{Stus-List} 7/8--9/10 Rigs

Russ & Melody russmel at telus.net
Mon Mar 8 13:29:19 CST 2010


Dear OldSteve,
This Hunter ad has a very simple explanation under the "Rig" heading.
http://sailingu.com/hc50_specs.htm

They are also seen on J-boats. Very handy rigs indeed. But DDW and wing & 
wing not really the best with this rig. It's great if you cruise with 
flying sails such as asym, gennaker, Code #, etc.

As we all know forestay tension is not opposed wholly by the backstay, the 
load also being shared by the upper shroud  -which is the reason the 
backstay can be slightly smaller than the forestay.
The B & R swept back upper shroud opposes the forestay load, sized to 
handle the whole load and off the wind the mast-head load is shared by both 
uppers.

The B & R and other rigs may have intermediate and masthead checkstays to 
control mast shape, as Chuck mentioned.

         Cheers, Russ
         35 mk-1


At 08:31 AM 3/8/2010, you wrote:
>Pardon my ignorance on the 7/8 and 9/10 fractional rigs.
>How do swept back spreaders avoid the need for running backstays?
>I would have assumed that the higher fraction would allow for a larger
>headsail and thus lessen the need for a large mainsail, and hence eliminate
>the need for running backstays. In effect a hybrid between masthead and 3/4.
>
>OldSteveH
>------------------------------
>
>Message: 5
>Date: Mon, 8 Mar 2010 07:47:28 -0400
>From: "Hoyt, Mike" <Mike.Hoyt at impgroup.com>
>To: <cnc-list at cnc-list.com>
>Subject: Re: {Stus-List} 7/8--9/10 Rigs
>
>Swept back spreaders usually eliminate the need for running back stays.
>Also they lessen the interference of the large genoas fouling with the
>spreader.  The downside is when travelling down wind they poke into the main
>when it is fully out.
>
>My last two boats have fractional rigs somewhere between 3/4 and 7/8 and
>swept back spreaders.  Neither uses running back stays.
>
>Mike
>
>________________________________
>
>From: cnc-list-bounces at cnc-list.com on behalf of cscheaffer at comcast.net
>Sent: Sun 07/03/2010 10:34 PM
>To: cnc-list at cnc-list.com
>Subject: Re: {Stus-List} 7/8--9/10 Rigs
>
>I believe the 7/8, 9/10, and 15/16 fractional rigged sailplans place the
>headstay so near the top of the mast, runners are unneccessary?   The
>backstay does the job.  Regardless, Beneteau has been building fractional
>racers without runners for a long time.  Angled spreaders maybe?
>
>Thoughts on runners: our C&C 34R has both runners and checkstays but they
>aren't there to support the headstay.  On this masthead rig, they pull back
>on the middle of the mast and straighten it, which puts more shape into the
>mainsail.  They are a pain in the ass, but the change in shape and the surge
>in speed is worth it, for me.   Our runners retract automatically, and the
>tails are marked, so they're pretty easy to set and release.  Below 10
>knots, their optional.
>
>Chuck




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