This week we’re doing project estimation & management. The task is to come up with as accurate an estimate as a newbie student can of how much it would cost to build a Herreshoff 12 1/2. We’ve got the construction plans for the boat, the Jamestown Distributers catalog, prices from our lumber and other materials suppliers … after that, it’s a slow steady process of coming up with a list of every single part that it will take to build the boat.

So, to do that, you build the boat in your head. The construction plan is invaluable here.

The first task of boat construction is the backbone. So, we look at the stem, keel, transom knee and transom. The drawing gives sided dimensions for some of these parts, and the rest we have to work out using a scale ruler.

Sided dimensions?? Oh man, I was hoping you wouldn’t pick up on that one. I’m sure I’m going to just bollix this up, but here goes.

Boat parts are measured in 3 dimensions: Sided, Molded, and Length, and they’re listed in tables of scantlings (essentially a parts list) in S x M x L format. The Sided dimension is often the dimension of the part that stays constant. For instance, if you look at a floor timber, you’ll see that it’s the same thickness front to back.

It’s not the same thickness side to side.. it’s taller at the outer edges than in the center. What normal folks would call the thickness is the Sided dimension here. The Molded dimension is usually the dimension that is curved, so the up-down dimension of this floor would be the Molded dimension. The Length is the dimension of the part following the grain of the wood. At least that one’s easy. The tricky bit is when you have a part that tapers along both its sides.
Herreshoff, for instance, is famous for tapering his frames from top to bottom. In that case, no faces are parallel (i.e., constant thickness), and the rule of thumb is to call the face that rests on a curve the molded face. So, let’s say you have a tapered frame that’s 1″ wide front to back at the top and 2″ wide front to back at the bottom; it’s also 1 1/2″ wide measured inside to outside at the top and 3″ wide inside to outside at the bottom. The Molded dimension is 3″ since that’s the thickest part of the part that’s resting on a curve. The Sided dimension is 2″ since that’s the thickest part of the part that is not resting on a curve. (BTW, here‘s where I grabbed that nice floor picture)

Or maybe I’m wrong. If you have a more concise or actually TRUE explanation, I’m all ears.
In our exercise, we’re working with the construction drawings, so everything is in 2D. In some cases, it’s a little tricky trying to figure out exactly what we’re looking at since a particular part may only show up as a little square if we’re looking at it on end in on one of the drawings.

IF you step back and grasp the scope of the task you’re up to, you’ll just put your pencil down and seek out the nearest chilled yeasty beverage. Or maybe a donut. Tough call. To keep your head in the game you have to narrow your focus and go through building the boat, one part at a time, in your head.

We start with the keel. Sided dimension on the keel is 1 1/8.” It curves from about 1 1/2″ wide at the forward end to about 8″ wide in the middle. Molded dimension is 8″. It’s about 8′ long. That gives us approximately 6 board feet of oak that we’ll need (board feet is measured as (Sided x Molded x Length) / 144 where all measurements are in inches). That’s good for pricing, but we need to make note that we’ll need that board to be at least 8′ long since we’re not going to be making our keel our of multiple short chunks of wood. We’ll need a chunk of wood that’s at least 6/4 (pronounced “six quarter,” meaning at least six quarters of an inch thick or 1 1/2″ thick) since stock is sold as 4/4, 6/4, 8/4 and on. We’ll also need stock that’s over 8″ wide to account for defects, sapwood, etc. Write down the finished dimensions we’ll need in our Table of Scantlings (accurate boat parts list), and write down the rough dimensions of the lumber we’ll need in our Materials List.
That’s part one. On to part two.

And so it goes. Part by part. Bird by Bird (thanks Anne Lamott).

I like setting up a spreadsheet for this.

Ok, if you’re a true geek you’ll notice that that’s a photo of a table of scantlings in Word. But honest, I made up a spreadsheet using the data I entered into that table. And no, that is NOT Star Wars fan fiction I’m working on on the left side either… it’s notes from class. Geez. I don’t live in mom’s basement, and I don’t go to GenCon, and I don’t have to worry about William Shatner telling me to get a life. Yet.

After that’s done, it’s time to go through the whole process again,
looking at the fasteners. How many screws does it take to hold this
plank in? What size? How many keel bolts? After that, how much paint will we need? How much varnish?

Of course, all that work is just a part of the picture.
If you’re building a boat in your head you start to see what you’ll need to produce each part as well as seeing the installation of the part itself. Since we’re estimating how much it’s going to cost to actually build this boat from scratch, we have to look at the whole process from start to finish. That means adding in the cost of the plywood we’ll use for the lofting and for making patterns. Paint for the lofting plywood and rollers to apply it. Drywall screws for holding the lofting plywood down. Pine stock for the frame molds, masking tape, pencils, battens… on and on.

Oh, and did I mention the cost of shop rental, heat, labor, insurance, and shipping?
Step away from the donuts. Step away from the six pack. Get focused, get back to work.
I’m not nearly done, but I’m working on it. Presentations are due Friday.