Two months after we removed the bow thruster of a 150-meter roro ship, our men once again mobilized to Algeciras, Spain to reinstall the unit. By performing both operations underwater, the thruster could be overhauled without making costly changes to the schedule to take the ship to drydock.

The reinstallation was carried out by reversing the procedure used for the thruster’s removal. The team once again set up a monitoring station next to the vessel. The divers then started the operation with a detailed inspection of the bow thruster tunnel. In the meantime, initial preparations were made in the bow thruster room for the reinstallation of the unit so that there would be no ingress of water once it was taken out.

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. Our diver/technicians lowered it into the water and brought it into the thruster tunnel. The team secured the unit and connected it to the bow thruster room.

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

We worked in shifts around the clock and finished the job within the available time frame. This allowed the ship to sail on schedule, which was a key benefit for the owner.

Performing a job like this takes a lot of planning. This can only be done successfully by staff who have familiarity with such operations and have the relevant know-how and equipment.

All types and sizes of thrusters

We can assist shipowners with almost any problem they encounter with their vessel’s 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, as was the case with this operation, but propeller blades or seals can also be replaced if needed or repair work on a specific part of a thruster can be performed on-site.

Both the removal and reinstallation of the thruster in Algeciras were done underwater, but this is not always the case. Our teams can also remove the unit before the ship enters drydock so that it can be brought to the manufacturer for overhaul ahead of time. When the vessel enters drydock the overhauled unit is ready for reinstallation without any delay. The reverse procedure is also possible. If the thruster is removed in drydock, we can reinstall it underwater in dry conditions at a later date after it has been overhauled. In this way the ship can leave drydock while the unit is still with the manufacturer.

Despite the scope of some these operations, bow thruster removals can be performed very fast. The removal of the unit can always be done in the wet, even if the blades need to be removed, because the thruster has to be overhauled.

If the bow thruster unit and blades need to be installed separately during the reinstallation, our teams make use of our flexible mobdocks that close off the tunnel on both sides. These can quickly be transported to any location. They allow our divers to work in a dry environment around the unit.

All these repairs are performed in cooperation with OEMs. They can be carried out with the vessel afloat with minimum impact on its schedule.