Underwater Bow Thruster Removal and Reinstallation

Four months after Hydrex diver/technicians removed the bow thruster of a 280-meter container vessel in Singapore, a Hydrex team once again mobilized to this location to reinstall the overhauled unit underwater with the use of the Hydrex flexible mobdock.

The superintendent of the ship was very satisfied with the first part of the operation. He said that “...the job was completed well within the timeframe of forty hours thanks to good team work of the Hydrex divers, the ship staff and the floating crane operator.” For this reason the customer asked Hydrex to take care of the reinstallation as well, which was carried out last month while the vessel was at anchorage in Singapore.

After setting up a monitoring station on a workboat next to the vessel, the team lowered the bow thruster in the water and maneuvered it inside the thruster tunnel. The team then used the lightweight flexible mobdocks developed by Hydrex to close off the thruster tunnel on both sides. This allowed the diver/technicians to evacuate all the water from the tunnel and create a dry working environment around the bow thruster.

The team then reconnected the unit to the thruster room. Next they secured the unit and installed the blades. Time constraints had prevented the reinstallation of the feedback chain which is necessary to communicate the pitch of the thruster blades to the crew. The diver/technicians reconnected this chain after they had fully secured the unit. After carrying out final testing, the team removed the mobdocks and flooded the thruster tunnel again, thus concluding the operations swiftly and successfully.
 

Source: Hydrex