Planking continues
Posted By admin on August 17, 2014
The crew has been making steady progress on the hull planking.
Here’s how things looked in mid June.
Port side
Starboard
The planks are trunnel fastened, with a few bronze hanging spikes to hold everything in place while the trunnels are set.
The butts are all spiked.
So are the hood ends.
In case you’re not familiar with trunnel fastening, it’s a great way to hold planks. The trunnels (aka “tree nails”) are made of locust. They’re often made in a machine that cuts them much like a pencil sharpener cuts a pencil. They’re cut to a set size, and then dried. This shrinks them a tiny bit. When the plank is installed, the carpenters drill holes through the plank and into the frame just a shade smaller (as in a few thousandths) than the trunnel diameter to insure a tight fit. The trunnel has a slot cut into it to accept a thin wedge.
The trunnel is driven into the plank using a large wooden mallet called a beetle.
Once the trunnel is driven into the hole, a wedge is set into the slot to lock the trunnel in place. The wedge widens the top of the trunnel ever so slightly and makes it act like the head of a nail.
As the trunnel gets wet, it expands and further locks into place. Even though the end grain of the trunnel is exposed to the water, the wood is so rot-resistant and compressed, you rarely see them rotting out.
One advantage of fastening with trunnels is that you don’t have to worry about hitting metal fasteners as you fair the hull. They don’t require bungs either, so they speed up the process of planking.
By mid-June, part of the lead ballast keel had been through bolted onto the keel.
The stairway leading down from the deck into the main salon has been set into place to show its location.
The deck beams are installed, and lodging knees are going in to brace everything.
That’s it for now!
Thanks again, Tom. Excellent photos– I love the curves of that hull, and the planks follow it like a charm, despite their being massive. Seeing that staircase in place was a real thrill too. Appreciate your service to those who can’t get there. One point: it might be helpful to explain the difference between “blind trunnels” and “through trunnels.” She was originally fastened with both, I suspect, though I do recall seeing (and driving a few) through trunnels in later years. Some very early examples of trunnels found in her planking were actually hand-carved apparently with a spoke-shave or some such tool. Must have been slow work!
Tim Murray
Square t runnels were driving threw a metal die to make em round and true. Then kerfed against the grain for blind or threw.