dftn
New member
Does anyone know of a good reference on calculating the windage forces on a yacht ashore on a cradle? I want to design a new cradle for my Twister 28.
Thanks
Thanks
Windage forces ashore
- Thread starter dftn
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richardandtracy
New member
If you want to go the whole hog refer to BS EN 6399 Pt2 (1997)
Failing that.... I've extracted a little from BS CP3: Chapter V: Part 2: 1972 (superseded)
Take a 50 year basic windspeed of 46 m/s (all of England & Wales) or 54 m/s (Scotland). Then the basic dynamic pressure will be 1300 N/m^2 (E&W) or 1790 N/m^2 (S) Multiply this pressure by 1.2 for a worst case bluff body. Take the area of your vessel exposed to the wind, multiply it by the pressure and factor above & hey presto. Your stand should then be at least as good at standing up to the wind as your house. (Then comes the question... Which is better insured?)
Regards
Richard
Failing that.... I've extracted a little from BS CP3: Chapter V: Part 2: 1972 (superseded)
Take a 50 year basic windspeed of 46 m/s (all of England & Wales) or 54 m/s (Scotland). Then the basic dynamic pressure will be 1300 N/m^2 (E&W) or 1790 N/m^2 (S) Multiply this pressure by 1.2 for a worst case bluff body. Take the area of your vessel exposed to the wind, multiply it by the pressure and factor above & hey presto. Your stand should then be at least as good at standing up to the wind as your house. (Then comes the question... Which is better insured?)
Regards
Richard
jimi
Well-known member
Best place for a Twister, they're nae use on the watter, ask Ken!
Jim
Jim
Twister_Ken
Well-known member
The major problems with having a Twister in the water are:
Peeling the grin off your face
Getting rid of the crowd of onlookers wanting to see you go astern
Apologising to drivers of Bav 34s for overtaking them
Being unable to see that lovely underwater shape
PS Madame tells me that baver is the French verb for to dribble. Je bav, tu bavs, etc
Peeling the grin off your face
Getting rid of the crowd of onlookers wanting to see you go astern
Apologising to drivers of Bav 34s for overtaking them
Being unable to see that lovely underwater shape
PS Madame tells me that baver is the French verb for to dribble. Je bav, tu bavs, etc
