Spliced Eye

[spin101]

Can anyone tell me the strength of a spliced Eye from the factory in a 1/2" rope. Maybe i don't know where to look but i can't seen to find it anywhere.

 

[skwerl]

The splice strength will typically be 95%-125% of the rope strength. The splice will NOT be the weak link.

If it's a lifeline and you're buying from Sherrill, you might wish to consider requesting a 'tight eye' instead of the standard large eye. The tight eye is just big enough for a carabiner to squeeze through. This eliminates the need to girth hitch the carabiner and it eliminates slop and bulk at the connection point.

Just specify a 'tight eye' when ordering. It's the same price.

It looks like this:

 

[spin101]

I believe the eye i have now on my climbing line is a 5". Considerably larger than the tight eye that you have shown. I wish i knew this before i ordered my line, i guess you live and learn. Would it be safe to use this for now if kept in good condition?

 

[tophopper]

Can anyone tell me the strength of a spliced Eye from the factory in a 1/2" rope. Maybe i don't know where to look but i can't seen to find it anywhere.

Most splices done properly are 90-95% efficient.
dont know that Id say up to 125% though, how can that even be possible?

 

[tophopper]

It may be because there is more rope in the spliced part of the rope.

Quite often in break testing the rope does not break at the splice. This means the splice is stronger than the rope.

I've also read that in testing some knots that the rope does not break at the knot like is commonly believed.

I realize there is more fiber in the splice but I'd like to see ANY documentation that says a splice is over 100% efficient, I just dont believe its out there.

I do agree the rope is more likely to fail elsewhere than the splice area, but technically, a splice is a bend(an eye splice), and any bend in a line will reduce its efficiency, by some amount.

 

[tophopper]

Are you suggesting that an eye splice IS stronger than the rope rating itself?

Regardless of where it may actually break, Id like to see ANY rope manufacturer get behind that line of thought.

Like I said, a splice is a bend, there is some strength loss in it.



Regarding the size of the splice, as skwerl alluded to, Yale cordage has done testing and found that the larger splices which need to be girthed over tested weaker than tight eyes, most likely due to the bend and choking in the girth.


No Dan I do not "agree" that a splice must be stronger than 100% of the rope's strength, even if it is more likely to break else where.

 

[clearance]

You guys are funny, life lines are 10-1 for safety, 90%-125% who cares how much at 6k ultimate, me, I just tie a bowline.

 

[tophopper]

I agree clearance...

in a climbing system our saftey factors make the point kind of moot.


I havent climbed with a bowline in my system in near 10 years, not even on Sundays.

 

[spin101]

Thanks guys for the feed back. You all have been very helpful in getting me started in the right direction, and the view points brought up in conflicting discussions goes into depth farther than any internship i could work would.
thanks again guys

 

[jmack]

girth

I believe the eye i have now on my climbing line is a 5". Considerably larger than the tight eye that you have shown. I wish i knew this before i ordered my line, i guess you live and learn. Would it be safe to use this for now if kept in good condition?

yeah that one is for girth hitches, its not safe send it to me right away so i can analyze then destroy it, just kiddin, its safe try running the girth hitch with a swivel snap until ya get yer new one

 

[Tom Dunlap]

One of the changes in the 2006 version of the ANSI Z133...AMERICAN National Standards Institute...will be that all body support rope terminations will be cinch-type connections. This means that loops won't be allowed on biners or captured eyes.

There are some ropes that a tight eye doesn't seem to work well on. The Velocity family doesn't take a tight eye without hemorrhaging the core through the sheath.

The solution for this, and any other large eye, is to seize or whip the eye down to an acceptable size to keep the biner from sliding around.

Using spliced eyes makes for a nice tidy climbing setup. Less bulk and it eliminates a knot that has to be tied, dressed and set everytime it's used.

There are instructions for making one kind of seizing here:

http://www.sailingservices.com/running_rig/splicing/stasetx_pcru_eye_spl.htm

 

[okietreedude1]

One of the changes in the 2006 version of the ANSI Z133...AMERICAN National Standards Institute...will be that all body support rope terminations will be cinch-type connections. This means that loops won't be allowed on biners or captured eyes.

