Our client contacted us for the replacement of their one of ship's main engine crankshaft renewal at Khorfakkan Port. This vessel was a chemical tanker with LOA 148 metres and year 2007 built. The vessel has two main engines of makers Bergen – Rolls Royce.
Ships STBD side main engine crankshaft was found damaged by the maker’s inspection due to these heavy damages to the crankshaft, the engine was non-operational.
The major challenges in this project were handling of engine block & crankshaft inside the engine room and crankshaft rigging to & from the vessel. Since the engine room skylights and other openings were not sufficient to take out the crankshaft, after discussion with vessel owners we planned to cut the ship’s hull at the engine room workshop area for proper access.
As many critical lifting operations are involved like the lifting of engine block and crankshaft, all lifting operations were done as per proper lifting plans and following safety risk assessments. The engine block weight was around 25 Tons and the crankshaft was around 5 Tons. Since the existing pad eyes on-board the engine room was not sufficient to lift these, we welded new heavy-duty pad eyes on-board and load tested. For lifting the engine block safely, suitable lifting brackets were fabricated which to fit with engine tie-rod bolts.
Since all engine items were removed, the client decided to go with overhauling of various engine components simultaneously with the job. Before the crankshaft installation, all the engine checks were carried out as per the maker’s instructions. Like engine journal bearing pockets calibration, bearing pockets trueness check by laser alignment, etc.
After the installation new crankshaft to the engine and fixing of all engine components to the engine, engine alignments with flywheel side and damper side couplings lased alignments were carried out. After alignments readings were adjusted to limit values, carried out foundation resin chock fast.
After flushing the internal and external lube oil systems, the running in program and load trials were completed as per maker guidelines.
The vessel completed the engine trial in the port berth and followed by a full sea trial at anchorage. The full repair was completed per the planned schedule and the vessel returned to service.