International Guild of Knot Tyers Forum

General => Chit Chat => Topic started by: roo on June 22, 2013, 10:52:14 PM

Title: Harness Tie In
Post by: roo on June 22, 2013, 10:52:14 PM
I saw an interesting discussion here:
http://www.8a.nu/forum/ViewForumThread.aspx?ObjectId=32418&ObjectClass=CLS_ForumGeneral&CountryCode=GLOBAL

What particularly caught my eye was this:
Quote
First response from the DAV sicherheitsforschung / German Alpine assocation Safety commission:

Yes, you can tie in the belay-loop. The force is 15 kN in the EN 12275 for harnesses, not 25 or 30 kN. Same test for tie in situation leg/waist-loop. So both is possible and correct. All manufacturers advice the leg/waist-loop, only Edelrid advices both methods. But in practice it doesn't matter. The difference is, that the tie-in-knot is a bit lower using the leg/waist method, if hang dogging and bouldering. The wear is not a strong argument, because you see it by both methods. The wear comes from lowering down and abseiling when you move your legs. Then you have a abrasion between the leg-loop and the rope (leg-waist-method) or the leg-loop and the belay loop (belay-loop-method). Maybe the rope is a bit more rough, but it's not a big difference.

Would any of you out there be willing to tie a loop or hitch (http://notableknotindex.webs.com/gnathitch.html) directly to the belay loop and forgo using the tie-in loops?

(http://www.rei.com/learn/expert-advice/climbing-harness/_jcr_content/images/image0.img.jpg/Anatomy%20of%20a%20climbing%20harness.jpg)
Title: Re: Harness Tie In
Post by: SS369 on June 23, 2013, 02:43:25 AM
I would be willing to if there was some reason, but I regularly tie in using the tie in loops. I generally try to follow the manufacturers recommendations, since they design and test their products.
That said, the brands I have owned and used over the years have not indicated that to tie in using the belay loop would necessarily be a good move.

I regularly, before heading out to do some climbing, inspect all my gear and if there happened to be signs for retirement then that is what happens, I retire it. Harnesses are cheap, comparatively speaking, to the failure of one.

I can't think of any reason to use the hitch you've linked to for this application.

SS
Title: Re: Harness Tie In
Post by: roo on June 23, 2013, 03:01:33 AM
I can't think of any reason to use the hitch you've linked to for this application.
It uses little rope, is simple, quick to tie and has nice security.  Just an option.
Title: Re: Harness Tie In
Post by: Luca on June 23, 2013, 03:13:38 AM
Hi Roo and SS369,

I do not intend anything with regard of mountaineering, but this thing is not new to me :while, for other reasons,time ago,I gave a look at some Italian forums about mountaineering, I noticed that a number of users, conscious of the fact that in the instructions booklet  of their harness was not recommended to use the belay loop for the tie-in,they walk over this,and used it anyway for this purpose. By certain people this was regarded as a practice to be deplored, for others it was indifferent(others were favorable to use the belay loop in certain situations,and the regular tie-in loops in other situations, but I do not know of what I speak, I guess that after the weekend someone will be back from his mountain excursion and tell us something more significant than what I write ..!)
Title: Re: Harness Tie In
Post by: SS369 on June 23, 2013, 03:20:35 AM
Thanks for the option suggestion, but I think I'll pass as I use a loop to attach with.
I hope that climbers do the smart thing and always have sufficient rope.
Many climbing knots are simple once they have been practiced enough (as it should be done).

Has the security of the gnat hitch ever been seriously tested, to the point of extreme strain/rope destruction?

"Nice security" based on hand testing is OK for non-critical applications.

Are you suggesting this hitch for potentially life endangering activities?

SS
Title: Re: Harness Tie In
Post by: roo on June 23, 2013, 03:24:12 AM
Are you suggesting this hitch for potentially life endangering activities?
Yes.  The Gnat Hitch has better security than the Buntline Hitch that is routinely used as carabiner hitch, for example, but resists jamming better.
Title: Re: Harness Tie In
Post by: SS369 on June 23, 2013, 03:34:54 AM
Hi Roo and SS369,

I do not intend anything with regard of mountaineering, but this thing is not new to me :while, for other reasons,time ago,I gave a look at some Italian forums about mountaineering, I noticed that a number of users, conscious of the fact that in the instructions booklet  of their harness was not recommended to use the belay loop for the tie-in,they walk over this,and used it anyway for this purpose. By certain people this was regarded as a practice to be deplored, for others it was indifferent(others were favorable to use the belay loop in certain situations,and the regular tie-in loops in other situations, but I do not know of what I speak, I guess that after the weekend someone will be back from his mountain excursion and tell us something more significant than what I write ..!)

