Our colleagues from QuantiServ Shanghai have just completed an intermediate shaft repair assignment on a 15’000 TEU container ship.
While underway to a southern Chinese port, the almost new vessel had suffered a breakdown to one of its line shaft bearings. Running steel to steel as a consequence of the bearing failure, the intermediate shaft got severely damaged.
QuantiServ Shanghai got contacted while the vessel was on tow to one of Chinas largest shipyards in the greater Shanghai area.
Our experts immediately got to work and presented to the shipowner and shipyard a repair plan and schedule, before the vessel even reached the shipyard. The plan included the re-design of the line shaft bearing, the design and fabrication of special in-situ machining tools and the execution of the work in three shifts, around the clock. All stake holders agreed to the plan.
Once the tools had been fabricated, our technicians performed the following work on board the vessel, while alongside in the shipyard. Some of the tasks had to be carried out multiple times, for example laser alignment checks before, during and after machining.
- Laser alignment checks and alignment calculation
- Dimensional and hardness measurements, non-destructive crack testing
- Removal of cracks, shaft journal area machining to under-size, then polishing
- Shaft alignment adjustment
- Bearing load jack-up tests
Our six technicians performed the work in two shifts, around the clock. The entire repair took just seven days to complete to the full satisfaction and appreciation of the shipowner, shipyard, classification society and shaft line bearing OEM.
Key data of the installation:
- Intermediate shaft total length: ~ 39 m
- Shaft diameter: 790 mm
- Shaft journal length: 1’200 mm
- Max continuous engine power transmitted through shaft: ~ 53’000 kW