Kamakura Period Large Sea Boat by catopower - FINISHED - Scale 1:50

[catopower]

Here's a nice short post for a change...

 

I'm constructing the rudder, or kaji, on the model in a similar fashion to what I've seen of the museum models. You'll notice that those models aren't very detailed in this area. Once I did was to use a separate rudder post, with the rudder itself glued onto that. The actual rudder and rudder post may have actually been a single piece. Given the size of tree needed to make up the hull, it's certainly not out of the question, as long as a single piece was sturdy enough.

 

 

There is a small hole at the top end of the rudder through which a rope was tied. This rope supports the weight of the rudder, making steering easier. The depth and large size of the rudder itself allows it to make up somewhat for the lack of a keel. Even so, I doubt that this type of boat could sail into the wind to any degree, relying instead on oarsmen for that.

 

As with later traditional Japanese boats, there were no rudder hinges. Instead the rudder post fit through a hole in the ōtoko, the great beam at the stern. The post is only slightly smaller than the opening in the ōtoko, and the opening is notched so that the rudder itself could pass through the notch, but the notch is too small for the rudder post to slip out. 

 

I've been reading recently that these were greased to allow easy movement of the rudder. But, friction meant that the hole would wear out over time and become enlarged and the ōtoko would need to be replaced. On the Hacchoro photo I showed in my last post, the rope tie-down was actually to secure the ōtoko. This could be untied and the ōtoko could be removed and easily replaced. This boat doesn't seem to have a similar tie-down feature, and I haven't been able to determine yet how the ōtoko was secured or removed.

 

 

[catopower]

Wow, this topic FINALLY went to 2 pages. It seemed like a lot of scrolling to get to the bottom of the first page – or is that just my imagination?

[cog]

press Ctrl + End ... way faster

[catopower]

Thanks Carl! But, I'm surprised at the length of page 1. I'm curious how the system decides when to paginate. It may just be a mystery of life...

 

Nothing to post about the model today. But, I do need to share that my brain turned to mush last night. I had the day off and was doing online research on some Facebook posts I saw recently regarding some boat types from the very southwestern corner of Japan's southern island of Kyūshū. The boats I ran across in posts looked similar, but all descriptions were in Japanese and I can only read a very small amount of Japanese. So, I end up doing a lot of online translation.

 

It takes a long time to translate and make sense of documents, figure out what their sources are, and then relate different documents together when they use different terms for similar types of boats.

 

In the end, I determined that I was looking at two distinctive types of boats, though they were closely related by rig and some of their hull features. For one of the types, there turned out to be a treasure trove of information on its design, sailing characteristics, construction and so on. Apparently, the information was collected by a man who's father built them. He collected the information so it wouldn't be lost forever.

 

At the same time, I found some old information on a former boat builder who became too old to continue the work. He turned to building models of his boats and there was information on an old exhibit that took place in a resort in the area where these boats were from. I think at least one of his models may still be on display there.

 

The type is called a Satsuma-han-sen or Satsuma-gata wasen, which simply means Satsuma-type Japanese traditional boat. Being built in the far south western corner of Japan, there is a lot of Okinawan influence (= Chinese influence) on the design of the rig. The information I found suggest heavy western influence and relates the rig to the lug rig. But, I think it's actually more related to the junk rig.

 

 

In any case, I was emailing back and forth with a couple people in Japan, checking with boatbuilder Douglas Brooks, translating text all day, looking up terms, referencing and updating my notes. Even with breaks, I barely got away from my computer and I think I shorted out my brain... 

 

But, on the positive side, I discovered that I had actually seen a replica of this type when I visited the Toba Sea-Folk Museum in Japan last year, and I have almost 2 dozen photos I took of the boat's details.

 

 

But, after all that, I'm not actually planning on modeling the boat, but just understanding the type and to keeping up-to-date with the wasen enthusiasts in Japan.

 

As soon as my brain solidifies, I'll get back to posting about the Kamakura period sea boat...

 

 

 

Edited September 26, 2017 by catopower

[Canute]

Clare, the workmanship to use all those wood pegs is beautiful. Their craftsmanship is superb.

