Tuesday, July 13, 2021

Lines-Taking at the Apprenticeshop

For the last year I’ve been having an interesting correspondence with someone who I believe found me via the lofting page at my website. I loft boats — drawing them full-size — on sheets of large format paper for amateur boatbuilders. Lofting is the first step in traditional boatbuilding, a method of deriving fair and accurate patterns for building moulds. Its use overlapped the former method of designing and building boats and ships from half models carved of wood. While I loft boats from a designer’s drawings (specifically their table of offsets), it is also possible to measure an existing boat and record its measured shape. This is called lines-taking and in my early work for museums I’ve measured many boats, including helping measure the lines of the 220' three-masted lumber schooner CA Thayer at the maritime museum in San Francisco. Josef remembered a favorite rowing boat from his days studying at the Apprenticeshop in Rockland, Maine, one he said was built largely by eye, modified from an L. Francis Herreshoff 17-foot rowboat. Josef had donated the boat to the Apprenticeshop but decided he wanted to document its shape for future reference. We worked out a schedule coinciding with the Apprenticeshop’s summer break and met in Rockland.
I like to loft small boats on a table. Standing is far more comfortable than working on the mould loft floor. I use a series of hollow core doors for a table, cleated together and carefully made flat atop sawhorses. We rolled out the paper and established a baseline along one edge then carefully placed the centerline of the boat above the line. We then marked off sections square to the centerline two-feet apart, matching the location of the frames in the boat. We would measure the boat at these two-foot cross sections, as well as the bow and stern profiles. We didn’t use a level on either the table or boat. What we did do was square the boat to the surface of the table. Many boats will show a twist due to age or perhaps dating from their construction. In our case the stem and sternpost were within an 1/8” of each other, a nice break in our favor.
For years I would measure boats by setting up a right angle, essentially an X and Y axis, and recording points on the hull. Taking a horizontal and vertical measurement to a rounded hull can risk some inaccuracy as the measuring point is meeting the hull at an acute angle. Barry Thomas, the former boatbuilder at Mystic Seaport, published an article describing his method, which in my opinion is far superior. I’ve modified it a bit but basically Thomas would mount a piece of paper to a plywood backing clamped along the section lines and squared upright. Using a tick stick one can touch points on the hull and meeting the hull at right angles improves the accuracy. Tracing the stick references the point. Not visible in this photo is a reference line we drew parallel to the centerline 20” from it. Each time we set up paper to measure a section we marked the point on the paper at the 20” reference line. We also took measurements at each lap, so in addition to getting the hull shape we also recorded how the planks are lined off, a big time-saver if Josef decides to build this boat.
The 20” reference point is visible at the bottom left edge of the paper (be sure to click on these photos to enlarge them for a better view). The tick stick tracings are carefully labelled showing what plank they represent. The metal blade of my bevel gauge was used where there wasn’t room to fit our tick stick. The notches in the tick stick ensure that we orient it correctly at our next step.
A shot of Josef using the small blade to record under the hull. The boat was blocked up on a pair of 4x4s to give us some room to work underneath.
Josef recording the shape of the stem face. He also slid the tick stick alongside the stem to record the rabbet line at each plank lap. At this point that piece of paper was crowded with marks, so good labeling is extremely important.
A look at our setup. Josef has just drawn a new centerline along the right edge of the paper and we are starting to loft the lines of the boat.
We lay each sheet of paper down on our lofting, referencing its bottom edge along our baseline and aligning the 20” reference mark with a point 20” from our vertical centerline (we are now working in a sectional view of the hull). The stick is laid back on each tracing and the point is marked. You can see the series of points lie in the cross-sectional shape of the boat at that station. We then take a thin batten and lay it on these points and draw the shape.
From our sections we can get heights and half-breadths that allow us to start drawing the boat full-size in profile and plan views. We’ve removed the boat and Josef is setting a batten along a plank line. For this boat, rather than lofting true waterlines and buttock lines (vertical and horizontal planes of the hull) we lofted the plank laps. It does the same thing, fairing and checking the accuracy of our sections shapes. In this case none of our points was off more than an 1/8” and most were exactly right. This lines-taking method really offers astounding accuracy. When we were done Josef rolled up the lofting to take home. He can later convert it into a scale drawing or at any time use it to build a replica. Douglas Brooks 84 South Maple Street Vergennes, Vermont 05491 USA (802) 877-3289 www.douglasbrooksboatbuilding.com http://blog.douglasbrooksboatbuilding.com https://www.instagram.com/douglasbrooksboatbuilding/ http://douglasbrooksboatbuilding.com/index_j.html 日本語

Sunday, July 19, 2020

New Book On Building the Cormorant Fishing Boat

I've posted to my Instagram page a link for a free digital download of my latest book, which chronicles my 2017 project building a traditional cormorant fishing boat in Gifu, Japan. Along with others I documented the work of Mr. Seichi Nasu, who was eighty-five at the time we worked together. The publisher is Tobunken, a division of the Japanese Ministry of Culture.


You can copy and paste the link shown there into your browser and in a minute or so the manuscript will download. Its in Japanese but you can enjoy the photos and drawings.

I blogged about this project back in the Spring of 2017 so you can go back and look at the construction of the boat in more detail. One fun thing that happened was posting a video of Nasu san nailing, which went mildly viral at my Instagram. You can see it for yourself here.

