Subject: Re: [harryproa] Rig comparisons - revisited
From: "Peter Southwood" <peter.southwood@telkomsa.net>
Date: 6/11/2008, 5:08 PM
To:
Reply-to:
harryproa@yahoogroups.com.au

Hi Arto, It is quite possible that the total weight of a stayed rig and the added material to reinforce the hulls will be more than that of the unstayed rig.
Cheers,
Peter
----- Original Message -----
From: Arto Hakkarainen
To: harryproa@yahoogroups.com.au
Sent: Wednesday, June 11, 2008 9:16 PM
Subject: Re: [harryproa] Rig comparisons - revisited

So I figured too. But the question that I cannot answer myself is the tradeoff between added weight and worse weight distribution in leeward hull and on the other hand probably less weight in the rig. But perhaps there are too many variables to make that decision without excessive calculation. And as was again pointed out, the free standing and balanced rig is quite good option in many ways.

Arto

--- On Wed, 6/11/08, Peter Southwood <peter.southwood@telkomsa.net> wrote:

From: Peter Southwood <peter.southwood@telkomsa.net>
Subject: Re: [harryproa] Rig comparisons - revisited
To: harryproa@yahoogroups.com.au
Date: Wednesday, June 11, 2008, 12:26 PM

Staying to the windward hull would reduce loads on the beams most of the time. This would not be a problem. The staying to the ends of the leeward hull would impose significantly larger loads on that hull than with an unstayed rig. major stiffening would be required, and this would significantly increase weight and cost.
If the mast relies on stays to prevent falling down when taken aback, there are other major consequences regarding safety, as it is difficult to get a suitable stay angle to support these loads. Unstayed does it all with much less complication.
Cheers,
Peter

----- Original Message -----
From: Arto Hakkarainen
To: harryproa@yahoogrou ps.com.au
Sent: Wednesday, June 11, 2008 10:20 AM
Subject: [harryproa] Rig comparisons - revisited

The earlier discussion on rig comparisons gave a lot of food for thought and started a new thinking process. As was pointed out in the earlier discussion the stay sail rig has merits but would produce different loads than the easyrig. Easyrig produces very concentrated forces and is easy to handle according to Rob. Staysail rig would produce quite large bending and compression loads to mast and stays and area between them.
 
Now I must admit that I don't have the knowledge or experience needed to estimate the effects to structure, weight, weight centering and weight up in the rig, which are all important issues in sailboat designs. I suppose that beams may need reinforcing if the mast is stayed to windward hull like in traditional pacific proa. On the other hand mast itself could be lighter even with the compression loads of stayed rig. Leeward hull may need some enforcing to support loads by stays and the weight distribution would move weight from center to ends of leeward hull. But what would be the total effect on this? Any educated guessses or knowledge/estimatio ns?
 
Arto

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