Transverse frame calculation

Cap both ends of your tube and throw it overboard in a hurricane . Will it come back twisted by the waves , or buckled? Not a chance. Not enough weight or inertia there. If you put enough power on one end of my boat and twisted it, like the loads one would get in a super tanker rounding the horn, sure it would buckle , but not with the amount of twisting load one would come anywhere near encountering in the real world. The boats are simply too small and light for that to be remotely possible. It is common knowledge that small steel boats are grossly overstrength , and resulting in their being grossly over labour intensive, and grossly expensive compared to what is needed. Nevins and Herreschoffs rules base the strength of scantlings on displacement. There is not nearly enough weight or inertia to damage an origami boat at sea or on a lee shore in most conditions. Strength to weight ratio is the real determinant.
Instead of building something in less than 100 hours which is 50 times stronger than will ever be needed, you are advocating taking many times longer to build something which is 60 times stronger than will ever be needed. What torture tests do you expect to subject at a hull to which is greater than pounding on a Baja lee shore in 8 to 12 foot swells for 16 days, or pounding across a Fijian coral reef in large swells for 300 yards,T-boning a moored steel barge at 8 knots, or a reef at 15 knots, then being bodily dragged off the reef with a tug? You can read about the latter incident in Don Shores book "Around the world on Viski".It's available from Harbour Chandleries in Nanaimo BC. The boatyards in Suva can also confirm their salvaging of "Viski". So, in addition to calling me a liar, you are calling all them liars which makes you a liar.
I hope to post some pictures of the 36 on the Baja lee shore soon as possible.
When one is trying to get a boat together affordably and get of the treadmill quickly and easily , then one would be wise to get his advice for someone who has actually accomplished that for the long term , not from those who have never accomplished what you are hoping to. Following the naive advice of armchair theorists, who have never managed to do what you are hoping to do, but continually spout advice on how you should go about what they have never themselves been able to accomplish , will result in one becoming a similar armchair theorist.

 

The tide floods thru that pass at many knots. Common in BC waters . It flows thru Seymor narrows at up to 15 knots. Add 8 knots to that and you can hit a rock in a sailing vessel at 23 knots.
Call me a liar? This makes you a liar!

 

You say hitting in the centre of a large flexible panel would save the day?
Thank you. You make my point exactly, about the advantages of origami construction, as opposed to framed construction ,on which there would be no large flexible panels to save the day. Framing would magnify the damage. You are finally starting to get it.You said it would buckle . Didn't show any signs of buckling,which disproves your theory, completely.
The barge was tied solidly to the wharf, no fenders, and the 36 T-boned her on the opposite side of the barge from the wharf. The barge had no give whatever. She was empty and riding high.

 

As have pointed out, I charge $30 an hour, not $100 an hour. You are a liar.
While no one has ever got hull together as quickly as I do, they get them together in a fraction the time of a framed boat, with much better results especially for first time builders.
I've never made any more than a fraction the $9,000 you quote, on any one hull. That is the price you framies charge , not origami builders.Now that's a scam, suckering people into paying you to waste time and their money.
You still haven't given me any figures on what you framies charge to put together a 36 foot hull and decks? You still haven't given an estimate of the number of hours you would expect to take to put together a 36 foot hull and decks in someones back yard, starting from absolute scratch, with no lifting gear but comealongs ,and very little equipment. Any one in any kind of boat, metal or otherwise, who buys my book will save thousands of dollars in equipment expenses. One guy said he made a couple of the blocks I describe in the book, and that saved him far more than the price of the book. A watermaker which costs $10,000 from west marine , but under $1,000 for the one in my book is worth far more than the $20 for the book, as is a roller furler for under $200,composting head for under $100, self steering for under $50, anchor winch for under $50 engine driven welder for under $50 etc etc.
What have you done for anyone that has saved people that much time and money? It appears your goal is to scam them into filling the pockets of marine hardware sharks , including yourselves, with your "Be reasonable and do it the expensive way, for my benefit " mantra. No wonder you are so defensive when some one shows people an affordable alternative to your scams.. ..

 

So, the steel cost $8000. Ok
The total cost of the steel and being fabricated is $17,000, ok

You say it takes you 90hours @ $30/ph = $2700

So where has the $17,000 - $8,000 - $ 2,700 = $6,300 gone?

What has cost $6300??

The claims, about saving time, money and easy structural designs etc, are made by you. It is you that must proved evidence of your claims. Otherwise they are just claims or an opinion as such and not verified independently. A claim to be counted as having merit, must be shown and documented. Words are easy, independent paper work to verify such claims…is another matter.

Such as a dwg showing a stamped “approved by XXX Class”, would suffice.

 

Steel cost is basic shell. Detail costs are cleats, lifelines ,handrails , engine mounts, self steering, hatches, winch bases, tankage, bow roller , anchor winch, mast tabernackle , exhaust, rudder fittings,vents, padeyes,fillers , etc etc , in other words detailing, which cost a fraction the cost of buying them and bolting them down on a non metal boat. That is why, when all the metal work is finished, a metal boat is much further along than a non metal boat, and a much bigger percentage of the total cost of the finished boat..