[catopower]

Hi Ken, 

 

Are you're referring to those faceted red and white painted vertical posts on the end of the beam at the bow? I don't know the Japanese term for those. I've tried modeling them before, but I keep screwing up that faceting pattern. I have yet to be successful.

 

[Canute]

I was looking at the strakes with the diamond shaped pegs (?) at the stem. Inlays or pegs?

[cog]

Clare, it's a site wide setting in general x posts per page. So if you have a number of longer posts (a lot of text, images) it may look even longer ... It is not the number of text lines and pictures which is used. You do not have the limitation of paper x inches before the text wanders off ... in fact the internet page is infinite aparently, however, there are limitations, but I will not bother you with that knowledge

 

Looking good !

Edited September 26, 2017 by cog

[catopower]

Ken, those are actually rectangular mortises that were cut, plugged and painted. The painting is just decorative. The mortises are cut, and small rectangular pilot holes are cut through them into the stem to take large, flat, iron nails.

 

 

These are nails that I got from Douglas Brooks, who has a small supply of them for his own Japanese boatbuilding projects. The one on the right is an original, hand forged in Japan. The two on the left were made for him by an American blacksmith from galvanized steele. 

 

So, those designs you like are just painted plugs, the boat does have some nice carved design work. From what I've seen, carvings like this aren't all that common. Nor is the white paint of the mortise plugs. It just depends on the region. 

 

But, you might appreciate the bow of this boat built in Okinawa, which uses wooden fasteners. 

 

 

This image is of a boat called a Sabani. You can see more about it on Douglas Brooks's website.

 

 

[Canute]

Love those"bow-tie" fasteners. Very nice cutting them in, they look like decorative inlay.

 

The nails look like large cut nails that we use for flooring.

[cog]

I recall those nails from Brooks' book on Japanese boats. I love the picture with those double dovetailed joins on the bow. It really shows the "Genius of Japanese Carpentry"

[catopower]

Ken, if you like those fasteners, you'll love this boat. It's a kind of semi-dugout called a Dobune (doh-boo-nay). The were used up until the 1960s, I believe, off the Noto peninsula in the Sea of Japan. This is only a model of one, but take a look at the bow. 

 

 

The photo is courtesy of Douglas Brooks, who took it when he was in Japan working on a boatbuilding project in Himi last year.

 

And Carl, since you mentioned his book, let me take the opportunity to plug it here! This is a "must have" book if you're interesting in Japanese traditional boats. 

 

 

I can't recommend this book enough. It's not a cheap book, but it is loaded with information and it is written in a style that makes for easy and fascinating reading.

 

If you're interested, I recommend buying it direct from the author off of his website as it helps to support his research work: http://douglasbrooksboatbuilding.com/japanese_wooden_boatbuilding.html

 

 

Edited September 27, 2017 by catopower

[cog]

You are quite right Clare, it is one of my favorites on my bookshelf!

[Canute]

Clare, their woodworking skills are fantastic. The fasteners on that model are knockouts. Thanks for sharing.

[Jack12477]

I have a signed copy of his book. It is a facinating book as Clare says. 

[shipmodel]

Hi Clare - 

 

Just caught up with your fascinating build.  Great work.  I especially like how clean your woodworking is, one misplaced mortice notwithstanding.  Everything fits together perfectly, like a Japanese puzzle box.  

 

I found a folding chair and will join the appreciative audience.

 

Dan

 

[catopower]

Hi Dan, 

 

It's great to see you here – by all means pull up a chair. Thanks for the nice comments. Funny thing is that it often FEELS like I'm trying to figure out a puzzle box...

 

 

Ken,

 

I was originally looking at taken on a different boat to model, a net-fishing riverboat used on the Agano river in the Niigata prefecture. It uses a lot of those fasteners and I couldn't manage them in the small scale and type of wood I wanted to use, they were too soft. So, I turned my attention to the Kamakura period sea boat at 1/50 scale.

