Next message: Rebecca Taft: "[world-cruising] To the Guy writing on "Life changes bring a new opportunity""
Check me on this one, but isn't there a rule of thumb that suggests 2
hp per 1,000 lbs of displacement as a ratio, or a starting point at
least, for determining engine size for a given boat? By that rough
yardstick both the Hardin and the Irwin would be powered about right.
You don't mention how strong the wind was, whether the boat was also
bucking current, or whether it was correctly propped.
How fast a boat of given displacement will go depends heavily on
currents, winds, and propeller size and pitch. So it doesn't mean
much to say Engine X pushed Boat X of 30,000 lbs at only 5 knots and
Engine Y pushed Boat Y at 7 knots. The other day I was making about
6.4 knots in a 25,000 lb boat with my engine (Perkins 4.108) turning
only about 1500. Of course I had about 8 knots of following breeze
and a 2+ knot current whooshing me along ... it was nice while it lasted ...
Cheers,
Phil
s/v Cynosure
lying Barillas Marina, El Salvador
At 12:17 PM 4/11/2007, you wrote:
>I am thinking of buying a Hardin 45 but I am not sure of the best engine
>size one of a boat that size should have.
>I accompanied a Hardin 45 down the ICW from CT to Fl and they had trouble
>making 5 kts against the wind in flat water. They had a 60HP diesel pushing
>the 30,000 lb boat with 13.5' beam. I was able to make 7.5 kts with my 30 hp
>diesel in a 39' Irwin weighing 16,000 lb.
>
>Do you think Hardin 45 are under powered or is more likely that boat needed
>a better match of prop size/pitch.
>I am a bit inclined to think boats of the Hardin 45 size need about 120 hp.
>
>Regards
>Barry
