Boat/Power

This is just an idea.

It would be nice to have a thread where people could give the minimum data so others would know how much power is needed to sail a trawler: For example

Boat: Eskimol 46'

LWL: 40.25'

Disp: 55000 lbs

Engine: Brakeoften 145HP*@ 2500

Top Speed: 8.5 knts @ 6.4 GPH

Cruising Speed: 1800 RPM 6.7knts @ 3.1 GPM

Everybody trying to understand fuel consumption, power needed, speed, and other trawler related issues, would come here and read the thread to compare with the possible or real boat of their dreams.

Best regards.

Fernando

*

Fernando,

There's just a few of us here that are interested in that stuff and we have talked a bunch about it in the past. You've got about exactly the same power loading as my Willy and I think we're a bit over powered but only by about 20hp (in your case) and 5hp in mine. Three or 4hp per ton would be closer to ideal but we'd be running at 75% load for cruise and most here believe one needs extra hp in a blow to make way. It dos'nt really matter as 98% of us have semi disp hulls and 25% of them think they have full disp hulls. And I see your top speed is your hull speed (as is mine) but most here think cruising at hull speed is the way to go and they are partly to mostly right as the most common semi disp hull does not run into the FD brick wall. Don't know how much more fuel is burned w the SD hull going at hull speed but I'm sure it is more than a linear curve would suggest but not as steep as w FD. I'm not even sure the term "hull speed" should be used on any but a FD hull. With anything else it's just a numerical function having little to do w the dynamic forces that apply to it's importance in boat design. Here people are more concerned w stairs or ladder to the FB or galley up or down. But everybody knows the slower one goes the less fuel one burns and if one slows down 10% one burns less than 10% less. And the thread you suggest I roughly keep in my head as I try to remember the stats on many other boats as I become familiar w them. Search the archives and you'll find much to read on this subject.

The Eagle is 58 ft, 80,000+ lbs, full displacment, and powered by a single DD 671, 165 hp, at 1500 rpm, 8 knots about 4 gph.* So not much power is need to push a boat through the water at hull speed.* **