ANODE SHAFT

Function and technical context

The shaft anode is the key component within a vessel's cathodic protection system, acting as an electrochemical sacrifice to preserve the propulsion shaft from galvanic corrosion caused by prolonged immersion in salt or brackish water. Being made of zinc alloy or other active metal, the anode preferentially oxidizes instead of the stainless steel or bronze shaft, thus avoiding accelerated degradation of a structurally critical component for power transmission to the propeller. Without effective cathodic protection, the shaft can suffer pitting, loss of section and, in advanced cases, fracture during navigation, with the consequences that this implies for the safety of the vessel and the integrity of the propulsion system. The TEN00526-1 anode is mounted directly on the propeller shaft, guaranteeing localized and efficient protection in the area of ​​greatest galvanic exposure of the transmission system.

When to replace this part?

Shaft anodes should be inspected at least once a season and replaced when they have lost between 30% and 50% of their mass, since below that threshold they no longer offer sufficient cathodic protection. The most common symptoms of a depleted anode are the appearance of pitting or oxidation stains on the shaft, irregular discoloration on the adjacent metal surface or visibly accelerated consumption compared to previous seasons, which may indicate parasitic currents in the boat's electrical system. It is recommended to replace the anode preventively at each annual grounding: it is a low-cost operation that prevents damage to the propulsion shaft, the repair or replacement of which is considerably more expensive.