This was done during two subsequent stops of the ship in Zeebrugge, on schedule and without having to go to drydock.

After the team set up a monitoring station next to the vessel, the divers started the operation with a detailed inspection of the bow thruster and tunnel. In the meantime, initial preparations were made in the bow thruster engine room for the removal of the unit so that there would be no ingress of water once it was taken out.

The divers’ first action was to take off the external thruster tunnel grids to provide access for removal of the unit. Next padeyes were welded inside the tunnel to hoist the thruster unit up and down.

The next step was to secure the gearbox with hoisting equipment. The team then disconnected the unit from the engine room and removed it from the thruster tunnel. It was then brought to the surface. The team then transported the unit to Rotterdam to be overhauled.

Two months later they picked up the thruster again and brought it back to Zeebrugge during the ship’s next stop in the port.

Because the thruster was fully assembled and prepared, it could be installed in its entirety without the need to create a dry environment in the tunnel as is required when the blades are installed separately. Hydrex diver/technicians lowered it into the water and brought it into the thruster tunnel. The team secured the unit and connected it to the engine room.

The operation ended with the removal of the padeyes and the reinstallation of the thruster tunnel grids.

Hydrex assists shipowners with almost any problem they encounter with their vessels’ thrusters. A wide range of underwater repair or maintenance work can be carried out on all types of thrusters. An entire unit can be overhauled, propeller blades or seals can be replaced or repair work on a specific part of a thruster performed by the diver/technicians while the ship remains afloat.