Diesel Usage Cruising the Intracoastal Waterway

[Knot Tide Down]

I have a 41' Lindmark trawler with twin Ford Lehman 120's and at 1500 rpm we do around 7 knts. The average gph for the total of 6500 mi at the end of our "Great Loop" cruise, was 2.3 gph (1.3 gph ea. engine).

[Jim Cate]

25K lbs, 18 knots, down the ICW???

No wonder people hate stinkpots...

Jim

[On The Water]

My 64' ex steamer consumes at 7 to 8 kts 5,5 to 6,2 Gal/h, with a single Cat D343 put in new in 1960 this is in nice weather and no tow

[donradcliffe]

The rule of thumb is 1 gph for every 20 hp, so your 375 hp Cat is going to consume about 19 gph at WOT.

[On The Water]

Yes at full power she would use more than i could aford.

I use the 250gr/hp rough formula, so at 300 hp its 75 liters (19 gal) an hour an at 375 hp its 94 liters (23 gal) an hour.

With an classic under body at 7 kts her wake is minimal so based on the 1 gallon for every 20 hp im using 110 hp to go 7 kts.
With the gr/hp calculation 88 hp for 7 kts.

From the old graphs in the engine log book it seems she used up to 24 gal/h when towing, but she is long retired now.

[rwidman]

Originally Posted by Randy

I was also wondering about the effects of 18 kts down the ICW would have on the locals!

There are parts where you can do 18 knots with no problem. Other parts are restricted or it's just not practical.

I find that travelling at or near hull speed greatly increases my fuel mileage. Also, on the ICW in the South, you will be dealing with tidal currents. This will be a factor in speed and fuel burn.

[djmarchand]

I plugged in your numbers into boatdiesel's power required calculator, although I have a hard time believing 25,000 lbs for a 43' boat. But anyway it shows 370 hp.

For older turbocharged diesels use 18 hp/gal/hr so that gives you 21 gph.

David