Straightening and Cropping Avoids Drydocking

By MarEx 2014-04-09 15:31:00

A ship with bent or cracked propeller blades might experience severe vibrations while sailing. The classification society might demand a repair before the vessel is allowed to sail on. By straightening the blades or cropping them, Hydrex can restore the propeller’s balance, resulting in a green light from the class for the vessel.

A propeller modification can easily be combined with any other maintenance or repair operation that needs to be carried out on the vessel, as was the case with several of the examples that can be found below. Thanks to the flexibility of the Hydrex teams this allows a vessel to keep to its schedule.

By taking advantage of the in-house developed cold straightening technique, damaged blades can be straightened underwater, allowing the ship to return to commercial operations without the need to drydock. Optimum efficiency of the propellers can be restored by bringing the blades back close to their original form. A new model of the straightening machine was recently put into service. It is compatible with the existing model and is used to restore more severely bent propeller blades.

If straightening is not an option, the affected area on the blade will be cropped to restore the hydrodynamic balance. This is done to achieve the greatest possible efficiency for the vessel. This kind of repair is carried out with the propeller blade cutting equipment that was also developed by the Hydrex research department. First a detailed underwater inspection is performed by a Hydrex diver/technician team to obtain the exact parameters of the damage which are then used for a detailed calculation of the ideal cutting line. This allows the customer to know in advance what the result of the operation will be. He can then make an informed decision.

The products and services herein described in this press release are not endorsed by The Maritime Executive.