I am currently working with my publisher in Connecticut on an English version of the book. I will definitely announce it on social media once its published, hopefully before the end of the year.

Friday, April 17, 2020

Do-It-Yourself Waterstone

Three years ago I blogged here about meeting Japan's only full-time miner and maker of natural waterstones. Without repeating what I wrote, here is the link:

A week ago I was walking my dog in the park below the falls in my town of Vergennes, Vermont. The park where we walked is visible to the left of the falls. My dog ran up the hillside and following him I noticed the entire hillside was covered with hundreds of stone offcuts. Each had natural irregular faces and one sawn face. The stone is a kind of green slate, I think. Obviously, these are all offcuts of some operation making finished stone, but what struck me was how flat the sawn faces were. I wondered if the stone might be good for sharpening, because I remember in talking to the Japanese miner, struggling to translate the Japanese name for the type of stone he uses, and our online dictionary coming up with the English terms "tuff" and "slate."

My block was irregular so I wanted to saw off one part.

I noticed a natural split and took a chance and it broke easily and got me nearly what I wanted.

I trimmed the rest with my saw using a $5 composition masonry blade. It cut easily, so I had a suspicion it would make a good sharpening stone.

Here is my block with the original sawn face up.

Using some water and my #150 grit diamond stone I was able to very quickly flatten it.

It looks like a very nice surface.

I did some sharpening on one of my plane blades and got a nice, mirrored finish. The stone seems soft enough to give away but still make a polished edge. I don't see any sign that it wants to fracture more. At over three inches thick I think I should get my money's worth out of it.

Friday, January 31, 2020

2020 Middlebury Winter Term - The Japanese Teahouse

This month I taught my fourth Winter Term at Middlebury College in Middlebury, Vermont. Previously I have built traditional Japanese boats with my students but this year, in consultation with Pieter Broucke, Dean of Art and Architecture, we decided to teach a structure. I chose the Japanese teahouse. Like my previous classes, the real subject (for me, anyway) was introducing students to the pedagogy of Japanese apprenticeship, something I know a little bit about, having studied with nine boatbuilders from throughout Japan.

As much as we can, we maintain a completely silent workshop. I try to give the briefest of introductions each day and then the students work in silence. Outside of the workshop they have readings about Japanese carpentry and apprenticeship, they journal and write papers. The idea is to try and create the kind of environment I have had to work/study in in Japan.

Except for an electric drill all work was done by hand.

Half lap dovetail for our tie-beams.

We did an initial partial assemble in our workshop.

Mortising the ridge beam for our rafters.

Our main carrying beam was very heavy, and had to be taken down the stairwell to our final site.

The finished teahouse frame was erected in the main lobby of Johnson Memorial.

The main beam was lifted in place by hand. The rope and block were for safety.

Fitting the natural post, which was buckthorn cut from College lands.

I designed a very simple teahouse around a six-mat tatami floor. At one end we incorporated a natural post bordering our tokonoma display alcove, which has a cherry floor.

A look at the main beam with posts supporting our ridge.

The class waiting for our dedication.

We had a crowd of about seventy-five people.

Pieter Broucke at our Shinto alter. Our first ceremony was for the carpenters and involved purifying them and the structure through some common Shinto rituals.

Then Ms. Yui Kato, an exchange student from Tokyo and a licensed tea master, conducted a tea ceremony.

We are exploring simple ways to infill the walls of the teahouse, including a combination of burlap hangings and shoji panels.

The view on the way home after the last day of class.

Sunday, December 8, 2019

Two Kyoto Bucket Makers

Now just back from building two boats in Japan. Just before leaving I visited two bucket makers in Kyoto whom I have profiled at this blog before, Nakagawa san and Kondo san. Nakagawa san is Kondo san’s former teacher. Nakagawa san currently has four apprentices. He is working with some European designers on his vessels.

Note how Nakagawa san rives wood at knots to get curved material for spoons, etc. Kondo san’s Japanese “shaving horse” (video) is also interesting, as is the making of sokui, or rice glue (video).



Friday, November 8, 2019

Now in Japan Building Two Boats

Blog post updated December 11, 2019.

This will be a very short post, one just to share with you a link to another blog where we will be posting information about the project currently underway. Look at this post weekly for updates through the month of November:


I hope you enjoy the text, photos, and video.

This research was supported by grants from the US-Japan Foundation, the Traditional Small Craft Association John Gardner Grant, the Niigata Arts Council, and an Indiegogo crowdfunding campaign. The project was in cooperation with The Apprenticeshop, America's oldest boatbuilding school located in Rockland, Maine.

Monday, September 16, 2019

Announcement - New Research Initiative in Japan

Last year I proposed a partnership with the Apprenticeshop, America's oldest boatbuilding school in Rockland, Maine, creating a boatbuilding exchange program in Japan. At the end of October I, along with Nina Noah, Director of Student Affairs and Outreach for the Apprenticeshop, will be going to Japan to work with a pair of boatbuilders making two traditional boats. We want to work together to develop projects in Japan where we can bring boatbuilding students to participate. We have a crowdfunding campaign here that is active until the end of October, 2019:

I invite you to visit our campaign, where you can learn much more about what we are doing. If you are a long-time visitor to this blog you know the scope of my research. I feel strongly that it is time to disseminate and teach these skills as much as possible, and I believe a boatbuilding school is the best way to do it.

Thank you for your consideration,

Douglas Brooks