Origami steel yacht construction

I launched her one month from the time the steel arrived, bare shell, then motored her north and went to earn more money. I pulled together two more 36 footers in june, took july off, then went back to my boat in August, and finished the detail in ten days, ballasted her, then spent another ten painting her.( 30 gallons of epoxy tar, and one of enamel.) Then I took some time of to recover. The beginning of September ,I spray foamed her and roughed the interior in. Then I took another break thru the last three weeks of september. Then, in early October ,I put the mast aboard and spent about ten days rigging her, and went for her first sail

 

I had a welding inspector aboard yesterday, approved of everything she saw.

 

In all the years I've worked in steel fabricating shops, I've never seen the burned edges of plate ground before welding , even lightly , even for x-rayed welds. The only grinding done was to remove left over slag , or to grind a 45 on, for penetration.
You'd get fired the first day, in any steel shops I've worked in, for being that tedious and slow.
Another case of the "Be reasonable and do it the hard way" philosophy.
The 38 ft frameless , Dudley Dix designed hull, that Wynand built was, despite a different way of getting to the same point , structurally , an origami hull, as with any frameless hull, of which there are many, by many different designers, all well proven, over decades, and hundreds of thousands of sea miles..

 

Now you can do a stability calc using your lines ( although it's better to use a computer and avoid the math and errors) but fist you'll have to find an accurate COG from weights and moments. Something else you cant provide.[/QUOTE]

The vertical centre of gravity varies widely, depending on the owner.
Some own only a case of beer and a change of socks , others make several trips with a pickup truck, cramming every available space on the boat with heavy gear, most of it well below the vertical centre of buoyancy, and at 1100 lbs per inch immersion, puts the boat down several inches on her lines.
The actual vertical centre of gravity could never be anywhere near the same spot, for any two very different owners
I've made the hull lines available since 1976

 

Personal experience shows I can build 3 frames a day easily and without working very hard or for a full day. There are 17 frames in the Witch. Do the math....


That's just under six days to make up the frames alone , the amount of time it takes me to tack together hull, decks, cabin, cockpit wheelhouse and skeg. Then add to that the time it takes to build a jig, set up the frames on the jig, bend longitudinals around them, fit plate to an already exisiting framework, do many times the amount of cutting, grinding and welding, and you have far more than the time to build a hull, that I take to finish tacking together all the detail work, ready for final welding.

 

I'll call bs on this post.

In the first place, if you've only worked one month a year for most of your adult life (as you've repeatedly claimed), you sure as Hell can't have also spent 'years' working in steel fabricating shops. Which claim is true, Brent, and which one is shameless exaggeration?

Secondly, to tell us that shop welders don't grind their 'burned edges' is also complete bs. You can walk into any welding shop in this country or yours, and see welders grinding torch-cut edges.

 

You're the only person I've ever seen use the term 'from start to launch' with 'launched' meaning 'bare hull afloat with a motor in it'....

<removed>

 

I've never seen them grind a smooth, well cut edge yet. Must have some crappy burners in your shop. I've met them too.
I began working in steel shops the year I finished high school , and worked of and on , first at Industrial Wire and Iron on Powell street in Vancouver for one year, at Mainland Foundary on Powell street for three years, first as a helper, then as a brake and machinery operator. Then Recold, then Great West Steel in Sakatoon, for a winter,then Canron in Vancouver, then A&G price in Auckland for a year and a half, then Great West Steel in Burnaby BC for a year, as a detail fabricator.
After that, I remained self employed, working on boats, since my mid twenties, roughly a month a year.
Haven't punched a clock since my mid twenties

 

Trust me on this one, son: the snottier you get on this subject, the more of a fool you'll look.

Our welders can weld rings around you and your amateur acolytes. Among other things they work on high-pressure natural gas pipelines up to 36" in diameter, in extreme weather and under harsh physical conditions--generally in cramped quarters in a hole in the ground. Every single pipeline weld they make is completely x-rayed. They don't make crappy cuts, and they do grind.

On the other hand, you worked maybe five or six years total in shops, way back when you were a kid--and apparently most of it wasn't even as a welder. I'm soooo impressed....

 

These last few posts are real doozies in direct contrast to his previous posts

I have a masters in Metallurgy and Chemical Engineering but I am no welder. I do however know when I see bs.

 

This is why you will find within a set of complete comprehensive stability calculations, a series of displacements covering a whole range of loading conditions and the resultant centres of gravity for each that is then used for individual analysis. Find yourself a certified stability booklet from a commercial boat (power or sail) in the marina near you (best bet to find one) and see for yourself.


I also find it doulbtfull that the majority of "owner weight crammed into every available space"is fitted below the centre of buoyancy as you say. This would mean that it is stored entirely within the bottom of the bilge. I think you already have a tank there right?

 

I had a welding inspector aboard yesterday, approved of everything she saw. (Brent Swain Post #543)

I think that we've been down this road, before, but giving Brent the benefit of the doubt, I'm interested in knowing the name of the inspector and to which standard & level she is qualified. I am also curious as to what this inspector's opinion would be on the welds found on earlier posts in this thread.


