Locking Brummels on ice tail.

ROYCE

ROYCE

Carpal tunnel level member
Location
Vermont
I climb on ice-tail. I love it. I have always gotten grizzley spliced eye-n-eyes from sherrill because hand spliced ice tail has the over-lap in the middle and always puffs out on me.
I have recently started splicing my own rope and was wondering if I could splice ice-tail with two locked brummels on each end, and then only bury a 6-8" tapered tail. This would allow for my friction part of the ice tail to be void of any internal fibers.
If you look at the Samson splicing instructions it calls for a long bury and an overlap in the center. I would like to avoid this if possible.
Both splices would also be lock stitched when done!!
 
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I climb on ice-tail. I love it...
If you look at the Samson splicing instructions it calls for a long bury and an overlap in the center. I would like to avoid this if possible.
Both splices would also be lock stitched when done!!

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I will catch hell for saying this, but I believe in putting out the facts and letting others make of them what they will. I think Samson is crazy (or just lazy) to apply their standard Class-2 instructions to Ice Tail (IT) for the reason that the specifications are grossly over-conservative.

Last year I pulled an IT splice to failure. My intent was not to break it, but to make the splice so short that it was sure to pull apart and I would learn something about pulling force vs bury length. I intended to do a number of such pulls to create a nice chart relating splice security to bury length. For the first test I chose a ridiculously short bury of 2 inches. Of course there was no Brummel and no stitching. The experiment was ruined when the rope broke at the end of the bury at 8000 lbs.

My current IT e2e's have buries of about 7 or 8 inches, no Brummels, but plenty of stitching at the throat. I am sure I could lift a pair of trucks with either one.

If I wanted to make a still shorter splice, I would use a locking Brummel and a bury of 4 inches and feel perfectly safe. If the bury were to somehow come out, the Brummel would then be left holding the load. A Brummel with a 4-inch tail is not going to rip the tail apart, so the Brummel would hold until it breaks.

What force would it take to break the Brummel? I have done several tests in hollow braids, including the Vectran core of Bee-Line. The Brummel is about equivalent to a very bad knot, reducing the rope strength to about 30% to 35% of nominal. In a line as strong as IT, that would still be enough to rip a person in half.
 
Wow, good information here. I agree with you 100 percent about that samson uses the class 2 splicing instructions and it's pretty crazy. I like ice tail for the reason that it is soft, supple, and very flexible. If you bury the tail and cross it over, you loose that flexibility, and diameter of the rope changes.

I was just curious if their were any strength reason's to burying so much tail and then crossing it over. It appears that your tests have proven differently to you. That you have very minimal strength loss, if any. My hips would explode long before the ice tail breaks ( I heed your warning and will conduct my own research and tests)

I have spliced up my split-tails with locking brummels on each end with eight inches of bury and i personally feel that their is no reason to believe that this is a week splice. I just wanted hard data to back up my theory.

I will be calling samson in the morning to ask them what their thoughts on the issue are.

thanks for the good insight!!!!
 
Whatever you decide to do its worth the $ imo to break one(controlled) to back up your thoughts. It is also good for peace of mind.
 
Yes, do a locked brummel with a short tail. I do it all the time.

I respectfully disagree with moray on the skipping of the lock. It may work fine, but the increased security of the lock is hard to argue.

Royce, let us know what samson says!

love
nick
 
I think I should clarify what I said. First I (respectfully!) don't disagree with Nick about using the locked Brummel--it is an excellent method to back up a splice with a short bury of uncertain security. I just don't like using it when there is no uncertainty about the security.

If you do use a locked Brummel, it is worth knowing how it actually works.

First, it is not a substitute for stitching the splice throat even though many people seem to believe it is.
Second, it has very little function as long as the splice remains intact. It does not weaken or strengthen the rope, but it would contribute something to the security of the splice because it develops some friction of its own.
Third, it does not mean you can make the splice bury as short as you want.

