The MAN 7L23/30H engine crankshaft of a vessel at Khor Al Zubair Port, Iraq, was reported damaged. RA Power Solutions has repaired a number of crankshafts of MAN 7L23/30H engines during the last 46 years of extending services all over the world. With our experience and based on the initial reports of damage shared by the vessel, we planned the strategy for the repair of the MAN 7L23/30H engine at Khor Al Zubair Port, Iraq.
The tooling was prepared, and two technicians having a valid seaman’s book flew to Khor Al Zubair Port, Iraq, with an onsite crankshaft grinding machine. The technicians also carried undersized crankpin bearings with them in order to facilitate the immediate commissioning of the engine after the necessary repairs were executed.
Damaged Crankpin Journal of MAN 7L23/30H Auxiliary Engine |
Damaged Crankpin of MAN 7L23/30H Auxiliary Engine |
Engine Details of the MAN 7L23/30H
| S. No | Crankpin Details | |
| 1 | Engine Make | MAN |
| 2 | Engine Model | 7L23/30H |
| 3 | Engine Number | Auxiliary Engine No #03 |
| 4 | Crankpin Diameter Standard | 185.00 MM |
| 5 | Crankpin Bearing Width | 70.00 MM |
| 6 | Grinding of Crankpin Number | #04 & #06 |
| 7 | Place of Execution of Grinding of Crankpin | Khor Al Zubair Port, Iraq |
| 8 | Name of Shipping Company | Reputed Company from Dubai, U.A.E. |
| 9 | Date Of Execution | 01.06.2026 to 10.06.2026 |
Crankshaft Inspection by MPI – MAN 7L23/30H Auxiliary Engine |
Crack Detection Using MPI – MAN 7L23/30H Auxiliary Engine |
Observation and Repair of the Crankshaft of MAN 7L23/30H at Khor Al Zubair Port, Iraq
i) On visual inspection, two crankpins, Nos. 4 and 6, were observed to be damaged. Crankpin bearing material was found in the oil sump of the entablature.
ii) Crankpins Nos. 4 and 6 were inspected for taper and ovality, and the following readings were observed.
| SIZE OF CR PINS BEFORE REPAIR | |||||||||
| A | Aa | C | Cc | B | Bb | Min | STD | Ovality | |
| CR-1 | |||||||||
| CR-2 | |||||||||
| CR-3 | |||||||||
| CR-4 | 184.93 | 184.97 | 184.75 | 184.70 | 184.82 | 184.79 | 184.70 | 185.00 | 0.30 |
| CR-5 | |||||||||
| CR-6 | 184.96 | 184.94 | 184.82 | 184.76 | 184.79 | 184.62 | 184.62 | 185.00 | 0.38 |
| CR-7 | |||||||||
iii) Other parameters, such as hardness and crack detection tests by MPI, were carried out, and no abnormalities were observed.
iv) It was jointly decided, in consultation with the owners, to undertake the grinding in steps of 0.5 mm onwards, as per the manufacturer’s guidelines.
v) After the grinding operation, both crankpins No. 4 and No. 6 were undersized by 1.50 mm, and all parameters were maintained as per the manufacturer’s specifications and recommendations.
Onsite crankshaft machining in process for MAN 7L23/30H Auxiliary Engine |
Final Dimensions After Repair
| SIZE OF CR PINS AFTER REPAIR | |||||||||
| A | Aa | C | Cc | B | Bb | Min | MAX | Ovality | |
| CR-1 | |||||||||
| CR-2 | |||||||||
| CR-3 | |||||||||
| CR-4 | 183.49 | 183.48 | 183.47 | 183.48 | 183.49 | 183.50 | 183.47 | 183.50 | 0.03 |
| CR-5 | |||||||||
| CR-6 | 183.50 | 183.49 | 183.48 | 183.47 | 183.50 | 183.49 | 183.47 | 183.50 | 0.03 |
| CR-7 | |||||||||
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Availability of Undersized Bearings for MAN 7L23/30H
RA Power Solutions technicians carried the undersized crankpin bearings to Khor Al Zubair Port, Iraq, and the engine was assembled and commissioned in their presence. RA Power Solutions maintains undersized bearings for popular engine makes to facilitate clients.
For all repairs, including the above crankshaft of MAN 7L23/30H, we provide records of the inspection report before and after the repair of the crankshaft. These reports are signed and stamped by the Chief Engineer of the vessel. On request, we can share these reports with our clients.
This case once again highlights RA Power Solutions’ proven capability to execute critical crankshaft repairs worldwide with high precision, strong technical expertise, and extensive field experience, ensuring reliable and timely solutions for marine and industrial engines.
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.
