■Tsushima/Aren Diagonal Shaft will be extended by 10m and the length of the tunnel mouth will be 20m.
Work began on June 25 to extend the tunnel by 10 meters at the Arensha tunnel entrance in Tsushima, where the entrance was installed in July last year.
On July 10th, the formwork was removed, revealing a concrete arch-shaped roof with a total length of 20 meters.
Until now, it was located about 5 meters away from the slope of the mountain and had been fitted with an emergency roof, but with this construction it will now be in contact with the slope. In the photo, the part where the formwork is still attached is the construction area.
The person is Katsuno Uchiyama, Tsushima Office Director.
