A Shipwright in Training

When I’d make an estimate of how long a particular project would take, my friends learned to apply a Tom Factor of roughly 2 or 3 times the original estimate.

Call me crazy, but I think other people have this problem as well…

Here’s the first stab we made at estimating how long this project would take. We did this about 2 weeks ago. The Whitehall estimates are in Blue.

It might be a bit hard to read these, but let’s highlight a few of the more optimistic ones:

Sept. 24, Molds Up (i.e., we’ve made all the forms for the boat and they’re attached to the floor and ready for the ribbands to be bent on them)

Oct. 5, Framed

Well, here it is, Sept 26th and we haven’t made a single mold yet.

We’re not really even close.

We’d estimated 2 days for lofting. It’s now 5 work days after returning from Mystic, and we’ve easily got one more full day of lofting ahead of us. That makes a Tom Factor of 3 so far.

The other day I said that we made a point of locking down the inner points first so that they didn’t have to move any more.

Well, that wasn’t exactly true either.

Life has a way of interfering with our plans.

Take this section of the long lines. You can see a couple of lines here in the center that are blue and red.

The blue ones are the original lines and the red ones are the corrections. When we were fairing out Diagonal B, we realized that this affected things that previously had been locked down.

Let’s go back to the body plan for a look.

When we drew out Diagonal B (the green line in this view) on the long lines, we found that it had a dip around Station 7. In order to correct this, we pushed Station 7 out along Diagonal B just a little, maybe 1/8th”. Diagonal distances are measured from the top downwards, so pushing the Sta. 7 batten down and to the left increases the distance it lies on the diagonal. On the long lines, this translates into the diagonal moving upwards. In the long lines photo above, you can see the red / blue lines arcing up and to the right have the corrected red line on the top. That’s Diagonal B as it looks in the long lines.

However, when you push the Station 7 batten down to increase the height of Diag B on the long lines, the batten also moves down along Buttock 3. If you imagine pushing that batten down a bit, you’ll see that the batten moves downwards on Butt 3. Buttocks are measured from the bottom up, so this has the effect of decreasing the hight of Butt 3 at Station 7 on the long lines. Again, looking up at the long line photo above, you’ll see that the lower red / blue lines arcing down and to the right have the red line below the blue one. That’s Butt 3 moving down.

Each time you move one thing, other things move along with it. And that’s the way it should be… all the parts of your boat are connected.

This has led to hours of staring and moving things around. You move one thing to get it fair and another thing looks like Ass. So, you move something else, or you split the difference, or you try to think of a 3rd option. It can make your brain hurt.

And so, after a full day on the lofting floor, we’ve got a few more long lines laid down. The satisfaction is that as we go, the corrections we’re making are smaller and smaller.

Thank God for that. I’m really ready to make things out of wood.

This entry was posted on Wednesday, September 26th, 2007 at 7:31 pm and is filed under Classes. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.