Two reasons for a headboard shackle on the main rather than a snap swivel: Headboard shackles are designed to accommodate a longer length from the sail cringle to the edge of the sail which generally is a fixed U shaped forging. This is much stronger than a pivoting closure that is found on a swiveling snap shackle of equal length. A snap swivel shackle is specifically built to allow the sail to twist and rotate under load, especially when used with a spinnaker. Hoisting loads on a mainsail are far more linear and rotation is less important. Also, headboard shackles are less expensive. Chuck Gilchrest Half Magic LF 35 Sent from my iPhone
> On Nov 9, 2021, at 8:17 AM, Della Barba, Joe via CnC-List > <cnc-list@cnc-list.com> wrote: > > > I don’t use a snap shackle any more for the jib, since it stays up for months > at a time or more. It is a screw-in shackle with safety wire holding it. > The main shackle is one that screws in and out. It has never loosened itself. > I think the longest the main has been up continuously is maybe 6 or 7 days > and it did fine. > Joe > Coquina > > From: David Knecht via CnC-List <cnc-list@cnc-list.com> > Sent: Tuesday, November 9, 2021 7:52 AM > To: CnC CnC discussion list <CnC-List@cnc-list.com> > Cc: David Knecht <davidakne...@gmail.com> > Subject: [EXTERNAL] Stus-List Main halyard shackle > > My boat came with a main halyard shackle of a type I have never seen anywhere > else. It has a pivoting arm that swings up after inserting through the > headboard and secured with a threaded pin. It has worked fine for years and > easy to remove and attach, which I do routinely when done sailing for the > day. Recently, I twice found it nearly completely unscrewed after a day of > rough weather sailing, and that is concerning. I don’t want to lose the > halyard up the mast. I am considering replacing it this winter with a > standard snap shackle of the sort used on my genoa halyard. I looked at a > rigging company web site and they used snap shackles for genoa halyards and > pin shackles for main halyards. The logic of that escapes me. On my boat, > I take down the roller furling genoa only a few times a season while the main > halyard is detached every time I go sailing. I have no idea what the forces > are on the main halyard but I would not think much greater than the genoa. > Any words of wisdom, or reason not to use a snap shackle for the main? > Thanks- Dave > > David Knecht > S/V Aries > 1990 C&C 34+ > New London, CT > > <image001.png> > > > > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
