Are the shield machine maintenance personnel managers?

No. According to the query on the Civil Servant Home website, the TBM maintenance personnel are only responsible for the maintenance of the TBM and are not involved in the management. A TBM is a tunnel boring machine that uses the shield method. The shield construction method is that the tunnel boring machine builds (lays) a tunnel shield (referring to the supporting segment) while excavating, which is different from the open construction method. Internationally, generalized shield tunneling machines can also be used in rock formations, but they are different from open (non-shield tunneling) tunnel boring machines.