Motoring Range to Cross the Pacific

[osirissail]

Sounds like a good investment would be a drifter sail or asymmetrical spinnaker for the eastern Pacific area. I have my friends relating about their 19 day to 30 day "drift" from the Galapagos to Marquesas with lots of time for polishing, varnishing, and reading. Supposedly there is a decent current heading west so even with only 10 kts of wind you can make decent speed over the ground. A good drifter/asy spinaker would be nice to catch whatever winds whisper by.

[roger.waite]

I am very interested in this re: next boat. While useful to know how little fuel others burnt, this is little use without knowing the engine, boat, willingness to sail light airs, etc. So I was wondering whether it would be more useful to share rough 'engine hours' budgets that folk can play with to estimate fuel needs for different boats & preferences.

Here are my guesstimates, which I would welcome comment on. I know "it all depends" on a host of equipment choices and manageable desires, but are these a reasonable starting point for planning fuel needs?

1 hour per day (times 30 days?) for charging (which we can halve or more with wind/solar gen, and minimising consumption, using self-steering, etc)

24 hours to get from the NE to SE trades (much less if patient)

24 hours to preserve sanity in flat calms (after that we roll about)

24 hours reserve (which expands if the weather is reasonably kind)

I assume boat is set up to make adequate progress in 12 knots of wind, and I sail as long as I am making ... oh 70 miles a day. Gut reaction is my figure of circa 100 engine hours (with reserve) may be high. What do people who have done the crossing think?

[cal40john]

Four jerry cans of gas made the round trip to Hawaii and back from Washington without being touched. Cal 34 had a 28 gallon tank to run an Atomic 4. Don't remember how much fuel it took to fill the tank in Hawaii.

John

[donradcliffe]

We have a 50 gallon tank in a Beneteau First 456, and carry 20 more in Jerry jugs for long passages. Fuel consumption is 1 gal/hr at 6 knots, 0.6 at 5 knots, or about 500 mile range. We usually motor if we can't sail more than 4.5 knots, but the boat sails better than it motors to windward in heavy air. We used about 50 gallons getting from Panama to the Galapagos. The only time we got down to our last 5 gallons was Bali to Singapore. In 15 years and 75,000 miles we have used the engine an average of 300 hours per year, about half the time for charging batteries. We never fill the jerry jugs for coastal cruising. I think a 75 gallon tank would be optimum--any more and the weight of the fuel starts to bog you down.

[roger.waite]

Yes. That is the sort of answer I got to. Throttle back a bit, sail a bit more, and I should be fine with 75-100 gals - as long as I have a reasonably efficient 40-45' hull and a moderately sized engine.

[osirissail]

Make that efficient hull and good sail inventory. Efficient hull and worn out sails or bad sail plan and you will be matching speeds with continental plate drift. Good sails and you can make good speed in 10 kts of wind. Don't forget ocean currents - they can add 24 nm to almost 75 nm to your daily run over and above your sailing speed. Route planning is very important to maximize nm per day. Did you ever wonder why the old sailing ships made a big circle north around the Atlantic on their way to Europe and way south towards the Equator on their way west instead of just going straight (great circle) across like the big freighter do now?
For sailing ships, the longer routes are sometimes much faster.

[maxingout]

One of my South African friends sailed west from Capetown to Auckland over a nine-month period in his fifty foot yacht with one tank of fuel, and he had diesel left over. He rarely motored offshore and mainly used the engine for close in maneuvering.

On board Exit Only, we carried enough fuel to motor 1400 miles when going on passage. We didn't often use all the fuel, but it was there if we needed it. Anytime my speed dropped below four knots, I turned on one engine. If continuous motoring was required, I would use the starboard engine for 12 hours and the port engine for twelve hours, rarely running both engines at the same time. My 1400 mile range was based on using only one engine at a time and motoring at five knots.

[Zanshin]

Maxingout - I'm not a catamaran sailor but would like to know if using 1 engine at a higher load is more efficient than using both engines with a lower load per engine. Also, do both engines have identical external loads (i.e. alternators to same battery bank)?

