RA Power Solutions was informed about the damage of crank pin unit no. 5 of MAN Diesel Engine Model No. 9L28/32 H on a vessel sailing near Indonesian Port.
Our team of two technicians arrived on board the vessel in a short time with the portable light weight crankshaft grinding equipment and instruments required to conduct the inspection. The VISA was obtained on arrival.
MAIN OBSERVATIONS OF CRANKSHAFT OF MAN DIESEL ENGINE MODEL NO. 9L28/32 H AFTER INSPECTION
i) The crankpin has standard diameter of 230.00mm and the crankpin bearing width is only 95 mm.
ii) The crankpin no. 5 was observed badly damaged due to the seizure of the bearing.The minimum & maximum size of crankpin was observed as following:
· Minimum diameter of crankpin recognized: - 228.49 mm
· Maximum diameter of crankpin recognized: - 228.86 mm
The above reading shows that the crankpin was already ground and was undersized by 1.00 mm.
The Ovality of 0.51 mm was observed considering the standard size after grinding of 229.00 mm.
iii) Hardness of the damaged crankpin was checked and was observed between 220 HB and 265 HB.
iv) The MPI for crack detection with high intensity magnaflux torch was conducted and no crack or abnormality was observed.
v) The deflection of the crankshaft was checked and was observed within limit.