I’ve been spending a fair bit of time working on the drawing(s) for the lattice pattern in the lantern head openings. When I set out on this exploration – you may recall from the first post in this thread – I had decided that the ‘X’ pattern shown in the sample lantern picture was not attractive to me. The ‘X’ form is not generally considered attractive visually to the Japanese either, who associate it to a gesture made with crossed forearms, and the term batsu!, which means no go, don’t do (that), wrong, etc…
Poor fellow – not looking too happy now is he? The negative connotation to the ‘X’ symbol is one of the reasons, it seems, why diagonal bracing is generally concealed in Japanese structures – it may be considered bad luck to put such a negative symbol in plain view. Also, there is the aspect of visual harmony with a form composed mostly of layered horizontal and vertical grid work, and the introduction of diagonal elements doesn’t mesh so well visually.
The lanterns I have looked at have a wide variety of foms and varying patterns in their grill work. This is perhaps one of the most typical sort of examples:
The example above with the non-splayed posts I find quite unappealing (it is however much simpler to make!). Also, the dense mass of crossing kumiko would block out a fair percentage of light getting through, which seems unfortunate, and the frames for the kumiko are altogether too thick for my liking. batsu on that!
Some lanterns take the vertical kumiko and tilt them in parallel with the splayed posts, like this example:
Mulling the design over for a while, and drawing from a pattern I used in the large door of the Bubinga step-tansu (which I detailed in posts back in January), I came up with this design:
I like the suggestion of rotation that this design gives, the shorter bars also could be considered shibui, somehow incomplete, not quite reaching their potential, perhaps haing lost their former fullness….
And that above design was what I was planning to go with until I had the upper ring of keta installed (detailed in the previous post). I then considered the fact that without any intermediate girts strengthening the lantern housing (as some lanterns have), the lantern head *might* be vulnerable to torsional loading. The splayed posts do a great job of resisting shear loads, but if the roof were grabbed by someone and twisted, all that would be resiting such a load would be the post tenons top and bottom, along with their pegs.
Thus I began to reconsider the ‘X’ bracing option, which would provide reinforcement for such possibilities. I still found the simple ‘X’ pattern of two crossed bars unappealing, however, I little doodling and thought about it led me to the following design, which borrows a bit from the previous iteration:
This SketchUp drawing took me several attempts to complete – part of the reason the drawing is separate out from the rest of the lantern structure. The form may appear simple enough, but the joinery for the kumiko as the points where they attach to the frame are compound in nature. The upper and lower frame pieces are parallelogram-shaped. The joinery should be entertaining.
I’m pleased with the look though, and think it will cast a nice pattern on the ground. Also, the pattern suggests the way in which the support post for this lantern is made, of four interlocked pieces.
Next in this series I will show the installation of the ridgepole, as I had planned earlier. Soon after that I will start working on the lattice frames along with the roofing boards and roof structural components. Stay tuned for post 18.