Ship Main Engine Damage Survey


SHIP MAIN ENGINE DAMAGE SURVEY CARRIED OUT BY ENGINEER SURVEYORS FROM CONSTELLATION MARINE SERVICES.

BACKGROUND

We, Constellation Marine Services (CMS) as independent ship and marine surveyors, often get instructions from our principals as Hull & Machinery underwriters to attend on board ships to carry out machinery damage surveys. Recently we got a nomination form one of our principals to carry out Main Engine damage survey on board a vessel and report on nature, cause and extent of damage to the Main Engine.

Our engineer surveyors upon receiving instruction for the survey contacted the concerned local Agents representing the Owners of the ship informing them on our appointment to attend a survey on board the subject vessel in relation to the Main Engine Failure and repairs planned by the vessel owners and requested them to advise us the berthing date/time of the vessel at the port.

CONSTELLATION ENGINEER SURVEYORS’S ATTENDANCE ON BOARD THE VESSEL.

Upon receiving information on berthing of the vessel from the vessel’s local Agents Constellation engineer surveyors boarded vessel immediately on berthing and met the Master and Chief Engineer to apprise them on our appointment to carry out the Main Engine Damage survey and related repairs to be planned.

With reference to our surveyor’s enquiry about the incident leading to damage to the engine Master informed that frequent damage to the Main Engine had occurred during the six-month period prior to the present planned repairs and had undergone repairs and replacement of some major parts including pistons and cylinders. The repairs on board was done by ship’s crew. Master added that the damage was mainly to the parts in cylinder units 1, 2 4 & 5.
Master further informed that the service technician from MAN Diesel & Turbo boarded the vessel at anchorage a week before for inspection of the main engine to find the root cause leading to high wear rate. A copy of his report was made available for the attending surveyors review.

As stated in the inspection report the technician during his attendance had carried out under piston space inspection where piston rings were broken. checked alpha lubricator for operation and timing and found satisfactory. Checked WATER MIST CATCHER from inspection door and found evidence that there have been high level of liquid (water) for some long time found Jacket water temp too low (down to 65 degree) and Chief Engineer informed regulating valve was not working. The report says that in general the liner surface and cylinder condition seems to have been affected by cold corrosion but by itself not explaining the very high wear rate (+2.8mm) M/E. is 7000 running hours only.

Random replica imprints had been collected by the technician for sending to do lab analysis as cat fines were suspected involved in the root cause. He recommended in his report that incase of cat fine contamination, all liners / pistons, crown, skirt, stuffing box, plunger /barrel and injectors will have to be exchanged + cleaning of HFO tanks and HFO purifier check.

Constellation Engineer surveyors requested the master to make available for review the engine room log book, Copy of Planned Maintenance System, Main Engine maintenance records, Manufacturer Service Manuel, Fuel oil Analysis report, Lube oil Analysis report, Bunker sample Analysis report.

Master advised the Ch. Engineer to provide the surveyors the required documents. There after the surveyors accompanied by the Ch. Engineer visited the engine room. The main engine noted to be MAN B&W make two strokes with five-cylinder units.

The Ch. Engineer made available all required documents for review by the surveyors. As informed by him the engine dismantling was to happen in a day or two. Accordingly we boarded the vessel to inspect the damaged parts of the engine.
Main Engine dismantling Process in Progress

MAIN ENGINE DISMANTLING PROCESS IN PROGRESS

NATURE OF DAMAGE

The damaged engine parts were inspected by us and following noted
S.NO. DESCRIPTION NATURE OF DAMAGE
1 PISTONS HIGH RATE OF WEAR& TEAR AND WITH CARBON DEPOSIT ALL OVER
2 PISTON RINGS SOME BROKEN, SOME MISSING DUE TO BROKEN PARTS BLOWN OF THROUGH THE EXHAUST UNIT AND TURBO UNIT
3 CYLINDER LINERS WITH DEEP SCORING AND SCRATCHES, HIGH RATE OF WEAR /TEAR.
4 PISTON RODS DEEP SCORING MARKS. WEAR/TEAR
5 CYLINDER COVER UNITS INTERNAL PARTS WITH HIGH WEAR& TEAR
6 FUEL PUMP WEAR& TEAR TO ELEMENTS&SEALS
7 PUIFIERS NEED OVERHALING

Pistons-Ship Engine damage survey

CAUSE CONSIDERATION

Constellation engineer surveyors verified all documents including fuel oil test reports, main engine maintenance records. It was mentioned earlier that MAN B&W technician had boarded the vessel at anchorage for inspection prior berthing of the vessel. Random replica imprints had been collected by the technician for sending to do lab analysis as cat fines were suspected involved in the root cause. On reviewing the analysis report it was confirmed that the fuel oil used by the vessel contained more catfines than allowed and were in larger in size. Catfines being abrasive in nature had caused high rate wear and tear consequential damage/breakage to the main engine parts resulting engine failure.

CONCLUSION

Constellation surveyors advised the Master not to use the fuel oil existing in the tanks. Accordingly, the fuel oil from the F O tanks was transferred to slop tanks and the tanks & lines were cleaned to receive fresh bunkers to be used in the engine after repair. The engine repairs completed in a month and refitted on board the vessel. New bunkers were received and used in the engine. After a trial test the vessel sailed to its destination port.

Prepared by Engr. K.D. Shenoy.

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