Last month, a team of Hydrex diver/technicians travelled to Tenerife to straighten the underwater propeller blade on a 246m cruise ship.
The crew had noticed that the engine was overloading. Damaged propeller blades will lead to a below average performance, as the engine will have a higher work load, resulting in increased fuel consumption and added stress.
By taking advantage of the Hydrex in-house developed cold straightening technique, damaged blades can be straightened underwater. This allows a ship with a damaged propeller to return to commercial operations without the need to drydock.
Optimum efficiency of the propellers can be restored by bringing the blades back to their original form.
Hydrex found that the four starboard side propeller blades of the cruise ship were bent. After the equipment arrived at Tenerife, the team started the operation with a detailed survey of the ship’s two propellers. This revealed that the port side propeller blades were in good condition and did not require any repairs.
With the survey completed, the team positioned the straightening machine over the bend in the trailing edge of the first damaged blade. In close communication with the team leader in the monitoring station on-shore, the divers returned the bent blade to its original state.
When the straightening was complete, the technicians cleaned the blade to ensure that any remaining loss of efficiency would be minimal. The same procedure was then repeated on the other three blades.
If straightening is not an option, the affected area on the blade will be cropped. By doing this, the greatest possible efficiency is achieved for the vessel.