Spinnaker Pole diameter?

[rogerthebodger]

As long as you use a bridle from the ends for any uphaul (or downhaul) the pole should only see compression forces and Euler's column formulae will give you an idea. My memory has diameter to the power 4 as a factor so doubling the diameter gives a 16x improvement to buckling ....... but it was so long ago!

But first the maximum compression forces need to be determined.

 

[awol]

But first the maximum compression forces need to be determined.

Or work it out for the sizes and Young's modulus of the material you intend to use and see if the numbers seem reasonable.

 

[rogerthebodger]

Or work it out for the sizes and Young's modulus of the material you intend to use and see if the numbers seem reasonable.

Using this

http://www.engineeringtoolbox.com/euler-column-formula-d_1813.html

And this

http://www.engineeringtoolbox.com/young-modulus-d_417.html

For the material used (aluminium alloy)

and this

http://www.engineeringtoolbox.com/area-moment-inertia-d_1328.html

Round tubular being Iy or Ix = π (do4 - di4) / 64

where

do = cylinder outside diameter

di = cylinder inside diameter

But it would still be nice to know the type of compression load that would be expected, but to be frank I don't think the compression loads on a normal spinnaker pole would be very high anyway.

Also if the pole has a centre uphaul and down haul there could be some bending under certain conditions of wind and wave action.

Some discussions here

http://www.boatdesign.net/forums/boat-design/loads-asymmetrical-spinnaker-pole-10174.html

And potentially loading on the spinnaker pole could be in fact in tension and not compression also dependent on conditions and the rolling and pitching of the boat.