" what it is prouven and works. They started in the 18th century. I know they have less experience than you, I know, I know.
Daniel
I know, you know that also