Is it Fair?

One of the definitions for the word "fair" from Merriam-Webster is...pleasing to the eye or mind especially because of fresh, charming, or flawless quality. This definition most resembles the use of the word fair when describing the lines of a boat. Or as my instructor would say, a fair line is any line that when drawn requires a choir of angels from heaven to sing. Today was Day 3 (off for Veterans Day yesterday) of the Drafting Course. We are working on the "Sixteen" which is as you may have guessed a 16-foot long boat. You may ask why not just use a computer-aided-design program? Good question. I think the purpose of drafting the lines of a boat by hand is part of the natural process of learning why and how things are done. The information learned in drafting will be applied to the lofting process but in a larger scale. Besides drafting can be fun! How fun is it to have the computer do all the work for you? The main purpose of drafting (by hand or computer) is to fair the lines of the boat for planking. The process of drafting the lines will ultimately correct and prove out the fairness before lofting.

The lines of the boat are shown in three views:

• Plan view (looking forward and aft)
• Profile (side view)
• Half breadth (looking from above down on half of the boat)

The process of drafting can be simplified into the following steps:

1. Drawing the grid (baseline, center line, aft and forward perpendiculars, water lines, buttocks and diagonals) on the backside of the vellum.
2. Drawing the master lines (sheer, stem/keel, rabbet, transom rake and load water line) on the front side.
3. Drawing Stations 2,4,6 and the Transom.
4. Developing Water Line 2A
5. Developing Diagonal C

Once those lines are plotted the remaining water lines, buttocks and diagonals can be developed. The transom is also rolled-out in detail as well. Finally, comparing the lines plotted in the half-breadth view and profile can be compared to the plan view thus "proving out" the correctness of the lines.

On Friday we will take our drawing and use it to build a half-hull model of the boat. On an interesting side note...Sean showed us today how to use a "Half-hull Contraption" to develop the station lines from a half-hull model. This is basically the reverse of what we are doing in class. In some instances a half-hull model is built by hand and the lines are faired by eye. This information is than transferred from the model to the hull. Pretty cool indeed!