Ringing in Engine Room While Sailing

[Chief Engineer]

transmission in reverse........prop had shown some signs of electrolysis due to stray current at marina...prop and zinc are tight.



I have heard of this before but I don't remember where.

[daddle]

The prop or strut can do this. Both should stop or change character if you turn the shaft by hand.

Maybe you are sailing too fast?

[bruce smith]

My fixed 3 blade sings at about 5 knots.

[sailorboy1]

Originally Posted by Chief Engineer

transmission in reverse........prop had shown some signs of electrolysis due to stray current at marina...prop and zinc are tight.



I have heard of this before but I don't remember where.

At what rpm? Probably a hamonic condition at a rpm range that should avoided (more to do with bearings and bushing wear). If so the chances of really finding the cause is slim. But changing anything in the drive train line-up might stop it, even as simple as putting the zincs at a different section of the shaft.