 

Most wasen models in Japan are either sugi (cedar) or hinoki (cypress). But, looking at the Dobune in that photo, you can tell from the wide, wavy grain pattern that it's a different wood. I suspect it's a much harder wood, which I think you'd need in order to cleanly use fasteners like that. I do want to experiment with modeling this feature at some point.

[catopower]

Okay, one last post about the Dobune. I found a few photos of a half-scale replica being built. The photos were on a Facebook page for boatbuilder Nasu-san. I don't recall his first name. He instructed Douglas Brooks on the building of a Ukai-bune, or cormorant fishing boat, earlier this year. Some of you who attended Douglas' talk in Mystic a couple years ago may also recall seeing a short video of Nasu-san pounding nails with a lively rhythm. 

 

I don't believe Nasu-san is building this replica, the photos were just on his page. There are more photos on Nasu Boatbuilding's Facebook page, if you're interested. It's in Japanese, though, but you'll find them in the Photos section: 那須造船

 

 

 

 

 

 

Note how the thick lower hull plank is actually more of a carved log. This type of construction seems pretty rare, and I believe it's considered a transition between the semi-structure hull type, as shown in my umibune model, and a structured, or fully planked hull. 

 

 

[shipmodel]

Hi Clare - 

 

Fascinating.  It reminds me a bit of the mortice and tenon construction of early Mediterranean boats, as well as the laced planks of Egyptian boats.  Am I right in interpreting the photos to show that the butterflies go all the way through?  Won't that cause weak points, especially where the butterflies are close together?

 

Dan

 

[catopower]

Hi Dan,

 

Good question. On one boat in particular, I have had that same question. But, on these boats, I'm sure the planking is too thick to run the fasteners all the way through.

 

I believe they're about as deep as that large fastener sitting on top of the wood in that last posted photo. So, the fasteners would have to be added to both faces of the planking. I don't know if they are done inline or staggered or if they even worried about it. I'll ask Douglas about it. Been meaning to do that because of the Aganogawa-bune, or Agano river boat, which is a beautiful, slender boat that his students at Middlebury College built a replica of.

 

 

Here's a photo from his blog, where he basically answers this question. A mortise is cut for the fastener, in this case, to the thickness of this fastener.

 

Douglas Brooks has a great blog site, which I think people here would really enjoy. Here's the entry for the fastener, which he refers to by the name used by his teacher in Okinawa, a huundu: http://blog.douglasbrooksboatbuilding.com/2009/12/huun-du.html

 

Oh, I just read in the blog that his teacher in Okinawa like to lay these out with an even stagger between the inside and outside. A very useful blog!

 

 

[catopower]

Time to get back to posting about the Kamakura period large sea boat...

 

First off, when I initially described the Japanese name Kamakura jidai no dai umibune, I may have been incorrect. I'm thinking now that it should actually be Kamakura jidai no taikaisen. Something to do with the way the Chinese characters are read, which I'm not so up on. For now, without the character for large, 大, (the full name written in Japanese is 鎌倉時代の大海船), it is still correctly read as an umibune or sea boat, so I'll do that. 

 

The next step after getting the raised planking into place was to start adding the yataka or the deckhouse. Now, this part of the build gets away from most boat building, as I think this is just a basic Japanese building structure that's been attached to a boat. Having built Woody Joe's Yakatabune kit may have helped a little. The overall structure is similar, though that boat was fashioned after those from the Edo period, which is 300+ years after this umibune. 

 

I had a hard time finding any information that helped, though I did buy the book The Genius of Japanese Carpentry, by S. Azby Brown, which did help me out a little bit. Mostly, it served to show me how little I know. Still, there were a couple pictures that showed features something similar to the umibune's deck house. Also, I built Woody Joe's Shinmei-zukuri shrine kit, which I hope would help a little in the old style building construction.

 

But, the umibune's deck house structure is very simple and lightweight. It is basically a frame work with a gabled roof which, on some paintings and models, pitches upward toward the peak. The only fixed walls are the lower half of the sides of the deck house. The ends appear to have been open, covered by no more than some kind of roll down screen, which I suspect must have been fastened down to the floor to keep it from flapping about in the wind. The upper half of the side walls was open, with a cover that is hinged at the top, and it usually depicted as hooked in an open position.

