A team of Hydrex diver/technicians performed a propeller blade cropping on a 190-meter container bulker berthed in Hamburg. Two parts of the tip of one of the four propeller blades were damaged and needed to be cropped to restore the propeller’s efficiency.
Cropping was the only option as the type of damage to the propeller blade did not allow cold straightening. This kind of repair is carried out with the propeller blade cutting equipment developed by the Hydrex research department. In cases like this, where there is an even number of blades an identical piece will be cropped from the opposite blade to restore the hydrodynamic balance of the propeller. By doing so, the best possible efficiency is obtained.
Single day operation restores efficiency.
One of the four blades of the bulker had lost two parts of its tip. An on-site solution was needed to restore the propeller’s balance and efficiency. A team was therefore mobilized from our headquarters in Antwerp to the ship’s location in Germany.
After the equipment arrived at the vessel’s location the team started the operation with a detailed survey of the affected propeller blade. The team then used the information acquired during the inspection to calculate and determine the correct measurements needed to modify the trailing edges of the propeller blade. Next the divers cropped the blade and ground its edge to give it the correct radius. The opposing blade was modified using the exact same cutting line, to give the propeller back its balance.
When the cropping was complete, the Hydrex technicians buffed the blades to make sure that any remaining loss of efficiency would be minimal.