Yamate Tunnel

The Nihongo|Yamate Tunnel|山手トンネル|Yamate Tonneru carries the Central Circular Route (C2) of the Shuto Expressway from the Takamatsu on-ramp in Toshima to the Ōhashi Junction in Meguro, Tokyo, Japan. The overall length is 11 km. The segment linking the Takamatsu on-ramp and Nishi Shinjuku Junction in Shinjuku opened to traffic on December 22, 2007. On the same date, an above-ground segment linking the tunnel to the Kumanochō Interchange in Itabashi and Toshima also opened. Lying 30 m below the surface, about 70% was constructed by the tunnelling shield method. The roadway consists of two lanes in each direction.

Another, as yet unnamed, tunnel is under construction as of December 12, 2007. It connects underground with the Yamate Tunnel, extending it to the Ōi Junction in Shinagawa. Nearly all of the tunnel lies beneath Yamate Street. When complete, the Yamate Tunnel, together with this extension, will surpass the Kan'etsu Tunnel on the Kan-Etsu Expressway, becoming the longest roadway tunnel in Japan. According to the schedule, in 2009, the Nishi Shinjuku – Ōhashi segment will be complete, and in 2013, everything from Ōhashi to Ōi will be open.

History

Construction on the Yamate Tunnel began in 1992. The Takamatsu – Nishi Shinjuku segment opened on December 22, 2007.

Facilities

The tunnel has many operation and safety facilities. Among them are emergency telephones and cameras at 100 m intervals. Fire-safety equipment includes infrared sensors, fire extinguishers, foam sprayers, and pushbutton alarms. Emergency exits leading to a separate emergency path are located no more than 350 m apart. Stairways lead up to Yamate Street. A duct running parallel to the roadway supplies fresh air and removes exhaust. Dust-collection systems are designed to remove 80% of particulates from the air.

Ramps and junctions

*Nishi-ikebukuro Interchange
*Nakano-Chojabashi Interchange
*Nishi-Shinjuku Junction
*Hatsudai-minami Interchange
*Tomigaya Interchange
*Ōhashi Junction

Other underground viaducts

The Yamate Tunnel passes above the Yūrakuchō and Ōedo subway lines. It crosses below the Tōzai and Marunouchi subway lines, as well as the Keiō and Keiō New Lines and the Tōkyū Den-en-toshi Line. Additionally, the tunnel parallels the Ōedo Line along a segment between Nakai and Nishi Shinjuku Gochome Stations. Nakai and Nakano Sakaue Stations, lying beneath the Yamate Tunnel, have escalators that pass between Yamate's two tunnels.

Additional reading

* 西澤丞著『首都高山手トンネル』求龍堂（2007年） ISBN 9784763007254

ource

This article incorporates material from 山手トンネル ("Yamate Tonneru") in the Japanese Wikipedia, retrieved December 22, 2007.