On page 121 of Bob Well's "Optimizing the East Coast 12-Meter", he illustrates a pivoting crane. The purpose is to distribute some of the load of the backstay into the mast and jenny struts, to keep the mast straight as tension is applied.
Has anyone experimented with this and would like to share experiences. I have been using it for a few years. Am I alone? are there any other tinkerer's out there?
Paul Proefrock [8)]
Pivoting Mast Crane
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Pivoting Mast Crane
by PaulP » Sat Mar 20, 2004 7:35 pm
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PaulP - Posts: 1225
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by Greg Vasileff » Sat Mar 20, 2004 10:54 pm
being that I have never seen this document, I am having a hard time understanding just what is going on. In my own mind, I don't see how a pivoting crane can do what you say any better then a conventional on.
Look forward to understanding this.
Might be a great idea to make this document available on line in a pdf file?
greg V
http://ghmyc.org/
Look forward to understanding this.
Might be a great idea to make this document available on line in a pdf file?
greg V
http://ghmyc.org/
- Greg Vasileff
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by PaulP » Mon Mar 22, 2004 9:11 pm
Greg,
As much as you enjoy tinkering and EC12's, I am really surprised you don't have the Optimizing Book.
The pivoting crane transfers some of the load of the backstay into the Jenny struts. When the load is increased on the backstay, the load is then increased on the jenny struts, keeping the top of the mast straighter. Tends to keep the mast straight or at a constant bend as the load is increased on the backstay. It is a great idea but can be a little finicky.
I am working on a way to include pictures in the forum but not there yet.
Paul P
As much as you enjoy tinkering and EC12's, I am really surprised you don't have the Optimizing Book.
The pivoting crane transfers some of the load of the backstay into the Jenny struts. When the load is increased on the backstay, the load is then increased on the jenny struts, keeping the top of the mast straighter. Tends to keep the mast straight or at a constant bend as the load is increased on the backstay. It is a great idea but can be a little finicky.
I am working on a way to include pictures in the forum but not there yet.
Paul P
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PaulP - Posts: 1225
- Joined: Tue Sep 09, 2003 10:46 pm
- Location: Manchester, MO
by Greg Vasileff » Tue Mar 23, 2004 9:55 am
OK, I get what you mean by pivoting now. Like a seesaw.
Since the EC12 rules don't allow remote adjustment of the backstay, I'm not so sure I would see a benefit to this setup. In fact I see more wrong with it then right. What you are doing with this seesaw crane is making two adjustments with one action. I would much rather make two adjustments with two actions, as it would give me twice the tuning options in just that one aria.
So, if I felt I needed more backstay to depower my mainsail, then the opposite action would be happening with my upper diamonds as they would be tightening and trying to keep the mast from depowering. I’m stuck with this setup.
Without a seesaw crane I have the ability to bend and shape the mast the way I want it.
greg V
http://ghmyc.org/
Since the EC12 rules don't allow remote adjustment of the backstay, I'm not so sure I would see a benefit to this setup. In fact I see more wrong with it then right. What you are doing with this seesaw crane is making two adjustments with one action. I would much rather make two adjustments with two actions, as it would give me twice the tuning options in just that one aria.
So, if I felt I needed more backstay to depower my mainsail, then the opposite action would be happening with my upper diamonds as they would be tightening and trying to keep the mast from depowering. I’m stuck with this setup.
Without a seesaw crane I have the ability to bend and shape the mast the way I want it.
greg V
http://ghmyc.org/
- Greg Vasileff
- Posts: 24
- Joined: Tue Nov 18, 2003 10:07 pm
- Location:
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