Joining two ropes with a lashing for a rappel

Hi Ben,
I have some points for you regarding technical matters: (this post is aimed at Ben - its of a technical nature).

 I went to Sterling with these ideas, talked to their engineers for four hours, broke samples on their hydraulic test bench, and at the end of it all, while they acknowledged the coolness, they said "we probably can't make money on it."  Not "This is bad," not "This is dangerous," but "sewing is quicker than splicing." Lame.

The reason why no climbing PPE manufacturers haven't switched over to Splices is due to 'scale'. What I mean by that is it will be very difficult for manufacturers to scale up quantity production of slings employing a spliced join. Sewing is a known and scalable technology - it can be computer controlled - so quality (ISO 9001) is assured.
Splicing is very labour intensive - not easy to scale. Also, you need a trained and experienced person to perform the splicing work (much harder to train and bring on-line a team of certified splicing staff. Much easier to train and certify people to operate stitching machines. The quality of a 'splice' is not easy to assure and/or be a 100% repeatable process, 100% of the time (it comes down to the individual performing the work).

That's why splicing hasn't been adopted by the worlds major PPE manufacturers (it will only exist in a very small number of highly specialist outfitters such as yourself). Business investors want to be able to scale the business for quantity production and at the same time, reduce labour intensive work and computerise it to the maximum extent possible (which helps to reduce human error).

I am unclear if 'splicing' can ever be computerised (ie handled by machines controlled by software)? My current understanding is that it is can only be done by human hand, and is very labour intensive?

..

Regarding UIAA labelling:

I have a copy of your authorisation to use the UIAA label on some of your 'spliced' sling products (see attached image). Its hard to obtain this type of certification, so congratulations on going down this path!  For example, "CE' product certification is very hard and expensive to obtain (I know from experience that it is very expensive to engage a 'notified body' for the audit/assessment process). It just means that you wont be able to sell your PPE products in the Euro economic zone without the 'CE' mark (but the USA market is large - so its likely not an issue for you).

I am curious about the EN 566 standard though... in order to obtain authorisation as you have done for the UIAA 104 label, by definition, you must satisfy all three EN 566 requirements (stability, stitching, and tensile strength). The tensile strength isn't a problem. How did you manage with the 'stability' requirement (150 gram mass suspended on a sample length of 'weft yarn' extracted from a sample of your sling)? Although the wording in EN 566 states "where a woven tape is used, the weft yarn of the tape shall not unravel when tested in accordance with clause 4.1". And so in all of your spliced products, are you able to be exempted from clause 4.1?

...

With regard to the hitches (which are a type of 'knot') used to unite your 2 'spliced' ropes (the topic of this thread), I presume that you have carefully considered that a person must be able to tie all the hitches in a systematic way, both accurately and consistently? Presumably, if you were to go down the path of selling these human rated 'spliced' ropes, you would provide user instructions for the general public on how to tie the knots/hitches? Would cold weather customers (eg mountaineers), and canyoneers in very cold water environments, struggle with the dexterity requirements? Have you considered all possible failure modes for hand tying of the hitching that unites the 2 ropes? Presumably, in strong wind, if a person loses the hitching cord (blown away in the wind) or fumbles with cold/numb hands, a backup plan is required (eg use a suitable maillon rapide / 'quick-link' to make the join)? Or use a 'strop bend' (Ashley #1493).

With apologies for the delay—MP limits the amount of responses I can make, so I can’t quote each person to reply.

 @Kyle Tarry:

I have a EN-564 line (UIAA 102) that weighs the same as the Petz RAD, but has a stronger core, and whose strength is further retained by being spliced.  Strong enough to be used as a haul line, thin enough to be used as a tagline.  Take the aggregate of lines normally used for hauling/fixing and tagging, and I believe there's a potential 80% weight savings in cordage.  That's approximate: some climb walls with way more ropes and loads than others.

My cordelette solution shouldn't be compared to sewn runners: I haven't done so, and I'm not sure anyone makes sewn slings eight and twelve feet long, like my Anchor Extenders are.  We'd have to compare sewn runners of the same length.  The Anchor Extenders, incidentally, are made of the same EN-564 line and UIAA-certified with the splice in.

