The Magazine for Underwater Professionals

Jan/Feb 2019


Stern tube seal repair on tanker in Tenerife

Entire operation onsite and underwater using flexible mobdock

Stern tube seal assembly of tanker ready for installation of the flexible mobdock

Late last year, a diver/technician team from Belgium-based Hydrex carried out an underwater stern tube seal repair on a tanker berthed in Tenerife, Spain. The ship was suffering from an oil leak, making an onsite repair necessary. Using a Hydrex flexible mobdock the team was able to carry out the entire operation onsite and underwater, saving the owner an expensive and time-consuming trip to drydock. 

“An earlier inspection had revealed that a rope had gotten entangled around the stern tube seal assembly, explains Hydrex. “The rope was removed by the divers during this inspection. Unfortunately the rope had damaged the seals and caused an oil leak. The owner of the tanker asked for the damaged seals to be replaced underwater so that he could keep his vessel on schedule.” 

Once the operation was approved all preparations were handled swiftly and the lightweight equipment was mobilised almost immediately, the company says. The team was onsite and ready to start the seal replacement when the vessel arrived in Tenerife. 


The operation started with a thorough underwater inspection of the stern tube seal assembly and removal of the rope guard. The team then installed the flexible mobdock to allow for work in dry conditions. 

During the operation the divers removed the three damaged seals and replaced them with new ones. Working together with the original equipment manufacturer allowed Hydrex to provide the customer with original spare parts. A technician of the seal manufacturer was also present during the operation. 

Taking advantage of the Hydrex flexible mobdock technique, the men were able to carry out the entire repair onsite and underwater. And because all of the required material is ready to be transported at all times, no time was lost making preparations. 

  • Inside the flexible mobdock work can be performed in drydock-like conditions

“By organising everything from start to finish the owner did not have to worry about making any arrangements for the repair,” says Hydrex. “After the seals had been successfully replaced he could sail his vessel to her next stop free of oil leaks.” 

The firm adds: “All Hydrex offices are equipped with the latest facilities, lightweight equipment and tools. This allowed for a timely arrival of the team in Tenerife with everything needed to successfully complete the job.”





Privacy Policy

Online Dispute Resolution