2005: A Major Development for Work on a Record-Setting Japanese Tunnel

February 27, 2005

A pivotal moment took place for construction on a railway tunnel in the northeastern part of Honshu, the largest island of Japan, when both halves of this structure were joined together. This breakthrough occurred about six-and-a-half years after the start of that construction project. That tunnel specifically courses through the Hakkōda mountain range in Japan’s Aomori Prefecture. The Hakkōda Tunnel, which connects the city of Aomori (the prefecture’s capital) with the town of Shichinohe, carries a portion of the high-speed rail line Tōhoku Shinkansen. With a total length of 419.4 miles (674.9 kilometers), that line serves as a vital link between Aomori and Japan’s capital city of Tokyo.

Approximately 600 people involved in building the Hakkōda Tunnel were on hand for ceremonies celebrating its breakthrough. The actual breakthrough was set into motion when Shingo Mimura (born in 1956), who was governor of Aomori Prefecture from 2003 to 2023, pushed a button to trigger a blast. The blast removed the remaining bedrock that stood between both halves of the tunnel.  

This event was recounted by Tokyo-based Kajima Corporation — one of the companies helping to construct the Hakkōda Tunnel — in a story appearing on its website. “The tunnel breakthrough marks an important milestone for the Tohoku Shinkansen bullet train line,” reported Kajima. “Once service begins, the time required for travel between Tokyo Station and Aomori Station will be dramatically reduced from four hours to about three hours.”

After the completion of the Hakkōda Tunnel in 2010, the first test runs of trains through this structure were undertaken on November 19 of that year. The official use of the tunnel by the Tōhoku Shinkansen began early the following month.

This structure, measuring 16.4 miles (26.5 kilometers) in length, is the longest terrestrial railway tunnel in all of Japan. On an international scale, the Hakkōda Tunnel is the world’s third longest, double-tracked, single-tubed terrestrial railway tunnel. The Hakkōda Tunnel has the added distinction of being the first rail route to pass through the Hakkōda Mountains. (The accompanying photo of this tunnel’s western portal was taken in 2020.)

Photo Credit: Mccunicano (https://en.wikipedia.org/wiki/User:Mccunicano?rdfrom=commons:User:Mccunicano) – licensed under the Creative Commons Attribution-Share Alike 4.0 International license at https://creativecommons.org/licenses/by-sa/4.0/deed.en

For more information on the Hakkōda Tunnel, please check out https://en.wikipedia.org/wiki/Hakk%C5%8Dda_Tunnel

Additional information on the Tōhoku Shinkansen is available at https://en.wikipedia.org/wiki/T%C5%8Dhoku_Shinkansen