A 200 m cruise ship experienced a failure in the feedback system of its bow thruster recently.
As a result, afloat repair specialist Hydrex mobilised a team to Phuket, Thailand to perform underwater repairs by using the company’s mobdocks.
These lightweight flexible mobdocks are easy to transport and are used to close off the thruster tunnel on both sides, the company explained. This allows Hydrex divers to empty the water from the room and create a dry environment around the unit.
In this way the operation can be performed underwater in dry conditions, whether it entails the removal or installation of an entire unit or, as was in this case, repair work on a specific part.
While on its way to Phuket, a breakdown occurred in the feedback system that confirms the position of the vessel’s bow thruster blades. Taking into account the strict schedule of the cruise ship, keeping it sailing was essential.
Hydrex was contacted by the the cruise operator and asked to find a fast, on-site solution
In co-operation with the thruster manufacturer, a plan was devised by the Hydrex technical department. This involved the Hydrex diver/technician team carrying out an inspection and any necessary repairs afloat without removing the unit from the thruster tunnel.
The customer accepted this proposal, as it meant not needing to drydock the ship, which saved substantial time and money.
Following essential preparations in the Hydrex fast response centre, all the lightweight equipment needed was mobilised to Thailand from the company’s Antwerp headquarters.
Upon arriving on-site, the team set up a monitoring station next to the vessel. They then installed the flexible sheets and removed all water from the thruster tunnel. Lights and communication lines connecting with the monitoring station onshore were also installed.
Next the bolts securing the cover of the gearbox were removed and it was opened. A video inspection of the internal part could then be performed. It was found that the feedback cable connection was broken. As a result, the chain indicating the position of the blades had become unattached.
The broken part was removed and inspected by the OEM’s technician and the ship’s superintendent. There was no possibility to replace the broken part with a new one. Instead it was repaired and reinforced on-site.
The cover was then put back into place and resecured. Tests confirmed the repair to be successful. It ended with the removal of the mobdocks and final tests were conducted with a fully loaded thruster.
Hydrex said that the team enjoyed a very pleasant and smooth co-operation with the ship’s crew, the thruster manufacturer and all of the other parties involved. This helped the team to perform the operation as fast as possible.
By using the mobdocks the customer was able to have the damage repaired without the removal of the thruster. This kept the vessel out of drydock, while maintaining the cruise ship’s sailing schedule.