What I have to compete with sewn runners are Seamless Runners: SK99 Dyneema inside a Dyneema cover.  No sewn seam to get in the way; all the load-bearing strands are protected from UV and chafe by the cover, and they weigh less than sewn runners of the same length.  UIAA 104, 24kN.

For those who hate on the sheepshank: it’s a bit of a thread drift, but I’m glad to discuss it in another place.  I’ve never heard it badmouthed before, but this MP forum is a real eye opener.  Let’s definitely have a thread about it.

@Jason4too:

I have lots of other spliced gear—check out my Seamless Runners, Friction cords, and Anchor Extenders.  This was just version 1 of an idea born of the recent bends thread.  I agree with you and others that the tiny hitched cord is not ideal: too fiddly with cold fingers.  I, for one, don’t fear learning new things, nor practicing them till proficient, but that tiny cord is….tiny.  Still, solutions start with ideas that get refined over time.

@Climb on:  If facts don’t hold sway with you, I’m at a loss to discuss.   I only deal in facts

@Mark: yes: what you said about Sterling is exactly what I summed up: sewing is quicker, for all the reasons you named.  If enough resources were invested, I’ll bet splicing could be at least partly automated.   I don’t see how, but there’s videos of machines folding boxes and making all sorts of complicated things.  Even grampa’s mechanical hay-baler is a thing of wonder, with all the sequences it does.

As for the EN testing, the lab put “not applicable” in the stitching box, because the join doesn’t depend on stitching.  They, and the UIAA, have the imagination to see that and adapt.  UIAA 104 and 102 are essentially identical to EN, so my certificate from the lab says “EN (whatever number is in question)…..pass”  I didn’t witness them testing the samples, so I’m not sure what all they did—it’s not of interest to me, since I test things on my own for specific failure modes. I’m glad you’re looking these things up though, so you can be persuaded that even if we disagree on bends, I’m not some fly-by-night maniac without skin in the game.

Ben Zartman wrote:

I have a EN-564 line (UIAA 102) that weighs the same as the Petz RAD, but has a stronger core, and whose strength is further retained by being spliced.  Strong enough to be used as a haul line, thin enough to be used as a tagline.

You said you were 20% lighter, but you actually are the same weight?  A RAD line is already strong enough to be used as a haul line and as a tag line, so additional strength does not really add value.

I'm not sure anyone makes sewn slings eight and twelve feet long, like my Anchor Extenders are.  We'd have to compare sewn runners of the same length.

240 cm (7.9 ft) sewn dyneema slings are very common.  DMM, Mammut, BD, Edelrid, and others make them.  They weigh ~70g and cost less than 30 bucks.  DMM also makes a 400 cm (13 foot) version.

Mountain Tools makes a similar rabbit runner type product, the Web-o-lette, available in 10, 12, and 14 ft lengths, which weighs 73g in the 10 ft size, and will hold a knot.

I do not see why you would insist that your products can't be compared to sewn runners.  You were comparing them to tied nylon cordalettes, why would we not also compare them to sewn slings that have similar size, construction, and usage?

What I have to compete with sewn runners are Seamless Runners: SK99 Dyneema inside a Dyneema cover.  No sewn seam to get in the way; all the load-bearing strands are protected from UV and chafe by the cover, and they weigh less than sewn runners of the same length.  UIAA 104, 24kN.

Your 60cm sewn runners cost $60 each (!!!!) and I don’t see a weight on your website, so it’s hard to compare.

Blue Ice also makes a runner with a dyneema core and a separate protective sheath.  They are $15 and 20g for the 60cm version.

Ben-  at the very least, you have achieved something remarkable here.  You’ve united the far corners of MP geekery (who are typically squabbling idly amongst ourselves at the most trivial of issues) into near full alignment.  

I will consider your wares in my next search for a problem I don’t currently have.  

Edit:  the only known person to actually find value in a sheepshank 

The sheepshank is a problem looking for a death in life-safety uses. Not bad-mouthing, recognition.

Your denials are telling. I’m speaking of all your items proposed. This is not to say all your products are at issue.

Kyle Tarry wrote:

You said you were 20% lighter, but you actually are the same weight?  A RAD line is already strong enough to be used as a haul line and as a tag line, so additional strength does not really add value.

