I have now been doing and using bury splices in 12-strand Dyneema long enough to have come to the conclusion that these splices should aways be lock stitched, regardless of whether or not they were made with a Brummel lock.
Without lock stitching it’s just too easy for something to snag the splice near the root of the loop and pull the tail all or partially out.
And, anyway, lock stitching, done the right way, only takes a minute, so why not do it?
To that end:
- Samson Rope has the best set of instructions I have seen, highly recommended, although it’s not specifically aimed at 12-strand Dyneema.
- That said, with a bury splice, I like to lock stitch the entire length from the throat of the eye to where the taper starts—might be overkill, but it doesn’t take long.
- I don’t think it’s necessary, or maybe even desirable, to put my usual preferred sailmaker’s whipping around the throat of the eye as you sometimes see, since the stitches through the rope may be a problem when the splice seats under load, whereas the lock stitching allows the splice to creep a bit as the load distributes evenly over all the strands.
- That said, if you are more comfortable with a whipping at the throat, as well as lock stitching, I think it best to use the Samson whipping (see above link for detailed instructions) since the line itself can move around under it more easily than with a sailmaker’s whipping.
- One place I disagree with Samson is on using nylon twine. It’s generally horrible to work with. As a sailmaker in a past life, I recommend waxed Dacron.
- Here are the tools I recommend, for this and many other marlinspike1 seamanship tasks.
Further Reading
Much more on rigging and sails:
- Boy, did I just date myself as an old fart. ↩︎
having done a bit of splicing/swagging as a tech in the entertainment industry, i would say that i prefer the bury to the brummel lock just because its easier to get everything balanced (in line if you prefer) as opposed to clearly separate between the 12 strand, 2 times, with the fid. The bury is straight forward and less mistake prone, to my view. i usually take out the building stretch by using a small lever hoist (say a 250kg swl) and crank it up till i cant no more, this will make all strands fall into place whilst giving you the final length of the cable (not so important in boat stuff, but important when ou flying humans on the end of it), and then i do the stitching with waxed twine.
on my small 29 footer, which is getting the rigging done in Vectran ive done brummels on the top ends and burys at the bottom, just because, when creep happens is much easier to redo the bury and readjust than having to remove the stay. work smart not hard i would say
Thanks for the tips, bookmarked!
Having retired from a Rigging shop, I feel I’ve seen more than most people. A few comments.
A Brummell lock needs 48 rope diameters minimum, in the bury. Because the tail goes through the standing part and the standing part goes through the tail. Then your 48 diameters of burry starts. We never found it necessary to lock stitch. In order for the splice to pull apart, you would literally have to break the line. This is because the tail would have to completely un-weave itself completely. We have never seen a tail pull out. I would recommend that if you want to lock stitch it or put a whipping on it. Take the completed splice and load it on a winch first. That will retention all of the strands that you disrupted while making the spice. Use a contrasting color whipping line so that if you need to take part, it’s so much easier to find the stitches to remove. Of course, there is nothing wrong with lock stitching a brummel lock splice. It’s a belt and braces approach.
A direct bury splice requires a minimum of 72 rope diameters of bury. It is absolutely necessary to lock stitch this style of 12 strand splice.
Lastly, your tapering should be perfect. Start your taper about halfway down the tail. After you have tapered and buried your tail. Take your hand starting at the throat of the splice. While squeezing hard, run your hand down the line. If you can tell where the burry ends, you did not taper it, enough. If you can feel where the burry ends, that is where the line will break.
One can make their own tool to pull the tail through the line. We would take some scrap 1 X 19 wire, and un twisted to get the core out. This is a straight piece of wire. We would find the middle, then bend it in half. Put the middle portion in a vice and crush it flat. Take the other end bend into a loop and Nicro press it together. Your center Is a nice and smooth and rounded. This would easily pass up the hollow of the braid. Take six of the 12 strands out by tapering it. These six remaining strands go through the end of the loop, in the center of the wire. Bend back on itself and not slip out, no need to tape it. Drop the micro pressed loop over a bench hook. You now have both hands to milk the tail through the center of your 12 strand. Pull the splicing tool out, taking the six untapered strands with it. Finish your tapering, milk it down and suck it into the hollow center. This is what we did when we had 26 splices to make in 2-1/2 inch Amsteel for the Navy. That’s a 10 foot bury for a Brummel lock.
One last thing, do not uncover Vectran core line. The UV will quickly degraded it.
Hi David,
Good tips.
That said, we have had this discussion before, but both Eric and I have found that even with a Brummell lock the buried tail can easily be pulled out of the splice if the point where it enters catches on something with the splice unloaded. Therefore I stick with my recommendation to lock stitch all splices. Also, I don’t agree that 48 diameters bury is adequate with a Brummell lock. Given that the lock adds no strength I prefer to use the standard 72 diameters for all bury splices, Brummell or not.
I’ve seen Brummel locks unravelling when under load when people didn’t observe the correct bury length, never saw it happen (so far) when the manufacturer specs are met.
You raise a valid point for uncovered synthetic fibre lines, indeed it may catch on something and pull the tail out. so its either stitching or covering that section with a sheath that prevents that from happening
about the Vectran
What i didn’t mention was that all the stays are getting covered in polyester mantle sheath, from normal working lines that were in very good condition but had no use, exactly for that: the UV degradation.
To help me gauge the UV effect i will have a small portion of covered and uncovered Vectran, exposed to the elements 24/7 so that i have a reference on what’s happening on the mast stays and when replacement should occur.
When im tapering the the strands i cut the pulled out strands at an angle and not at 90 to itself, in order to not create a “bump”. Then with the remaining 6 long strands i also taper them at the very, again by cutting 5 of them at once at a shallow angle (with a stanley knife blade on its own). i leave the 6th strand to have its full lenght.
i found this to give me the smoothest possible taper.