 

I’m getting jolly confused here.

I asked you to provide a break down of your costs, here:
http://www.boatdesign.net/forums/cl...se-frame-calculation-32584-17.html#post373624

So details like winch, turnbuckles rigging wire etc, you correctly state them as “outfitting”. And the cost of such is attributed to item
“6. Outfitting”, not “1. Structure”.

But now, these costed items in 6 Outfitting, are suddenly back as a cost into in 1 Structure/Materials..??

So again, what has cost $6,300 in the total costs of 1. Structure/Materials, which is NOT in 6. Outfitting?

Does this detailing cost come under 1. Structure, or 6. Outfitting? And it is part of the 90hours or additional?

Or is it that since you are quoting from 26 years ago, you can’t remember, so you embellish?

 

According to page 4 in this local sailing club publication, the current through Georgeson Pass is 50% of the current in Active Pass,

http://www.frasersquadron.ca/files/Fairlead/Fairlead 2008-01.pdf

The highest current mentioned in this tide-table, for Active Pass, is 5.9 knots, so I think Brent's claim of 15 knots needs some explanation

http://www.dairiki.org/tides/monthly.php/act

I have made 11 knots on the GPS in my 30ft Fisher going through the Glenelg narrows in Western Scotland, so it could be possible, maybe he just needs to be a bit more specific.

 

Brent
The tube analogy was to try and show you how adding transverse framing stiffens and strengthens a hollow shape such as a hull subject to torsion. You declared that it doesn't and gave a flat plate as an example I was giving you an illustration that it can and used a cylinder. I think you are overshooting the mark a bit. Savy ?

You misunderstand the barge as well
A large flexible panel can be flat and have a strong rigidly framed perimeter, the panel acts as a diaghram allowing it to stretch without buckling. The extra material available on a curved surface makes it more prone to buckling in collision. Frames restrain and allow the force to be taken in tension.

The implication you use is that the boat is extra-strong, the anecdotal tale though is highly subjective.

Yes you distort the truth to your own marketing ends that is clear by now to everyone. I had a direct experiece before of you posting a fiction on the origami website remember ?

You have lots of attitude but no apparent aptitude to learn or improve.
Take the economic line you constantly use as opposition to frames, you will never address the simple query: What would it cost in time and material to add a forward bulkhead and or 2 or three transverse frames to your 36 footer? I'd estimate in reality you could do it in a day for less than $100.

But this was never about 21 or 36 footers it's about your complete and deliberate misunderstanding of structural basics, which you seem to go to great lengths to obfuscate.

For example shallow curves in shells don't add phenominal strength, transverse frames do stiffen a vessel, buckling is always the principal mode of failure not yield etc etc.
But you just keep jumping to highly subjective anecdotes to prop up your failed arguments. If a frameless 21 footer of your design makes the NW passage it doesn't mean you have your structural reasoning correct.

 

Gas Bottle Origami

Brent, are you seriously saying, that the situation in both of the pictures is equal and origami bottle boat needs only thin shell and some tiny longitudinals to handle rigging and keel forces?

 

No it was one of your 36 footers built to your plans, and it wasn't doing 15 knots either. It split the welding around the back of the keel and drove the keel up into the boat bending those frames. I've got the pictures here.

Also your own boat had the keels driven into the hull after a grounding as did others all built to your design.

So this 40 footer is yet another one.

Other builders Like Evan put linked floors right across for better strength, but you didn't and still don't in your plans. You've got them ending on the plate on a weld line from a tank top. Now that's poor detail IMO.

That's you approach. Any scantling rule or any naval architect would tell you that was a weak design, but you let your clients design your boats through failures. If it breaks you beef it up add frames and pretend it never happened.

So how does this failure based design pan out when a 60 footer collapses it's bow or splits a weld in catastrophic failure. They'll probably disappear without trace. Might be nice if you actually thought this one through and looked at some analysis before that happens hey?

Except when your thick skull lead to the flaw?

On the same tack as your tall tales are You going to accept my challenge and ram the harbor wall at 7 knots to show what a strong boat you have designed ? With some reliable witnesses? You imply that hitting the barge proves something................exactly what ?
Don't trust your design at 7 knots (I sure wouldn't ) then do it at 5 knots, same deal, otherwise shut the tall tales up and we'll suggest some real tests, since they are so invulnerable to damage. Think of it as a solo demolition derby.

 

Wow you are doing your homework, thanks for that.

 

Rigging forces are a taken by the half inch web across the cabin top, the 2 inch sch 40 pipes from the web to the chine, and keel forces are taken by the tankage and webs across the keels from tank edge to chine. We have buried the side decks, without the lee rigging slackening off in the slightest way.I have sailed twice from Tonga to BC , the last time non stop, with the first 4,000 miles to windward each time, against a strong , squally trade wind, without the lee rigging slackening in any noticeable way.
I believe, when working with a heavy material , we should put the structural material where it is needed, not where it is not.