Repair of Crankshaft of MAN B&W 6L 48/60

RA Power Solutions was approached by a leading shipping company based in Singapore regarding a problem faced by them in crankpin no. 02 of the main engine of MAN B&W 6L 48/60. The vessel was at the outer anchorage of Mundra. Our Two technicians boarded the vessel.

The major specification of MAN B&W 6L 48/60  crankpin and engine are mentioned below:

Following are the main observations of damaged crankshaft of MAN B&W 6L 48/60

1. RA Power Solutions team was surprised to note that the crankpin having a standard diameter of 415 mm was undersized by 2.0 mm and the size was maintained as 413 mm by a crankshaft grinding company based in South India.
2. Our engineers were advised by the chief engineer that after grinding the engine was commissioned and failed within twenty-five minutes of operation. On investigation, the crankpin bearing was found to be damaged with bearing material embedded on the crankpin.
3. RA Power Solutions engineers removed the white metal from the crankpin and were surprised to note the ovality of about 0.60 mm.

It was concluded that the company who was engaged for the grinding of the crank pin sent the technicians who were not properly trained and hardly had any experience. They were not able to maintain the tolerance as required by the manufacturer.

Action taken by RA Power Solutions

• After the initial inspection of crank pin no. 02 the grinding started. The main challenge was to remove the ovality which was as high as 0.60 mm and crankpin was already down by 2.0 mm (413.00 mm after grinding)
• RA Power Solutions undertook the grinding and was successful in removing the ovality by under sizing the crankpin further by only 1.0 mm, the final size was maintained as 412.00 mm with all parameters strictly as per the manufacturer specification and tolerance.
• The crankpin no. 02 after polishing showed the roughness of 13 to 15 RA value which is considered to be a very high standard of the finish.

Assistance provided in assembly of Connecting Rod

• Our technicians assisted the ship staff in inspection of 3.0 mm undersize bearing, checking the oil gap, axial play, free movement of connecting rod, and all technical aspects.
• After cleaning the engine was recommissioned and taken for the trials.

Appreciation of work by client for repair of crankshaft of MAN B&W 6L 48/60

The owners suffered heavy losses due to the wrong grinding of crankpin executed by the company based in South India. By availing RA Power services which has forty-three years of experience in this field they were more than satisfied with the quality of the job executed by us.

For more details on the crank pin grinding repair up to 700 mm diametre please email us on info@rapowersolutions.com Call at +91-9582647131,+91 9810012383.