Subject: Re: : Re: [harryproa] Bucket List harry forum
From: "Rob Denney harryproa@gmail.com [harryproa]" <harryproa@yahoogroups.com.au>
Date: 10/21/2014, 6:58 PM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

 

Raps,
Some things to consider about screechers:
1) They are carried all the time, but only used occasionally.  The weight of the sail, furler, winches, lines and the beefing up required to support them has to be carried all the time, but they are only used occasionally.  Not a problem for a heavy boat, but for a light one, definitely something to consider.  Round numbers on Bucket List could be an extra 35 kgs, which is 5% of the total weight.  
2)Screechers need tight luffs.  This is impossible with an unstayed mast.
3) there is nowhere to sheet a screecher on a proa.  
4) Shunting a screecher will not be fast, or fun.
5) It is likely that the authorities will require a pulpit at each end if there are any extras.  


In zephyr conditions, the breeze increases dramatically with height.  Lots of sail area down low (screecher) is not the best way to exploit it.  The standard 60' mast on Bucket List  boat is pretty high, but for light air days, a top mast 40' long would give you an 80' high mast, for very little added weight or windage.  This would be a far more effective light air rig than a screecher.

Solo Transpac 2016 is on my Bucket List bucket list.  Would be amazing to have you there as well.

regards,

rob

  

On Wed, Oct 22, 2014 at 12:39 AM, Raps callion captian_rapscallion@yahoo.com [harryproa] <harryproa@yahoogroups.com.au> wrote:
 

Thanks for the explanation Rob. I love the boat, and will be first in line for a charter.  The solo Chi-Mac and Trans Pac are my bucket list races, and this boat looks good for both of them.  I have experience with pitch poling on beachcats, but nothing bigger. 

I know a bruce number above 2 is awesome, but the first thing I would get if I bought one is a crazy huge screecher for the zepher days. I hate light air days in a multi, watching monos drift by.... I know.. I know... more complexity... bigger pain in the butt....but for all of the added pain, I'm really glad I have my crazy huge screecher on zepher days. 




On Monday, October 20, 2014 8:55 PM, "Rob Denney harryproa@gmail.com [harryproa]" <harryproa@yahoogroups.com.au> wrote:


 
The buoyancy of the mast is plenty.  As soon as the mast hits the water, the boat swings round so the mast is upwind.  if the mast was removed, the boat would right from the windage on the hull, beams and tramp.

The boom has 80 kgs/176lbs buoyancy (200 was a good guess), which should be enough, especially as any waves and the wind are both working to right the boat.  

You are right about pulling the boom beneath the water.  There is a strut required.  It is attached to the mast at deck level and the lazy sheet runs through the end.  The strut sinks to ~45 dgrees and the sheet can be tightened, pulling the boom under the water.  

A lee float was not considered for the following reasons:
1) weight in the wrong place
2) complexity
3) they may stop a sideways capsize, but that is much less likely than a pitchpole.  In a pitchpole, the bow goes in and then the boat capsizes to leeward.  Almost certainly, the first part of the float to get wet will be the top.  Then, it will make it impossible to right the boat without outside assistance.  

If the sheet fuse is used, capsizing will not happen.  I certainly do not wish to encourage people to capsize, just because the boat can be easily righted.   

Foils are complex and prone to damage when they hit things.  This is not what Bucket List is about.  If you want a foiler, then it would be better to start from scratch, as the boat would be very different.  

regards,

rob

On Mon, Oct 20, 2014 at 10:13 PM, captian_rapscallion@yahoo.com [harryproa] <harryproa@yahoogroups.com.au> wrote:
 


I think the boat could be righted the way Rob suggests, as long as there is enough flotation in the mast and boom, but I think that in order for there to be enough flotation, some kind of mast and boom float(s) will be required. The boom float will likely need 200lbs of buoyancy to work in any kind of swell, and I think it would be difficult to winch the lazy sheet from the skyward hull enough to right the boat in flat water - much less in 5' to 7' waves.

I know Rob is all about flat panel hulls these days, so instead of a leeward pod on the leeward hull like jezzaro, how about a cylinder like hull on the leeward side of the hull to help prevent capsize. It could be inflatable, so it shouldn't add too much weight. Seriously, if the goal is to provide a boat people can charter in a race they have never done before, sailing a type of boat they have never sailed before, I think training wheels aren't such a bad idea.

I've righted my 32'cat at least a half dozen times using the mast float, so I have an idea how much force it takes to right a bigger boat. I can tell you that without some kind of gin pole to change the angle of the lazy sheet there are going to be some significant issues with the righting procedure, and a nacelle or leeward pod will give you the needed reserve buoyancy to help prevent capsize, and provide the needed angle the lazy sheet would require to right the boat.


Rob,

Why not go all the way and make the boat a foiler??


Use the foil configuration found at the bow of C-fly on the leeward hull.



 




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Posted by: Rob Denney <harryproa@gmail.com>
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