.crosshead bearing failure .cross head bearing .chbf .ch bearing .c/h bearing  

Crosshead bearing failure:

.cross head bearing failure   .chbf   .cbf

Possible causes/ Possible defects of cross head bearing failure are: 

1. Fatigue failure: 

     Due to reuse of old spare, ageing, unavailability of spare crosshead pin – hand polished spare used. 

• Reduced lube oil flow: 

 Due to oil leakages at pipe connection (chock oil passage).  

Excessive clearance due to wear down of pin. 

• Excessive firing load: 

 Due to improper power balancing. 

 Early firing due to early injection.

• Misalignment: 

 Due to uneven wear down of guide shoe & crosshead pins.  Piston rod bent, excessive liner wear. 

• Crosshead pin may have high hardness: 

 Due to wear down/ scoring over prolonged time.  

• Oil groves in bearing enlarged:

        Due to erosion/corrosion. 

• Slack tie bolts/ inadequate tightening.
  • Improper tightness of crosshead bearings nuts.

Minimizing crosshead bearing defect:

How to minimize /prevent: 

1. Oil in circulation is of correct quantity. – 15-18 times per hour circulation. (For 2 stroke engine LO= pump capacity/15) 
2. Purification is constantly carried out. 
3. Ensure oil topped up at regular intervals, of not more than 10% of sump volume.
4. Oil testing and appropriate remedial action taken. 
5. Carry out regular crankcase inspection. 
6. Check for crosshead oil leakage at cross head pipe hinges and oil flow pattern. 
7. Regular clearance check between guide shoes & pins.
8. Crosshead bearing clearance check. 
9. Take M/E performance data & power balancing.

Action as CE in case of crosshead bearing failure:

As a Chief Engineer facing a crosshead bearing failure at sea, CE should take the following actions:

1. Stop the main engine immediately to prevent further damage.

2. Inform the bridge and the company about the situation.

3. Obtain permission for immobilization from the port authority if near coastal waters.

4. Ventilate the crankcase properly and ensure all personnel wear appropriate PPE before entering.

5. Inspect the damaged bearing to identify the cause of failure. Look for signs of:

   – Scoring, pitting, or cracking on the bearing surface.

   – Wiped out overlay alloy

   – Reduced oil wedge dimensions.

   – Water contamination in the lube oil system

6. Check the crosshead pin for cracks using Non-Destructive Testing (NDT) methods.

7. Examine the crosshead guides and guide bearings for any defects.

8. If possible, dress up minor damages on the bearing as per manufacturer instructions.

9. Replace the damaged bearing with a spare if available. Ensure the new bearing is installed correctly following maker’s guidelines.

10. Clean the pin and bearing thoroughly before reassembly.

11. Record all clearances and compare with maker’s tolerances.

12. Ensure proper tightening of all bolts and fasteners.

13. Run the lube oil pump and turn the engine on turning gear to check for proper oil flow and unrestricted movement.

14. Perform a running-in procedure as per the maker’s instructions if a new bearing is installed.

15. Monitor engine parameters closely during initial operation after repair.

16. Prepare a detailed report of the incident, including photos, for company records and classification society.

17. Review and implement preventive measures to avoid future failures, such as:

    – Regular oil analysis and purification.

    – Proper alignment checks.

    – Scheduled bearing inspections.

    – Monitoring engine performance and power balance.