Everyone knows that the security of the splice depends on bury length, but no one ever mentions that the security of the Brummel depends on this as well. If a short bury were ever to pull out, the resulting tail of rope constitutes the "lock" of the Brummel. If this tail is too short, and the rope tension is sufficient, then the braid in the tail will not hold. When the tail comes unbraided the lock has failed and the tail will pull right through what remains of the Brummel.

The two photos are before and after shots of a locked Brummel test in 5/16-inch Tenex. The tail is about 4 inches long. In the second photo the Brummel has begun to fail at 2740 lbs. Had the tail been only an inch or two long, it almost certainly would have unbraided and failed. Note the extreme compression of the Brummel: if one ever saves your hide from a bad splice, this is what it would look like.

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4464792571_f74a738182.jpg
 
No it's Tenex alright--I got it from the Ebay rope guy. Had it been Vectran the breaking strength would have been much higher than I measured (about 4500 lbs).

The picture shows a test in real Vectran; this was an E2E in 8mm Bee-Line someone made for me to test. The eye on the left survived essentially intact; the one on the right failed at 5300 lbs when the splice bury slipped out. The locked Brummel then tightened up and held, even though it also shows some strand failures.

This was an interesting experiment for several reasons. The vectran core itself, about 1/4 inch in diameter, was tested separately and broke at 9600 lbs. A locked Brummel was also tested by itself, and failed at about 2800 lbs (average of 3 tests). The locked Brummel, by itself, delivered less than 30% of rope strength. In combination with the splice it does almost nothing until the splice fails; it does not weaken the rope--that only happens if the splice fails and the Brummel deploys.

How then did the weak Brummel hold when the much stronger splice failed at 5600 lbs? This was a rare lucky result due to the fact my test rig is hydraulic. The pull from the cylinder stops immediately when the splice begins to fail. There is still some stored energy in the rest of the rig (chains, shackles, and the log frame to which everything is attached), and that energy has to be dissipated as the splice slides apart. There was still enough left when the Brummel had become a tight little knot to break fibers on both sides of the Brummel but not enough to break the Brummel entirely. In this particular case a falling load capable of slipping the splice almost certainly would have broken the Brummel as well.

None of these numbers should worry a climber. As long as the Brummel can withstand more force than the climber can, it is strong enough!

4197284955_3f0f18cc05.jpg
 
Numbers are well in a safe range in my mind. Like many have said, your hips will explode, or the tree will fail, long before the brummell does.

I have yet to hear from samson. They have called my back, however we are playing phone tag at the moment. Will keep you posted
 
I have some 1/2" Tenex that color. I think it looks nice.

Any buried splices must be stitched or whipped, no matter what rope construction. I think some people do believe that locking brummels don't need stitching. The splice may be locked, but what's preventing the bury from coming out? I've seen it 1st hand all the time, even from some rope manufacturers.
 
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I have some 1/2" Tenex that color. I think it looks nice.

Any buried splices must be stitched or whipped, no matter what rope construction. I think some people do believe that locking brummels don't need stitching. The splice may be locked, but what's preventing the bury from coming out? I've seen it 1st hand all the time, even from some rope manufacturers.

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Thank you!! I agree with this statement fully. This was brought up in a climbing competition. Where a climber was climbing on locked brummells he spliced himself, with no stitching. This was passed because they believed the locked brummell was enough on it's own. We back up all our gear that we climb on. Carabiners, cams, we spike the line, why wouldn't you lock stitch a splice, even if just as a back-up. I believe every spliced should be stitched.
 
Hey John, have you considered using that much thinner tech chord from all gear with an overlapped splice? They finish up a bit thinner than ice with the same splice.
 
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Whatever you decide to do its worth the $ imo to break one(controlled) to back up your thoughts. It is also good for peace of mind.

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Yep.
 
has anyone found that Samson's recommondation for a finished 33" e2e is to start with 80" of ice. I end up with 33" starting with 72" every time, weird.
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I end up overlapping the buried tapers about an inch (not the 8" as instructed by Samson) just to keep that constant diameter throughout the e2e, for a consistent feel
 
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