[TK-F430]

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

[AMG]

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

[TK-F430]

Originally Posted by AMG

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

Thanks......max. speed is 33 knots.

[MYCaptainChris]

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.

[CODOG]

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.

[TK-F430]

Thanks CODOG.

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

[TK-F430]

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

[CODOG]

Originally Posted by TK-F430

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

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.

[TK-F430]

Originally Posted by CODOG

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.

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.

[Mets]

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.

[CODOG]

Originally Posted by TK-F430

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

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.

[TK-F430]

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