Two and a half months after Hydrex diver/technicians removed the bow thruster of a 363-meter container vessel in Rotterdam, a Hydrex team once again mobilized to reinstall the overhauled unit underwater with the use of the Hydrex flexible mobdock technique.

The operation was performed in stages at several locations to allow the vessel to keep to its sailing schedule. The first part of the procedure was carried out during the vessel’s stop in Le Havre.

Hydrex used its cradle, designed especially for thruster operations. This device allowed the Hydrex divers to lower the bow thruster unit into the water in Le Havre and maneuver it inside the thruster tunnel in one take.

Furthermore, Hydrex used its in-house-developed mobdocks to close off a thruster tunnel. Mobdock is short for ‘Mobile mini drydock’ because they enable diver/technicians to create a dry environment to work in, while the vessel stays afloat. These mobdocks have been used during thruster operations for 20 years now. Initially rigid mobdocks were used, but later a lightweight flexible variant was designed and put in use.

After all water was removed from the tunnel, the team secured the unit and connected it to the engine room.

This finished the first part of the operation. The divers returned to the Antwerp headquarters, ready to mobilize again when the vessel was arriving at the Port of Rotterdam.

Deployment to Rotterdam was done using one of the Hydrex workboats.

In Rotterdam the team once again used the lightweight mobdocks to close off the thruster tunnel on both sides. Once this was done they installed the thruster propeller blades one by one. With the thruster blades in position, the ship left Rotterdam on schedule.