My comment about static thrust not being a very relevant criteria is because most E boaters want to go as fast as possible with as little energy expended as possible. There is a presumption that motors of equal static thrust have equal ability to drive the boat at design speed. I believe this is the 'logical' basis behind the 1 electric hp = 2 or 3 or 5 ICE hp nonsense.
If you are mostly concerned about accelerating your boat from a standstill or overcoming a huge amount of windage then static thrust is relevant.
Denny
----- Original Message -----
From: Joe Siudzinski
To: electricboats@
Sent: Friday, July 31, 2009 5:47 PM
Subject: [Electric Boats] Static Thrust was Re: Trolling Motors
dennis wolfe <dwolfe@dropsheet.
(snip)
> Its static thrust (bollard pull) is not relevant to how fast it will push the
> boat. Thrust is a stupid way of comparing motors as the boats are not used
> tied to a stationary dock.
Denny:
I'd like to explore this a bit, as, on the contrary, I consider static
thrust a very relevant selection criterion (which, unfortunately, is never
published by outboard manufacturers)
outboard motors on my 36' sailing catamaran which have served me wonderfully
for seven years of cruising (each has about 2600hours on it). My top speed
with both engines wide-open is 7.8kts, which, quite frankly, I only did once
"just to see what she would do". My normal cruising speed is just below
5kts.
My criteria is indeed static thrust because over the years I have faced
situations whereby I had to maneuver the boat in confined spaces into some
very strong winds whereby the boat is barely moving with the engines wide
open as you head into and try to turn across the wind. This to me is a most
important selection criteria as, in my example, an equivalent 9.9hp motor
with high-speed prop and gearing fails miserably in this situation.
Staying on topic of electric boats, I am exploring adding an electric drive
(outboard?) as a tertiary drive system since I have excess solar and battery
capacity. I've been comparing static thrusts for the above reason.
Perhaps you would care to elaborate as to why I'm looking at the wrong
specs?
JoeS.
[Non-text portions of this message have been removed]
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