In-Situ Machining Solutions (UK) Ltd have successfully carried out diesel engine repairs to two 4000 tonne coastal tanker vessels.
The object of the repair was to replace the damaged camshaft support bearing block which had severely worn causing excessive fretting to the bearing housing area of the cambox resulting in bearing failure and broken cams.
In-Situ Machining Solutions were contacted by the ship owner to affect the repair via the engine maker who frequently use In-Situ Machining Solutions as their preferred on-site machining specialists to carry out precision on site machining repairs in all corners of the world.
This work consisted of machining the damaged bearing block housing oversize and introducing a new bearing block fitted with screwed on make-up plates to accommodate the new housing sizes.
An existing portable on site milling machine was modified to suit the dimensions of this particular engine’s geometry. Setting of the machine was undertaken by means of straight edge and DTI gauges using unworn areas of the cambox as reference.
Once set, the machining of the fretted bearing housings were carefully machined to remove sufficient material to enable suitably sized make-up plates to be secured to the new mating bearing block.
As machining work progressed sizes were constantly taken to ensure the accurate positioning for the new bearing block as this had to in perfect line with the remaining eight bearing housings to ensure trouble free rotation of the camshaft when in operation.
On completion of the machining work the new bearing housing was fitted in place, secured and checked for alignment using laser equipment and also via a mechanical means by introducing and rotating the camshaft in the existing eight bores and DTI gauging the new housing which verified the alignment to be accurate within 0.02mm
All work and the approach adopted and executed to the repair by In-Situ Machining Solutions was to the complete satisfaction of the ship owner and OEM.