"Wayne.B" wrote in message
...

Why let it freewheel, a freewheeling prop generates more drag than a
stationary one?

Cheers
Marty

That's true but it's not that easy to safely stop a 30 inch prop on a
2 1/2 inch shaft from free wheeling. This topic gets a fair amount of
discussion in the trawler groups. People have tried various jerry
rigged schemes like pipe wrenches and wrapped lines on the shaft tied
off to engine mounts but neither of those schemes holds much appeal
for me, and it is very advantageous to have the idle engine quickly
available for maneuvering. Everything's a trade off. There is no
disputing the fuel save however even though it may not be fully
optimal. We arrived in Florida at 5:00AM this morning after 2 1/2
days off shore. The fuel saved by running slow speed, single engine
was in the neighborhood of 150 gallons.

The other thing we've done that has saved significant amounts of fuel
is to install high output alternators on both engines, and couple them
to the house bank with battery combiners. The saving comes from
reduced generator run time since we can now use the inverter for
routine AC needs when underway without discharging the house bank. The
reduced generator time also lowers maintenance and replacement costs.


Wayne, you have the wrong GB. :-)

(I run at 7.5 kts on a single, 120hp diesel, burning less than 2 gph)

Eisboch

On Tue, 20 Nov 2007 12:22:05 -0500, "Eisboch" wrote:

Wayne, you have the wrong GB. :-)

(I run at 7.5 kts on a single, 120hp diesel, burning less than 2 gph)

Maybe so but I can't see us out cruising for 5 and 6 months at a time
on a 36. That was our retirement model, 6 months in Florida and 6
months north on the boat. As it is, the 49 is completely loaded with
"stuff". My wife just can not understand the concept of traveling
light.

She *really* wanted a triple cabin boat, allegedly so there would be
room for grandchildren and their parents. This lead to some
interesting conversations with brokers when they'd ask how many
grandchildren we had. The answer was, and still is, zero. Both sons
got married this year however so that's a start. :-)