Yanmar 6N18AL-DV engine crankshaft on the vessel reported damage. A vessel owned by a leading Malta-based company advised RA Power Solutions regarding the problem faced by them in the crankshaft of Yanmar 6N18AL-DV.
The vessel was at Chittagong, Bangladesh. RA Power Solutions deputed two technicians to Chittagong, Bangladesh, with onsite crankshaft grinding equipment and the necessary instruments required for inspection.
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The Major details of Yanmar 6N18AL-DV Engine/Crankshaft are as follows:
| S. No. | Crankpin Details | |
| 1. | Engine Make | YANMAR |
| 2. | Engine Model | 6N18AL-DV |
| 3. | Crankpin Diameter Standard | 145.00 MM |
| 4. | Crankpin Bearing Width | 64.00 MM |
| 5. | Place of Execution of Grinding of Crankpin | Chittagong Port, Bangladesh |
| 6. | Name of Shipping Company | Reputed Company from Malta |
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Brief of Inspection Conducted by RA Power Solutions Technicians
i) Onboarding of the vessel, our technicians were informed that the lubricating oil pressure dropped, and on investigation, three number of the Crank pin bearings were found seized.
ii) The Ship staff was requested to remove connecting rods from all six crankpins.
iii) The bearing metal, which was embedded on the crankpin diameter, was removed for inspection purposes.
iv) All six crankpins were subject to dimensional inspection, and excessive ovality ranging from 0.60 MM to 0.70 MM was observed.
The dimensions are given below
| SIZE OF CR PINS BEFORE REPAIR | |||||||||
| A | Aa | C | Cc | B | Bb | Min | STD | Ovality | |
| CR-1 | 144.60 | 144.35 | 144.90 | 144.39 | 144.65 | 144.36 | 144.35 | 145.00 | 0.65 MM |
| CR-2 | 144.73 | 144.32 | 144.70 | 144.30 | 144.86 | 144.36 | 144.30 | 145.00 | 0.70 MM |
| CR-3 | 144.60 | 144.45 | 144.55 | 144.40 | 144.78 | 144.35 | 144.35 | 145.00 | 0.65 MM |
| CR-4 | 144.60 | 144.48 | 144.62 | 144.40 | 144.75 | 144.40 | 144.40 | 145.00 | 0.60 MM |
| CR-5 | 144.62 | 144.38 | 144.63 | 144.34 | 144.88 | 144.38 | 144.34 | 145.00 | 0.66 MM |
| CR-6 | 144.74 | 144.38 | 144.72 | 144.34 | 144.67 | 144.67 | 144.34 | 145.00 | 0.66 MM |
v) The crankpins were subject to crack examination by MPI process, and no crack or abnormality was observed.
vi) The hardness was checked of all six crankpins and was found marginally higher on the crankpin bearing, which got seized.
vii) Considering the above observation, after the inspection, it was decided to undertake the grinding of all six crankpins.
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Requirement of Special Purpose Grinding Tool
- RA Power Solutions have developed and manufactured a special-purpose tool to undertake the grinding of crankpins of Yanmar 6N18AL-DV, having a crankpin width of only 64.00 MM, which is considered to be very small.
- Grinding of all six crankpins was done, maintaining the final size of 144.20 MM with the tolerance of -0.02 MM.
Supply of Undersize Bearings for Yanmar 6N18AL-DV
RA Power Solutions supplied undersized bearings of 0.80 MM on the vessel, and the engine was put into operation immediately. We maintain a large stock of Crankpin and Main Journal bearings for Yanmar 6N18AL-DV, and also for other popular makes and models of engines.
In case of Yanmar 6N18AL-DV Crankshaft Repair, we have available in our stock crankpin bearings up to 2.80 MM undersize and have saved a number of crankshafts from rejection.
We have been regularly executing on site crankshaft repairs and in situ crankshaft grinding in Dubai, Fujairah, Qatar, Saudi Arabia, Oman, Iraq, Togo, Malta, Freetown, Egypt, Malaysia, Iran, Indonesia, Vietnam, Jordan, Tanzania, etc.
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We have a team of trained technicians available 24/7 and can be deputed on short notice. Some of our technicians also have a valid US VISA and can fly to South America, Caribbean countries, etc.
For more information regarding crankshaft grinding services, Yanmar 6N18AL-DV Crankshaft Repair, please contact us at rajshahani@rapowersolutions.com or info@rapowersolutions.com or call us at +91 9582647131 or +91 9810012383.
