Aspects of a Shiingen tsuba structure and some wild speculations from my side...

[zanilu]

Good morning everybody!

 

I have in my collection this Shingen tsuba:

 

 

 

Dimensions 86.9 mm x 87.4 mm, thickness 4.6 mm at seppa-dai, 5.7 mm at mimi.
It is rond shape (marugata - 丸形) with a three layers structure of brass and iron (tetsu/shinchū san-mai shitate - 鉄・真鍮三枚仕立). The the main decoration is made of woven brass wire (sinchū harigane amiko (真鍮針 金編込) while the central brass plates and the fukurin (覆輪) are decorated with small flower-like punch marks (kohana ishime-ji - 小花石目地). The two hitsuana (櫃孔) are 
also lined in brass.

The following aspects can be noted:

1. The tsuba has an iron core that extends from the nakago-ana (中心孔) to the brass fukurin (覆輪). A magnet is continuously attracted to it going from the center to the outer edge. The iron core seems to be a solid plate underneath the woven brass wires of the main decoration of the tsuba. See Figure 2.
2. The “radial” wires are passing through holes in the central brass plates that are staggered between the omote (表) and ura (裏) sides. Those on the ura side are located approximately  halfway between those on the omote side. See Figure 6, where the holes on the omote central plate are shown as withe dots. The corresponding holes on the ura plate are located at the end of the red dashed lines. The holes show, in most cases, a lot of burr on their edges, see Figure 3.
3. Underneath the “radial” and woven wires, here and there, a “stray” wire can be seen running    on top of the iron core at an angle relative to the “radial” wires, see Figure 1.77. These    “stray” wires seem to have a diameter similar to those of the woven wires.
4. Looking from the outside toward the center of the tsuba in the area where the central brass plate ends where the “radial” wires are we can see that below the holes in the central brass  plate there is a sort of cavity in the iron core, see Figure 6.
5. The thickness of the brass plates is approximately 0.6 mm, for both the central one and the  fukurin. The “radial” brass wire have a diamter of approximately 1.2 mm, the woven ones of 0.6 mm.

 

This is what I have seen so far. What  follows is just speculation based on the above evidence and some imagination from my side.

The arrangement of the “radial” wires, with the staggered holes in the omote and ura central pates, suggest that they are not individual wires but are rather a single wire woven in some way around the iron core. The iron core shall have some kind of opening allowing the wires to go from the omote to the ura central brass plates as shown in Figure 7. The wire is then woven around the circular crown between the openings and in the center and the edge of the iron core to form the “radial” wires.

To keep the omote and ura brass plate are extremely important for the weaving of the “radial” wires thus they are likely held in place and secured to the iron core by brass pins hammered and chiseled to hide them.

 

Figure 2

 

Figure 3

 

Figure 4

 

Figure 5

 

Figure 6: Schematics of FT-0142 obtained by tracing on top of overlapped images of the omote (表) and ura (裏) sides. The woven brass wires are not reported for the sake of clarity. Blue stands for the brass plate, red for the brass wires and grey for the iron core plate. The “radial” brass wires on the omote side are reported continuous lines. Those on the ura as dashed lines.

 

Figure 7: Possible shape of the iron core with holes passing through to allow a single brass wire to be woven around the circular crown between the holes and the core edge. The portion of wire that are not visible are shown in purple.

 

What is your opinion? Do any of you have additional information on the construction of this kind of Shingen tsuba, maybe from damaged ones? 
Please feel free to contribute with any idea or fancy hypothesis!

Regards
Luca

[Brian]

Fantastic analysis Luca! I may have to turn this into an article. Well done.

[b.hennick]

Thanks for the great analysis. I will look at shingen tsuba differently now.

[zanilu]

Thanks Brian 

 

1 hour ago, Brian said:

Fantastic analysis Luca! I may have to turn this into an article. Well done.

No need to do it. I am working on a review on Shingen tsuba similar to that I already did for Kaga Yoshiro.

 

Regards

Luca

[Toryu2020]

Tremendous example - very interesting analysis.

 

-t

[Steves87]

Excellent, thank you for sharing.

I have seen examples before with what looks like lacquer between the wires. I used to assume this was for holding the wires still, or for preventing rust from forming internally. This example you have does not appear to have this, some do, some don't.

Do you think oxidisation of the iron core is possible for this construction, without the lacquer present?

Was this by any chance the Shingen Tsuba from the G. Murtha collection?

[zanilu]

Hi Stephen 

 

No traces of lacquer on this piece, and as far as I can tell from pictures also on similar pieces from the same class of Shingen. 

If you have seen examples like this one with lacquer it would be interesting if you can post some images. 

 

On the contrary there is a lot of black lacquer on other styles of Shingen Tsuba. Like this one for example 

 

 

In the close up shots you can see some corrosion on the iron core but nothing major. If there is relevant corrosion in other ares I can not tell. 

 

The Tsuba is coming straight out of Japan. I do not know nothing about it's whereabouts before that. 

 

Regards 

Luca 

[Steves87]

Thanks Luca, you have no doubt seen this Web page https://varshavskycollection.com/shingen-tsuba/ but it appears some of the examples are similar to your style of Shingen. It is hard to tell, but some appear to have the lacquer on them?

[zanilu]

Stephen 

 

I am aware of Mr. Varshawsky  site. In fact I used it as a reference for the historical prespective in the evolution of the definition of Shingen tsuba.

Not all the pictures of the website have enough resolution to allow to see the presence of lacquer on this kind of tsuba. On some it seems there is lacquer on others not. On higher resolution pictures found on the web or on books in my library there seems to be no lacquer. I have no definitive answer at the moment. 

For sure on the piece in my collection there are no traces of lacquer in the woven brass wire region.

 

Regards

Luca