seattleboatguy
Senior Member
I was very interested to read the feedback from my earlier post "2 trawlers, same engine, different fuel consumption???". The great posts that were contributed on fuel consumption (many thanks to all who contributed) left me very surprised and disappointed with the performance of twin screw trawlers. I come from a sailing background, and as I start looking at a trawler for my next boat, I like the great maneuverability of twin screws, and the idea that I can keep on going if I loose an engine far from a SeaTow base. However, I incorrectly assumed that, with twice as much thrust, I could cut way back on the throttles and still cruise at the same speed as a single screw trawler. Not so. The best example is the data from Moonstruck and SomeSailor.
Moonstruck
120 hp Lehman, single screw
7 knots, 1.5 gph
SomeSailor
120 hp Lehman, twin screw
8 knots, 4 gph total, or 2 gph per engine
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?
Moonstruck
120 hp Lehman, single screw
7 knots, 1.5 gph
SomeSailor
120 hp Lehman, twin screw
8 knots, 4 gph total, or 2 gph per engine
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?