splicing Icetail

Hey Norm, would you recommend the straight bury for Dead Eye slings and Adjustable slings as well? It does seem to make sense that if it buried the proper length it would hold just as well as the "through and through". When making dead eyes for crane slings I am absolutely looking for the strongest possible splice and it looks like the straight bury might be the best way to do it.
 
[ QUOTE ]
... Very detailed splicing instructions with pictures (for those of us that can't follow written instructions; Nick)...

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Hey, what's that supposed to mean!!! I can follow written directions!

I can't wait to get my paws on a copy of the new manual!

love
nick
 
In support of the lock

Back to the matter at hand.

As I understand it, the straight bury is the strongest splice for single braid ropes, followed by the through-through (red book) splice, and third place being the locked brummell.

Let's keep in mind that the strength of the first two options does come at a cost. The locked brummell is the most secure of the splice. In all splices, the stitching/whipping is a crucial part of the splice. That's not bad, as long as it stays intact. However, lock stitches can come off. It happens to tree folk occasionally. Sometimes it results in splice failure.

Any whipping can be REdone if it comes off, but say you splice a sling for someone, they use it for a few months, then the lock stitch comes off. Two things can happen at this point.

1) They recognize this is bad, and throw it in the back of the truck, then 2 weeks later they restitch it themselves and put it back to work. What they don't know is that while it wasn't being used, the tail backed out an inch or so. Maybe not a big deal, but maybe bad things COULD happen.
2) They DON'T recognize the potential problems and continue using the sling. It'll hold in most cases, but somewhere down the road, something could snag the rope the right way and pull the tail out, hopefully while it's not under load.

If this was MY rope, or belonging to most the people here, it wouldn't be a problem either way. But many people are not as rope-wise as the average tree-buzzer. If this was a locked brummell, the tail can't really back out a little, you'd have to pull on the rope in a very wierd way to get the tail out.

Anyone have any numbers on efficiency of locking brummell? I think I have some reports at home from some breaks I did that held 85-95% of reported breaking strength. I'm content with that in most cases.

And in climbing applications, I ALWAYS prefer the locking brummell over anything else.

love
nick
 
Re: In support of the lock

I'm not sure this means anything, but I spoke with Samson last week about getting some splices tested, or at the very least getting some documentation about the breaking strength after splices have been put on their ropes and their answer was basically as follows:

We don't normally do it, but sure we can break your splices at a cost of $$$$$$$$ (basically a HUGE amount of money).

The specs that are in the catalogs are based upon spliced ropes (that way they can hook the rope onto the break machine) and therefore the advertised break strength IS the ABS after splicing. This being the case I wonder what splice they are using on the ropes????? I guess it would be the splices in the "Red Book" but it sure would be nice to know. My reason for bringing this up is that for 7/8" Ultratech for instance the strongest bury would be for miles.... well not quite miles, but you get the idea (plus it would be a core to core on both ends). I didn't think the break machines where that big.


Because the advertised strength is based upon a spliced rope does that allow us to drop the standard loss of 10% or so when making products? I agree with Nick that having the information on break testing with the locking Brummel would be great to have, surely someone has done this test and has the information somewhere???
 
Re: In support of the lock

This is an interesting discussion, but the point of my concern is that all readers know a 2" bury is not safe, irregardless of what brummell is used.
Does anybody contest that?
 
Re: In support of the lock

[ QUOTE ]

We don't normally do it, but sure we can break your splices at a cost of $$$$$$$$ (basically a HUGE amount of money).

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I hate that! Last time I called them, I think they quoted me $60/break. Not a BAD price, but it's a LOT of money.

[ QUOTE ]

I didn't think the break machines where that big.

[/ QUOTE ] a 7/8" technora would be buried 42", if you were burying 48 rope diameters. And a few inches for the eye to make it an even 48" for the whole splice, times 2 makes it a total 8' long, plus some more rope in the middle of the rope between the splices...now we're up to 12'. Many break machines ARE way bigger than this.

[ QUOTE ]

...having the information on break testing with the locking Brummel would be great to have, surely someone has done this test and has the information somewhere???

[/ QUOTE ] I hate guessing when I know the information is out there somewhere. We just have to set it up and do a test (that someone has probably already done)

love
nick
 
Re: In support of the lock

[ QUOTE ]
This is an interesting discussion, but the point of my concern is that all readers know a 2" bury is not safe, irregardless of what brummell is used.
Does anybody contest that?

[/ QUOTE ]

Mike, first we have to determine WHAT rope we're talking about here. 2" would be just about adequate in a 1/8" polyester single braid. In 3/4" rope it would be well short . At this point we cannot at this point say either way. I doubt anyone would see that as acceptable in the through-through splice or the straight bury on any rope that we use. At the sound of it, it SEEMS short to me. However, keeping in mind we are urged by ANSI to conform with manufacturers recommendations, and currently no manufacturer provides directions for splicing any rope with a locked brummell. Is this to mean that we should avoid this splice? I doubt it.

