The electrical contacts
effectively conduct
even minor currents to
the grounding potentialGrounding propeller shafts prevents corrosion damage and engine
breakdown. By using the BAC Shaft Grounding system it will be possible
to reduce the potential to about 0mV
Per Lynge Olsen, BAC Corrosion Control A/S(^70) ⠿ MARINE MAINTENANCE TECHNOLOGY INTERNATIONAL | APRIL 2016
⠿ CORROSION
I
n all vessels with a rotating propeller
shaft, an electric potential occurs
between the rotating shaft and the hull.
In particular around the bearing, due
to water in the lubricating oil, there may be
corrosion, which over time may lead to engine
breakdown (turbine, gears, shaft generator
etc) unless this potentially serious issue is
allowed for. Furthermore there is a risk of an
explosion in the crankcase.
Preventing propeller shaft damage
Stay grounded
The electric potential between the
propeller shaft and the hull may also cause
a strong current to run in the bearings when
the protective oil film is destroyed due to
wear and tear or becomes polluted with sea
water. This electric current causes deep holes
in the surface of the bearings. Unusually
large wearing down of the bearings can often
be tracked back to this reason. Problems
can be avoided, and the cathodic protection