Proposed Article: Boatbuilding

A Two-part Article with Plans and Instructions for Building a Wooden Boat
Proposal by Tay Vaughan
March, 1987
--- Never Finished ---

INTRODUCTION

Many people perceive the design and building of fine wooden boats as a magical art undertaken by wizened old timers who sit with sharpened pencils at slanted drawing boards and work with hammers and hand planes in shops filled with sawdust and shavings and the smoky smell of pot-bellied stoves.

The truth is, however, that boats are really like television sets and houses and airplanes; they are the assembled result of a logical sequence of understandable activities during which available parts and materials are made into a finished product. By reducing the boat design and building process to its step-by-step components, this art becomes science and the magic becomes reality, and most anybody can actually build a boat in his (or her) garage or basement.

In the first part of this article, we will explore the science involved in designing a boat. We will use a program called AutoYacht to develop the shape of the hull itself, and we will use Versa Cad to add detailing and script to the plans. We will outline each step in the process and will use the new three-dimensional spreadsheet, BoeingCalc, to predict costs and to organize our list of required materials. In the second part, we will take our plans and materials list and actually build the boat in a simple step-by-step cookbook procedure. You will be surprised how easy it is!

PART ONE: THE DESIGN

We begin with what a naval architect calls the "design criteria". These are simply a boat owner's performance and service requirements. How many people, what power, for ocean or lake use, spartan or fancy ... these determine the final design of the craft. For this boat-building project we have imposed the following criteria under the assumption that this may be the first boat you have ever built:

Inexpensive Light-weight Easy to build 2501b. payload Self -propelled in case you make a Big Mistake; so you can lift it onto a car rack; so you don't need special tools or skills; to carry at least one person with gear; because oars are cheaper than motors.

General design criteria such as these then become the designer's guideposts as he makes detailed decisions regarding the architecture of the boat. Some woods will bend better than others without steaming or soaking. Plywood is least expensive when purchased in four by eight foot dimensions. Most lumber is sold in two-foot length increments. Number six-sized wood screws have smaller heads than number eights, and may pull through thin plywood which is bent or cold-molded under tension. A designer's practical experience and intuition, carefully brought to bear on the creative process, is where the magic and mystery are most likely to enter a novitiate's view of the process. Thus, as we develop the design of our wooden boat, we will clarify these decisions so that the more you understand, the more will the magic and mystery be reduced to natural law.

Knowing our weight payload requirements, we can determine approximate size. The ancient Greek philosopher and scientist Archimedes determined that a floating vessel displaces a volume of water of a weight equal to her own weight and all she contains. Quoted from a classic 1927 text on ship stability, in this case "her" refers to the vessel, of course. In pure science there is seldom a mermaid or even a fat lady in a tub of water. However, you may yourself test the Archimedes principle by collecting and measuring the runoff from your own bathtub: a cubic foot of fresh water weighs about 64 pounds. Salt water would weigh 25 ounces more per cubic foot and on large vessels carrying great loads of cargo, salinity is a significant hydrostatic consideration. For our boat, we will include a huge safety margin and ignore these differences.

Shape is another thing altogether. Determining a vessel's form is where CAD programs are very useful. According to Archimedes, you could go to sea in a stiff cardboard box as long as its displacement volume were enough to support your weight (with a little extra volume for freeboard so waves don't splash over the gunwale and put you under). However, a box is not the sleek shape we have in mind for our project and is better left to supertankers and container ships which are, indeed, nothing but simple rectangular shapes with rounded ends and far less complex in form than most yachts.

The graceful moulded lines seen in many production boats on the showroom floor can be easily drawn using AutoYacht and a computer.

Press Fl to view typical hull drawings.

The Mysteries of boat design, you see, are discovered in cantations such as Master Curve, Prismatic Coefficient, Metacentric Height, and Quadratic B-spline, descriptive terms used regularly by the priesthood but fearsomely difficult for the uninitiated! You may be relieved to know that we will not be studying calculus, geometry, and other mathematical tricks before we design and build our boat. We will just go ahead and start, which is the same reasonable approach taken by many computer literates when they boot up new software without reading the accompanying instructions. Just keep in mind that these mysteries have science at their root, and science can be learned by most people. Specialized CAD programs such as AutoYacht automate a great deal of the science and math. And as the computer literates have found, you can always go back to the manual; if you wish to learn the finest details and concepts, texts are available and are referenced in the appended bibliography. As we begin to develop the lines of our boat around the design criteria listed above, we begin to make the first of many compromises. The nicest-looking lines may be easily constructed in fiberglass, but that's expensive and perhaps too difficult for us (and smells of styrene and acetone). Straight lines are easier to build than curves, but we don't want our sleek boat to look like a container ship. We want it to move through the water with some grace and stature. So maybe we will mix straight lines with a few simple curves.

Press F2 to view the first lines of our boat

.......................... End of Sample Draft for PClife.........................


N.B.
PC Life was a disk magazine for the IBM PC published starting in 1986 in Syracuse, New York by publisher and editor Mike Sullivan. In contrast to the mostly text-based disk magazines in existence at the time, PC Life was more graphical and multimedia in style, with various animation and interaction, although the extent of the graphical style was limited by the technology of the time which required that the publication fit on a floppy disk and be compatible with CGA graphics. It lasted through 1988, publishing two issues in each of three volumes. [From https://en.wikipedia.org/wiki/PC_Life]