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Specs
Posted: Thu Oct 20, 2011 2:28 am
by johnp
What does 300 CBF mean? it lists the length, Beam, and Draft in meters and then this 300 CBF??
Re: Specs
Posted: Thu Oct 20, 2011 7:51 am
by steamboatjack
Not much to go on but try centre distance between frames?
regards
Jack
Re: Specs
Posted: Thu Oct 20, 2011 6:58 pm
by marinesteam
Block Coefficient
It is the amount of space taken up by the hull in a box defined by length at water line, beam at wterline and draft. Smaller numbers will descibe a finer hull, larger numbers a block hull, like a modern cargo vessel.
The number seems wrong for this though, as it should be < 1
Or (this makes more sense in the context)
Bouyancy Force Coefficient (noted CBF)
Think this is an indicator of buoyancy independent of the fluid (fresh or salt water) and can be used to determine the capacity when calculated using the proper contstant for the fluid.
Ken
Re: Specs
Posted: Thu Oct 20, 2011 7:05 pm
by johnp
the plate says 6.51 x 2.21 x 0.92 MTRS
300 CBF. 27 persons
Re: Specs
Posted: Fri Oct 21, 2011 4:01 pm
by marinesteam
I plugged the size numbers into Delftship and a boat of this size has a displacement of roughly 3 tonnes (metric) so I'm thinking that the CBF relates to bouyancy but it could only be coincidental that the numbers are similar.
Must be a lifeboat hull. Otherwise, that seems to be a lot of capacity for a 21' boat. But the numbers do kind of make sense if you assume that 300 is some decimal place change from tonnes or kg's.
3t = 3000kgs = 6613 lbs ---- 27 x 165lbs (average person) = 4455 lbs x 1.25 safety factor = 5568 lbs
This leaves about 1000 lbs for the hull, which seems about right or still could be a big leap of logic, you decide.
Ken
Re: Specs
Posted: Sat Oct 22, 2011 8:12 am
by steamboatjack
30mm centres between frames
Re: Specs
Posted: Sat Oct 22, 2011 8:12 am
by steamboatjack
sorry 300mm