 

From the model that used to be in the Tokyo Museum of Maritime Science.

 

 

 

Using the above drawing, I began to lay out it out. Being fairly 

 

 

As you can see in the photo above, I reinforced some of the joints with wire, which has yet to be trimmed off. 

 

Also added are the remaining aft outer rails or segai, and the rowing platforms called rodai. 

 

Below is a birds-eye view with the mast temporarily stepped. Still haven't decided if I'll have it in sailing configuration or not.

 

 

And then a close-up of the beginnings of the deck house structure.

 

 

Just winging it here...

[druxey]

Delightful stuff, Claire! You are doing a beautiful job on this.

[cog]

"Just winging it here... "

          Doesn't look that way though ...

[catopower]

Thank you for the nice comments Druxey, Carl.

 

It feels a bit simple at times, given the purely straight lines of so much of this build!

 

 

[catopower]

It's been a while since I've update my build log. After a long stretch of overly quiet time with my regular job, things got really busy for a couple weeks. That was on top of a series of projects and tasks I needed to get done this week. Today was pretty much my first full day of rest after spending yesterday playing catch-up on all the things around the house that I've had to put off. 

 

Getting back to the Umibune here, but, unfortunately, I kind of jumped ahead without taking many intermediate step photos. 

 

As I mentioned before, this has build a project where I've been really trying to figure out the details of the subject as I'm building it. This has led to one issue of building the deck houses, or yakata, on the model as I go. With these fragile structures, it would have been a lot easier if I could have built them off the model. But, it is what it is.

 

As you can see, I started the framework for the aft structure and added a peak roof beam. I also added one to the main structure. You'll note that the roof of the aft structure runs perpendicular to the centerline of the vessel. Also, the frame construction is a little odd, because the aft section of the vessel narrow toward the stern. It's not all that clear how this affects the roof, as the reference drawing doesn't show a top-down view of the roofs, and the roof's shape is not discernible from the scroll painting. Since the walls don't actually cant inwards very much, I figure that it's simplest to build rectangular, as if all the joints were at 90 degree angles.

 

 

 

In addition to the deck house structures, there are a pair of cross-beams mounted up high on posts. I don't know exactly what these structures are for. But, often, the mast is shown leaning on them. Also, the height of the cross-beams is above the top of the roofs, so it might be possibly to lay something across the top, again, perhaps the mast. These were used to tie pole-mounted lanterns to (see the scroll painting) and might have also been used to tie banners.

 

 

I set the mast in a lowered position, leaning on the forward crossbar, but I don't know if that's how I'll display it. Still have to think about the sail.

 

You can see I also added the wall panels on the main yakata. I wasn't sure how these would have actually appeared. To me, it looked like these might have been something like rattan. Not wanting to weave these, I ended up taking very thin dowels and glueing them side-by-side to a wooden backing. When the glue was dry, I then pressed across the dowels at a 90 degree angle with a dull blade. This crushed them a little, making not only the cut, but leaving the suface slightly rounded at each cut. From a distance, I think they look okay. I will probably do the same thing for the upper panels, though they will be mounted in an open position, "hinged" open, and secured by some kind of hooks to the underside of the roof. At least that's the plan.

 

 

[Tigersteve]

Very cool project. 

Steve

[catopower]

Somehow, I managed to forget to post an update here, even though I have made some progress on the model. Unfortunately, I didn’t take many photos of certain intermediate steps. But, it's been over 6 months, so I'd better write something here!

 

 

Building the Yakata Roof

Not really knowing how the yakata or deck houses were constructed, I began working on the roof, hoping something would come to me at some point. The roof itself was a bit confusing, as the drawings I’ve been using and the models I’ve been following as guides differ in the matter of the roof boards, the shape of the roof , and details.

