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  #3081  
Old 01-05-2014
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Re: Pros and cons of steel sailboats

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Originally Posted by Brent Swain View Post
When I graduated, I began working in steel shops, first as a labourer then as a specilalist, on the brake presss , section rolls, plate rolls, and other machinery. This gave me good, hands on experince on what works on steel and what doesnt, and how steel behaves when worked. During htta time I bought a 36 ft ferro cement hul and finished her. She had a short keel with rudder attached. With my zero expoerinence, I thought she would be a much better boat, with the rudder 6 feet furtehr aft. But considering my zero experience at the time I defered to the exertise of her "world reknown designer "a huge mistake, as time and miles would prove conclusively. I spent al spare time reading everything I couod find on Yacht design.Skenes Elements of Yacht Design, became one of my best sources, altho I learned later, he didnt understand cruising priorities, like directional stability, and solid functional gear , or the amount of gear a cruiser will carry out of necessity.( something many current desingers have no idea of ) Then, after a winter cruising BC, I set sail, at the ripe old age of 23, singlehanded , for New Zealand.
I arived in New Zealand with $5 and 5 lbs of rice. Luckily there was a labour shortage there ( bus scab wages)
I hired on as a labourer at a steel fabricating shop, and at much lower wages I found myself advising thenm on simple solutions to problems which were baffling them which I would quickly come up with simpe solutions to. It clearly showed me the uselessness of the qualifications they had. I decided then and there not to underestimate what I could do.
At that time Ganly's Snowbird was featured in Sea Spray magazine, a 30 footer made of 3/16th plate. One thing which had limited my interest insteel was the myth that it had to be 1/8th inch plate . My fero hul was far heavier than 3/16ht plate ,and except for her lack of directional stability and her rudder being in the wrong place she sailed fine.
After cruising up thru the western Pacific, I lost that ferro boat in Fiji, when she broke loose from a mooring. Had she been steel, she would have suffered zero damage in the same conditions.
So I left all th egear off her at a shipping agenbty and flew home to build the steel boat I had been designing. I took my drawings to Stan Huntingford ,a highly respoected local designer. The first thing he suggested was a plywood deck ,a huge mistake , to improve stabilty.Then he suggested multi chines, which reduce stability.. The he told me that a 4 inch bulwark would hold a 4 inch layer of water over the entire deck ,when the boat was heeled 25 degrees going to windward. Withj such a highly respoected designer spouting such harbrained logic, I thought I couldnt do any worse alone ,than he could. A local writer and circumnavigator, who had dealings with him, confirmed my thoughts. The only other options, Covins were similarly hairbrained interiors ,like a collection of closets and crawl spaces, with a huge amount of boat wasted on cockpit, and a huge amounbtof bits and pieces making a hirendously more complex and labour intensive construction than needed or even relevant ,based on my years of steel working expereince, and only ten gauge plating with all it's problems. So I desinged my own boat, sucessfuly .
Time to go. More editing to come
Brent,

Thanks for the first part of your story. Was the first boat Origami style or more conventional steel construction? Hope you will continue with the remainder of the Brent Swain story. When and how did you get into designing the other boats and doing it for others? How many designs, how many boats, etc? Also, building of the designs?

Years ago, here in coastal NC, especially down on Harker's Island, there were old time boat builders who built trawlers and fishing boats of all sizes in wood. I am told that these people would build from a set of simple formulas. The first frame had a certain angle/size, the next a little different, the next still different. I have read that they would sometimes work out the frames (and consequently the design) on the back of an old envelope. The boats were rugged and would last many years (however, steel construction seems to be replacing the old wood construction). How to do the calculations was just passed down form generation to generation. These guys built successful boats, but their skill seemed to center around carpentry more than it did in understanding the forces and stresses working on the boats. I'm guessing that over time and through the generations, they knew, from trial and error in the field on their and other's boats, that a boat of a certain length/beam, needed frames and planking of a certain size. Most of those builders are now gone.
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  #3082  
Old 01-05-2014
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Re: Pros and cons of steel sailboats

I think you'll find people building boats of all sizes by that sort of rule of thumb and experience method on beaches all over the world.

I remember reading about an old beach builder in Bequia - he built fishing dinghys in the 15-20 foot range. His basic proportion rule was "A T'ird de length is de wid', plus a little more, more or less".

If basic function is all that matters it works O/K for relatively unsophisticated workboats but it won't build much of a yacht.
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  #3083  
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Re: Pros and cons of steel sailboats

I want to chime in on a couple of points here. Not an expert but I own two steel sailboats and have looked at a few more when searching for what we have.

IIRC the rule of thumb is that 10 gage or 1/8" steel is about as thin as you can weld without too much heat distortion. Again generally speaking, scantlings for 10 gage work down to about 40 feet, so below that 10 gage is "overbuilt" which is why so many small steel boats are proportionately heavy.

