The project
Metalock engineers surveyed the damage and submitted proposals for repair which after some discussions and modifications were accepted by Lloyd’s Register of Shipping, provided that subsequently they carried out regular inspections. Five years on the vessel, under new ownership, it was still fully operational as a diamond mining vessel for Benguela Operations(PTY) Ltd in South Africa.
Portable milling machine
Once the new bearing pocket was fully stitched into place, a portable milling machine was set up on the bedplate and the top of the insert machined flush to the joint face. At the same setting, the bearing cap joint faces were machined to size. With the new bearing cap fitted, a boring bar was optically aligned through the centreline of the undamaged bearing pockets and the new pocket line-bored to the correct diameter.
The repairs were completed and full engine tests including a two hour long full power trial were conducted. Following these successful trials the MV Aberthaw Fisher was returned to service and after a series of regular inspections by Lloyd’s, eventually regained its full classification. To effect the repair, the damaged pocket was cut out by chain drilling, machining and hand fitting, to accept a steel insert machined from a single solid piece of steel to precisely fit the shape formed in the bedplate.