So I guess this means no more bowlines??????

That will make the TCCs more interesting to see how many rookie climbers know how to tie the dbl fishermans style knot. Ive seen veteran climbers that tie it wrong.

I think thats a poor decision by the ANSI committee.

 

[Tom Dunlap]

David,

You're right about people being able to tie a cinch type knot. There are other solutions to the issue besides tight eyes or scaffold hitches though.

The Z133 was available for public comment for a long time. I don're recall ever reading any opposition to this issue though.

 

[coydog]

Does the core pass or part of it pass through the splice loop for the tight eyes or is it only the jacket, I ask this because I know a climber that does spliced eye terminations in his sixteen strand and doesn't incorporate the core into the splice. I've expressed my reservations but he swears it's the correct way to do it.

 

[skwerl]

Here's the Samson instructions. I was going to post the New England instructions but they are virtually identical and in a different format, too large of a file to upload.

You can also go to the rope manufacturer's websites and poke around for the splicing instructions.

 

[tophopper]

Does the core pass or part of it pass through the splice loop for the tight eyes or is it only the jacket, I ask this because I know a climber that does spliced eye terminations in his sixteen strand and doesn't incorporate the core into the splice. I've expressed my reservations but he swears it's the correct way to do it.

Id say he is correct,in 16 strand climbing line there is no core inside the eye.

 

[clearance]

Here only workers compensation board certified splicers are allowed to splice lifelines of any kind. Must be a reason for that, maybe important it is done properly, but who knows.

 

[tophopper]

I prefer splicing my own.

and its very important its done right.

 

[okietreedude1]

Coy,

its just the cover that makes up the eye.

If you buy a Yale 16st that is spliced at the yale factory, they do a mechanical assisted splice that is cover and core together. Impossible to do without mechanical assistance.

 

[TheTreeSpyder]

Like I said, a splice is a bend, there is some strength loss in it.

In flat (Tenex etc.) or flattened (core removed around eye of 16 strand) there is minimal leverageable dimension on the bend; therefore minimized strength loss. Leveraging the force against the line takes the same as any other leveraging; stiffness to resist the bend and length dimension to multiply that stiffness(then in nonflexible things like steel beam, multiply length from input force to bend too; but not in ropes). The flat / non-round rope eyes are like flat rope/webbing in that they offer minimum resistance to the bend; and being flat minimum- Zer0 multiplier of that stiffness; therefore the eyes are not leveraged against as in round line. So, we have 2 legs of support, with minimum, minimum loss at the bend; in a flat eye.

The round line device, that maintains it's roundness on the bend will have equal leveraging against a bend in any direction; for being round (having same diameter/axis from any direction) the bent axis/dimension will always be the same in above explanation. Therefore, some say round is the unleverageable shape; which isn't really true; just equally leveraged shape from any angle through it.

Flat, will have a favorable dimension to bend, that gives about no leverageable dimension on bending on 1 premium axis in either direction. But, scrunching flat webbing across long dimension will give higher multiplier in Leveraging = Stiffness (resistance to bend) X Bent Dimension formula. So flat, will have a favorable direction/axis to bend on, and unfavorable axises too. For only round gives equal leverage against line from all directions/axises.

In hollow round line that will lay flat; this is not a problem, for the line will flatten on any axis, unlike webbing. Line is round to give easier knotting and unknotting, predictable leveraging on bend, and easier working around bend; not because it is stronger than webbing etc. The weakness in webbing/flat rope is in the handling/knotting ease and working around a bend(can get tore up easier by more friction on device/line/webbing); but sitting still on a bend doesn't do this; so flat is favorable for sitting still on bend. Thus, i favor 3/8" Tenex 5k cords, for the strength, and minimal strength loss on the tight 1/2" bend around a host line.



My understanding of the new regulations Tom has been trying to let us know about for quite some time (click-link). Bowlines on a snap are okay, cuz the round eye lets the loading correctly orientate, whereby the squarish shape of a krab offers corners that could hang that self adjustmeant up. Even though a krab and snap are both really single leg/ moused hook design that loading should be along back spine only, the bowline goes on snap and not krab.