 

I've probably mentioned this before, but the scroll painting I’ve been referencing shows a curved rooftop with the roof boards running down from the top, and so does the drawing I'm using. However, some other models and drawings show boards that run lengthwise along the rooftop. Now, lengthwise boards make it easier to curve the rooftop, so that would seem to make sense. Even the museum model I've posted photos of has the boards running down from the rooftop, but with no curvature. Still, the scroll painting and drawing I'm using both show the curved roof board running down from the top. Well, I like the look of the roof in the scroll painting, and it is the only real historical record, correct or not.

 

I had already cut and glued up the roof tops before I was convinced to curve them, so I had to try to add the curvature after the fact. You can see the roof assemblies in the photo below, taken at a meeting of the Hyde Street Pier Model Shipwrights. 

 

 

I realized after gluing up the boards that I should have used used a waterproof glue, like Titebond III, or maybe II would have been okay. As it was I used Original Titebond, so soaking the planks for bending caused many of the glue joints to fail, though I didn’t really have to use that much soak time with this wood.

 

To bend a roof assembly, I simply clamped it between two heavy strips, dampened the wood, and applied pressure against the whole assembly. The amount of bend needed was pretty small, so this seemed to work well, bending each board in the assembly by about the same aount. Again, it wasn’t an ideal procedure, as I didn’t use waterproof glue, and the boards separated pretty easily when wet. But, they glued up easily after it was all done.

 

Now, if you look at the following close-up of one of the museum models, you can see the ends of closely space rafters sticking out. I was a bit puzzled as to how you can have rafters like this and have roof boards that run in the same direction unless the edges of the boards ride on the rafters, but this doesn't seem very stable. 

 

 

 

But this is all I had to work with at the time, so I just added rafters to the roof assembly at the seam of each of the boards. Only recently did I find a couple nice photos showing the underside of a roof that made more sense of this kind of structure. Now, it's too late for this model, but it's something I can maybe use in the future.

 

 

In any case, the roof were glued on, which made the model look a lot more complete, though there is still much to do...

 

 

 

[druxey]

Welcome back, Clare! Nice to see progress on your model.

[catopower]

Thank you, Druxey! 

 

Sorry I'm not more of a regular poster. Fortunately, this is a project that does keep moving forward, so there will be more posts. But, I only work on this one from time to time – it takes me a while to figure out what to do next and how to do it!

[catopower]

Some more pics to share...

 

You might have notice all the rails along the sides of the boat. You may have also wondered how they were fastened down to the beams. I don't know if this was true of all boats of this type, or if this changed over time, but I went with rope bindings that some models show.

 

 

Clearly such bindings weren't enough to keep the rails from slipping off the beams, but similar binding were used in the early days with the sculling oars where the handle section attaches to the shaft. Some kind of peg/key would likely have prevented the sliding, while the rope simply held the parts together.

 

Now, if the rope binding is used to hold the rails to the beams, why aren't they used to hold the rowing platforms to the rails? I don't know. Perhaps because those platforms are larger, and need to be very stable, they are fixed to the rails using a more sophisticated fastening.

 

In any case, on my model, I wanted to add these bidings. Here are some photos I took while experimenting with a GoPro camera I got last year...

 

I wonder how many of you do the same thing with glue? When I'm working with many knots, I put a dab of white glue on the back of my thumb, so I have a constant ready supply without having to reach for a glue bottle.

 

As for the bindings, I had to tie them carefully, so they all looked exactly the same as they wrapped around the beams and rails. In the photo below, you can see how they wrapped in kind of a figure-8 pattern, with the loops of the 8 wrapping underneath the beams. That hole in the bottom of the boat is where I glued in a piece of brass tubing to receive a mounting rod. There are a pair of these. The voids around the hole got filled in later.

 

 

 

Below, you can see the progress on the bindings, with most of them tied here.

 

 

You might also note the additional progress on the deck houses. Here, they have a central external beam attached. Also, note that the raised beams ("goal posts") have been changed. One of the round ones I had mounted earlier broke. So, I took the opportunity to change them to the rectangular style shown here. 

 

Pretty soon, I'm going to have to figure out how to finish the sides of that aft deck house...