During the course of the repair, the turbine blades were welded, because, after a long period of operation, cracks and cavities had appeared; however, the turbine wheel was not properly rebalanced after these repairs had been completed.
The turbine blades were welded. This was during the course of the repair. Cracks and cavities had appeared. This was after a long period of operation. The turbine wheel was not properly rebalanced. This was however. This was during the course of the repair. These repairs had been completed.