In all the years I've worked in steel fabricating shops, I've never seen the
burned edges of plate ground before welding , even lightly , even for x-rayed
welds. The only grinding done was to remove left over slag , or to grind a 45
on, for penetration. You'd get fired the first day, in any steel shops I've worked in, for being that tedious and slow. Another case of the "Be reasonable and do it the hard way" philosophy.
(Brent Swain Post #544)

If using a burning machine on a track/carriage, I'd agree that one does not need to do more than remove the carbon & slag. When freehand cutting, however - especially the cuts we have seen from the video photos - the grinding will be more aggressive. I don't believe that Brent has ever seen U.T. weld preparation. Not to put words in their mouths, but I don't think that any of the engineers, steelworkers, those involved in steel fab., etc., believe this either. What a coincidence! What does "the book"(Standards) that some of the companies(Brent worked for?) had to adhere to, say?

CSA(canadian Standards Association) W59-03(Reaffirmed 2008)
"Welded Steel Construction(Metal Arc Welding)"
Section 5.3.1
"Surfaces and edges to be welded shall be smooth, uniform, and free from fins, cracks, and other defects that would adversely affect the quality or strength of the weld. Surfaces to be welded shall also be free, within 50mm(2in) of any weld locations, from loose or thick scale (except for tightly adhering small islands of scale), slag, loose rust, paint, grease, moisture, and other foreign material that will prevent welding to the acceptance criteria of this Standard."

Section 5.3.4
"Occasional notches, not more than 5mm(3/16in) deep, on otherwise satisfactory surfaces shall be removed by machining or grinding.
Any company wishing to have CWB(Canadian Welding Bureau) certification, must adhere to these standards." (Section goes on to describe welding/treatment of much larger notches)

 

Wow. I hope the client paid by the hour for that one! Was this the project that made you decide to retire?(lol)

I talked to a guy who wanted to GTAW an origami boat, including the centre-line. I suggested that it would be a brave man who was willing to stand in the bight for that long!

 

This is another bit of rope that has a noose being knotted in the end:

For decades the designer of Brent boats has been telling people that a stability curve was derived and that it goes variously to 175 and180 degrees. Despite numerous requests for that same curve it has never materialized. Never been published and was unable to be provided to clients who bought the plans.

The same with hull offsets and hull lines, to any request for those the designer just said they were either completely unnecessary, or variously implied they were just artificial mathematical constructs of no use. Designed to “line the pockets of bureaucrats and naval architects engineers and other snake oil salesmen”.

When it was pointed out that you can’t derive a GZ without either a 3D computer model or a set of lines the designer suddenly started claiming he not only had the lines but used them to derive the GZ curve. But he still didn’t have weights and moments calculations or a vertical COG !

Now interestingly he says it’s “lies” that he didn’t have the lines and that they are included with all plans sold ( But apparently he still doesn’t have the GZ curve nor the weights and moments). He also doesn’t say that he just started including the lines in the past few weeks. They were apparently provided to him by someone else from offsets they took of a hull or a model.

There is no practical possibility of Brent boats having a vanishing stability of 175 degrees it would be miraculous for a small steel boat with that hullform.

When considering that stability is one very important aspect of safety that should be properly assessed, it’s a marketing deception of a very great magnitude. How many people were swayed to buy the product and employ the builder with unfounded and false stability claims?

For Brent Swain this is all very easily disproved. Provide the weights and moments derived COG and the GZ curve along with the lines. Since the claim is that the GZ curve came from the lines no less, that is impossible without the other two.
The indication is that the Brent boat designer has never done a proper stability calculation and was more than a little confused of the actual requirements.

The claim of vanishing stability at 175 to 180 degrees is clearly misleading conduct. And like many of the structural arguments another grossly incorrect claim that should be condemned.

 

Yep, stability is going to be a thorny one for the BS marketing spin to cover up.

And here's some relevant posts that AdHoc found on the origami site that i'll post since he's away travelling for a bit.



Brent says
The boats all have positive stability to 175 degrees.


Question to BS:
How do you calculate that stability figure and what standard do you design to?



BS reply

Stability:
I have a model of the 31 foot twin keeler made of 3/16th plywood for
the hull and 1/8th inch plywood for the decks and cabin giving the
model the same vertical centre of gravity as the full sized shell. I
gave it the same ballast ratio as the full sized boat in lead,and the
equivalent sized mast in fir.
In water I found it extremely difficult to get it to stay upside
down . If I placed it very carefully upside down on totally calm water
it stayed that way briefly. With the slightest disturbance, a half
inch ripple for example, it would snap upright instantly.Waves big
enough to capsize a boat wouldn't dissappear as soon as they'd done
their dirty work, and the sea become instantly calm.
If I tried , however, to place the boat down at an angle of say 5
degrees, it would right itself instantly.
This example is just a shell. The full sized cruising yacht would
have much greater righting ability, as 90% of the stowage in the boat
is well below the waterline.
As Bruce Roberts has well stated,everything below the centre of
buoyancy in a loaded cruising boat counts as ballast ratio as long as
it's well secured.
When reality and theorie disagree , get real and trust reality.


Structural standard:
The only reliable standard for yachts is "what have they done, what
punishment have they proven themselves capable of taking without
structural failure , how many trouble free miles have they traveled."
There is no mathematical equivalent of use and abuse in the real
world .

Reply to BS (abridged)
So basically you calculate neither