MAN 6L35MC Main-Engine Crankshaft Replacement
MINIMIZING DOWNTIME FOR CHEMICAL TANKER – INSPECTION LEADS TO COMPREHENSIVE REPAIR INCLUDING LINE BORING AND SOURCING REPLACEMENT CRANKSHAFT
Goltens was engaged to inspect the main-engine crankshaft on a 23-year-old, 11,700-dwt chemical/product tanker anticipating that the crankshaft could be salvaged with in- situ machining. The tanker had suffered major bearing failures on three of its main journals. Inspection revealed major damage to the running surfaces of the main journals that could not be rectified within the OEM’s specifications. Goltens therefore recommended replacement of the crankshaft as well as a full inspection of the bedplate for potential replacement.
Block removed from bedplate
Rigging condemned crankshaft from engine room
Laser alignment check of main bearing pockets
Line boring of main bearing pockets
Fitting of main bearing caps once crankshaft is installed
DRY-DOCK AND SUPPLY CHALLENGES
The vessel was unable to secure a shipyard berth within a reasonable time frame and turned to Goltens for support. After numerous potential dry-docking options in Southern India and the broader Middle East were abandoned due to capacity issues, Goltens managed to secure a space alongside at a shipyard on the West Coast of India. The repair would have to be done with the vessel in the water.
Complicating matters further was the long lead time from the OEM for the delivery of a new crankshaft and associated spares required for the repair and rebuild. The customer again turned to Goltens for options. Our trading specialists were able to secure a suitable crankshaft of the same make/model of engine from a vessel heading to the breaker’s yard. Once secured, the replacement crankshaft was fully inspected in the presence of Class and cleared for use.
REPAIRS PROGRESS SMOOTHLY
Goltens’ team mobilized to the yard complete with the required tooling to place lifting pad eyes and remove obstacles to the rigging of the crankshafts and other larger components. The engine was then fully disassembled with major components transported to Goltens’ workshop for overhaul. On board, the in-situ specialists used lasers to check the main bearing pockets for damage and determined that, although the engine required line boring, the bedplate could be salvaged.
While the engine components were being overhauled and the replacement crankshaft transported to site, Goltens completed line boring of the engine now fitted with three replacement bearing caps provided by Goltens in preparation for installation of the crankshaft.
DOWNTIME KEPT TO AN ABSOLUTE MINIMUM
The technicians installed the crankshaft and rebuilt the engine before completing successful sea trials and handing the repaired engine over to the ship’s Chief Engineer. Goltens specialists completed this challenging repair with the vessel afloat, supplying the crankshaft and other key components and arranging for an emergency berthing space.
Once again, Goltens completed a major repair while dramatically reducing vessel downtime for the owner.
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