Posted by : sanjay swain Wednesday, August 7, 2013

EXCESS CYLINDER OIL CAUSES TURBOCHARGER OVERSPEED

THERE ARE SEVERAL REASONS WHY MAIN ENGINE TURBOCHARGERS BREAK DOWN, REPORTS DENZIL STUART, BUT GARD P&I CLUB IN NORWAY RECENTLY RECEIVED A LARGE CLAIM INVOLVING ONE OF THE MORE UNUSUAL REASONS.

THE ENGINE IN THIS CASE (6­CYL OF APPROXIMATELY 16000KW) WAS EQUIPPED WITH TWO TURBOCHARGERS, STILL COMMONLY USED BY MANY SHIPS TODAY. THE CYLINDER OIL LUBRICATOR REQUIRED MANUAL ADJUSTMENT TO EQUATE TO A CONSUMPTION OF BETWEEN 320-3801 PER 24H. THAT MEANS THE ENGINEER HAD TO REDUCE THE CONSUMPTION MANUALLY IF THE ENGINE LOAD WAS REDUCED TO BELOW 75% FOR MORE THAN FOUR HOURS.

REDUCTION IN ENGINE LOAD DURING BAD WEATHER

THE UNDERLYING CAUSE OF THE BREAKDOWNS WAS FOUND TO BE THE SAME IN ALL CASES. DURING NORMAL RUNNING BETWEEN 75% LOAD AND MAXIMUM CONTINUOUS RATING (MCR) EVERYTHING WAS NORMAL. THE PROBLEM STARTED DURING PERIODS WHEN THE ENGINE-ROOM WAS UNMANNED AND THE OFFICER ON THE BRIDGE (DUE TO BAD WEATHER) REDUCED THE ENGINE LOAD TO LESS THAN 75% WITHOUT NOTIFYING THE DUTY ENGINEER. THE ENGINE LOAD WAS KEPT LOW (UNDER 75%) FOR A FEW HOURS AND, AS THE WEATHER IMPROVED, IT WAS GRADUALLY RAISED TO FULL MCR.

EXCESS CYLINDER OIL IN EXHAUST MANIFOLD RESULTING IN FIRE

WHEN THE ENGINE WAS RUNNING ON REDUCED LOAD WITHOUT REDUCTION OF THE CYLINDER OIL CONSUMPTION, A LOT OF THE EXCESSIVE CYLINDER OIL ENDED UP IN THE EXHAUST CHANNEL. WHEN THE OFFICER ON THE BRIDGE INCREASED THE LOAD IT ALSO INCREASED THE HEAT IN THE EXHAUST CHANNEL WHICH, DUE TO THE EXCESSIVE AMOUNT OF CYLINDER OIL, STARTED A FIRE IN THE EXHAUST CHAMBER. IN ADDITION, THIS RESULTED IN EXTREME OVERSPEED ON THE TURBOCHARGERS, WHICH VERY OFTEN ENDED UP WITH SERIOUS DAMAGE AND TOTAL BREAKDOWN. THE END RESULT IS OFTEN COSTLY OFF-HIRE AND OTHER LOSSES FOR THE OWNER AND ALL INVOLVED. MOST INCIDENTS OCCUR WHEN THE ENGINE-ROOM IS UNMANNED.

LESSONS

AND THE LESSON FROM THESE BREAKDOWNS? GARD SAYS THAT IF THE ENGINE IS BUILT IN SUCH A WAY THAT EXCESSIVE AMOUNTS OF CYLINDER OIL CAN BE PRESENT IN THE EXHAUST CHANNEL WHEN THE LOAD IS REDUCED, ALL OFFICERS AND ENGINEERS SHOULD BE MADE FULLY AWARE OF THE DANGERS.

FURTHER, THE SHIP MAN­AGEMENT TEAM MUST ENSURE THERE ARE CLEAR INSTRUCTIONS TO OFFICERS ON REDUCING OR INCREASING THE ENGINE LOAD WHETHER THE ENGINE-ROOM IS MANNED OR UNMANNED AS WELL AS IN EMERGENCIES.


WHEN THE ENGINE WAS RUNNING ON REDUCED LOAD WITHOUT REDUCTION OF THE CYLINDER OIL CONSUMPTION, A LOT OF THE EXCESSIVE CYLINDER OIL ENDED UP IN THE EXHAUST CHANNEL. WHEN THE OFFICER ON THE BRIDGE INCREASED THE LOAD IT ALSO INCREASED THE HEAT IN THE EXHAUST CHANNEL WHICH, DUE TO THE EXCESSIVE AMOUNT OF CYLINDER OIL, STARTED A FIRE IN THE EXHAUST CHAMBER. IN ADDITION, THIS RESULTED IN EXTREME OVER­SPEED ON THE TURBOCHARGERS, WHICH VERY OFTEN ENDED UP WITH SERIOUS DAMAGE AND TOTAL BREAKDOWN. THE END RESULT IS OFTEN COSTLY OFF-HIRE AND OTHER LOSSES FOR THE OWNER AND ALL.

Recent

SANJAY SWAIN. Powered by Blogger.

- Copyright © MARINE EBOOKS -Metrominimalist- Powered by Blogger - Designed by Johanes Djogan -