Thanks Bob
I'll post my results when I get a chance to make more test runs.
In the July, 2000 issue of "Power and Motoryacht" magazine there was an
article "Super Saver, the Sequel" by naval architect George L. Petrie. It
is a technical explanation of the fuel saving strategy and was a follow-up
to "Super Saver" in the July, 1999 issue. I've not been able to get a copy
of the original "Super Saver" issue in which the author, Capt. Bill Pike,
reported 30% improvement on a gas powered Harbormaster. George Petrie
calculated an estimated 20% savings for a hypothetical twin diesel.
However, all of this is about planing hulls, not displacement trawlers.
Thanks for the warning on the rope shaft brake. Unless locking the shaft
makes a significant improvement in mpg (I will test with the Floscans) I
probably won't bother with it.
As I recall the line on the GB shaft lock looked like 1/4 inch nylon braid,
maybe 3/8.
Jim Fidler "Fiddlesticks"
Jim,
Thanks for the flow scan info..that is the way to really find out if
is more effecient--and confirms what I have felt.
However the light line is not a good idea--as the line winds on the
shaft before it breaks it can cause side pressure on the bearings and
perhaps even distort the shaft. I don't know what size line he used, but
takes a lot of pressure to stop a 24 inch prop from free wheeling at 8
knots--much more than 1/8" line would handle.
I always used chain vise grips to lock a prop shaft.
Bob Austin
Thanks Bob
I'll post my results when I get a chance to make more test runs.
In the July, 2000 issue of "Power and Motoryacht" magazine there was an
article "Super Saver, the Sequel" by naval architect George L. Petrie. It
is a technical explanation of the fuel saving strategy and was a follow-up
to "Super Saver" in the July, 1999 issue. I've not been able to get a copy
of the original "Super Saver" issue in which the author, Capt. Bill Pike,
reported 30% improvement on a gas powered Harbormaster. George Petrie
calculated an estimated 20% savings for a hypothetical twin diesel.
However, all of this is about planing hulls, not displacement trawlers.
Thanks for the warning on the rope shaft brake. Unless locking the shaft
makes a significant improvement in mpg (I will test with the Floscans) I
probably won't bother with it.
As I recall the line on the GB shaft lock looked like 1/4 inch nylon braid,
maybe 3/8.
Jim Fidler "Fiddlesticks"
> Jim,
> Thanks for the flow scan info..that is the way to really find out if
it
> is more effecient--and confirms what I have felt.
>
> However the light line is not a good idea--as the line winds on the
> shaft before it breaks it can cause side pressure on the bearings and
> perhaps even distort the shaft. I don't know what size line he used, but
it
> takes a lot of pressure to stop a 24 inch prop from free wheeling at 8
> knots--much more than 1/8" line would handle.
> I always used chain vise grips to lock a prop shaft.
>
> Bob Austin