My small boat, 33', is 10gage. The big boat, 44', is 1/4" first 3 plates then 3/16". But I have seen much bigger boats in 10 gage. Here is a link to a relatively famous 44'er in 10 gage. (3mm)

1989 Custom cruising ketch Sail Boat For Sale - www.yachtworld.com

Quote:
Hull Construction: Ten-gauge steel plating was stress-relief welded. Larger plates are used in the under body and topsides. Plates at the turn of the bilge were rolled to fit the molded radius of the round hull shape. About seven sections were installed and the ones at the stern and bow ends were multi-rolled to fit the changing radius of this conical development. The framework of the hull was floated into place while the welding of the plate was done. Afterwards it was spot welded to the hull plates.
We looked at a couple of Colvin Gazelles. On one you had to crawl through the engine room to the aft cabin.

We also looked at a big (52?') Colvin ketch, damn near a schooner. Deeply raked masts, I mean Deep. That boat was 10 gage! Talked in person to the original owner/builder and I queried him closely on that point.

Her saloon was immense with a huge curving leather setee. You could waltz in there, with no handholds. Getting to the aft cabin you squeezed past the engine room, then crouched very low, nearly on your knees. The main bunk, a double, was to one side. IIRC the foot of the bunk was behind a bulkhead sorta like a quarter berth. We couldn't figure how to get In or out.

So, yes, 10 gage boats are out there and fairly common and yes some Colvin interiors are "interesting."

Last edited by hpeer; 01-05-2014 at 10:19 PM.
  #3084  
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Re: Pros and cons of steel sailboats

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Originally Posted by SloopJonB View Post
I think you'll find people building boats of all sizes by that sort of rule of thumb and experience method on beaches all over the world.

I remember reading about an old beach builder in Bequia - he built fishing dinghys in the 15-20 foot range. His basic proportion rule was "A T'ird de length is de wid', plus a little more, more or less".

If basic function is all that matters it works O/K for relatively unsophisticated workboats but it won't build much of a yacht.
Funny you should say that.

My thought is that Bob designs yachts and Brent builds boats. With this distinction it is easier to see and understand the differences. Their objectives are vastly different.

Both gentlemen build craft that float, and these craft convey their passengers about. Brent's boats are for the cash strapped home builder, project guy. Dirt under the fingernails, wants to know hew she works. Bobs yachts are finely crafted works of art for the well healed and lucky who are fortunate enough to have his work.

The argument baffles me. Of course they can't agree, they aren't doing the same thing. Not even remotely. It's like arguing the rules of "football" between an American and Englishman. They both have balls () and played on a field and score. But, ones round and black and white, the other is brown and weird shaped.

In my world there is room for both, in fact it is a better world for having both and the choice.

For some reason I kinda fear I'll piss 'em both off, although that's not my intent.

Carry on.
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Last edited by hpeer; 01-05-2014 at 10:21 PM.
  #3085  
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Re: Pros and cons of steel sailboats

That green vessel seems more of a yacht then a boat. Some finely crafted vessels have been made in steel. On another thread Steve posts on voyaging in an aluminum yacht. I'm curious if after owning two fine steel yachts if you starting now what material you you prefer.
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  #3086  
Old 01-06-2014
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Re: Pros and cons of steel sailboats

Quote:
Originally Posted by hpeer View Post
I want to chime in on a couple of points here. Not an expert but I own two steel sailboats and have looked at a few more when searching for what we have.

IIRC the rule of thumb is that 10 gage or 1/8" steel is about as thin as you can weld without too much heat distortion. Again generally speaking, scantlings for 10 gage work down to about 40 feet, so below that 10 gage is "overbuilt" which is why so many small steel boats are proportionately heavy.

My small boat, 33', is 10gage. The big boat, 44', is 1/4" first 3 plates then 3/16". But I have seen much bigger boats in 10 gage. Here is a link to a relatively famous 44'er in 10 gage. (3mm)

1989 Custom cruising ketch Sail Boat For Sale - www.yachtworld.com



We looked at a couple of Colvin Gazelles. On one you had to crawl through the engine room to the aft cabin.

We also looked at a big (52?') Colvin ketch, damn near a schooner. Deeply raked masts, I mean Deep. That boat was 10 gage! Talked in person to the original owner/builder and I queried him closely on that point.
...............

So, yes, 10 gage boats are out there and fairly common .........."
We use metric scantlings almost universally now so it can be confusing using US plate gauge sizes, but Isn't 1/8" 11 gauge or 3.2mm ?

See Standard Gauge for Sheet and Plate Iron, Ted Pella, Inc.

