eight meters and weighs 41 tonnes. It will be installed on super large shield tunneling machines with a diameter of 16 meters.

The main bearing was developed by researchers from the Institute of Metal Research of the CAS. This development marks China's mastery of integrated techniques such as independent design, material preparation, precision processing, installation, debugging, testing and evaluation of the main bearing of a shield tunneling machine.

Previously, China had achieved production of homemade shield tunneling machines, but the main bearings still had to be imported. Since 2020, the CAS cooperated with more than 20 institutes and enterprises to deal with 12 core technical issues and in this process developed 10 sets of main bearings for shield tunneling machines, with a diameter ranging from three to eight meters.