Main gear breakdown
We have experienced damages in the main gear produced by the breakdown of one pinion. The broken parts of the pinion damaged some teeth of the main gear, which had to be rebuilt by welding and grinding.
After the reparation, the torque of the TBM was limited to minimum and safe values, in order to finish the TBM advance till reach a place where it was possible to replace the whole bearing. During the excavation with the rebuilt gear, a lot of controls and preventive measures were taken to ensure the performance of TBM.