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 Post subject: Trapeze Attachment Point
PostPosted: Sun Jul 17, 2011 10:29 am 
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Location: Latrobe, PA, USA *** Show YOUR Location - Edit Profile ! ***
I have a pretty-highly modified H14 Turbo to which I've installed a reacher/screetcher system with a high mast tang at about 1 foot below the all-aluminum mast.*

When I came upon a deal for some Prindle trap wires they were long- closer fit to the upper tang and since things were already crowded on the lower, standard tang I arranged them on the upper and modified their length to fit.

My real question is the effect of this additional leverage on trapeze effectiveness-
Do any 'real' Hobies mount the trap wires to a higher mast point?
Why or why not?

*Many other mods related-
shroud attachment continued from side rails to hull lip (as new Euro H14s),
A-frame reacher/spinnaker post furler- which doubles as a mast stepping system (ala AquaCat?),
oak-reinforced dolphin striker,
self-designed experimental hydrofoils,
front rail jib attachment and control like H16s...
hmmm, wondering if I need diamond wires for this...

_________________
Raise your sail one foot, and you get ten feet of wind.
起你的一只帆,和你10英尺的。 -- Chinese Proverb
William D. Latinette @ Latrobe, PA, USA w. H14 Turbo X 2... wildlatin23@hotmail.com


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PostPosted: Sun Jul 17, 2011 6:02 pm 
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Joined: Mon Jul 14, 2003 7:11 pm
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Location: Detroit, MI
You're not obtaining any additional righting moment by moving the trap wires to a higher point. Righting moment depends entirely on the position of your body, which doesn't change by moving the wires.

There's a practical reason why the wires are attached where they are - it's where the shroud tang is. There are several disadvantages of moving the trap attachment higher:
- more windage
- longer wires are more expensive
- the "weight on your feet" is less the more vertical the trap wires become


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PostPosted: Wed Jul 20, 2011 3:12 pm 
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Yes, I understand after studying more on righting moment. It seems that the extension from center ala' wings, etc. for trapping is the ultimate- but then the official word from Hobie is don't trap off the wings... yet I see it often in pics and videos.

Here's a point to consider which I found...
Quote:
Trapeze height: ...As puffs hit, they bend the mast tip to leeward, depowering the main. Because the trapeze wire attaches higher than the shrouds, the crew’s weight counteracts the pressure from the breeze, keeping the mast straight and giving you power in marginal conditions.
http://www.nedsailing.nl/Artikelen/Sailing%20World,%20Mills,%20Power%20Trapezing.htm

I certainly wouldn't try any of this with an comptip mast but the all Al one should be fine (I hope :o )...

_________________
Raise your sail one foot, and you get ten feet of wind.
起你的一只帆,和你10英尺的。 -- Chinese Proverb
William D. Latinette @ Latrobe, PA, USA w. H14 Turbo X 2... wildlatin23@hotmail.com


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PostPosted: Wed Jul 20, 2011 5:44 pm 
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Location: Detroit, MI
wildlatin wrote:
Yes, I understand after studying more on righting moment. It seems that the extension from center ala' wings, etc. for trapping is the ultimate- but then the official word from Hobie is don't trap off the wings... yet I see it often in pics and videos.
That advice applies to the "backrest" wings on the Getaway and Wave - certainly not to the wings on the 17, 18 and 21.

wildlatin wrote:
Here's a point to consider which I found...
Quote:
Trapeze height: ...As puffs hit, they bend the mast tip to leeward, depowering the main. Because the trapeze wire attaches higher than the shrouds, the crew’s weight counteracts the pressure from the breeze, keeping the mast straight and giving you power in marginal conditions.
http://www.nedsailing.nl/Artikelen/Sailing%20World,%20Mills,%20Power%20Trapezing.htm

I certainly wouldn't try any of this with an comptip mast but the all Al one should be fine (I hope :o )...

That article is about trapezing on a dinghy (a 5O5, specifically) which has a mast like a limp noodle compared to any catamaran. I doubt you would notice any difference on a catamaran - Comptip or not.


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