The Forums

[JP] JR Central: Deformed Shield Machine Forces Over Six-Month Halt in Shinagawa Maglev Tunnel Excavation

Source: Nikkei (Nihon Keizai Shimbun)
Original title:
JR東海、品川のリニアトンネルで掘削機が変形　作業を半年以上停止へ
Date: October 8, 2026, 17:46
Original language: Japanese
Web link: https://www.nikkei.com/article/DGXZQOFD ... 1C2000000/
Accessed: October 8, 2026

JR Central announced on October 8 that deformation was found in part of the shield machine excavating the North Shinagawa section of the First Tokyo-Area Tunnel of the Chuo Shinkansen maglev line in Tokyo. Excavation has already been halted, and investigation, inspection—including preparations—is expected to take over six months.

An abnormal noise from the shield machine was detected on July 29, and excavation was stopped the same day. Before resuming excavation, JR Central plans to conduct cause investigation, inspection, repairs, and briefings for local stakeholders.

Prolonged suspension could delay completion of the North Shinagawa section, and JR Central stated it cannot currently estimate how long the stoppage will last. No replacement timeline has been offered for the section's previously projected February 2030 completion.

Although the Shizuoka section of the Southern Alps Tunnel received construction approval in July, that section alone is expected to take over ten years to complete. According to JR Central, even with the current delay, the North Shinagawa section is still expected to be finished sooner than the Shizuoka section, so this excavation halt will not affect the Shinagawa–Nagoya opening timeline.

[JP] Chipped Excavator Parts in Maglev Tunnel Construction; North Shinagawa Section Timeline May Slip

Source: Asahi Shimbun
Original title:
リニア工事で掘削機の部品が欠ける　北品川工区、工期遅れの可能性も
Author: Masayuki Yūshi (Yūji Masuyama)
Date: October 8, 2026, 17:36
Original language: Japanese
Web link: https://www.asahi.com/articles/ASVB82S3 ... L00MM.html
Accessed: October 8, 2026

JR Central announced on October 8 that damage—including chipped parts—was found on the shield tunnel boring machine at the Chuo Shinkansen maglev tunnel construction site in Tokyo's Shinagawa Ward. Work had been halted in July after an abnormal noise was detected from the machine, pending investigation. The company states there has been no impact on the surrounding environment.

The site is the North Shinagawa section of the First Tokyo-Area Tunnel, running from JR Shinagawa Station through Shinagawa and Ota wards toward the Tama River. Damage found included a chipped section of a metal gear and scratches on the device that smooths the machine's rotation.

Determining the detailed cause will take at least six months, with additional time needed before construction resumes. As a result, the section's scheduled completion date of February 2030 may be delayed.

[JP] North Shinagawa Section: Extended Halt to Tunnel Excavation Expected; Cause Investigation to Take Six Months or More

Source: Tokyo Shimbun (Tokyo-np)
Original title:
北品川工区、掘進停止長期化へ　JR東海のリニア建設　掘削機内部に損傷、原因の調査に半年以上の見通し
Date: October 8, 2026, 18:26
Original language: Japanese
Web link: https://www.tokyo-np.co.jp/article/520515
Accessed: October 8, 2026

According to JR Central, the abnormal noise occurred on July 29 at the construction site beneath Nishi-Shinagawa 1-chome, Shinagawa Ward, Tokyo. Internal inspection of the halted machine revealed damage to the pinion gear that drives the cutter head—the 14-meter-diameter cutting face at the machine's front end (a chipped section visible at the center of the gear).

. .
Web link: https://www.tokyo-np.co.jp/article/520515
Accessed: October 8, 2026

[JP] Component Damage Confirmed on Large Excavator in Shinagawa Maglev Tunnel; Inspection to Take Over Six Months

Source: TBS News Dig
Original title:
品川区地下のリニアトンネル掘削工事で大型掘削機の部品に損傷確認　点検完了に半年以上　工事再開はさらに先の見通し　JR東海
Date: October 9, 2026, 04:06
Original language: Japanese
Web link: https://newsdig.tbs.co.jp/articles/-/3000532?display=1
Accessed: October 9, 2026

Component damage has been confirmed on the large excavator used in the Chuo Shinkansen maglev tunnel construction beneath Tokyo's Shinagawa Ward, and construction is expected to remain suspended for at least six months for detailed inspection and related work.

JR Central halted work in July in the North Shinagawa section after an abnormal noise was heard from the large shield tunnel boring machine during underground excavation.

According to JR Central, inspections to date have confirmed multiple instances of damage, including a chipped section of a gear connecting the machine's front cutter section to the motor. Further inspection and investigation are expected to take at least six months, with additional time required before construction can resume. However, the company states the delay is not expected to affect the maglev line's overall opening timeline.

Source: News On Japan (English-language news portal; source: TBS)
Original title:
Damage to Tunnel Boring Machine Halts Tokyo Maglev Work
Date: October 11, 2026
Original language: English

Web link: https://newsonjapan.com/article/151009.php
Accessed: October 12, 2026

An English-language report corroborating the October 8–9 coverage of the Kita-Shinagawa section stoppage:
Construction of the underground tunnel for Japan's Linear Chuo Shinkansen in Tokyo's Shinagawa Ward is expected to remain suspended for at least another six months after damage was discovered in several components of the large tunnel boring machine, according to JR Central.

JR Central halted excavation in July at the Kita-Shinagawa construction section after unusual noises were detected during underground tunneling operations. Subsequent inspections revealed multiple damaged components, including chipped gear teeth connecting the machine's cutting head to its motor. Further inspection and investigation will take at least six months, with additional time required before excavation can resume. JR Central maintains that the suspension will not affect the maglev line's planned opening schedule, despite the extended delay to tunneling operations in Shinagawa.

The Linear Chuo Shinkansen is designed to connect Tokyo and Nagoya using superconducting magnetic levitation technology, with the Kita-Shinagawa section forming part of the new line's underground infrastructure.