traditional designs and traditional methods

[PAR]

The centers can be done by hand, using one of a few different methods, but frankly, even with a pocket calculator, it can become quite involved, easily inviting mistakes with all the key punching and dyslexia potential.

I learned this way (slide rule) but welcome the accuracy and speed of the software generated number crunching, though I still prefer the preliminary sketches to be done by hand.

I suggest we do it a more primitive way. I read years ago about a south American builder that built "free form" hulls. He erected a backbone of the length desired, carved a stem and stern post, then made up a midship station mold. The planking stock was bent over the mold and tacked to the stem and stern (or transom). The boat was then conventionally framed, decked and fitted. His work was done by eye, but we could have some minimal guidelines for the keel, stem, stern and midship mold. The results would be interesting, especially if they all met on a lake. Each would be slightly different, largely dependant on the density of the planking lumber, but this has some interest in me. A 15'er would permit scarfed 8' ply panels to be used full length for the planking, which could control the shape to a large degree. A 15' boat is small enough it garner interest, get built cheaply and quickly. What do 'ya think . . .

[Tactic]

carve half models,take the lines from them...build

[PAR]

Taking lines off a half model is a relatively new thing in the history of yacht design and wasn't practiced by everyone. Most were built by eye, the head builder or designer being responsible for the shape of molds or stations. Some had rules, which generated boats of specific shapes for different uses, this was the way the Vikings and others did it. The sharpie was a rule built boat, requiring a set percentage of LOA to decide the beam, flare requirements, freeboard desires, location of the chine, etc. These rules had modifiers for load carrying or speed interests.

[chandler]

Par
Relatively new thing? N.G herreshoff never drew a lines plan that is known of, he carved half models took the offsets from them and gave them directly to the loftsmen.
Tactic
I like the idea however I think you need to be a true artist as N.G. was, which I am not
Par
Give me a break, I'm 49 years old and have never had to use a slide rule in my life. Are you from the swamps of Florida???

[cyclops]

I am 68 and useda sliderule in highschool.

[PAR]

The wizard of Bristol did use models and also invented a machine to grab offsets from them. In fact it was two machines, one was a pantograph to draw the stations, the other picked up the offsets.

This was a little over a century ago and reasonably new in the history of yacht design. He designed one yacht before he entered MIT (he isn't noted as a graduate, though was there 3 years) in the middle of the civil war, but really didn't get into wholesale design until the 1880's (he was busy with boilers). His early yachts were modeled, but the lines and offsets were not removed by machine. L. Francis can remember only the machine so it's invention must have been in the 1890's. Other contemporaries of the day didn't model, though may have had one built to their lines. Capt. Nat is thought to have carved about a thousand models in his career.

Lines plans came to be widely used by the late 15th century, in the worlds larger navies. The commercial fleets followed suit.

Modeling tells you little without a very trained eye and/or lots of carving skill. Most people can "visualize" a lines drawing, or at least see things that may or may not be desirable, which isn't the case when a model is in hand.

Yep, I am well into the woods in central Florida, but no swamp around here (plenty of gators though). This is the point of Florida where the "Evacuation Route" signs tell you to go. It's quite hilly here (hard to believe when compared to the rest of the sand bar like Florida) My property is about 180' above sea level. You know we, hill folk having little and not very reliable electricity, must resort to sliderules. In fact, I'm peddling a foot cranked generator to keep this machine running long enough to write this. I'll then down load it to a 5 1/4" floppy which I'll then have converted to a CD over at the barber shop (the only CD burner in town) so that I can then walk up to the library and post it on line (the only place that has internet access in town) after which I'll tote a cord of seasoned oak back to the house so she can cook dinner, which, of course was freshly killed this morning by a passing 18 wheeler. I'll be kind and not mention this tasty windfall, to the nice man across the way as I expect he'll be depressed over losing his loved spaniel (tastes like chicken, well, with a little garlic and onion, maybe)

[chandler]

I guess maybe I did have to use a slide rule in high school, I know in college we were allowed to use calculators.
Par
Sounds like where I live in Maine except we don't have to rely on road kill, just go out in the yard and wack a deer on the head with a hammer while it's watching my dog hump a bear.

[SailDesign]

Chandler - you must have bene in the year behind me. I'm 50 and we used slide rules in high school and college because the only calculator (note the use of the singular) available was too frikkin' expensive for students. My first calculator was a 4-function Sinclair that cost me a week's wages. Now I can buy a whole computer for less than a week's wages....
Go figure (on your slide rule)
Steve

[chandler]

Really Steve? I thought we were using texas instrument scientific calculators.
I may be wrong , probably am, but I do know the text books had logs and trig functions in the back of the book. Are we that old?
I do remember buying my first computer in the early 90s. A lightening fast 66 turbo for about $3000. I guess we are that old

[PAR]

Steve, that was my problem, there was only one calculator available (TI 99 wasn't it?), it was very exspensive (by that era's standards) and most classes didn't permit one, because (I assume) it provided the few owners of one an unfair advantage. The usual point of the problems presented was to prove you understood the concepts and could complete the ellements necessary for a correct outcome. So, everyone used sliderules. I still have a rather fine one of brass and mahogany with a pearl inlay. It's in a case with a nice divider and ruling pens, that haven't seen the light of day in many years. My "T" square still gets some use and has been hanging on the same nail for many years also.

My first computer was a 286-16 IBM, I replaced it with a screaming hot 386-20 which had a 40 MG drive (I thought I couldn't possibly use all that space) and a full 2 MG of ram. If it didn't crash several times a day, I wasn't working hard enough. This getting old thing sucks . . .

[chandler]

Well think of it this way Par, now you can buy a puter with 100s of gigs hardrive, gigs of ram, cable internet, more cd drives than you can use a big flat screen monitor for probably half what you paid for the 2 or 386, plus you don't need a home stereo cuz the puter does that too

[chandler]

Oh and by the way,
Whatever happened to the idea of a subforum on traditional methods of design for traditional boats for all of us computer illiterate folks still using computers with less than a gig mghz and windows 98?

[RHough]

I still have a slide rule. I even know how to use it.

These days I use Excel, same formulas, but the machine doesn't tend to forget where the decimal place goes...

I discovered that I love working with wood and building boats. It used to be balsa and model airplanes, now its plywood and boats.

I'm all for learning how to do things, without that knowledge you can't know if the fancy program you just downloaded off the net is lying to you or not.

If software can get me where I want to go, it's the best tool for the job.

Traditional to me doesn't mean that you can't use computer aids to get where you would be anyway (just faster and with fewer mistakes).

I'm with PAR in one way. People that go sailing with a GPS chart plotter and have no idea how to navigate are going to get into trouble sooner or later. Just as someone that uses hull design software without knowing anything about boat design will.

[gonzo]

They still build boats on the eye in the Outer Banks of North Carolina. The set the keel, stem and transom and a two set of frames (spreaders). Then they fill in between. These are boats of up to 60' and 35Kt speeds.

[cyclops]

Rhough. I really like the loaded boats with Radar GPS VHF SSB, you name it and the only thing they absolutly know how to operate manually, is the wine cooler.