Yanmar Diesel Generator Model no. 8N280L-EV Crankshaft Repair

Product Description

RA Power Solutions was approached by one of largest shipping company based in Athens Greece regarding breakdown of Crankshaft of YANMAR Diesel Generator Model no. 8N280L-EV. The vessel was to take a berth at Mundra port India and the stay of the vessel at port was limited to only 13 hrs.

Following is the details of the crankshaft of Yanmar Diesel Generator Model no. 8N280L-EV 

Action taken by RA Power Solutions for successful repair of Crankshaft of Yanmar Diesel Generator Model no. 8N280L-EV.

i) As mentioned above we were given only 13 hrs of time at Mundra Port India to inspect the crankshaft and to execute the repair. In this situation we decided to depute a team of three technicians onboard the vessel instead of two technicians which is our normal practice. 

Following are the main observation:

Action taken by RA Power Solutions for successful repair of Crankshaft of Yanmar Diesel Generator Model no. 8N280L-EV.

i) As mentioned above we were given only 13 hrs of time at Mundra Port India to inspect the crankshaft and to execute the repair. In this situation we decided to depute a team of three technicians onboard the vessel instead of two technicians which is our normal practice. 

ii) After boarding of the vessel the detailed inspection of crankpin no. 4 which got damaged was conducted.

Following are the main observation:

a) The diameter of crankpin no 4 was checked and following dimensions were observed:

     i) Minimum diameter observed    - 224.15 mm

     ii) Maximum diameter observed   - 225.00 mm

     Above shows the ovality of 0.85 mm.

b) The crankpin no. 4 was subject to hardness check and was found within limits except on few scattered points where it was observed in the range of 500 HB.

c) The crankpin was subject to crack detection by high intensity magnaflux torch and no cracks or abnormally was observed. 

d) Due to the seizure of crankpin bearing the radius fillet of both the sides was badly damaged.

Successful Repair of Crankshaft of Yanmar Diesel Generator Model no. 8N280L-EV in a short time of 13 hrs. 

a) Our technicians worked non stop and were able to successfully repair the crankpin no. 4 by undersizing and grinding it to 1.0 mm.

b) After grinding & polishing following minimum & maximum crank pin diameter was maintained:

   i) Minimum diameter observed    - 223.98 mm

  ii) Maximum diameter observed   - 224.00 mm

c) The above reading shows the crankpin was undersized by 1.0 mm from 225.00 mm to 224.00 mm thus maintaining the ovality of only 0.02 mm which is far superior than the tolerance stipulated in the manufacturer manual. 

d) The formation of radius fillet at both ends was a big challenge as it was badly damaged and time available was limited. The radius fillet was also repaired successfully. 

e) The 1.0 m undersize crank pin bearing was available on board the vessel. 

f) RA Power Solutions technicians also helped the ship technical staff in calibration of connecting rod, measurement of big end bearing and other areas.

g) It is normal for RA Power Solutions to take such challenging jobs where the damage to the crankshaft due to an accident is very serious and time available is short.