Due to their operational characteristics, fast patrol craft create high levels of turbulence in the stern area. This raises the level of oxygen in the water which leads to increased corrosion rates. Patroltek automatically compensates for the variations in operational conditions, ensuring the hull receives the optimum level of protection from corrosion at all times.
The power unit incorporates the controller and is constructed for ease of maintenance. It incorporates solid state circuitry to transform and rectify the ship’s AC supply into a low voltage DC output. Operation of the power unit is fully automatic with a built-in manual override. The power unit is capable of supplying a maximum current of 50A using only a Master unit and 100A with a combination of a Master and Slave unit.
Manufactured from a variety of different materials including platinised titanium, mixed metal oxide or lead silver. Typically anodes are recessed to maintain a streamlined hull profile. They are robustly constructed and their low electrical resistance requires a minimal driving voltage (typically 8 – 10 volts). The anodes are fully insulated from the hull and have glass reinforced polyester backing shields which improve current distribution and prevent localised over-protection.
The reference electrodes are insulated from the hull and are manufactured from either silver/silver chloride or zinc. The references are generally recessed and provide a stable potential against which the potential of the ship’s hull can be measured.
Shaft Earthing is a vital component, which is used to properly earth the propeller shaft to the hull of the ship to prevent pitting of the shaft bearings. It also ensures that the propeller shaft is receiving the full benefit of the impressed current cathodic protection system.