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[JP] Maglev Tunnel Construction in Nagano Paused Due to Flammable Gas Detection
Source: NHK News Web

Original title:
リニア関連の工事 可燃性ガスが基準値超えで一時中断
Date: September 17, 2026, 13:07
Original language: Japanese
Web link: https://news.web.nhk/newsweb/na/nd-20260917de50796
Accessed: September 17, 2026

JR Central announced that tunnel excavation work for the Chuo Shinkansen maglev line in Nagano’s Oshika Village detected flammable gas exceeding national safety standards, prompting a temporary halt.

On September 8, methane and hydrogen sulfide were found near the tunnel’s leading edge in the 15 km+ Ina Mountain Tunnel connecting Oshika and Toyooka Villages. JR Central explained at a September 16 local meeting that ventilation equipment is being installed as a safety measure, pausing work for about one month. JR Central stated: “[Translated quote] The possibility of health impact is extremely low.” This is the first suspension of maglev tunnel work due to flammable gas detection.

[JP] Oshika Village Maglev Liaison Council Reduces Meetings to Three Per Year Amid Member Burden

Source: Shinmai (Shinano Mainichi Shimbun Digital)
Original title:
自治会代表の委員に負担感　大鹿村のリニア連絡協議会、会合を年3回に削減
Date: October 5, 2026, 18:21
Original language: Japanese
Access: Members-only article
Web link: https://www.shinmai.co.jp/news/article/ ... tk86f715n0
Accessed: October 5, 2026

The Oshika Village Maglev Liaison Council has decided to reduce its meetings from four to three per year starting next year.

The reduction reflects two factors: as Chuo Shinkansen construction has progressed, comments and questions from committee members have declined, and neighborhood association representatives on the council had requested a lighter workload. The liaison council serves as a forum through which JR Central informs residents about construction status and works to mitigate impacts on living environments, with committee members able to question JR Central directly.

[JP] Aokigawa Section Excavation to Resume Early 2027 as Ventilation Equipment Parts Procurement Delayed
Source: Minami-Shinshu Shimbun (South Shinano Newspaper), via Yahoo News

Original title:
掘削再開は年明けに リニア中央新幹線青木川工区 換気設備の部品調達に遅れ【長野県大鹿村】
Date: October 10, 2026, 06:02
Original language: Japanese
Web link: https://news.yahoo.co.jp/articles/90a8d ... b18c104d39
Accessed: October 10, 2026

JR Central announced on October 9 that excavation will resume around January 2027 at the Aokigawa section (3.6 km) of the Ina Mountain Range Tunnel in Oshika Village, Nagano Prefecture, where tunnel excavation has been suspended.

The delay stems from procurement delays for parts of the in-tunnel ventilation equipment, meaning the suspension will last more than three months longer than originally anticipated. At this section, combustible gas concentrations exceeding threshold values were detected near the tunnel excavation face on September 8, prompting a temporary work stoppage. JR Central had been reinforcing ventilation equipment and other measures, initially anticipating a suspension of roughly one month (Chunichi Shimbun).

The detected gases included methane and hydrogen sulfide exceeding standard levels at the "cutting face" (excavation forefront) of the tunnel.