Official

Before you can see the construction of the bridge, I would like to introduce the outline of the bridge, though Zakuri.

If you look at the map from the upstream of the Nihonbashi River, there are quite a few bridges connecting Chuo-ku and Chiyoda-ku, such as Ryukan Sakura Bridge, JR Bridge, Shin Tokiwa Bridge, Joban Bridge, and Tokiwa Bridge.

There are three bridges named "Tokiwabashi", but the middle is "Tokiwabashi (formerly Tokiwa Bridge)". This is the place where the bridge has been built for the first time. During the Edo period, this place was the Masugatamon, Tokiwa Hashikado, located on the outer edge of Edo Castle, where a wooden bridge was built. In the Meiji era, the gates of other outer edges of Edo Castle were demolished, but the stone walls of other broken gates were used, and this bridge was replaced from wooden bridges to stone bridges in 1877. You. It is considered to be the first bridge where Western culture was represented on a bridge.

After that, at the end of the bridge of this double arch, the Bank of Japan head office designed by Kingo Tatsuno will be built.

This Western-style Ishibashi and building have come to be included in the photo as a picture-like landscape, and the West-like landscape of Tokyo has been transmitted nationwide.

In the Taisho era, Shin-Towa Bridge was built on both sides of this bridge before the Great Kanto Earthquake, and Tokiwa Bridge was built as a road bridge after the earthquake. There is a theory that the middle bridge, which has been around for a long time at this time, has been officially used to distinguish bridges, but there are many different theories and I do not understand well. Since then, Jobanbashi has been preserved along with the stone wall of the castle gate of Tokiwa Hashikado to this day, and is the oldest stone bridge remaining in Tokyo.

However, it was discovered that the 2011 earthquake in Great East Japan Earthquake affected the masonry of the bridge, and construction for restoration began.

(The main pillar of Jobanbashi at the end of 2013)

The construction of the bridge was not seen from the Chiyoda-ku side. So I decided to take a look from the side of the bridge.

It is Joban Bridge seen from Shin-Tokiwa Bridge, upstream of the Nihonbashi River. Beyond that, you can see Tokiwa Bridge, and in the upper right, you can see the main pillar of Ichiishi Bridge over there. There is an overpass of the Metropolitan Expressway on the top, so the Nihonbashi River is full of bridges.

This time, I will look at Joban Bridge from Tokiwa Bridge on the opposite side. The two arches seem to have already been shaped, but some dust-like smoke is rising on the bridge.

I'll enlarge it because it's a bit far away.

It seems that the restoration work of the "wall stone" masonry on the side of the bridge has already been completed, and the stone at the top of the bridge is now being restored. A stone like a bridge nameplate on the side of the bridge, called a "name marker", was already installed.

I would like to take a look at the Bank of Japan. Here, detailed information on the structure of the bridge, the history of the bridge, and the restoration work of the bridge are listed, so you can get various information. Because it is a construction site, it is covered with fences, but there is a place where the fence is transparent, so you can look into the construction from there. I was able to stretch out and see it from the top of the fence.

The method of restoration work is to mark the original place on each stone, dismantle it once, rebuild it from the foundation such as abutment, and return the stone to its original place. In the work of laying stones on the road surface, I was doing the work of shaping the stones with electric files and tonkachi to match the dimensions.

Because it is a masonry bridge, if there is a gap in one stone, it may affect the whole, so I felt that it was a task that required very precision when I looked at it.

From now on, the installation of the main pillars and balustrades at the top of the bridge will be carried out. Many of them are repaired as much as possible and continue to be used as they are, but it seems that painful parts can be replaced with new materials.　　

Most of the stone bridges in Japan are distributed in Kyushu, so this bridge is very valuable as a masonry bridge that can be seen in eastern Japan. In addition, it is difficult to see the restoration work, so if you are interested, please take a look.

(Date of coverage, October 28, 2019 (Monday))