I’m playing a little “catch up” on my blog regarding the Oguraike boat. As a reminder, this is a boat used for fishing and sightseeing in Kyōto, which was the former capital of Japan, prior to the Edo period. The boats were used until the pond was drained in the 1930s as part of a reclaimation project. My model is a 1/10-scale reproduction, based on the research of Mr. Tomohiko Ogawa, an artist and boatbuilder living in Kyōto.
Again, I don’t know the term for the bottom connecting plank, but with it now in place, I went ahead and added these mortises. On the actual boat, nails are driven into the side, to fasten the plank to the shiki, or bottom board. Nails are also driven up through the bottom edge, to fasten the plank to the hull plank. On the real boat, it would make more sense for this to be nailed first to the hull plank, then that whole plank assembly nailed to the bottom board.
This type of construction seems like an evolution from the days when these bottom edge planks were actually log sections. If you go back far enough, these log sections were much larger, and were evolved from the original dugout hulls. Over time, these hulls were expanded by splitting them, and nailing then to center planks, expanding the hull width, while planks were fasted atop the hull pieces, deepening the whole hull.
In any case, I decided that the next step was naturally to add the hull planks. I cut two strips of Japanese cedar to size, soaked them, and clamped them to a board to bend them to their rough shape.
On the real boat, the planks were most likely bent in place, using props, not unlike this makeshift set up. While propped into place, the boards would have been fitted by saw, using a technique called suri-awase. If you’re curious about that technique, you should definitely visit the website of Douglas Brooks, or read his book, Japanese Wooden Boatbuilding. In my case, with a small model, fitting the plank into place is just a matter of using a plane and maybe a little sanding.
Planks were glued into place. While I don’t show it here, I used my temporary frame to clamp the planks into place at the proper angle. I learned sometime back that it’s always best to leave the planks a little long. The ends can always be cut at a proper angle later.
I also make sure to cut the plank a little wider than necessary. This is actually in keeping with actual Japanese boatbuilding practice. A batten is used to mark a fair line for shaping the edge of the plank. Again, not unlike the way the actual boats are built.
In my case, you may notice that I built my temporary frame to allow some space for the battens to lay nicely against the inside of the hull planks. With the battens clamped into place, I can mark the top edge of the hull planks with a pencil. Then, I use the micro plane to shave away the excess wood. This makes a lot of nice smelling shavings – the best part about working with Japanese cedar.
For the beams, or funabari, I again used Japanese cedar, though on many wasen, parts like these and stems are made from hinoki, or Japanese cypress. For me, the biggest problem with using Japanese cedar is that the thickest wood I can get is about 6mm, which is not thick enough for beams. So, I have to laminate wood together to get the needed thickness. Because of the grain structure, this sometime requires a little matching, so the two layer construction isn’t so obvious.
The main beams for the Oguraike boat are pretty simple, as they don’t the edge of the boat, at least not in any way that’s visible. So, fitting them is pretty easy to do. The ends simply need to be shaped to fit the angle and curvature of the hull planks.
The final step that I’ll mention here is the addition of the uwakoberi, or the cap rail. This is pretty simple, as it’s a thin piece of wood that’s a little wider than the thickness of the hull planks. This has to be edge-bent to fit nicely on the hull planking. Japanese cedar is very soft, and with a short soak, is clamped to the work board and bent to shape.
The bend doesn’t often take too well, but for a piece this thin, I don’t worry about it too much, as afterwards, I can go ahead and glue the strips and pretty easily hold them into place with clamps and rubber bands.
The last thing I’ll cover here is the fitting of the forward most main beam. There are really three main beams on this boat, all fitted to the main hull. There is one more smaller beam, but that will be fitted to the bow section later.
The forward main beam has extensions that actually fit across the top of a notch cut into the cap rail. So, I had to cut away this part of the cap rail. Cutting this section is pretty easy, as the cutout is really along the whole forward end of the cap rail. Later, there is a wider cap on the bow section that fit’s into the end of this piece.
Now, one thing I did, which I find I probably should have done, was to glue the beams into place at this stage. I did this to give the hull some strength, as the planks are really unsupported. However, this prevented me from using the temporary hull former framework to aid me in attaching the bow. But, more on that later.
Next up is the fitting of the transom, which turnout out to be quite a challenge for me, as I had no guide as to how this was done in real life. Perhaps in some museum somewhere, there is recorded the method for how this type of boat was built, with it’s log-style transom and separate bow. I’ll definitely be bringing this up with the wasen study group.
By the way, this type of hull is very much like that of a well know type of large river yacht, or kawagozabune. Mr. Taketoshi Tanaka, former president of The Rope Tokyo, recently completed a model of this type, so perhaps I will try to contact him about it.
I don’t know if you can see it very well, but this model of a kawagozabune from the Tokyo Museum of Maritime Science has a general hull construction style that is very similar to the Oguraike boat, just much larger.
In any case, in the next post I’ll be wresting with the transom, probably for the entire post…