Origami steel yacht construction

I've never disputed the fact that Brent has designed successful boats; he and his boats have a proper place in the scheme of things. What I object to is his oft-expressed contempt for other designers, professional engineers and engineering standards, professional boatbuilders in general, and professional welders in particular.

Despite what he claims, following proper welding techniques is not just a scam, intended to milk clients or employers out of money. Although we don't make boats here, we do weld pipelines. And our welders each spend an eight-hour day one-on-one with an examiner once a year, demonstrating their welding skills so they can be recertified. Their skill is not some sort of con game ('snake-oil salesmanship' as Brent derisively calls it). And neither is that of similarly-certified shipyard welders.

 

Hey troy,

Your right, no reason to bad mouth others, although in my trade, there is a pasasitic bueracracy that has evolved that unnecessarily makes things more expensive than it should be. You can say some people feel better with standards and they will pay for it with higher costs and some who can deal with just a handshake and trust.

 

Correct me if wrong, but the Van de Stadt 34 is 4mm steel and the Brent36 is 3/8" which is 9mm.

My 26 is ten gauge hull plate, my 31, 36 and 40 are all 3/16th. I only suggested 3/8th for a 60 footer.

 

The first is Jean Marc's boat. The last time I saw her was October 02 off Christmas Island . She sailed back to BC in November that year. Fortunately, Jean Marc likes hurricane force winds. He cruises Hecate straight in the dead of winter, for the thrill. He owns the old cannery in old Bella Bella, BC.

The second is a sister ship, with some modifications . Harvey , her owner is a geoduck diver, who sometimes cruises the west coast of Vancouver Island during diving trips.
Both were origami boats , built in port Hardy, with 3/8th inch 5086 aluminium hull plates, no transverse frames.

I believe Ron Pearson and Greg Elliot designed the boats.

I only attack when being attacked, as my postings on other sites clearly show.

 

Really? Is that why you refer to professional welders as snake-oil salesmen, for doing their jobs properly--and as people of lesser intelligence than you, for doing the finish welding you're unwilling to do or incapable of doing?

And is that why you go off on tirades about any materials or methods other than the ones you use being total crap, and scams designed to bilk people out of their money?

 

Time for a reality check. A steelboat is only as strong as its welding, moreso if it is frameless.
Unless a proper X ray quality procedure weld was done, the welding would always be weaker than the plate.

Most steel welding is stronger than the surrounding plate, far stronger than any connections in any other material, which makes it far stronger than any loads it will encounter. Steel welds breaking are extremely rare on any small steel boats. In nearly 40 years of cruising, I haven't seen any weld failures on finished boats, despite most being built by amateurs, with no welding credentials. You have to deliberately screw up, and work hard at it, to get it any weaker than the surrounding metal. 7024 has a tensile and compression strength of 70,000 lbs , in a surrounding metal of 60,000 lbs

 

So which is it? Stronger, or weaker?

 

For a few hundred dollars and a few more days work the 36 footers could be made much more robust and be dragged into class compliance. That has happened with some of the BS origami boats.

It would be more like weeks, and for the first time amateur , more like months. That has ended the dream for far to many amateur boat builders.



The level of his personal attacks against polite posters to try and deflect a technical argument that puts him in a poor light are now 'on file'.

Only impolite posters.

Brent doesn't need moral support he needs technical support.

Experience of boats in the surf is far more accurate than speculation.



After pointing them out several times, the lies kept being repeated

The boat was on a beach, no-one questioned that fact. It's Brent's interpretation of events and resulting conclusions that's at question. To use a beaching as justification of a poor design detail is poor logic.
Beaching in big surf for weeks, without serious damage, is proof of structural integrity, far beyond paper speculation.



You also misunderstand the role of class societies and regulatory bodies in construction guides. They exist to set a minimum safe level of structural design considering factors which most non engineers are blissfully unaware ( Brent fits this category perfectly ). You can deviate and even discard the rules if you can show by your own analysis that it's robust, that is you calculate the stresses, and fully consider the criteria for strength fatigue and buckling.

They were all calculated in the real world of extreme conditions, a far more reliable test than any paper calculations.

Brent deviates from the rules and claimed that his design was not only stronger but much cheaper and easier to build than what he called 'dinosaur' methods. But he is wrong on every count.

