50: Fuel consumption, range

[Cheechako]

From my 42 ft cat experience: If any breeze at all motorsail. You can head up another 15 degrees if needed and high idle the lee engine and still go quite fast at very minimal fuel consumption..

[boatman61]

Originally Posted by mvweebles

20 years ago a guy took a Grand Banks 42 trawler from California to Hawaii. These boats carry about 500 gallons and have a range of maybe 1500 nms at slow 6-kts leaving you about 700nms short of Hawaii. To extend range, in addition to m to carrying fuel in barrels, he decided to run on one engine at a time. To reduce drag, he removed one prop. To balance hours on the engines, in the middle of the pacific, he removed his installed prop and reinstalled the other prop, then ran on that engine. He speculated he extended his range by about 20%. It was a crazy feat. BTW - he was single-handed and swapped props alone.

There is a fair amount of information on this as many powerboats have twin engines. In my delivery career, I probably moved 40-50 powerboats - singles and twins - non-stop from Southern California to the PNW area (roughly 1000 nms) , and a few dozen to Cabo San Lucas (900 nms). Folks in this sphere of offshore cruising take fuel consumption extremely seriously. If you could extend range by 50%-60 just by running on one engine, a LOT more power boaters would do it.

Feel free to give it a try though.

Peter

No need to give it a try.. I've use this method on all my Catamaran deliveries.. they're not trawlers with all that weight and beam, another thing.. everyone who's posted so far is talking max speed or 'cruising speed'.. which for most owners is usually just short of full throttle.
Also, take into account the route from Panama to the Galapagos is notorious for little to no wind.. from there your running before the wind using sails.
This (me) delivery skipper is a different breed, I don't thrash the engines or the boat and I've all the time in the world unless the owner has a schedule.

[donradcliffe]

The only time you will need to consider motoring range is from Balboa to 1-200 miles west of Galapagos. I had a 200 liter tank and another 100 liters in jugs, and ended up buying 160 liters in the Galapagos. In contrast, I only consumed 75 liters sailing from the Galapagos to Marquesas, and another 60 liters during a month's cruising the Marqueses and Tuamotus to Tahiti.

[boatman61]

Another thing to consider is.. A Grand Banks 42 has a displacement of 34,000lbs
A Lagoon 50 is just 19,900lbs..

[mvweebles]

Originally Posted by boatman61

Another thing to consider is.. A Grand Banks 42 has a displacement of 34,000lbs

A Lagoon 50 is just 19,900lbs..

Curious how this explains your statement that running on one of two engines doubles the range?

[donradcliffe]

Originally Posted by boatman61

Another thing to consider is.. A Grand Banks 42 has a displacement of 34,000lbs
A Lagoon 50 is just 19,900lbs..

Sailboatdata says the Lagoon 50 is 44,000 lbs. But it doesn't drag as much water behind it as the square transom of the GB42. The GB42 gets 2 mpg at 8 knots, and nearly 3 mpg at 7 knots.

[boatman61]

I am saying that a 2,500nm journey during which I did just 3 days proper sailing saw me arrive at the Azores with fuel to spare (a little) with half the hours on each engine @ 2,300rpm on a boat with the same tankage and engines as a Lagoon 50 than if I had run both engines.. so I definitely did not burn anywhere near the same quantity of fuel that has been stated by other posters.. okay maybe it was x 1.9 or x 1.7 but that's still a lot of extra miles.
Also, as has been stated, motoring with the main up compensates for drag etc with that little boost..

[Mayeus]

Originally Posted by mvweebles

The curves show 5-6 lph at 2200-2400 RPM. Factors affecting speed are LWL, load, conditions, etc. 8.0 kts is around 1.1 SWL for a 50-ft cat. Assuming a clean bottom and decent props.

With all due respect, are you sure you're the right person to deliver this boat from the Caribbean to Tahiti?

Peter

Why would you say that?

I have since received some notes from a guy who delivered the boat from France. He says: "@2700 12l/hr, @ 2500 9l/hr." But the log book doesn't show boat speed. I doubt we would be doing 8knots at 2200-2400rpm?

[Mayeus]

Originally Posted by donradcliffe

The only time you will need to consider motoring range is from Balboa to 1-200 miles west of Galapagos. I had a 200 liter tank and another 100 liters in jugs, and ended up buying 160 liters in the Galapagos. In contrast, I only consumed 75 liters sailing from the Galapagos to Marquesas, and another 60 liters during a month's cruising the Marqueses and Tuamotus to Tahiti.

I understand there is only one place to get fuel in the Galapagos and one needs to pre-order, 3 days ahead, with an "exact" amount of fuel required. Fuel over what you have ordered will not be available and it is not possible to take less fuel than what you have ordered.

[Simi 60]

Originally Posted by Mayeus

and it is not possible to take less fuel than what you have ordered.

So they just keep overfilling the tanks and let diesel run into the water?

[boatman61]

Originally Posted by Simi 60

So they just keep overfilling the tanks and let diesel run into the water?

No.. it means you pay for what you ordered regardless of whether you can or cannot take it on board.

[donradcliffe]

Originally Posted by Mayeus

I understand there is only one place to get fuel in the Galapagos and one needs to pre-order, 3 days ahead, with an "exact" amount of fuel required. Fuel over what you have ordered will not be available and it is not possible to take less fuel than what you have ordered.

I've been twice, one to Academy Bay and one to Wreck Bay. There was a gas station in Academy Bay which sold diesel, but I was required to buy it through the Port Captain at 3 times the station price. In wreck bay, 4 boats teamed up to buy two 55 gallon drums, and we siphoned it into jerry jugs on the jetty. Fortunately I was not the last boat to get my share, as there was some water in the bottom of one of the drums.

All I can say is that things change, and you have to deal with whatever is available when you arrive. In another place, I bought it dipped out of the fuel tank of a local boat with a pitcher and a funnel. The only thing that is certain is the more "agents" are involved, the more you will pay, and the more Spanish you know, the less you will pay.