Step salsa down in size.

[Stumble]

On my A-Cat I am running a 10:1 internal mainsheet cascade with 9mm salsa in order to provide a good hand by the time it gets to me out on the trapeze. The problem is it's a relatively big line bent around smallish blocks. my plan is to replace the standing portion of the salsa with 1/8 amsteel, but am not sure how to go about it.

My first thought is to end for end the salsa into a 8mm dyneema piece, then that into a 6mm piece, and on down to 3mm, but this seems like a lot of discrete steps. Does anyone have a guide for how large each step down can be?

[Brion Toss]

Hi there,
A cascade has at least two pieces of rope; how is yours configured? Once I know that, we could talk options.
Fair leads,
Brion Toss

[Stumble]

Brion,

It's a 2:1 initial running 3mm amsteel that cascades to a 5:1 with 9mm salsa,then falls to a ratchet block to exit the boom, then another ratchet flip flop block to trim from. The issue is the salsa is too large for the blocks and pulls itself into a large rope plug that keeps the line from running cleanly.

If I replace the salsa with 3mm it runs fine, but is far to small to grip by hand, so what I am trying to do is taper the salsa into thin quick running line to keep it from binding. My plan right now is to end for end splice the 9mm into 6mm, then 4mm, then 3mm. It is a little cumbersome and a lot of steps, but other than a machine tapered line I am not sure how else to get it to work.

[Brion Toss]

Hi again,
How about inserting the 3mm directly into an adequately-large single braid. Bury it a couple of feet, and stitch a lot, neatly, for a smooth transfer of energy. Whip the end of the single braid at the transition.
One trick here is to position the transition such that it goes through few if any blocks.
Fair leads,
Brion Toss

[Stumble]

Unfortunately there is no way to arrange it so that the larger doesn't run through blocks.

I did consider trying to use the Samson Smooth Ice cover installation splice but couldn't get the larger line to bury in the smaller. The size difference was just too large. I could certainly just bury it up the middle, lock stitch it, then whip it to see if it holds, but I am concerned this wouldn't transfer the load appropriately, and would jam in the blocks.

edit:

I received my order of line and documented all the testing I did as well as my final result.

In order to be as efficient as possible I wanted to go from 9mm salsa to 3mm dyneema in as few steps as possible. I think with one of the Toss splicing wands it maybe possible to eliminate a step, but I don't have one so can't test it.

I have no way to test strength, but because the tapers are somewhat shorter than ideal the stress risers created are likely going to cause the line to break. In this application reducing the leingth of the total splice was more important than retaining maximum strength because the total package is far stronger than needed for the expected loads.

1) 9.5mm Salsa was end for end spliced into 6mm dyneema each end was tapered 17" from the crossover
- tapering the Salsa first was required to make this step. Here a wand would have been prefered.
2) Then 6mm dyneema was end for end spliced into 5mm dyneema on a 17" taper.
- I suspect that with a wand the 6mm could be buried into 4mm, but with the Selma finds I couldn't get the line throug
3) 5mm was spliced into 4mm. With each side tapered 14"
4) 4mm spliced to 3mm. With a 11" taper.

So from the Salsa to the 3mm amsteel is a total of four splices, and a distance of a little over 5'.
If I am correct that 6mm could be buried into 4mm directly then it would be 3 splices and not quite 4' long.

What I found is that generally dyneema will open up enough to accept a bury from up to 1.5 times its original size. I need to replace my #4 Selma fid before making the finish rope and posting pictures, and I have no idea where this would have an application other than here, but I have found it a fascinating experiment that will cut weight from my boat and reduce line friction at the same time.

[Brion Toss]

Hi again,
The wonderful people at New England Ropes tested inserting 5/16" Endura 12 into 5/8" Regatta Braid, and got a break in the latter, at full strength. This was with a 6ft bury, as I recall, making it about 115 diameters. No reported rope distortion. I'm much more inclined to insert small into large, as a result, especially where the differences in size are great.
Fair leads,
Brion