[maxingout]

Originally Posted by Zanshin

Maxingout - I'm not a catamaran sailor but would like to know if using 1 engine at a higher load is more efficient than using both engines with a lower load per engine. Also, do both engines have identical external loads (i.e. alternators to same battery bank)?

I tried to run the engines as close as possible to recommended RPM when motoring offshore. On Exit Only the engines seemed to settle in about about 2200 to 2500 rpm. Diesels seem to be healthier when you run them hard. When I pushed the throttles forward to higher RPMs, they gradually moved back to the 2200 to 2500 RPM level, and so that's where I let them run. That gave me the five knots I wanted when running under power.

I had identical 90 amp Balmar alternators on each 28 hp Yanmar. I also had fixed three blade props on each engine.

[bulabro]

Thanks for the great input on this thread. I want to be able to motor when the COG drops below 4 knots so it seems to me that a reasonable fuel tankage would be 150 gallons. That means converting one water tank">fresh water tank (50 gallons) to diesel and adding 50 gallons in jerry cans. At 5 knots, with a one gallon per hour burn, I should have a range of approximately 750 miles. I don't see us doing the crossing with any less. Anyway, thanks for the input.

[osirissail]

Bulabro, critical question - - what is the water tank you are planning to convert, made out of? Fiberglass? Steel? Aluminum? If fiberglass, what is the tank coated with inside? Check with the boat manufacturer for their okay or recommendation as to converting the tank to diesel. Then you will have to also change the hose/pipe from the tank to the engine area or main fuel filters. And you will have to change the "fill" or inlet hose from water hose to diesel fuel rated hose. Or install a fuel rated 3-way valve and a boost pump if you want to fill the main diesel tank from the auxiliary tank. Which is probably the better idea. Plus add a diesel filter to clean the fuel from the aux tank to the main tank.

[TAREUA]

When I crossed the Pacific it was with two 10 gallon tanks, one 5 gal. jerry can on deck and a 1 cyl. engine. My worries were always more on water than fuel storage. I had a small watermaker that the wind generator could keep up with, and didn't have a diesel generator or freezer aboard. I was happy to sail at any speed that kept the boat tracking on a line, which was above two knots. To me, 24 hrs sailing at 3 knots is great, and 24 hrs of motoring is a headache. I also was blessed with good luck on the trade winds as well.
The boats mentioned at the start of the thread seem like pretty good light air boats, an attribute that might go down hill with the addition of too much extra fuel. It would be interesting to know how many boats of that size use more fuel for charging than for propulsion.
In my experience it is coastal cruising that eats up the fuel not the ocean crossings. My current boat has a 6 cyl. 100hp engine and carries 300g in fuel. I'm planning to remove some of that tankage, as it keeps getting old.

[Bash]

Originally Posted by bulabro

If you were heading out to cross the Pacific in a 44' production boat, say a Jeanneau, Hunter or Beneteau, how much fuel and what kind of range would you want to be comfortable. I have no interest in sailing for days in zero wind making a knot or two headway. But it seems as though the three boats listed have a very limited fuel capacity. What kind of motoring range makes the journey comfortable.

A Hunter 44 carries 51 gal diesel. (Hunter 46 carries 100 gal.)
Jeaneau 45 carries 63 gal diesel.
Beneteau 45 carries 53 gal diesel.

I doubt that most sailors would find this an insufficient amount of fuel for a Hawaii to mainland crossing. The trick is to avoid the Pacific High, not to motor through it.

[TAREUA]

Bash, do you know what kind of range those 50-60 gallons would give them? I would be comfortable with about 200 mile range as a minimum.

[donradcliffe]

For motoring in light airs in a Beneteau 45 I burn 1 gal/hr at 6.5 knots or 0.6 gal/hr at 5 knots, giving me 300-350 mile range with 50 gallons. For motoring into headwinds, such as the Baja Bash or the Red Sea, its more like 1 gal/hr at 4-5 knots or 200 miles minimum range.