https://www.youtube.com/watch?v=CNEjDtqHQ5Y

On August 10, the made-in-China largest diameter (16.07m) mud-water balance shield machine "Canal" launch. The slurry Tunnel Boring Machine completely developed, designed and manufacture by China. Manufacturer Chinese company CCCC Tianhe Machinery Equipment Manufacturing Co., Ltd. 

It will use in reconstruction project of Beijing East Sixth Ring Reconstruction (Beijing-Harbin Expressway-Luyuan North Street) project. Tunnels length for project total 7341 metres. Outer diameter 15.04 metres. Longest tunnel 4770 metres. 

tunnels have an outer diameter of 15.4 meters and a total length of 7341 meters. The longest continuous excavation at one time is 4770 meters.

http://finance.people.com.cn/BIG5/n1/2021/0811/c1004-32188659.html