1 Timberlaine Estate, Gravel Lane, Quarry Lane, Chichester, West Sussex. P019 8PP

When steel is immersed in sea water (e.g. a ships hull) small galvanic currents are initiated at anodic areas of the metal surface, causing Such corrosion predominates at the stern of a ship, where the combined effects of increased turbulence and differential metals results in accelerated corrosion rates. The application of Cathodic Protection effectively suppresses these corrosion cells by applying an opposing current from external anodes and if the propeller is to receive the benefits of cathodic protection then there must be a continuous electrical circuit between the propeller and the ships...

However, it is accepted that in practice, such a low value is outside the range of most commercial multimeters and is therefore difficult to determine. It is for this reason that many ship operators prefer a permanent visual indication in the form of a shaft condition monitor, which provides a constant display of shaft potential and confirmation that the bonding equipment is successfully maintaining this at a level not exceeding the optimum value of The M G DUFF system of shaft bonding comprises a split slipring arrangement and ancillary brush gear, which is designed to facilitate ease of assembly...

SHAFT BONDING CONDITION MONITORING The condition monitoring system provides a permanent and readily available indication on the condition and therefore, effectiveness of the shaft bonding system. To ensure a continuous cathode bond and freedom from shaft bearing damage the Condition Monitor should display shaft potential not exceeding 50 mV. Readings in excess of this value are indicative of worn bonding brushes or poorly maintained brushgear and/or sliprings. SLIPRING CONDITION VOLTMETER Monitoring Brush which runs on the main shaft bonding INSULATED spindle. This brushgear is connected Monitor...