How to handle one engine failing?

[Jeff F]

In the sailing world conventional wisdom has always favored a locked shaft. But that doesn't make it fact . Maybe it's speed dependent or prop dependent.

Off topic, but many electric drives are now touting generation capabilities for sailboats. I've been curious about that in terms of drag caused by loads from generation.

Sent from my moto g play (2021) using Trawler Forum mobile app

 

[rslifkin]

In the sailing world conventional wisdom has always favored a locked shaft. But that doesn't make it fact . Maybe it's speed dependent or prop dependent.

Off topic, but many electric drives are now touting generation capabilities for sailboats. I've been curious about that in terms of drag caused by loads from generation.

Sent from my moto g play (2021) using Trawler Forum mobile app

In the sailing world I think that came from old school full keel designs. With those, if you have a 2 blade prop and can lock it vertically so the blades are mostly hidden by the keel, the prop is hardly exposed to any water flow and therefore produces very little drag.

 

[Fish53]

I had this occur many years ago and used a simple and secure way of locking the shaft. I replaced one flange bolt at the transmission end with a longer bolt, put a piece of chain on the bolt and fastened the other end of the chain to a convenient bolt on the engine.

 

[Per]

if the prop is freewheeling the drag produced = the energy needed to spin the prop and shaft. in aviation terms this is sort of induced drag.


if the prop is locked, the drag produced is = parasite drag.


you could measure those at various speeds.