Design Criterea

Im fifteen years old and a boat enthusiast. Ive been in and around boats since I was 3 and fishing since 6, so boats are my passion. This year in school, a semester long project was given in which the students needed to pursue a passion, and somehow make that passion a reality. As with my passionion being boat I wanted to design and build a boat. Being only fifteen building a boat is a little unrealistic given the fact that I dont have the materials or near the experiance needed to complete such a task, but I thought that a model to scale would do just the same.

What do I need to include in my design, for the boat to be a functional design? I want my design to be no different than if it was a design for an actual boat. Does anybody know what it takes to complete a full design?

Alex

 

a model to scale would do just the same.

Good thinking. A design by itself is enough of a project for a semester, in fact it's going to be a tall order, I think. There's plenty of precedent for a designer building a model of his design. Many of us do this from time to time, to make sure a design will be what we think it will.

The first thing you need to decide is what sort of boat. How big, how expensive, what style, what used for, etc. etc. My advice would be to keep it very simple (a semester isn't very long!), and to keep to a type you're familiar with. A professional designer will never create a design out of thin air -- he'll draw on his own vast (hrrmph!) experience, and he'll do research to get ideas and to get more familiar with the sort of boat involved. He needs to be able to see the boat in his mind's eye before he starts drawing, even though it may change radically as he draws it.

I would suggest a simple skiff-type boat for several reasons, and I would go to your local library and request, from interlibrary loan if they don't have them, Understanding Boat Design by Ted Brewer and Instant Boats by Harold Payson (International Marine Publishing Co.). The first is a very short description of what a design consists of. The second has examples of the drawings for small simple boats. Of course, there are other similar books, but I think that one would be especially good, for a basic open boat. And you'll want to study as many designs similar to yours as you can find, to see how they're arranged. It's not cheating unless you copy exactly, and what fun would that be?

You should draw a Deck Plan & Profile drawing (or Sail Plan & Deck Plan for a sail boat) to show what the boat will look like from the side and top. And you should have a Construction drawing which shows the various parts, with each one briefly described in a note on the drawing or (better) a separate materials list, so the builder knows what to use and what size to make it. This drawing would have a top view, a cutaway side view showing the inside of the boat, and a cutaway section view or two cutting crosswise through the inside, to show how things fit together in that direction. Look at some plans if you don't understand what I mean. Everything should be drawn to scale, just as accurately as you possibly can. If you draw at the scale called 3/4" = 1'0" where 3/4 inch of drawing equals 1 foot of boat, each inch of boat is 1/16" of drawing and you can use a household ruler, using your calibrated eyeball for the quarter inches. For a small boat, use 1 1/2" = 1'0", where each 1/8" of drawing represents an inch. If you want to do it really right, get and learn to use an architect's scale with these scales on it, but you can do pretty well with a good ruler and a lot of care. Keep your pencil very very sharp and don't spare the eraser!

A larger boat would have a separate Arrangement drawing, but for an open boat the Deck Plan view above will do. And a larger boat would have a Hull Lines drawing to specify the hull shape, but with a simple "hard-chine" plywood shape, you can define the hull shape reasonably well by specifying all the corners. It would probably be a good idea for you to do a separate Hull Lines drawing, but it's possible to use the construction drawing for a small chine boat. You should include a Table of Offsets, which is a list of measured points along each corner, sufficient for the builder to lay out each curve as you intend. I think Brewer mentions this (don't have a copy handy) but if not, ask!

A professional designer would do calculations to figure out the amount and position of the weight of the boat, the underwater volume of the hull (also how much and where), and from all that, how she'll float. But plenty of good small boats have been built by sticking closely to known types. Pay attention to any other similar designs you can find, to make sure you have about as much immersed boat as they do, where they do. In other words, don't draw a lot of underwater boat forward and little aft, or vice-versa, because she won't float that way.

It's not a bad idea to build a poster paper model first, as soon as you have your hull lines, or even as a way of figuring out your hull lines. I like to put these together with tape or a hot glue gun. You can do a lot of adjusting of these pretty fast, to get what looks good to you. You can float it (briefly!) in the sink and it'll help you figure out the shapes to cut out of balsa or whatever, to make your final model.

I designed a boat when I was fifteen. I dragged it out for a look last month and it's actually not bad. Good luck!

 

Good reply, Chris. But I would like to take a different tack...

Elcapitan- Designing and building a boat would be a very challenging endeavor. But why not just build a boat of someone else's design? In my opinion, just BUILDING the boat would be a major accomplishment, wouldn't you agree?

Just consider a couple of practical things before you build. If you built one, would you have a place to use it? Do you have a place to build it? Do you have a backyard? a garage? A basement? A friend with a backyard who might be willing to team up with you? It sounds to me like it could be a team project. Afterall, the goal is to achieve a dream and if you can better do that with a partner, then it really wouldn't be cheating. Maybe you have a relative with space you could use for a few months? You could certainly do this outdoors, just using a tarp to cover your materials when not building.

With simple wood working tools (a couple of saws, sandpaper, files, screwdrivers, etc) and less than $200 or so, you can build a small kayak, canoe, or rowboat from common materials available at any home supply store (home depot, lowe's, etc.). You can even build a sailboat, using a tarp for a sail! You might want to use some powertools to speed up production (a drill, power screwdriver, sander, and maybe a jigsaw or circular saw would be all you could possibly need), but if you don't have access to these things, maybe there's an adult that you know who might be willing to make a couple of the more difficult cuts for you? If you draw out the lines it shouldn't take more than an hour or two of his time to help you out. Some guys here are real experts who could knock out one of these boats in just a single weekend, so if you're careful and ask a lot of questions, I'm sure you could do it in a year!

