Wiring shrouds to spreader end

Moderator: GreenLake

Wiring shrouds to spreader end

Postby samdivita66 » Sat Oct 26, 2019 10:52 am

Hello!
My first post on the DaySailer.org Forum! During our last sail of our newly acquired 1965 DaySailer I, one of the spreader bars broke off. I've just received two new heavy duty alum. spreader bars and wire. I'm wondering if my wrapping/attaching was not correct to cause the break (I had re-wired them due to damaged wire). I thought I had followed the original while using photos to guide me, but something happened. Does the shroud wire need to be able to move through the wiring? Or, should the wire that I attach be tight to prevent movement? I noticed this video: https://www.youtube.com/watch?v=fb76xB8lVdk

Can anyone advise on this important step?

Thanks,
Sam
samdivita66
 
Posts: 7
Joined: Sat Oct 26, 2019 10:29 am

Re: Wiring shrouds to spreader end

Postby GreenLake » Sat Oct 26, 2019 1:11 pm

Sam, welcome to the forum.

First, a bit of house keeping. I'll move this thread to the "Rigging" section, because it's equally applicable to all types of DaySailer, and of general interest.

The wiring always serves the purpose of keeping the shroud attached to the spreader, but it can also serve the purpose of fixing the location of the spreader on the shroud. If your spreaders are the kind that have an extra-beefy bracket that firmly holds the spreader horizontal, I would allow some play. Otherwise,the spreader, if placed where it should be when the shrouds are tight, would be under some tension when the shrouds are slack, and the upper portion between the tang on the mast ("hounds") and the spreader in no longer stretched.

However, if you have the old-style spreader brackets that are simply a pin through the spreader tube, and which allow a bit of wiggle around the horizontal position, I would recommend locking the spreader end in place. That style of spreader is easily damaged if you catch it on anything while the mast is in storage or being raised. Fixing it to the shroud means any push downward is resisted by the shroud (and as long as you cinch the lower ends of the shrouds to the mast, there's some protection in the other direction as well).

After breaking the same spreader twice (!) within a week, I changed that one so the place where it attaches to the mast is jury-rigged in a way that allows it to swing up and down 10-15°. However, it is firmly wired in place, using a technique different from the one shown on the video. First, it seems to me that the wire I used was stiffer. I started out as shown, but wrapped each end firmly around the shroud (using pliers) five or six times, clipped the end, and using pliers made the end lie flush with the last winding.

Whichever technique you use, make sure to wrap the connection in self-amalgamating (rigger's) tape, unless you have a rubber or plastic spreader boot. Your sails will thank you.

On my boat, the wiring is just tight enough to firmly hold the spreader, but can be adjusted (after the main has been raised) with a vigorous shove from below with a paddle (pushing at the spreader directly where it meets the shroud). The last time some adjustment was necessary was over 20 trips ago. . . .
~ green ~ lake ~ ~
GreenLake
 
Posts: 5455
Joined: Mon Jun 18, 2007 3:54 am

Re: Wiring shrouds to spreader end

Postby samdivita66 » Sat Oct 26, 2019 3:27 pm

Thank you for your thorough response. I think I have a better sense of this now. The spreaders do attach with simple pin/bolt and so it seems likely that the break may have been caused by the shrouds not adjusted properly (there was noticeable slack as we sailed on the port side, the side that broke). I am sharing a couple of photos attached to this reply. Perhaps you wouldn't mind commenting on what type of spreader brackets I have...and then subsequently how tightly I should attach the spreader to the shroud by wire. Thank you! Sam
Attachments
spreader.shroud.jpg
spreader.shroud.jpg (26.59 KiB) Viewed 1298 times
spreader.mast.jpg
spreader.mast.jpg (28.11 KiB) Viewed 1298 times
samdivita66
 
Posts: 7
Joined: Sat Oct 26, 2019 10:29 am

Re: Wiring shrouds to spreader end

Postby GreenLake » Sat Oct 26, 2019 7:27 pm

Sam, I think I can make out that you have the brackets that extend a bit from the mast (and in principle would allow for the hole for pin to not be as close to the end, which would give more support). I can't really tell from your pictures but it looks like the difference to what I have is more a matter of degree: the hole is still almost at the end. (BTW, you should be able to upload somewhat higher resolution, even with the limits that the forum software imposes).

If there's about 1/2"-1" wiggle at the tips, you could go with the wired in place. But even so, be careful when you store or raise the mast to not pull or push at the spreader ends along the direction of the mast. That's how they break - it's not when they are properly rigged and in use.

You'll have researched that, but the location of the spreader ends, normally would be such that it bisects the shallow angle made by the shroud. Positioned like that, the spreader would be held in place by geometry and no up/down force experienced at its tip. If the brackets force a more horizontal position, that would be OK, but then the wiring would need to take any residual up/down loads. You definitely don't want to have them drooping, because that would change the geometry to where the tension on the shroud would tend to want to force the spreader further down.

All in all, the spreaders are designed to be loaded in pure compression and if you strain them in other directions they tend to fail and break.
~ green ~ lake ~ ~
GreenLake
 
Posts: 5455
Joined: Mon Jun 18, 2007 3:54 am

Re: Wiring shrouds to spreader end

Postby samdivita66 » Sun Oct 27, 2019 9:22 pm

Thanks again for your detailed response. I will consider all of this learning as I work with my spreaders. I appreciate that you took time to be thorough here.

Sam
samdivita66
 
Posts: 7
Joined: Sat Oct 26, 2019 10:29 am


Return to Rigging

Who is online

Users browsing this forum: No registered users and 2 guests