BoatBanter.com - View Single Post - What are the pros and cons of a folding prop?

(Shen44) wrote:

Subject: What are the pros and cons of a folding prop?
From: Rosalie B.

We have a feathering prop (vs a folding prop) and we do get an
increase of about 1/2 knot under sail, and it also backs better under
power. I haven't tried to quantify the backing under power - it is
just what we feel.

Disadvantages are - you lose a bit of power forward because the blades
are flat and the prop takes a bit more maintenance than a fixed prop.

[We were sailing but had the engine on in neutral so the prop was not
feathered - we were running the refrigeration- and when we had
finished that, we turned off the engine and feathered the prop, and
our speed increased 1/2 knot - same wind and current. Now I know this
is not a completely scientific test, but it is significant to us.
There are also people in our group who did tests with a fixed prop
over a measured course, and then did the same tests with a folding
prop over the same course and found a similar result.]

Question. Your engine was running but you were in neutral gear. Why wasn't the
prop feathered? i.e., does the prop "unfeather" when the engine starts or when
you put it in gear? What causes the prop to feather?
This is an area I'm not familiar with, though I frequently use VP/CP props.

I don't know what a VP/CP prop is.

When our engine is running the shaft is spinning because we have a
Borg-Warner transmission. Our shaft spins whenever the engine is on
regardless whether it is neutral or not. The prop feathers when the
engine is turned off and the shaft stops spinning. The stopping of
the shaft spinning feathers the prop if I understand it correctly.
You really wouldn't want the prop feathered if the engine was on - if
it feathered when you went through neutral when docking or something
it would be very awkward.

grandma Rosalie