And the lessons you learn will definitely teach you a lot of things that will be applicable to building a boat of any size, or even designing one in the future.

There's a gentleman here named Lewisboats who designs very simple boats that seem very appropriate for first-time builders. Here's the link to his page-->LewisBoatWorks Most of his boats would make very nice cartop fishing vessels and, if you find one, you might even be able to attach a small trolling motor later on. Many of his boats are less than 12 feet long and require little more than a couple of pieces of plywood and some spare lumber.

Also, look at the PDRacer. This is a very simple little boat for spec racing. Yes, it's a race boat, intended for competition, super-cheap construction, fast building, and all around fun. It's a ridiculously low cost, boxy little boat. It won't win any beauty pagents, but it can get you into the water for the price of 2 sheets of exterior-grade plywood (from the home supply store) and a few simple pieces of wood and commonly available glue.

I don't know if these ideas will be feasible for you, but check them out and think about it before you rule out the possibility of building a real boat!


Ben

 

Toot, I agree there are boats that Alex could build, even in a semester. I'm in the middle of designing and building such a boat myself, in fact inspired by my own long ago fifteen-year-old designing and building experience. I'd still advise him to build a model first, especially of his own design. First of all, it's fun! And then, he'll learn a LOT about his design and about building, not least maybe the confidence to build full size. And then he can build the big one next semester!

 

Hey! I see that Elcapitan is from Raleigh, NC. Are there any members in that area? If Elcapitan is really interested in building a boat, maybe you could offer a little assistance in one form or another? *nudge nudge* Maybe you have some extra epoxy laying around, or some scraps of 2x2" pine, or glass tape, or some other such? Cuz you know, if you've finished building a boat lately, epoxy doesn't have an infinite shelf-life. I'd rather give it away than let it go to the dumpster. I doubt a small boat would need more than a half gallon.

Whoops!!! Sorry... this isn't my project. LOL
Elcapitan should decide what he wants to do for himself.

I just wanted to propose the building option to him. I remember when I was about 15, it seemed like a lot of projects were beyond my capabilities, but looking back on it, I could have done it if I had the right support.

So I just wanted to point out that if he wanted to build a boat, there might be some flesh-and-blood resources out in his area that might be able to help him make it a reality. For example, if he were in Chicago and he had the wood, I'd offer to cut it for him for one of those simpler designs. I mean, really, how hard would it be to cut a dozen 2x2's and 2 sheets of exterior ply for a 12 foot boat? Besides, my fancy circular saw, chop saw, scroll saw, etc just haven't been getting enough of a workout lately... and I doubt it would take more than an hour or so of my time...

But of course, the choice is his to make.

 

Hey, Toot, where were you when I was fifteen? <grin>

 

True. He could do both. In fact, he SHOULD do both. Maybe design his own and build a model, and then build a real one from somebody else's plans to get a feel for building. Then, he can make modifications, as necessary, to his design based upon his practical knowledge.

The reason I suggest plans building for him in particular is that, around here, I suspect he will get a LOT of technical assistance if he were to build, oh... I dunno... say... a Lewis Boat (paging Mr. Lewis!) whereas building his own design might make internet assistance a little more difficult. I know there's also a lot of internet info available on the PDR's as well so following one of these aforementioned designs for a fullsize project would ensure the highest likelihood for success.

 

Are you kidding me? That long ago, I probably wasn't even a twinkle in my daddy's eye!

 

Now, to actually answer the question Alex actually asked....

I suggest taking a look at some of the links available from Mr. Lewis' website. You'll see that a functional boat really doesn't need much at all-

A hull- a simple, slightly curved piece of plywood is fine for this. The hull keeps the water out of the bottom of the boat and lets it float.

Some bulkheads- sometimes as simple as a 2x4, the bulkheads keep the boat from flexing side-to-side and on smaller boats usually give you a place to sit.

A couple of stringers- running the length of the boat, the stringers give you something to attach the hull to and keep the boat from flexing stem-to-stern

and

A bit of freeboard- part of the hull, it's the distance from the waterline to the top edge of the boat so water doesn't flow over the bottom of the boat and sink you. The more weight you want to carry, or the bigger the waves, the more freeboard you need.

Every other thing you've ever seen on any boat in your entire life is just for showing off.

 

That long ago, I probably wasn't even a twinkle in my daddy's eye!

Sad but true. We get too soon old, and smart still seems out of reach.

 

Way to go Alex, no need to rush, it comes fast enough on it's own. Just like you at fifteen I made a model for school ( which really impressed the teacher and got me a perfect final mark, others made plans for and built chairs). The passion led to fixing up boats in yards and sailing schools. By the time I was twenty I was working on my own 36 footer. The 50 footer I am building now is close to a model I built when I was forteen. Keep up the dreaming.

Murielle

 

Wanted also to mention, get familiar with boat designing software. Make sure you still understand the good old ways of boat designing but CAD is the way boats are designed and will be now, it gives so much flexibility and quick info. Even working with an existing design but working it threw CAD will give you a lot for your futur projects.

Cheers
Murielle

 

if you have internet access, look for Greg Carlsons' free "Hulls"program. I have learned a lot playing around with it. not too sophisticated but a good learning tool

 

do you know where that program is available?

 

http://www.carlsondesign.com/#Fun_Shareware - that should take you right to the spot on the page.

Ron Fossum