Shiprepair & Maintenance: April 2020
Underwater repair experts Hydrex recently mobilised a team to Phuket, where they completed necessary work on a 200m cruise ship. The vessel had experienced a failure in its bow thruster feedback system, which specifies the position of its bow thruster blades. The repair team used Hydrex’s flexible mobdocks, panels? which close off the thruster tunnel at both sides, allowing the divers to drain water from the room and create a dry environment. This enabled the divers to carry out an inspection and repairs afloat, without removing the unit from the thruster tunnel and without disrupting the sailing schedule of the ship.
Additionally, a monitoring station connected to by both lights and communication lines was set up next to the vessel. Inspections carried out by the diving team revealed a broken feedback cable connection. After its removal and secondary inspection by an OEM technician and the ship’s superintendent, the broken cable was repaired and reinforced on-site. Further tests were carried out to ensure the repair work was successful, including a final performance test with its fully loaded thruster.
After completing repairs on the bow thruster, Hydrex moved its equipment to another quay in order to begin emergency operations on a second cruise ship, which had suffered grounding damage while on route to Phuket. The vessel had already scheduled a dry docking in Singapore to complete extensive repairs but could no longer travel the distance unassisted.
Hydrex’s underwater inspection found that the portside shell plating had a large gap near to its freshwater tank, as well as significant deforming of the bilge keel (in this area). Another four smaller hull penetrations were found in front of the gap and large scraping marks and indentations were found behind it.
After the approval of the ship’s superintendent and attending class surveyor, the Hydrex team fitted a doubler plate (designed to follow the deformed hull’s contours) over both the gap in the hull and patches covering the smaller holes. Both repair products were made on-site and installed underwater and, to provide extra protection, the team welded a stiffener over the plate and a section of the hull.
Following further inspections and class surveyor approval, the temporarily repaired cruise ship was allowed to sail to Singapore for drydocking.