SAFETY PRECAUTIONS
-On FWE get immobilization permission and propeller clearance from bridge.
-under piston spaces and scavenge space ventilate by blower.
-Stopped engine
-Shut off starting air supply At starting air receiver
-Block the main starting valve
-Shut off starting air distributor/distributing system power supply
-Shut off safety air supply
-Shut off control air supply
-Shut off air supply to exhaust valve – Only with stopped lubricating oil pumps
-Engage turning gear
-Shut off cooling water
-Shut off fuel oil
-Stop lubricating oil supply
-Lock the turbocharger rotors
-isolate expansion tank than only drain jacket drain jacket cooling water and open purging valve so that air pressure helps in draining.
CHECKING CROSSHEAD BEARING CLEARANCE
The top clearance between the journal and a new bearing shell is the result of a summation of the production tolerances of the bearing assembly components.
The top clearance for a new bearing will normally be in the range stated in Data. Note that the figures are to be used for guidance only.
For the top clearance of a specific bearing, see the measurement in the Adjustment Sheet
1. Open the crankcase door at the relevant
cylinder.
2. Turn the crank throw concerned to BDC.
3. Measure the clearance in the crosshead bearing by inserting a feeler gauge between the bearing cap and the crosshead
journal at the top of the upper bearing shell, at both sides and fore and aft.
4. The difference between the actual clearance measurement and the measurement recorded in the Adjustment Sheet (or the clearance noted for a new bearing installed later) must not exceed 0.1 mm. If so, the crosshead bearing must be disassembled
for inspection. For evaluation of the bearing shell, check my blog.
5. The wear limit for a crosshead bearing shell is confined to a 50% reduction of the oil wedge length L. If the wear limit exceeds the 50% reduction, the bearing shell must be replaced by a new one.
-On FWE get immobilization permission and propeller clearance from bridge.
-under piston spaces and scavenge space ventilate by blower.
-Stopped engine
-Shut off starting air supply At starting air receiver
-Block the main starting valve
-Shut off starting air distributor/distributing system power supply
-Shut off safety air supply
-Shut off control air supply
-Shut off air supply to exhaust valve – Only with stopped lubricating oil pumps
-Engage turning gear
-Shut off cooling water
-Shut off fuel oil
-Stop lubricating oil supply
-Lock the turbocharger rotors
-isolate expansion tank than only drain jacket drain jacket cooling water and open purging valve so that air pressure helps in draining.
CHECKING CROSSHEAD BEARING CLEARANCE
The top clearance between the journal and a new bearing shell is the result of a summation of the production tolerances of the bearing assembly components.
The top clearance for a new bearing will normally be in the range stated in Data. Note that the figures are to be used for guidance only.
For the top clearance of a specific bearing, see the measurement in the Adjustment Sheet
1. Open the crankcase door at the relevant
cylinder.
2. Turn the crank throw concerned to BDC.
3. Measure the clearance in the crosshead bearing by inserting a feeler gauge between the bearing cap and the crosshead
journal at the top of the upper bearing shell, at both sides and fore and aft.
4. The difference between the actual clearance measurement and the measurement recorded in the Adjustment Sheet (or the clearance noted for a new bearing installed later) must not exceed 0.1 mm. If so, the crosshead bearing must be disassembled
for inspection. For evaluation of the bearing shell, check my blog.
5. The wear limit for a crosshead bearing shell is confined to a 50% reduction of the oil wedge length L. If the wear limit exceeds the 50% reduction, the bearing shell must be replaced by a new one.
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