Words by Dave McMillan, former CEO of Vard Marine Inc. (1989-2020)
In early 2002, we were awarded a contract by Grand Bahamas Shipyard to develop a scheme to remove and replace a broken main engine crankshaft on the Carnival Cruise Line vessel “M.S. Celebration”. This was a huge challenge to figure out a way to lift the 250 tonne main engine block high enough to allow removal of the 65 tonne crankshaft – all of this activity taking place inside the engine room. Our structural team developed the concept of two “H” frames that were assembled inside the engine room and positioned at either end of the engine block – see Figure 3. The “H” frames were then connected together using two lifting beams which were then attached to the engine block top section and lifted the whole unit up about 2.5 metres. This gave sufficient space to allow removal of the crankshaft and clearance to take the unit out through a hole in the ship side as shown in Figures 4 & 5.
The greatest challenge had been to ensure that all pipe spools being removed from the engine room were tagged correctly to allow a smooth refit after the work on the engine was complete. At the end of the first day, it was discovered that, due to the large number of spools coming out of the engine room, the tagging process had failed to capture all of the spools and there were dozens on the dock without any identification. Thankfully, our on-site team had recognised this was a risk and had made videos of each individual system to show the sections that were to be removed and by process of elimination, we were able to identify the system, and location, of all of the unmarked spools.
The shipyard had estimated 10 days for the complete job, but our scheme was so successful the work was completed in eight days with the actual crankshaft being removed and replaced in only three days.
