RA Power Solutions was advised about the damage to the crankshaft of MAN B&W 9L27/38 on board the vessel. The vessel was stranded at Lumut Port Malaysia due to the non-performance of the main engine of MAN. We deputed a team of two technicians with the necessary onsite crankshaft grinding equipment to undertake the inspection and repair of the crankshaft.
The details of the Engine are mentioned below
| S. NO | Crankshaft Details | |
| 1. | Engine Make | MAN Aux. Engine |
| 2. | Engine Model | 9L 27/38 |
| 3. | Crankpin Diameter Standard | 250 mm |
| 4. | Crankpin Bearing Length | 96 mm |
| 5. | Place of execution of crankshaft repair | Lumut Port Malaysia |
Following are the main observations of the crankshaft of MAN Aux. Engine Model No. 9L 27/38
- On visual inspection by our technicians, it was observed that crankpin no. 2 has a deep depression mark measuring about 40 x 25 mm.
- The minimum and maximum dimensions of crankpin no. 2 were observed as following
- Standard dimensions of crankpin: 250 mm
- Minimum size observed: 247.80 mm
Thus the ovality of more than 2.2 mm was observed.
- Our technicians reported that damage to the Crankpin is more as the micrometer is not able to take the reading due to the nature of the damage. The crank pin was subject to crack detection by MPI and no cracks were observed.
- The hardness was taken off the crankpin. The hardness ranging between 260 to 300 on the HB scale was observed. On a few scattered areas, the hardness was as high as 616 on the HB scale.
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Planning for Repair of Crankshaft of MAN Engine Model No. 9L 27/38
- During the discussions with the technical staff of the vessel, it was informed that a crankshaft repair company from Singapore inspected the damaged crankpin no. 2. They observed higher hardness and have undertaken local grinding of the hard spots by a hand grinder. The exact depth of hand grinded area cannot be measured.
The decision was taken by RA Power technicians to undertake grinding of the crankpin.
- Our technicians checked the hardness of the crank pin at every step while under-sizing it, to our surprise, the hardness was coming down as the grinding was done.
- Our technicians have undertaken the grinding to the undersize of 4.0 mm and the maximum hardness observed is 328 mm.
- The damaged crankpin has been successfully repaired.
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Damaged to the crankpin by a Singapore-based company
Due to the lack of knowledge and experience the hand grinder was used to check the hardness which in turn rather damaged the crankpin. A crankshaft is the most expensive part of a diesel engine and experienced companies must be engaged for repair. It is our experience of forty-two years that hardness increases whenever there is a seizure of the bearings and in most cases it is a skin hardness that reduces after grinding is done.
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For guaranteed repair of the crankshaft, MAN engine crankshaft repair, please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.
