[Rhodes22-list] Critical Standard Mainsail Standing Rig Dimensions For Rhodes 22

[Roger Pihlaja]

Saroj, Keith, et al,

I just went thru my files & looked up the dimensions & geometry of Dynamic Equilibrium's standing rigging and mainsail before I modified  the masthead casting.  First of all, here are the dimensions of a standard Rhodes 22 mainsail:

Max Luff: 21 feet - 8 inches
Max Foot: 9 feet - 0 inches
Mainsail Area: 110 square feet
Boom Length From Aft Mast Face To End Of Boom: 9 feet - 8 inches

Nominal Backstay Angle Relative To Horizontal When Backstays Are Taut & Mast Bend = 0.00 Chord Inches: 65.68 deg

Horizontal Distance Along Top Of Boom From Aft Mast Face To Backstay:
With Boom In Upper Position: 10 feet - 1-1/2 inches
With Boom In Lower Position: 10 feet - 9-1/2 inches

NOTE 1: In the lower boom position, the boom clears the backstays by 13-1/2 inches when the boom is horizontal, angle = 0 deg
When I do the algebra & trig, the boom would have to rise to an angle = 67.3 deg relative to horizontal to hit the backstays
The aft end of the boom would have to rise up by 107 inches to hit the backstays
This is a very extreme angle for the boom & highly unlikely 

NOTE 2: In the upper boom position, the boom clears the backstays by 5-1/2 inches when the boom is horizontal, angle = 0 deg
When I do the algebra & trig, the boom would have to rise to an angle = 53.9 deg relative to horizontal to hit the backstays
The aft end of the boom would have to rise up by 93-3/4 inches to hit the backstays
This is a very extreme angle for the boom & highly unlikely

Boy, from these calculations, I don't see how you managed to get the boom caught between the backstays unless your upper boom position is a lot higher than mine or your boom is longer?

Hopefully, these standard Rhodes 22 rig dimensions will help you resolve your boom/backstay interference issues.

Roger Pihlaja
S/V Dynamic Equilibrium