Would it be safe to assume...

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GalaxyGirl

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Sep 14, 2012
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267
Location
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The broker says the boat gets 10 gallons per hr at 10knots. The engine is Caterpillar model 3406, six cylinder. Boat is 60' and weighs 160000lbs.

What would be a safe to assume fuel burn at 7k? 3/4 gallon, you think?

Can a surveyor determine the actual fuel burn during the survey?
 
What does 3/4 mean?

There is an active thread on "Efficiency" that should help answer the question. Describe the vessel, cruise RPM at 10 knots and prop size for a bit more input. Also, PM Delfin - he knows the older Cats well.
 
GalaxyGirl, you basically described my boat (60') except for the weight. My boat weighs around 65,000 pounds loaded up for travel. Did you mean to say 60,000 lbs, not 160,000 lbs?

I have 3406C Cats and with my boat I'm guessing that I get somewhere around .9mpg, so a bit less than 1mpg. That's at hull speed. If I step up the speed the mpg goes down.

The only real true ways to determine fuel burn is to install FloScan gauges (or similar brands) and have a very accurate measurement, or fill the tanks, keep track of your hours and miles traveled and do the math.
 
Sounds a little optimistic, assume it's right, slowing the boat well below displacement speed will improve fuel mileage dramatically. My 48' 66,000lb boat gets 1 knmpg at 9.5knts and 2.6 knmpg at 7knts. If you were willing to run my boat at 5knts, 4knmpg is possible.
 
Glad to see you post that Scary.

Everybody seems to think "disp speed" is the speed to go. Why else give it a name right? Sounds like a wise old salt thing to adhere to.

Most any boat on this forum can just whack off a knot and basically be spot on.

Most boats here are semi disp like an IG or GB or NT. But many are still semi disp but close enough to full disp (like a DeFever) to adhere to the one knot less rule.

But for a full disp boat running at HS is almost insane.
 
The broker says the boat gets 10 gallons per hr at 10knots. The engine is Caterpillar model 3406, six cylinder. Boat is 60' and weighs 160000lbs.

What would be a safe to assume fuel burn at 7k? 3/4 gallon, you think?

Can a surveyor determine the actual fuel burn during the survey?

A single 60 ft should get better than 1 mile per gallon. 10 knots is over the hull speed range, 7 to 9, so it would be wasting fuel.

I doubt a surveyor could determine the actual fuel burn as it depends on a number of factors. The Eagle’s original specifications, cruising max speed 10 knots, 1200 gallons range is 2000 miles or 1.66 miles per gallon/6 gallon/hour, but at 10 knots it’s pushing a lot of water. In the avatar the Eagle is going about 7 knots at about 2 miles per gallon. I don’t run at 10 knots as it’s a waste of fuel for 1 or 2 extra knots.

Does the boat actually weight 160,000 lbs? That is heavy for a 60 ft.
 
I would be very hesitant to by boats like the ones you are looking at didn't have a fairly complete set of logs that would show what the vessel has been burning over a variety of trips for the last few years.

While I think flo scans are great...not sure they are as accurate as they claim throughout the whole range of measurements or what many posters have not calibrated them as accurately as the company says they should...could be wrong on that...just skeptical of some numbers I've seen (and having just done 2000 miles on my engine I have to wonder). Another accurate means of measuring fuel consumption is a small graduated tank plumbed into your fuel system...no doubts there.

I NMPG seems too much at 10 knots and too little at say 8 knots....but I would need more info.
 
....many posters have not calibrated them as accurately as the company says they should...
Absolute true, however, when they are calibrated properly, they are hard to beat.
 
GalaxyGirl, you basically described my boat (60') except for the weight. My boat weighs around 65,000 pounds loaded up for travel. Did you mean to say 60,000 lbs, not 160,000 lbs?

I have 3406C Cats and with my boat I'm guessing that I get somewhere around .9mpg, so a bit less than 1mpg. That's at hull speed. If I step up the speed the mpg goes down.

The only real true ways to determine fuel burn is to install FloScan gauges (or similar brands) and have a very accurate measurement, or fill the tanks, keep track of your hours and miles traveled and do the math.

Thanks finally for clearing up the GC mystery. So she's buying your boat and you just didn't want to tell anyone, so instead you've made up the last 1000 posts. :facepalm:

Now, I see, said the blind man.:eek:
 
A single 60 ft should get better than 1 mile per gallon. 10 knots is over the hull speed range, 7 to 9, so it would be wasting fuel.

I doubt a surveyor could determine the actual fuel burn as it depends on a number of factors. The Eagle’s original specifications, cruising max speed 10 knots, 1200 gallons range is 2000 miles or 1.66 miles per gallon/6 gallon/hour, but at 10 knots it’s pushing a lot of water. In the avatar the Eagle is going about 7 knots at about 2 miles per gallon. I don’t run at 10 knots as it’s a waste of fuel for 1 or 2 extra knots.

Does the boat actually weight 160,000 lbs? That is heavy for a 60 ft.

Unless they made it up, specs say Dry Weight: 160,000lbs
 
Hey, why not start with a working tug. That way you can help to offset the $20,000 it costs to fill up each time. Also, it's really a pretty tug.
 
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