Hydrex has reported that it recently repaired a four-bladed, 18-foot diameter propeller underwater in Flushing (The Netherlands) with a diver/technician team, including restoring the propeller’s balance and bringing its performance back as close to optimum as possible.

With a bent blade, straightening was not an option. Hydrex stated that the affected area on the blade was cropped to restore the hydrodynamic balance. The repair was carried out with company-developed propeller blade cutting equipment.

First, a detailed underwater inspection was performed by the company’s diver/technician team to obtain the exact parameters of the damage, which were then used for a detailed calculation of the ideal cutting line.

After the bent propeller blade had been cropped, the opposite blade was cut at the exact same cutting line. This was done to restore the propeller’s balance. Finally the edges of both blades were ground out and smoothed.

By cropping the damaged blade the team allowed the ship to return to commercial service without the need to drydock.