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Azimut Fuel Capacity

Discussion in 'General Yachting Discussion' started by BruceS1, Mar 28, 2022.

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  1. BruceS1, Mar 28, 2022
    #1
    BruceS1

    BruceS1 New Member

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    I am scheduled to pick up an Azimut 60 Fly in La Paz and take it across the Sea of Cortez to Puerto Vallarta. Specs for the yacht say she carries 2,800 liters of fuel, however, the factory range calculations are all based on 2,520 liters. The manual describes a 10% quantity of fuel that "cannot be pumped". My first assumption was that this 10% was a reserve - it could be accessed in an emergency but should not be used as part of a normal range calculation. Now I am not so sure. Perhaps this 280 liters is inaccessible due to the design of the fuel tanks making the true capacity of usable fuel on board a maximum of 2520 liters. In order to maintain a safe reserve this would cut my actual available fuel down to ~2,200 liters. that's pretty far below the 2,800 advertised...

    Does anyone know whether this 10% is a reserve or is it, in fact, not accessible under any circumstance.

    Thanks!
  2. Capt Ralph, Mar 28, 2022
    #2
    Capt Ralph

    Capt Ralph Senior Member

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    Usally not a reserve. Just not usable. These last liters are saved for trash, water and microbial waist that are heavier than fuel.
    Stuff you do not want picked up into the engines.
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  3. olderboater, Mar 28, 2022
    #3
    olderboater

    olderboater Senior Member

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    If they say it cannot be pumped that that means just that and it's not a reserve. On top of that 10% reserve is very tight for a trip like that and I'd never proceed on the basis of needing 2200. I wouldn't go over 1900-2000. Do you have any actual fuel consumption numbers from the boat, from metering?
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  4. Capt J, Mar 28, 2022
    #4
    Capt J

    Capt J Senior Member

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    NO it is NOT a reserve. No it cannot be used. 1" or 2" of fuel sloshing around in a big fuel tank isn't usable. In fact I base all of my range calculations on a 20% reserve, or 30% in your area where there aren't other stops. Running at 9-10 knots will get you much more range.
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  5. mapism, Mar 28, 2022
    #5
    mapism

    mapism Senior Member

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    Do you possibly have the original Italian manual, and if so could you post the exact statement published in it?
    Your statement which I'm quoting doesn't make a lot of sense - if nothing else, because fuel is sucked and not pumped, from the tanks to the engine injection pump.

    Anyway, my guess is that the rationale behind such recommendation could be the risk of sucking air rather than fuel, hence stalling the engine(s).
    I mean, of course there are internal dividers inside the tanks, to reduce fuel sloshing to a minimum and in turn keep the pickup point always submerged till the last drop of fuel (don't take me literally on the term "drop", of course!).
    But in heavy seas, a very low fuel content could be moved away from the pickup for long enough to leave the pickup dry, hence sucking air from it.
    And this is bound to stall the engine, hence needing to prime it in order to restart it.
    Not exactly the most pleasant thing to do, in heavy seas and inside a hot engine room!

    Another possibility is what CR mentioned in his post #2, but usually the very bottom part of the tank is even lower than the pickup, precisely to avoid sucking any garbage. And the fuel quantity under the pickup that this area can hold is trivial - like 20 or 30 liters, when talking of a 2800 liters total capacity. Not even worth mentioning in the manual...
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  6. Capt Ralph, Mar 28, 2022
    #6
    Capt Ralph

    Capt Ralph Senior Member

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    A mut manual?? Can I get a copy please??
  7. Capt Ralph, Mar 28, 2022
    #7
    Capt Ralph

    Capt Ralph Senior Member

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    Let us say drawn from. Sucked is such a romantic term..
    A lift pump is named so to,,, pump fuel from the tank to the HP injector pump.
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  8. Capt Ralph, Mar 28, 2022
    #8
    Capt Ralph

    Capt Ralph Senior Member

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    To the OP; Don't push the fuel capacity. It's going to be a LSD (Low Speed Displacement) ride if you want range.
    Does the boat have any history on this route before? Any fellow captains run this before? Bunkered where?
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  9. mapism, Mar 28, 2022
    #9
    mapism

    mapism Senior Member

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    Well, as you know I'm not familiar with the documentation normally supplied in the US, aside from having learned here that it can be hit and miss, or even not available at all.
    I guess we could see this as yet one more reason for trying to get hold of the original one, because aside from being mandatory on any CE-certified boat (hence necessarily existing, in some builder's database), it's less likely to include any puzzling translations...

