When a 204-meter cruise vessel suffered an oil leak in its stern tube seal assembly, Hydrex was asked to carry out a permanent seal replacement. The repair was carried out with the Hydrex flexible mobdock technique and performed in stages to allow the ship to keep the tight schedule of the cruise it was on.
A small Hydrex diver/technician team met up with the ship in Kusadasi, Turkey and removed the starboard side rope guard. This was done to shorten the time required for the actual replacement of the stern tube seals. It was essential in fitting the operation within the short stop the vessel made in the next harbour on its trip. The team was then completed with additional diver/technicians and sailed to Greece on board the cruise ship.
As soon as the vessel arrived in Piraeus, the Hydrex diver/technicians set up a monitoring station next to the ship and made all necessary preparations for the main part of the operation. The team then installed the Hydrex flexible mobdock around the stern tube seal assembly. This created a dry working environment underwater in which to carry out the repair in the drydock like conditions, necessary when replacing seals.
After the diver/technicians had opened up the assembly they removed the damaged stern tube seals one by one and replaced them with new ones. A subsequent leakage test showed that the repair was successful. The team then closed the stern tube seal assembly again and removed the flexible mobdock. This ended the second part of the operation well in time for the cruise ship to sail to its next stop with its passengers.
In Istanbul, Turkey, the team met up with the vessel again and refitted the rope guard onto the stern tube seal assembly, concluding the operation. The ship could continue its journey free of oil leaks without going to drydock and without any changes to its schedule.
[mappress] Subsea World News Staff , February 03, 2012; Image: Hydrex