10 gauge is listed as 3.6mm which is getting closer to the minimum we usually ever use which is 4mm. And 4mm plate is easier to roll for round bilge steel craft which reduces the construction cost but the welders don't like such thin plate. Neither do I.

In larger boats the bottom plate fwd is often a size up from the topside and aft bottom plate since slamming loads are greater in the forebody. There is also Corten steel which is stronger and often used in larger boats that have thinner plate.
My own preference is for a bit less framing, thicker plate and consequently a decent corrosion allowance with steel.

The formulas juggle plate thickness, frame spacing and design pressure head. Since the plate usually counts for a significant part of the section modulus of the framing (it's outer Flange) it's not necessarily such a great weight penalty to have thicker plate and there are sweet spots in the 'design space' which are driven by juggling commonly available framing sizes spacing and plating thickness to get an optimal weight to strength.

Last edited by MikeJohns; 01-07-2014 at 02:20 AM.
  #3087  
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Re: Pros and cons of steel sailboats

Quote:
Originally Posted by SloopJonB View Post
I think you'll find people building boats of all sizes by that sort of rule of thumb and experience method on beaches all over the world.

I remember reading about an old beach builder in Bequia - he built fishing dinghys in the 15-20 foot range. His basic proportion rule was "A T'ird de length is de wid', plus a little more, more or less".

If basic function is all that matters it works O/K for relatively unsophisticated workboats but it won't build much of a yacht.
As much as we'd like to think sometimes that we are very advanced technically, we still build boats, ships, planes, buildings, roads, and almost everything that way (rule of thumb and experience) today. We just don't call it rule of thumb. We will, however, talk glowingly to potential clients about our experience in the field. In every industry, there are trade standards and specifications. And government comes up with more, called building codes and standards. And even when we sit down to engineer or design something, we will use formulas that were often developed by trial and error (called experience and experimentation). Then, on most really complicated items, we will then spend much time and money, testing and confirming on prototypes, that our calculations were correct and that we didn't overlook something. Never mind, that we have already put in safety factors in our design. You calculated the forces to be "X". But then, we'll put in a safety factor of maybe 2.5X or even more, just to be sure. And even when we push the knowledge envelope with something new, we will have used the past experience and techiques to guide us.

And those boats from Harker's Island. Some were small, but many were 40-70 ocean going trawlers. And in a time before Hatteras Yachts and other such names, some of those builders built sportsfisherman boats occasionally. It is true that trawlers are not built like yachts. While pretty and finely executed, most yachts would fail miserably as trawlers or other workboats. Yachts and workboats are different animals.
  #3088  
Old 01-06-2014
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Re: Pros and cons of steel sailboats

Peer:
You didn't "piss me off" at all. In fact the point you made is one I have been trying to make all along. BS and I are in very different businesses. I have no problem at all with his business. I do not like BS the person. I do have a problem with his general, narrow minded attitude towards boats that are not like his or sailors who choose a different style of cruising to his. I have real problem with his personal attacks on my wife who he has never met or seen.To me he is an ignorant and boorish person who has trouble with the truth. I also object to his lame efforts to talk about naval architecture. He is not qualified to discuss naval architecture and in doing so her makes some very stupid errors and misleading statements time and time again. He should stay within his area of skill. Which is considerable, i.e. steel boatbuilding. You will not find me discussing steel boatbuilding techniques here for the exact same reason. I am not a steel boat builder. But I am very happy to discuss naval architecture and the designing of yachts. In have no need to invent facts or stretch the truth. I can provide countless examples of the success of my work.
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Last edited by bobperry; 01-06-2014 at 12:48 PM.
  #3089  
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Re: Pros and cons of steel sailboats

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Originally Posted by bobperry View Post
Marty:
The mast is getting some last minute detailing. The tiller fitting is being fitted to the cf stock. We still need a cove stripe,name and hailing port. But the list is getting shorter.
As soon as the rig is up we can take the measurements for the sails. I think this could have been done from my rawings but there is a level of perfection in this project that has each of the players working to produce his best work and I'm not going to argue sails with Frank Schattaur. I'm am certain the sails will be impeccable.
I have been very happy with the work I have had done by Schattauer sails.. But as I recall, they only use Dacron.. Will Francis Lee have Dacron sails?
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Re: Pros and cons of steel sailboats

David:
Yes, the first set of sails by Schattauer will be dacron.
Because the rig is right out of a Farr 40, slightly different "J", we can use some used Farr 40 sails but so far the used Farr sails that Kim has found have been surprisingly expensive. Kim is very good friends with the Schattauers and also used to own the boat the Schattauers own now, TIOGA.

I suppose in time Kim will entertain some more exotic sails but for now the push is to get the boat out of the shop and into the water.
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