The "Rules' have only given us extremely expensive and labour intensive boats, which put them out of reach of far to may people. They have paid zero attention to the biggest obstacle to people living out their cruising dreams , time and money.

Let the rule makers pay the cost of their decrees.

The hull has a big wow factor but it takes just as long to launch the boat.

Took me one month from steel on the ground to launch. I started in April with $4,000 and was sailing by October and she was liveable.

We started one 36, the second one I ever built in the first week of February, launched her in April and she went for her first sail in May, then headed for Mexico the same year. Boating people living around Maple Bay in 81 can confirm this.

It's weaker than a framed hull becasue Brent misunderstood the mechanics

Hasn't proven to be, in extreme conditions. It is you who don't understand the mechanics, of origami sailing hulls.

Its just as expensive to build ( by a few hundred dollars) as a properly framed version.

Definitely hasn't proven to be, especially if you count time. Huge time savings in origami boat building, especially welding time.

Brent has an appalling understanding of steel structures.

Then why have they been so successful in all conditions over 30 years?

All these points have been addressed in full in several threads on this forum, which you can read for yourself.

Reality trumps speculation , every time.

 

you can't inspect quality into a weld or anything

 

Some have said
Give us a midships section and well calculate the ultimate stability.
Ultimate stability can't be calculated from a midship section.
The buoyancy of my wheelhouse, when inverted , is the equivalent of adding 3,000 lbs to the keel. It is not on the midship section. .My trunk cabin has over 8,000lbs of buoyancy when inverted. It is ignored in stability calculations, making any numbers you get from them, irrelevant.
With a traditional sheer , the buoyancy in the raised ends adds considerably to ultimate stability. They are not counted.
Elsewhere on this site, it was mentioned that the 40 foot design that the young Aussie girl had to abandon in the Indian ocean, was put inverted in calm water by a crane, and it righted itself quickly. Some have claimed that, according to ultimate stability calculations , that is impossible. The ultimate stability calculations probably predicted she would, lose all stability at around 127 degrees.
I find model experiments address all these variables, far better than calculations.
Meanwhile, in the absence of any reliable calculations , we can only use considerations of what improves ultimate stability. It a seems that the only boats which have had problems with ultimate stability are those with excessive beam and flush decks. A beach ball needs only a tiny ballast ratio to make it 100% self righting. A raft is not self righting with a 75% ballast ratio. The more a hull resembles a beach ball ( High camber on the cabin top, trunk cabin and wheelhouse, etc) the better ultimate stability it will have. The more it resembles a raft( excessive beam, flush decks) the less it will have.
So keep the beam moderate and use trunk cabins and wheelhouses, stick to that which enhances ultimate stability throughout the design, and you won't have a problem. There is nothing more anyone can do, Creative accounting doesn't change reality at sea.

 

It's clear you either haven't read the Transverse framing thread.

Forget the degrees that's a complete sidetrack. It's knowledge that counts not where it comes from. It's just that knowledgeable people often tend to have degrees. But a lot of very knowledegable people don't have degrees, they have the intelligence to know when to ask for information.

Brent made an *** of himself on that other thread, this one is a continuation of the debate that ran there.

It's not just the welds its the detail as well. There's plenty of guides for trades people for building and welding steel constructs together.

If you have his book then beware the 'engineering' in it, none of it is correct.

Most of this has been said before.

You don't build Brent's boats from lines drawings or offsets ( do you understand what the line drawings are here?) posting the lines drawing would make no difference to the sale of BS design sketches. It's the flat shape that defines his hull. This is significant becasue people keep making the same mistake.

The lines thing is important it points to another which was apparent deceit:
Brent has no proper stability calc for his boats and has never been able to provide one. Yet he claimed to have derived a stab curve using the lines (that went to 180 degrees no less), but he's never been able to provide those lines or the stability curve to people building his boats, ergo he was lying. So he was asked to provide those lines or even a testimonial that they existed.

Telling clients that boats are stable to 180 degrees and that he did the calcs was just more marketing fraud. It's on obvious points that he gets caught out by knowledegable people. Taht is people who know the basics about sailboat design.

If you read the other thread you'll find his boats aren't stronger, significantly cheaper or even significantly quicker to build than any other reasonable design.

You really should read the transverse frame thread first. Then everything will drop into place.