Mike, if we're talking about the quarter inch core of Beeline or HRC, a 2" bury is 8 rope diameters. Some say the lock in a locked brummell is to keep the tail from slipping while under low loads, some say the lock IS the splice. If it IS the splice, the tail only need be long enough to maintain the integrity of the braided tail. Maybe in this case, 8 rope diameters is long enough...testing would be the only way to find out for sure.

Also keep in mind, in HRC and Beeline, the cover is whipped to the eye at the point of bury. This surely provides additional security/compression to keep the tail together.

I have a small batch of beeline eyes to be tested. I'll definately post the results when I get them.

love
nick
 
Re: In support of the lock

Nick we're talking about 1/4" core I assume, that's what most use for double braid hitch cord.

Let me ask you this, how strong is a locking brummell with an untucked tail, on 1/4 inch technora (is that bee lines core?)?
 
Re: In support of the lock

Beeline has a vectran core, and I think HRC is the same.

To answer your question, I have the answer to that question for a polyester rope, but not technora. I'll post it when I get home.

love
nick
 
Re: In support of the lock

I'd Like to hear the results of break testing as i'm going to try and get myself certified to some extent to splice. despite marlow ignoring my emails. If Marlow are of no use, i'm going to splice a few samples of everything i can and get it break tested and store the results...posted of course

If you want to see a manufacturer recommending a Brummel look no further

Jamie
 
Re: In support of the lock

Mike that is for a dynemma or vectran splice. the non locking brummel can still slip as the tail is passed through the standing part.

i had a long post typed up but realised that it repeated the same info that was already up if you were producing a straight bury on 8mm beeline with a vectran core its recommended that there is a 2 fid length (48 diameter) bury.

Due to the locked part of the locked brummell it is (from my observations of how the splice is constructed) very unlikely to pull out.

When the splice is lockstitched (after the locking part of the splice) that will hold the bury in place under low loads but when loaded the rope will grip itself and hold it inplace.

i prefer longer tails in my locked brummells so i can make the taper smoother but due to locked splice being there i am nowhere near the 2 fid lengths.

i would like to see break test results for a locked non locked and straight bury. maybe in the new year...

Jamie
 
Re: In support of the lock

With a locking Brummell, if the tail has slack, the full load goes on the Brummell, the braids start to unravel, and the splice fails.
When you pull on a beeline tied with a scaffold knot, the cover rips off and the core pulls out before the line breaks. Think about that.
 
Re: In support of the lock

Jamie, that link you posted is not for a locking brummell splice, it is for a through-through splice. The tail goes through the standing end twice before being buried.

love
nick
 
Re: In support of the lock

There is a manual on the New England website but the lengtf of the bury is not mentioned but the entire splice (two locks and bury is measured to 1 1/4 fid) My ice tail is 8mm, the tail is approx 50mm or about 6 times the diameter.
I weigh 70kg, each of the splices on my split tail then takes 35kg, each of the locks again takes 17kg, right? I still don´t feel insecure but I follow this very interesting discussion and am ready to change if I´m proven wrong.
Searched for splicing tests but didn´t come up with anything so far.
Svein
 
Re: In support of the lock

[ QUOTE ]
...I weigh 70kg, each of the splices on my split tail then takes 35kg, each of the locks again takes 17kg, right? ...

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I'm not sure this train of thought can be used as justification for a less that great splice. It is at those low loads where the splices would slip. Your Icetail has a strength of 3900 kg. When you sit into your harness, you are putting a load of less that .005% of the breaking strength of the rope onto each splice. We don't have exact numbers to know where the chinese finger trap action begins, but you have to admit .005% sure sounds very low!

love
nick
 
Re: In support of the lock

Thats exactly my point, with very low load splices might gently be pulled out so I feel I´m better off with a locked Brummel where the locks holds the splice. The very low load also makes it higly unlikely for the rope to unravel.
Svein
 
Re: In support of the lock

Nick i thought that the Brummell is what you are refering to as a through through splice and a locked Brummell has the tail and the standing part passed through each other.

Oh and Trebjodn i'd prefer slightly longer tails, I cant remember how long you said they were but it was short.

Oh and Marlow eamiled me back saying that they have no facilites to test rope splices...hmmmm looks like i'm off to get them load tested until they break. In our world of buck passing i want some means of stating that they are strong enough to be fit for purpose.

Jamie
 
Hey Rich, I just did a crane job all day yesterday using spider leg slings with strate buries. We lifted a stump cut that weighed 6,000# with 1 of the spider legs and it held just fine. I have been using spider legs with strate buries for 6 monthes with no problems. The key is to make the proper full volume bury along with a proper taper. NO SHORTCUTS. ALL SPLICES ARE STITCHED according to rope classification (Class I or II).
 
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