Til innholdet

Shaft grounding

Earthing the propeller shaft to the ship's hull prevents corrosion and spark erosion in the shaft bearings and gearboxes. The earthing is provided by spring loaded silver graphite brushes, and monitored by a compact mV meter.

Why earthing the propeller shaft?

When the propeller shaft revolves it is more or less electrically insulated from the rest of the hull. This can result in spark erosion in the shaft bearings and gear.

Propeller shaft grounding provides a very low electrical resistance to the hull, preventing erosion damage. It also includes the propeller to the boat’s cathodic protection system.

Silver Slip Ring

Shaft grounding
Silver slip ring arrangement for shaft.

The system consists of a slip ring with an inlaid silver track. The ring is built to fit the specific shaft diameter.

A low resistance connection to the ship’s hull is provided by spring loaded silver graphite brushes.

The effectiveness of the system can be controlled by a display monitoring the potential difference between the shaft and the ship’s hull.

A slip ring system is convenient when shaft pulling is planned to happen quite frequently. It is also recommended in “greasy” environment.

Silver Slip Band

Shaft grounding
Model of silver slip band system.

The silver bands are fixed to the shaft by stainless steel clamps.

A low resistance connection to the ship’s hull is provided by spring loaded silver graphite brushes.

The effectiveness of the system can be controlled by a display monitoring the potential difference between the shaft and the ship’s hull.

Both systems are delivered with or without a mV-monitor. The potential difference is easy to read with a multimeter as well.

Silver brushes are consumables and are available in our web shop.