No Pitch, No Problem! In-Situ Tunnel Thruster Repairs on Cruise Vessels

Operational Tunnel thrusters are necessary maneuvering tools when it comes to operations in the cruise business. With vessels entering and departing ports each and every day and some of these ports do not have tug support for a vessel's needs, severe penalties and costs could be incurred by the cruise operator if these essential pieces of equipment are not in service. Considering the focus on safety and reliability that exists in this market, operators are reluctant to take their assets out of service for repairs as this will require cancellations and skipping of ports. This is where the Subsea Solutions Alliance is called upon to make critical repairs.

Instead of taking the vessel out of service for a period of time and exchanging the affected tunnel thruster, a critical in-water repair was selected to put the system back into service. Developing a repair time line and repair procedure in accordance with the Original Equipment Manufacturers and Class requirements, the Subsea Solutions Alliance performed the critical exchange of the OD box together with the OEM in the Southeastern USA. As required by the client and regulatory bodies in the port, the OD Box was exchanged in a completely dry environment utilizing the Subsea Solutions Alliance flexible hyperbaric door system. Cruise operators and port authorities where these vessels operate require the reporting of ANY risk of oil discharge to the sea; irrespective of how low the risk maybe. Considering this severe focus on the environment, a hyperbaric dry repair was selected.  

With the vessel along side the diver / technicians from the Subsea Solutions Alliance went to work. Access to the tunnel thruster was achieved by removing part of the tunnel thruster grating system with our carbon arc gouging system. Attachment points were wet welded into place utilizing the Subsea Solutions Alliance's "A" class wet welding procedures. Once attachment points were in place the flexible door system was installed and a dry hyperbaric environment was developed. Just like in the dry dock, the factory trained diver / technicians of the Subsea Solutions Alliance opened the rear section of the tunnel thruster and exchanged the affected OD box. Within 12 hours, the damaged parts were replaced and the vessel's tunnel thruster was put back into service. The vessel left on schedule with a newly repaired tunnel thruster.