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Fairline Squadron 78 Range

Discussion in 'Fairline Yacht' started by T.K., Oct 9, 2007.

  1. T.K.

    T.K. Senior Member

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    I have these engines on my new Fairline Squadron 78, 2 x Caterpillar C32-1572 Diesel, 1572hp each. Her fuel capacity is 5900 liters and she weighs 46.25 tons (dry weight). Can someone provide me with her approximate range at 17 knots, 20 knots and 24 knots.

    Thanks in advance.

    Tarek
  2. AMG

    AMG YF Moderator

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    Hi, I think you need to know the top speed to be able to calculate the range at different speeds.
  3. T.K.

    T.K. Senior Member

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    Thanks......max. speed is 33 knots.
  4. MYCaptainChris

    MYCaptainChris Senior Member

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    guess

    At a guess
    I ran a Ferretti 80 with the older CATS and at 20 knots didn't see alot of change from 100 USG/hour.

    You may find the exact specs on the CAT site.

    Sorry I'm lacking more info, a bit short on time to research and calculate.
  5. CODOG

    CODOG Senior Member

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    I'll have a bash:)
    I reckon she will have to be no more than 54 tonnes to achieve 33 knots with that installed power. So I've used that as half load.
    I've assumed a small loss of efficiency as speed decreases, typical of this type of hull.
    I've taken 90% of total fuel to allow a wee reserve margin, and also some nominal genny consumption.
    I've also used 210 grammes per kilowatt hour for specific fuel consumption, which is a decent average at these sort of speeds and rpms.
    If 33k @ 54t needs 3140hp or 2342kW, then I quick calc that...
    24k @ 54t needs 1270kW, so endurance is 12.5 hrs, range is 300nm.
    20k @ 54t needs 895kW, so endurance is 17.7 hrs, range is 354nm.
    17k @ 54t needs 670kW, so endurance is 23.6 hrs, range is 400nm.
  6. T.K.

    T.K. Senior Member

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    Thanks CODOG.

    Found this.....don't know my boat's speed though at the various engine speeds.

    Attached Files:

  7. T.K.

    T.K. Senior Member

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    For the C32 (1675mhp) Diesel Engine and mine even have less output (1572mhp):

    @ 2100 rpm ==> 11.6 hrs
    @ 1900 rpm ==> 15.8 hrs
    @ 1800 rpm ==> 18.4 hrs
    @ 1600 rpm ==> 26.0 hrs

    Any idea what the boat's speeds would be at the above engine speeds?

    Thanks in advance.

    TK
  8. CODOG

    CODOG Senior Member

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    Do you have a C32 power curve handy ? (I'm at home and cant find one on the net) We could do an approximation from that.
  9. T.K.

    T.K. Senior Member

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    Thanks again CODOG......here it is.
    The C32 has a flat power curve between it's vessel cruising speed of 1,900 rpm and its maximum speed of 2,300 rpm.

    Attached Files:

  10. Mets

    Mets New Member

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    Maybe check with Fairline? They must have some little calculator program they could give you that would tell you all the info you would want to know for any given speed. Or at least I would do that if I owned a boat manufacturer.
  11. CODOG

    CODOG Senior Member

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    Hi TK, the endurance figures youve quoted and the power curve you posted are for the C32 @ 1675mhp. You actually have the 1572mhp rating so any speeds I estimate against these rpms wont be accurate.
    Also, the endurance figures above are based on 100 % of your fuel capacity and using a displacement hull prop law curve which will give better range at slower speeds than a deep-v hard chine hull. You wont be able to achieve those hours at those rpm in reality, although its not a million miles away. When I get a minute I'll dig out a power curve for your 1572mhp Cats and do a bit more of a calc, but in the meantime I'm still happy with the ranges I estimated at the speeds you asked for.

    And yes, you could ask Fairline for these figures (it would be interesting to see how they compare) but this ways more fun.
  12. T.K.

    T.K. Senior Member

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    Thanks again CODOG.
    I calculated the above hours @ the various engine speeds based on 90% of the fuel capacity.
  13. Danvilletim

    Danvilletim Senior Member

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    Anyone know what boost pressure is on Caterpillar C30. I thought turbos were suppose to kick at 1650?
  14. Capt Ralph

    Capt Ralph Senior Member

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    Turbos don't kick in. Pending engine load and expanding exhaust gasses determine the boost a turbo generates. Then, waist gates control any overboost. Yes, at higher RPM they do their work because this is where the expanding exhaust gasses are really expanding and flowing.
    Are you having problems?
    Last edited: Dec 13, 2021
  15. Capt Ralph

    Capt Ralph Senior Member

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    I would hope the air box pressure are in your manuals and purchase survey. Engine displays may show this info also.
  16. mimmmar

    mimmmar New Member

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    Hello Tarek. I think you know a lot about SQ78. I bought a new one this week. I will make some improvements. I wonder if you can help me. I will especially need electrical projects. I would really apreciate if you help. Kind regards.