dyneema

Stretching 12mm Dyneema rigging after adding two eye splices

Dave Warnock

Dave Warnock

— 2 min read
Stretching 12mm Dyneema rigging after adding two eye splices

We have just a few days before we move out of this manse (ministers house provided by the Church). Before we move out on Monday we need to get all our Main Mast rigging spliced and then stretched (to remove the shortening created by the construction of the splices).

Jane has been busy doing the splicing (with occasional need for some brute force by me). We have recorded a video on how we do that as 12mm dyneema is a lot more difficult to splice than 9mm.

Today, first dry day this week, I started preparing the timber frame for stretching these shrouds (2 cap shrouds) and stays (2 backstays and 1 forestay). The longest is 14.5m compared to the 10m or so that has been our previous maximum. The challenge is the the end of our frame stretches over the patio and has a lot less strengthening and is not fastened down.

I had an idea that has made things simpler. The crane scale is now at the "top" end of the shroud which means the chainplate loop and bottom of the shroud both have our low friction Acetal thimbles for the lashing and work exactly as they will on the boat (except horizontally).

The chainplate loop knot getting nice and tight. The Acetal thimble working perfectly.
On the right of the picture is the block and hook for the pull-along. That pulls on both ends of the lashing at the same time to use the lashing as a multipart purchase.
Our 3rd attempt to stop the 9" x 2.5" plank from bending. When the shroud is tensioned. We reached almost 1,500kg today

I first added some lengths of angle steel to one side of the timber, didn't have enough so added some scrap bits of timber on top. Then I added some of the aluminium strip left over from our toerail (approx 50mm x 6mm) to the edge of the other side. The green buckets (full of water) are on legs which stop that part of the plank bending down and provide some ballast to hold the plank down.

Even with all the strengthening the end of the plank was bending quite a lot and lifting the green bucket at least 50mm into the air.

Tomorrow, I'll add a thick plywood sheet along the end as a long "leg" that will not allow the plank to bend. It will also allow me to hang a lot more weight on it to keep the end of the plank down. Hopefully then we can get back utp 2,500kg which I feel is a reasonable target.

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