Andrew
I agree big forces at play but if you keep the preventer tensioned the forces act through very little distance (basically movement of the sail from one side to the other, sort of like heaving to with the jib.different if the preventer is slack and experiences a sudden shock load Dwight Veinot C&C 35 MKII, Alianna Head of St. Margaret's Bay, NS _____ From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Andrew Burton Sent: May 10, 2013 11:17 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List Gybe preventer Personally, I like to have one as close to the end of the boom as possible--all the way from the end to the bow, if I'm running. Think about the forces on the boom when the preventer stops an accidental gybe; they are not straight down, which is how the boom is strongest. The forces are more from the side (because the preventer is led forward to hold the boom in one place), which is the weakest part of the boom. Another thing to consider is that if at all possible, you should lead your preventer inside your lifelines so you don't wipe out or bend a couple of stanchions if you gybe. All that being said, it's kind of difficult to find a place near the end of the boom if you don't have a loose-footed main so the preventer will probably be attached at the mainsheet bail. I use a preventer pretty much all he time my sheets are eased, even in light stuff, a powerboat wake can cause the boom to swing into the back of a head. I wouldn't go with anything too stretchy; Dacron is fine. I usually use a single line from the boom to a block on the rail and back to a winch, so it's easy to adjust when I trim the sails. Andy C&C 40 Peregrine On Fri, May 10, 2013 at 8:56 AM, Joel Aronson <joel.aron...@gmail.com> wrote: The doctor who spoke at the Safety at Sea seminar said the #1 thing you can do to prevent injury is to rig a gybe preventer. My mainsheet sheets mid-boom. I know you need a rope with stretch to absorb shock. I was thinking of making a preventer as follows: Dyneema loop around the boom just aft of the mainsheet blocks. 3 strand nylon with snap shackles to attach to the loop and toe rail. Is that too simple? Should it run through a block to a cleat or clutch? -- Joel 35/3 Annapolis 301 541 <tel:301%20541%208551> 8551 _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com -- Andrew Burton 61 W Narragansett Ave Newport, RI USA 02840 http://sites.google.com/site/andrewburtonyachtservices/ phone +401 965 5260 _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2241 / Virus Database: 3162/5813 - Release Date: 05/10/13
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