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Old 11-05-2013, 10:18 AM   #4
SomeSailor
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City: Everett, WA
Vessel Name: Honey Badger
Vessel Model: 42' CHB Europa
Join Date: Oct 2011
Posts: 784
Quote:
Originally Posted by seattleboatguy View Post
So, SomeSailor has twice as many horses in the engine room, drinking twice as much diesel, but cruises at about the same speed as Moonstruck. Why don't trawler skippers just shut down one of their engines, once they are clear of the marina?
It's still about the economics of it. My neighbor has a very similar sized single engine trawler. He runs well below his hull speed (best mathematical efficiency) because he's pushing his single engine harder than would be efficient. With twins, I can operate less efficiently (two screws, two engines running) and still make my hull speed in a range that is most efficient.

If he and I were to run side-by-side AT hull speed (most efficient for the hull) I'd probably burn less fuel. He has to push his single to get there is all.

At some point, the displacement numbers become important variables in terms of efficiency. I don't know where that number is though? 40', 50' 60' LOA? It would be a fairly simple model to build though.
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