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Old 11-15-2018, 12:21 PM   #16
menzies
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City: Jacksonville
Vessel Name: SONAS
Vessel Model: Grand Alaskan 53
Join Date: May 2014
Posts: 7,235
Quote:
Originally Posted by DDW View Post
As N.B. Sea says, these electronic engines don't seem to mind running at low settings. 1300 rpm is 33% load, 7.1 knots, 1.9 gal/h. 3050 rpm on the other hand is 99% load, 17.6 knots, 19.2 gal/h. A top cruising speed would be 2500 rpm, 13.3 knots, 12.1 gal/h. If I'm in a hurry to get somewhere, I take a jet plane - cheaper and much faster . The displacement mode cruise is a little better than half as fast, and over three times as fuel efficient.

Note that the % load is torque produced vs. torque available at that speed.
Interesting. My Lugger LP668T engines rate totally different. Perhaps because of the low HP rating.

High Output Rating.............FWHP (kW)/rpm 130 (97)/2400 174 (129)/2400
Medium Duty Rating.......... FWHP (kW)/rpm 113 (84)/2400 154 (114)/2300
Continuous Duty Rating..... FWHP (kW)/rpm 105 (78)/2200 140 (104)/2200

So while they show 2200 as continuous duty, I usually cruise at 1700-1800 and achieve close to full displacement speed all things being equal.
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