240 cm (7.9 ft) sewn dyneema slings are very common.  DMM, Mammut, BD, Edelrid, and others make them.  They weigh ~70g and cost less than 30 bucks.  DMM also makes a 400 cm (13 foot) version.

Mountain Tools makes a similar rabbit runner type product, the Web-o-lette, available in 10, 12, and 14 ft lengths, which weighs 73g in the 10 ft size, and will hold a knot.

I do not see why you would insist that your products can't be compared to sewn runners.  You were comparing them to tied nylon cordalettes, why would we not also compare them to sewn slings that have similar size, construction, and usage?

Your 60cm sewn runners cost $60 each (!!!!) and I don’t see a weight on your website, so it’s hard to compare.

Blue Ice also makes a runner with a dyneema core and a separate protective sheath.  They are $15 and 20g for the 60cm version.

No, I said the aggregate weight of static cordage could be reduced.  I didn't know people were hauling on the RAD.  Maybe I'm late to the party--it's good to know other people are thinking thinner and lighter as well.

You should compare my products to sewn runners, but to ones of the same lengths, and there see the superiority of splices over sewn seams.

I don't have any 60cm sewn runners: that's the whole point--I'm eliminating sewn seams.  My Seamless Runner is $60.  Funny, the exact same runner from a rig shop geared toward boats wouldn't leave the door for less than $100.  Sure, the price threshold is high, like any luxury brand, but they exceed in value all other products out there.  In other words, those who have taken the plunge and begun using them have found them worth the price and then some.  Many of my customers return for more pretty quickly.

Can you link to the Blue Ice runner you mention? I only see tubular ones, but no mention of a separate core.  Also, they all have a gauche sewn connection.

I think you missed your calling, Ben. You should be a politician.

I think this is a very interesting topic. People are hauling on the PUR and RAD line, the former is specifically advertised as such.

I would like to understand the advantage of a spliced sling vs a sewn one.

The blue ice runners are an infinite loop of dyneema in a tubular protective sheet and sewn on the ends. There is a video on YouTube talking about the construction I think.

Back to the topic of a spliced eye in a rope. I do not see the benefit for myself, since I only have three ropes (a single and a pair) and would not want to afford another one for a very niche use case that I can cover well enough with my normal ropes and an appropriate knot. However if someone is using the rope often and does see a benefit for themselves, why not? People are free to innovate and people are free to buy what seems to solve their need.

Pavel Pavelovish wrote:

I think this is a very interesting topic. People are hauling on the PUR and RAD line, the former is specifically advertised as such.

I would like to understand the advantage of a spliced sling vs a sewn one.

The blue ice runners are an infinite loop of dyneema in a tubular protective sheet and sewn on the ends. There is a video on YouTube talking about the construction I think.

Back to the topic of a spliced eye in a rope. I do not see the benefit for myself, since I only have three ropes (a single and a pair) and would not want to afford another one for a very niche use case that I can cover well enough with my normal ropes and an appropriate knot. However if someone is using the rope often and does see a benefit for themselves, why not? People are free to innovate and people are free to buy what seems to solve their need.

A sewn sling has a series of bar tacks where the ends of the webbing it's made from overlap.  That overlapped spot is hard and inflexible: it has to be carefully managed when girth-hitching the sling to a pin or building an anchor.  Not super-hard to do, but often annoying.  The stitches that secure the sling are exposed to UV and chafe, and the sling itself has usually all the load-bearing fibers exposed to the elements, rather than decently covered.  I'll be interested to see how these Blue Ice slings are put together.

Pavel Pavelovish wrote:

.........The blue ice runners are an infinite loop of dyneema in a tubular protective sheet and sewn on the ends. There is a video on YouTube talking about the construction I think.

David Gibbs wrote:

Having a spliced loop in the end of my climbing rope would make this whole idea a non-starter for me.

+1

...and tacky.

Complexity is already a problem which causes problems further down the track. It looks too complicated and overdone IMO.

Simplicity is the ultimate sophistication...

Never had any problems with the EDK.  I've rapped with that hundreds of times on clean terrain and on terrain littered with obstructions and cracks for it to get stuck in.  It's happened once, and was fairly easy to free.  This is 99% a solution in search of a problem.  And it's "rappelling".  

this is revolutionary Ben you’re a literal genius, may I kiss your climbing shoes?

