Originally Posted by Seaworthy Lass
Evans, I have a query about the Brummel. Is the twist in the holes detrimental? Some methods leave the twist in, others work to kink it out, and the method of using both ends to work with avoids it altogether. What is best?
Also in some methods the working end goes through the standing part first and in others vice versa. Is one preferable?
First, all the best testing has indicated that the splice without Brummel is on average a bit stronger than with Brummel - this is statistically measurable. New England
Ropes looked into this extensively when we were looking at lifelines
, and recommends without Brummel (but of course then you do need to sew it so it does not slip under low load cycling).
Second, if doing a brummel you want to disturb and twist the fibers as little as possible, but the difference between a twisted and untwisted one is in fact not easy to see in tests with statistical significance. The best brummel method is to use both ends, but if you are going to splice a loop to each end you can usually only do that method at one end.
Third, you want the Brummel passes to be close to each other, and properly done it does not matter which is first. But it will be measurably weakened if they are some distance from each other. This was counter-intuitive to me at first (I thought it should make no difference) but longer distance allow uneven stresses to develop on the pass thru's.
Originally Posted by Dockhead
That looks great!!
I don't need anywhere maximum strength for my application, but still -- what is in your picture is actually what I wanted in the first place. How is it done? How is the ring "cleverly captured"? Maybe I'll do the rest of them like that.
First, the 'tight eye' geometry (like the design you have been making) will reduce the strength by 15-20%. Which is also about how much crunched/tight tapers can reduce strength. Usually this is not a problem because the dyneema is so strong and the aluminum
low friction rings actually have relatively low working loads (compared to the dyneema).
Second, just FYI, the very very easiest way to do this, is to splice an end to end loop right thru the middle of the low friction ring (rather than around the outside). That way you don't have to do anything at all 'clever' to capture the ring - you just have a closed loop thru the ring, which cannot ever slip off. This does reduce the bend radius, but the important part is that it is still a big enough radius to be 100% full strength.
Third, there are four ways to 'cleverly capture' the ring. (1) when you make an end for end splice you will note that you create a closed hole in the line (where the end for end splice comes together). So the first way is just to put the ring in that hole and tighten it up. (2) you put a double loop around the ring, and you put a pass thru on the first loop (half a brummel) at the top of the ring (180 degrees from the other end) which slip nooses the ring and then the sewing or sleeve you see in the picture just keep the second loop from slipping off. (3) You add/splice in a small piece of cordage 'under' the ring to hold it. (4) you do some beautiful sewing (really just a pretty extension of #3, adding some light line to capture the ring) . . . .see this picture from an Italian friend who (I think) makes the nicest looking rope
work in the world.
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These are all full strength if done correctly. I believe #2 is the vendee/volvo best practice. #4 is perhaps mechanically the best but takes too much labor for the pros to want to do.
I might note that in the first photo
I posted above, which is from the Antal website, you can tell just by looking that the tapers are too short
. . . . . if you want the strop to be short . . . . too short to make properly long tapers, then the correct thing is to make a 2x longer loop (which gives you more room for the tapers) and double it over . . . . . . .or an 6x lashing. If you go down this road you just have to make sure the design can equalize tension between the various strands.