crankshaft
27 Feb , 2026
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RA Power Solutions was called by a leading shipping company based in Baku, Azerbaijan, regarding a major breakdown in their auxiliary engine, a MAK 6M20, installed on the vessel.
The non-operation of two auxiliary engines stranded the vessel. Considering the urgency of the situation, RA Power Solutions deputed two technicians along with a specially designed onsite crankshaft grinding machine capable of grinding crankpins with small diameters and narrow widths.
In the case of the MAK 6M20 auxiliary engine, the standard diameter of the crankpin is only 152.00 mm, with a bearing width of 71 mm. The design of our onsite crankshaft grinding machine is such that it can be mounted on the crankpin diameter through the inspection window, and grinding is executed in situ.
The details of the engine are as follows:
| Engine Details | ||
| S.No | Crankpin Details | |
| 1 | Engine Make | MAK |
| 2 | Engine Model | 6M20 |
| 3 | Auxiliary Engine Number | #01 & #02 |
| 4 | Crankpin Diameter Standard | 152.00 MM |
| 5 | Crankpin Bearing Width | 71.00 MM |
| 6 | Grinding of Crankpin Number | #01, #02, #03, #04, #05, #06 |
| 7 | Place of Execution of Grinding of Crankpin | Baku, Azerbaijan |
| 8 | Name of Shipping Company | Reputed Company from Baku, Azerbaijan |
| 9 | Date Of Execution | 27th October to 29th November 2025 |
Upon arrival on board the vessel, our technicians conducted an initial inspection of all crankpins. They found excessive ovality in all six crankpins of the MAK 6M20 engine.
We have provided a copy of the preliminary dimensional inspection report below.
| SIZE OF CR Pins Before Grinding of A/E 01 | |||||||||
| A | Aa | C | Cc | B | Bb | Min | STD | Ovality | |
| CR-1 | 151.72 | 151.95 | 151.73 | 151.78 | 151.74 | 151.84 | 151.72 | 152.00 | 0.28 MM |
| CR-2 | 151.73 | 151.92 | 151.72 | 151.88 | 151.74 | 151.81 | 151.72 | 152.00 | 0.28 MM |
| CR-3 | 151.74 | 151.85 | 151.73 | 151.84 | 151.73 | 151.82 | 151.73 | 152.00 | 0.27 MM |
| CR-4 | 151.73 | 151.93 | 151.74 | 151.85 | 151.75 | 151.89 | 151.73 | 152.00 | 0.27 MM |
| CR-5 | 151.71 | 151.85 | 151.69 | 151.80 | 151.71 | 151.78 | 151.69 | 152.00 | 0.31 MM |
| CR-6 | 151.76 | 151.93 | 151.73 | 151.87 | 151.74 | 151.85 | 151.73 | 152.00 | 0.27 MM |
The technicians at RA Power Solutions ground all the crankpins and maintained the following dimensions.
| SIZE OF CR Pins After Grinding of A/E 01 | |||||||||
| A | Aa | C | Cc | B | Bb | Min | Max | Ovality | |
| CR-1 | 151.00 | 150.99 | 150.99 | 150.98 | 150.99 | 151 | 150.98 | 151.00 | 0.02 MM |
| CR-2 | 150.99 | 150.98 | 150.97 | 150.98 | 150.99 | 150.98 | 150.97 | 150.99 | 0.02 MM |
| CR-3 | 150.99 | 150.98 | 150.98 | 150.97 | 150.98 | 150.99 | 150.97 | 150.99 | 0.02 MM |
| CR-4 | 150.99 | 150.98 | 150.98 | 150.97 | 150.98 | 150.99 | 150.97 | 150.99 | 0.02 MM |
| CR-5 | 150.99 | 150.98 | 150.97 | 150.97 | 150.98 | 150.99 | 150.97 | 150.99 | 0.02 MM |
| CR-6 | 151.00 | 150.99 | 150.98 | 150.98 | 150.99 | 151 | 150.98 | 151.00 | 0.02 MM |
All other parameters, including hardness, MPI, and deflection, were within acceptable limits. We jointly decided to grind all the crankpins, and RA Power Solutions machined them to a final size of 151.00 mm (1.00 mm undersize) as per the above dimensions.
During the stay of our technicians on board the vessel, the crankshaft of Auxiliary Engine #02 was also inspected. We detected excessive ovality showing the same pattern observed in the crankshaft of Auxiliary Engine 01.
The preliminary dimensional inspection report is provided below:
| SIZE OF CR Pins Before Grinding of A/E 02 | |||||||||
| A | Aa | C | Cc | B | Bb | Min | STD | Ovality | |
| CR-1 | 151.73 | 151.85 | 151.74 | 151.84 | 151.75 | 151.82 | 151.73 | 152.00 | 0.27 MM |
| CR-2 | 151.73 | 151.85 | 151.72 | 151.83 | 151.70 | 151.81 | 151.7 | 152.00 | 0.30 MM |
| CR-3 | 151.72 | 151.85 | 151.71 | 151.84 | 151.69 | 151.83 | 151.69 | 152.00 | 0.31 MM |
| CR-4 | 151.75 | 151.85 | 151.72 | 151.84 | 151.73 | 151.86 | 151.72 | 152.00 | 0.28 MM |
| CR-5 | 151.73 | 151.84 | 151.69 | 151.82 | 151.70 | 151.84 | 151.69 | 152.00 | 0.31 MM |
| CR-6 | 151.73 | 151.92 | 151.72 | 151.89 | 151.75 | 151.84 | 151.72 | 152.00 | 0.28 MM |
Our technicians ground this crankshaft and maintained the following dimensions. They successfully commissioned both engines in their presence.
| SIZE OF CR Pins After Grinding A/E 02 | |||||||||
| A | Aa | C | Cc | B | Bb | Min | Max | Ovality | |
| CR-1 | 151.00 | 150.99 | 150.99 | 150.98 | 150.99 | 151 | 150.98 | 151.00 | 0.02 MM |
| CR-2 | 151.00 | 150.99 | 150.99 | 150.98 | 151.00 | 150.98 | 150.98 | 151.00 0.02 MM | 0.02 MM |
| CR-3 | 151.00 | 150.99 | 150.98 | 150.98 | 150.99 | 151.00 | 150.98 | 151.00 | 0.02 MM |
| CR-4 | 151.00 | 150.99 | 150.98 | 150.99 | 150.99 | 151.00 | 150.98 | 151.00 | 0.02 MM |
| CR-5 | 151.00 | 150.99 | 150.98 | 150.98 | 150.99 | 151.00 | 150.98 | 151.00 | 0.02 MM |
| CR-6 | 151.00 | 150.99 | 150.98 | 150.98 | 150.99 | 151.00 | 150.98 | 151.00 | 0.02 MM |
RA Power Solutions offers onsite crankshaft grinding and repair services under a wide range of conditions, whether on a ship at sea or at a power plant/cement plant in a remote location. RA Power guarantees all crankshaft grinding services, ensuring the crankshaft and diesel engine perform satisfactorily after repairs.
For more information on onsite crankshaft repair, grinding of crankshaft, and crankshaft polishing, please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.
Summary
Article Name
MAK 6M20 Crankshaft Repair in Baku, Azerbaijan
RAJ SHAHANI
Raj Shahani
Publisher Name
R A Power Solutions
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