Terry E wrote:

Thanks for the vid.  I make shorter versions of that for my quickdraws, but the core is braided cord, which can be spliced rather than just wound unis (Uni Directional Fibers), which they don't indicate how (or whether) the ends are attached.  Notice their cover doesn't wrap around the eyes, but requires a separate piece and an awkward wrapper.

For those who accuse me of solutions looking for problems, isn't this the same thing?  Why is there not rage toward Blue Ice?  I say, good on them for innovating.  And good luck with the sarcastic thugs here on MP.

Ben Zartman wrote:

You should compare my products to sewn runners, but to ones of the same lengths, and there see the superiority of splices over sewn seams.

Alternative products from established manufacturers (Mountain Tools Web-O-Lette, Bluewater Titan Rabbit Runner, Yates Rabbit Runner) are all rated to 13 kN or more as single strand, they will pass the UIAA 22 kN minimum strength when clipped into a loop, and they are sewn in a controlled manner that ensures you aren't likely to get a bad unit.  And, they are 1/3-1/2 the price.  The lack of sewing seems irrelevant on rabbit runners, since there is a bulky loop at the end anyway, and the stitching can't migrate down into the masterpoint because it's clipped.

https://www.mtntools.com/cat/mt/web/mt_webolette.htm

https://www.bluewaterropes.com/product/13mm-titan-anchor-slings-rabbit-runners

https://www.yatesgear.com/index.php?route=product/product&product_id=1022

Caveat emptor, etc.

Sad that everyone here can’t appreciate being dragged by the sheer force of zartmans unique genius into a future where gear is less flexible, more dangerous, and more expensive, but weighs a little less.

We’d all still be living in caves if it weren’t for heroes like him.

Ben Zartman wrote:

A sewn sling has a series of bar tacks where the ends of the webbing it's made from overlap.  That overlapped spot is hard and inflexible: it has to be carefully managed when girth-hitching the sling to a pin or building an anchor.  Not super-hard to do, but often annoying.  The stitches that secure the sling are exposed to UV and chafe, and the sling itself has usually all the load-bearing fibers exposed to the elements, rather than decently covered. 

I follow advances in gear technology, and adopt them regularly, but if this is an example of your rationale, it's kind of a stretch. Look I respect your inventiveness and your enthusiasm, but those things you mention are quite trivial.

Consider this thread and the responses here to be good market research.  There are technology inventions, like camming devices, which were so obviously a great addition to the toolbox that they were adopted very quickly.  Other tools, like belay glasses, appeal to some people and not others.

I am not in the market for the solution to the problem "two rope rappelling without knots", because to me, it is not a frequent enough problem to need addressing:

1. I find that rope hangups with rope pulls after rapping occur just as frequently, if not more frequently, because the end of the rope wraps itself around something. People typically know how to deal with this, and your product doesn't decrease the likelihood of this, more common, event.

2. Situations where the middle knot in two ropes will have a likelihood of getting caught are highly situational and can often be anticipated and dealt with in advance.  For example, at Red Rock where low angle terrain and large features can cause this, the second person to wrap can move, walk the knot down to the point where the pull is less problematic. I do this all the time if I anticipate an issue.

3. A large % of routes people climb these days, especially modern routes, are equipted for rapping so one doesn't need 2 ropes, many many routes I do I use a 60 or 70 or 80 and there is no knot.

But good luck if this is your passion.

Ben Zartman wrote:

(...) haul and tag lines that weigh 20% of what normal ones do, and pack in a quarter of the space!

Several people have for tag lines, more so in canyoneering where there is less stuff to snag on and less problems with wind. Pulling down these lines are not fun. They tangle easily too. I have one thats like 65m of about 1/8" amsteel... but it must have been a bad batch of coating, it comes off as a sticky rubbery mess onto carabiners and gums up carabiner pulleys.

