Prevent costly damage and ensure the longevity of your vessel’s propulsion system with BAC Impalloy’s high-performance shaft grounding system.

When a propeller shaft rotates, it becomes electrically insulated from the ship’s hull by the lubricating oil film in the bearings, creating an “oil wedge” with a high resistance. The dissimilar materials used for the propeller and hull, typically bronze and steel, form a galvanic couple where the hull is the most active part. This difference in electric potential creates an electric current that tends to discharge across the lubricating oil film as an electric arc, leading to spark erosion and subsequent bearing breakdown.

Installing a shaft grounding system as part of the ship’s cathodic protection system can prevent this. A difference in electric potential between the ship’s hull and the shaft system of less than 50mV minimizes the risk of arcing. 

BAC Impalloy’s well-proven and easy-to-install Shaft Grounding system effectively minimizes these risks by reducing electrical resistance between the propeller shaft and ship’s hull to less than 0.001 Ohms. Our system includes high-quality silver band slip rings and silver carbon brushes, ensuring a reliable and efficient connection that prevents galvanic and spark corrosion.