• As a Chief Engineer how would you inspect a bearing that is being prepared for survey?

inspection and survey of a bearing

.bearing survey   .bs    .mebs    .mbs

Prior to Opening Bearing for Repair/ Survey:

• Take immobilization permission from port authority
• Enclosed space entry permit must be taken
• Perform tool box and risk assessment of the job
• Ensure to check the previous bearing opening/ survey report
• Check details of the records and clearances
• Check shore lube oil analysis record
• Check work done report or log book for any important points on the bearings (grinding or pin/ under or oversize bearing etc.)
• Check all the photographs of the last opened bearing
• Check all bearing related service letters from the manufacturer
• Perform onboard lube oil test and note down the results

Safety check for main engine:

Before undertaking any work on the engine, the following safety checked should be carried out: 

1. Permission granted to immobilize engine.
2. Risk assessment should be carried out.
3. Work permit to be taken.
4. Starting air shut off and locked off. 
5. Open the indicator cock.
6. Engine cooled down sufficiently to allow L.O pump to be shut down.
7. Check that no one is working on the vicinity of the shafting. 
8. Take propeller clearance from bridge.
9. All lifting gear, shackles etc checked for defects and check they are within certification.

Tool box meeting should be carried out, only the person in charge of operation is to operate the T/G.

Bearing Inspection

.bearing inspection

1.  Dis-coloration
2. Estimate percentage of discoloration
3. Signs of overheating
4. Lacquer formation
5. Removal of overlay
6. Microbial attack
   1. Scoring
7. Due to impurities/abrasive particles in the lub oil
8. Bearing wear particles
   1.  Pitting marks
9. Foaming of the lub oil
10. Spark erosion due to earthing problem (mainly on thrust & main bearings and journals)
    1.  Flaking
11. Ageing, water in lub oil
    1. Signs of Fretting due to
12. Incorrect tightening
13. Applying oil/grease at the back of bearing shells before assembly
    1. Wear down

– Measure the thickness of the bearings

• Cracks
• overloading
• Use dye penetrant check
  • Oil Grooves
• Enlargement of grooves due to erosion/corrosion
  • Oil holes

– enlargement/blockage

1. Dowel pin/holes if fitted

– slackness

 Replacement of bearings to be done as per maker’s instruction. For e.g., if overlay alloy is wiped out or oil wedge in the bearing is reduced in dimension etc.

Journal / Pin 

• discoloration
• Roughness
• Hardness check
• Surface finish
• Diameter/ovality check
• Crack detection
• Oil holes check

If scoring, pitting, cracks etc. exist in the pin, same to be polished, grinded, or reconditioned

• The pin and the bearing to be thoroughly cleaned and lube oil to be put before fitting
• Take enough photographs while doing the maintenance or survey

After Repair/Survey:

– Ensure the bearing and other parts are secured as per manual instructions
– The tightening value of the hydraulic bolts to be crosschecked and it is to be done in the presence of senior engineer officer
– Engine to be turned by turning gear for at least 10 minutes with lube oil pump on and oil pressure recorded
– The turning gear current to be observed during this process
– Once the engine is closed and ready, running-in to be performed as per makers instructions
– Record all the parameters
– Prepare the maintenance/ survey report
– File the report in ship’s record and send the complete work with photo proof to the office. This can be used as a reference during continuous machinery survey and the concerned bearing need not to be opened.