Haul lines, people have been going to thin ones, but not too thin, they have to still work well in a PCD, so that usually limits it to about 7mm normal accessory cord or 6mm high tech cord. More so on very clean overhung sport or trad lines and where the weight to haul is minimal, like a backpack with some jackets and water, and abrasion isn't much of an issue. Normal Big Wall is too rough and the weight to haul is too high for very thin ropes. You could certainly make a case for a more expensive but much lighter rope that could still handle big wall use with a fatter diameter, like say 8mm Amsteel or something... Inherently its hollow so no sheath to take abuse, its all structural. There are double braid ropes, but they are so much more time consuming to splice and I imagine it would be a tough sell the cost of one of these ropes vs a cheap static to beat up.

Imagine all your slings taking up less room over your shoulder, your rack of quickdraws packing smaller, your hooks and birdbeaks slung without knotted webbing.  Imagine an anchor-building cordelette without knots in it, that was stronger, lighter, and wouldn't absorb water, like nylon cordelettes do!  Even without the weight savings, the reduction in bulk of using spliced materials like I'm developing is huge.

Yeah, all this has been discussed before in other threads. Several people have done it. I have 120cm rabbit runners that weight significantly less than 60cm loop slings. Theoretically totally strong enough single strand compared to the strength of like a good sized cam, quite comfortably strong doubled up... but single strand and then knots for some reason and you get into a realm of questionable strength that you don't want to be in. I might know that... but if I hand it to a partner, they wouldn't. The spliced rabbit runners that I have seen sold commercially step way up in size to allow single strand to still be 22kN, in which case the weight and bulk savings are no longer that significant.

I went to Sterling with these ideas, talked to their engineers for four hours, broke samples on their hydraulic test bench, and at the end of it all, while they acknowledged the coolness, they said "we probably can't make money on it."  Not "This is bad," not "This is dangerous," but "sewing is quicker than splicing." Lame.

Yes. This has been discussed. The time cost of splicing vs sewing is massive. For a company like BD, Mammut, etc... trying to sell a high volume of slings at a competitive price, sewing is the way to go. For a smaller company that doesn't care about high volume and just wants to sell some to the weirdos like us, they can do splicing and just jack the price up. If someone develops a machine which can splice significantly faster than a human, flawlessly... then maybe that could change one day.

Ben please tell me. What is the name of your company? 

I’m an arborist and work with spliced rope ends all the time.  There are a few specialty applications where I find them useful, but by and large they lack versatility and don’t add considerable benefit.  

In my field it is common practice to attach the rope to your harness (saddle) using a spliced end and carabiner. It’s a fast and simple system but will need examined closely to apply to a world of dynamic falls.  Maybe the recreational climbing world will get there someday.  

Tree work cordage has many splices applied as an end stop (so that devices can not slide off the end of a line).  This is better done as a Guache style sewn loop not a true splice.  A true splice like demonstrated here doesn’t actually change the diameter or flexibility of the cord as much and many devices can still slide off the end.  I could see an ATC or similar letting an 8mm line with a spliced end slip through.  

As far as tying knots behind a splice is concerned, it’s only a minor annoyance.  Spliced ends are usually only 6ish inches long and their rigidity makes it hard for them to slip back through a knot.  I could see it being hard to untie a heavily loaded knot too close to the splice.

In general, spliced ends are most useful when the user plans to clip and unclip frequently.  Thus I could see their application being useful in anchors and draws, where speed and repetition are factors.  Potentially in rappels and hard point connections, but I have major reservations there.  Maybe with properly designed carabiners?

As far as the original proposed method of rappel, I’m a pretty hard no.  Rappels need to be obvious, fast and repeatable.  That little strand of BS between the splices is not practical for regular use.  Maybe a soft shackle or a carabiner.  But if my climbing partner tried to set up a rappel like that I would swat them and tie an EDK instead.  Sure, the original pictured method could be useful in outlying circumstances.  Tuna cans hammered into cracks are occasionally useful for rappel as well.  

Maybe this was explained earlier, but I’m confused on the material specifics of this spliced rope.  It’s a 6mm dyneema core spliced on the ends?  Is there a sheath?  Does the splice integrate the sheath?  Is this just a static haul/rap line or climbing line as well?  

I think the OP has gotten pulled into the ego game of posting here.  Clearly splicing has applications, but this is a marginal one.  He’s making a very hard sell that asks the user to learn new methods, acquire specialized equipment and pay more for it.  That might work out for draws or other short cordage if there are benefits but I don’t think there’s a big enough market for spliced rope ends.

Gates out!