RA Power Solutions received a communication from one of the reputed shipping companies based in Indonesia advising that the crankshaft of auxiliary engine no. 1 has failed. It needs inspection and necessary repairs. RA Power Solutions deputed a team of two technicians along with in situ crankshaft grinding equipment and necessary calibrated measuring instruments to Galle Port in Sri Lanka.
The engine details are as follows
| S. NO | Crankshaft Details | |
| 1. | Engine Make | MAN |
| 2. | Engine Model | 7L 23/30 H |
| 3. | Crankpin Diameter Standard | 185 mm |
| 4. | Crankpin Bearing Width | 69 mm |
| 5. | Main Journal Diameter | 210 mm |
Following are the main observations during the inspection of the Crankshaft of MAN 7L 23/30 Engine
- All the crankpins were subject to dimensional inspection for taper and ovality except crankpin no. 3, the ovality observed on all the crankpins was between 0.16 mm to 0.27 mm. In the case of crankpin no. 3, the ovality observed was 0.66 mm. The hardness of all crankpins was observed between 220 and 230 on the HB scale.
- All the crankpins were subject to crack detection by the MPI method. High intensity, magna flux torch was used for MPI. No crack or abnormality was observed on crankpins except crankpin no. 3 on which multiple hairline cracks/ skin cracks measuring between 50 mm to 75 mm were observed.
- On visual inspection bearing line marks were observed on all the crankpins, crankpin no. 3 had deep bearing line marks.
- No damage on the radius fillet or lubricating oil hole was observed.
Execute repair of the crankshaft of MAN 7L 23/30 H Engine
- All the crankpins except crankpin no. 3 was ground and polished to the undersize of 0.5 mm. In the case of crankpin no. 3, our technicians had no option but to reduce the diameter by 1.5 mm to remove the crack observed during the MPI.
- All the crankpins were polished.
- The crankshaft was fitted with 0.5 mm and 1.5 mm undersize bearings and the engine was put on operation.
- The crankshaft of the MAN 7L 23/30 H Engine is performing satisfactorily.
RA Power Solutions Pvt. Ltd. undertakes onsite repair of crankshafts up to 700 mm in diameter. All our technicians are experienced and have undergone in-house training in our dedicated training school which is equipped with crankshafts of different profiles and diameters. The latest design of in situ crankshaft grinding equipment and the experience of our technicians in crankshaft grinding and polishing results in the maintenance of close tolerance within 10/20 microns and achievement of surface finish of less than 20 Ra value which is far better than international standards.
This blog is written by Mr. Raj Shahani (Managing Director of RA Power Solutions). He has more than forty years of experience in the field of engine repair and is a technical adviser to various shipping and heavy industries based all over the world.
For more information on crankshaft repair equipment, crankshaft repair equipment, please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.
