Staged bow thruster replacement keeps cruise vessel on schedule

2017-08-30T06:27:44+00:00 August 30th, 2017|Refurbishment|

A 208-m long cruise vessel sailing in the Caribbean suffered steering problems after one of its two bow thrusters malfunctioned.

Having to depend on a tug every time the ship berthed would quickly become very expensive. However, taking the vessel out of service to have the bow thruster replaced would cost the owner both money and reputation.

A solution was therefore needed that could be carried out on-site without interrupting the vessel’s schedule. Hydrex with its flexible mobdock technique and experienced diver/technicians took on the job.There was only an eight hour time frame at each port of call during the ship’s Caribbean cruise. It was therefore important that the operation was split into stages that could be finished before the vessel had to sail.

Planning and constant communication between Hydrex technical department in the office and the team on location was essential in achieving this, the company said.In the case of the cruise vessel in the Caribbean, the repair itself was one that the teams had undertaken on many occasions, but the ship’s time table was the tricky part, as her strict schedule included many short stops. Hydrex technical department therefore proposed a scope of work that would allow the replacement to be performed in stages at several different ports.

The diver/technician teams have performed repairs in phases on numerous occasions, including another recent bow thruster operation, carried out in France and the Netherlands, and an underwater stern tube seal replacement on a cruise vessel sailing between Turkey and Greece. The removal of the bow thruster blades and the unit was done under water. The installation of the new bow thruster at the next port needed to be undertaken in the dry to avoid water ingress into the unit.

This was done with the mobdocks.The mobdock technology was developed by Hydrex in-house and is used to close off a thruster tunnel. Mobdock is short for ‘Mobile mini drydock’, as they enable the diver/technicians to create a dry environment to work in while the vessel stays afloat. Mobdocks have been used during thruster operations for over 20 years. Initially rigid mobdocks were used, but later a lightweight flexible variant was designed and these can be quickly shipped to anywhere in the world by air.