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

[Saroj]

This is just fantastic information, Roger.  In the upper boom position on
Pathfinder, which is my normal sailing position except where reefing is
advised, the clearance is just an inch or two with the backstays tightened.
That is from memory.  I've got to take measurements this week to get precise
about it.  I would think that my boom is standard issue because it has that
furling feature wherein if I pull on the boom towards aft, I can rotate the
boom and theoretically at least could roll the main sail around it for
reefing.  I've never heard anyone on the list talk about doing this, but I
recall reading about this somewhere quite a few years ago.

I wouldn't describe what happens as "getting caught between the backstays".
It is more that when tacking, the boom gets caught on either backstay.

Is it possible that I am tightening the backstays too much and decreasing
the distance between the mast and the stays?  This seems unlikely as the
mast doesnt' really have that much flex down low at that point.

Again, many thanks.

Saroj

----- Original Message ----- 
From: "Roger Pihlaja" <cen09402 at centurytel.net>
To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
Sent: Tuesday, July 06, 2004 8:38 PM
Subject: [Rhodes22-list] Critical Standard Mainsail Standing Rig
DimensionsFor Rhodes 22


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


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