    But before the OP asks, aside from being available to help with the language, sorry but I don't have the manual myself.
    And I believe the builder would only supply it to recognizable/registered owners of any given boat/model, or to their dealers.
    Haha, guilty as charged for not having thought of the ...romantic flavor attached to sucking! :D
  10. BruceS1, Mar 28, 2022
    #10
    BruceS1

    BruceS1 New Member

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    Thanks to everyone who replied. This helps a lot. The boat has not made this run before and it is her maiden voyage, so no history. We will run her down from La Paz to San Jose del Cabo before making the crossing, so I'll have about 125NM to see how she handles before choosing a final route. She will be heavy coming out of La Paz - full tanks, Williams tender and 5 - 7 folks onboard. This should give us a pretty good sense of her fuel efficiency before we set off. The run to PV is 280NM but there is an alternate option - make for Mazatlan (185NM) and refuel there. Will make the final call in San Jose based on (brief) history and weather.
  11. Capt Ralph, Mar 28, 2022
    #11
    Capt Ralph

    Capt Ralph Senior Member

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    Even across da pond, we can communicate.

    Stay well my friend
  12. Capt Ralph, Mar 28, 2022
    #12
    Capt Ralph

    Capt Ralph Senior Member

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    Ouch, loaded with,,,, people...
    Run slow and well. I assume you are the captain. Do you have a mate or crew?
    Hate it when owners & guest are on board.
  13. olderboater, Mar 28, 2022
    #13
    olderboater

    olderboater Senior Member

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    Take Mazatlan. Nice break, shorter cruise, no fuel concerns. We didn't even have fuel concerns but went that route.
  14. Pascal, Mar 28, 2022
    #14
    Pascal

    Pascal Senior Member

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    I m kind of surprised nobody has asked if there is a way to check fuel levels. No, I don’t mean an electric fuel gauge no matter how fancy it is. I mean either sight tubes if the tanks are high or a dipstick if the boat has keel tanks. I believe either are a must have

    Sure you can fill the tank till They burp which in any civilized country will get you in trouble

    being a new boat with electronic engines there must be flow meters with totalizers. Keeping an accurate fuel log of what the mains and the gen have burned is pretty easy. Seamanship 101

    before leaving download the fuel curves for the engines so you can double check the fuel meters.

    I have to say that using sight tubes or dipstick plus a fuel log, I have never Had any issues
  15. Capt J, Mar 29, 2022
    #15
    Capt J

    Capt J Senior Member

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    There is NO way you can make 280nm at cruise in that size Azimut. You have 2 options do an overnight at 1000 rpms overnight, or stop in Mazatlan.
  16. Pangea 3, Apr 3, 2022
    #16
    Pangea 3

    Pangea 3 New Member

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    Fuel in filters, pipes and hoses cannot be burned
  17. mapism, Apr 3, 2022
    #17
    mapism

    mapism Senior Member

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    Agreed, but you must be used to some remarkable megayacht if you think that filters and pipes can hold 74 gallons of fuel... :)
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  18. Capt J, Apr 3, 2022
    #18
    Capt J

    Capt J Senior Member

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    the bottom 10% of the tank can’t be burned either. The pickup is going to be an inch above the bottom of the tank or more and fuel sloshing around in the tank. Boats angle in longitudal tanks also is a factor.
  19. mapism, Apr 4, 2022
    #19
    mapism

    mapism Senior Member

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    I'm not sure to see the difference with what I said in my first post of this thread...o_O
  20. Pizzazz7, May 3, 2022
    #20
    Pizzazz7

    Pizzazz7 New Member

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    It is not clear to me if the last 300 liters of fuel is useable or not. One way to check if you are not fully loaded is to use a transfer pump from one of the tanks to the other until empty, then fill the empty tank up and see how much it takes. You can also use the process to calibrate (or confirm calibration of) your tank level sender.

    I have done some long-distance cruising on a smaller boat (15 tons, 2x 450 hp) and my conclusion is that you want to plan your trips until nearly empty to minimize weight and maximize mpg. The bigger Azimut will be less sensitive to the weight though, so may be less of a factor. If you do not have the time to install a sight gauge, you can just connect a transparent hose somewhere in the fuel line, with a valve and check the level every 3-4 hours. It will give you a lot more confidence than the fuel level tank gauge.