Hello Luca.

Climbing is a dangerous endeavor, no doubt about it. Sometimes egos and bravado influence what happens and what someone does. Sometimes with grave consequences.

I have no fear that the belay loop is a strong attachment point and can be used. It has to be strong because that is where you attach to belay and abseil from. Clipping a carabiner in that spot provided makes more sense than to make a sling to use the other tie points.

There is a little mental thing about using multiple tie in locations even though the belay loop uses them both. Psychology can be a good thing. ;-)))

Following the design criteria and recommendations of the maker is usually best policy.

SS
Title: Re: Harness Tie In
Post by: SS369 on June 23, 2013, 03:45:57 AM
Are you suggesting this hitch for potentially life endangering activities?
Yes.  The Gnat Hitch has better security than the Buntline Hitch that is routinely used as carabiner hitch, for example, but resists jamming better.

You did not answer the other question. > Has the security of the gnat hitch ever been seriously tested, to the point of extreme strain/rope destruction?

For me, since I do little tree service work, don't use a hitch in the way your are suggesting. But when I have needed to secure a rope to a carabiner a double overhand noose has been my choice. There are other options of course.

SS
Title: Re: Harness Tie In
Post by: roo on June 23, 2013, 04:25:10 AM
You did not answer the other question. > Has the security of the gnat hitch ever been seriously tested, to the point of extreme strain/rope destruction?
I'm sorry I missed the thrust of your question.  Anyway, yes, I have subjected the Gnat Hitch to numerous (dozens?) of extreme strain tests.  It shows no indications of problems.
Title: Re: Harness Tie In
Post by: alpineer on June 23, 2013, 05:46:08 AM
I think there are more (shape)variables tying in with a hitch, not that it can't work.
I really wouldn't have any qualms tying onto the belay loop, although I think traditionally the idea here is to minimize the number of components (i.e. the belay loop) in the system. 
Title: Re: Harness Tie In
Post by: SS369 on June 23, 2013, 12:25:34 PM
You did not answer the other question. > Has the security of the gnat hitch ever been seriously tested, to the point of extreme strain/rope destruction?
I'm sorry I missed the thrust of your question.  Anyway, yes, I have subjected the Gnat Hitch to numerous (dozens?) of extreme strain tests.  It shows no indications of problems.

I am interested in any test pictures or data you would be willing to share please.
Thanks in advance.

SS
Title: Re: Harness Tie In
Post by: Dan_Lehman on June 24, 2013, 04:12:20 AM
An issue with hitching to a harness is that the SPart's
hard loading will move the rope around whatever it's
tied to --a concern of rope-on-harness wear.
Whereas with an eye, both legs are drawn away,
so the case there is one of compression and less
abrasion.  The belay loop, in the usual semi-wide
webbing, is if anything (IMO) less well suited to
bending rope to, to folding/crunching around it.
(The connection for the leg loops seems to be
a more rounded cross-section.  And one can run
a twin eye so to make the cordage broader.)

Frankly, I'd like to see a 'biner snell put to the test,
to get a hard, smooth metal interface.  But with this
come the concerns about how well locking the gate
is.  The snell should ensure proper orientation/loading.


--dl*
====
Title: Re: Harness Tie In
Post by: agent_smith on July 03, 2013, 03:08:57 PM
The notion of 'no single point of failure' springs to mind here.

Lower body harness designs broadly come in two flavors:
1. Independent segments consisting of waist loop + leg loop bridge (with separate interlocking belay loop) - this design is commonly used in lead climbing applications.
2. Single loop only.

In item 1 above, best practice is to tie the rope directly through the harness in a way that encapsulates/captures both segments.

In item 2, you don't have a choice - there is only one loop to attach to (Note: These types of harnesses are common in 'commercial groups' such as challenge ropes courses, climbing gyms, school groups, etc. They are a cheaper (no frills) alternative.

...

When giving professional advice to clients in relation to item 1 above, I only advocate tying the rope so that it encapsulates/captures both independent segments. I do not recommend tying the rope solely through the 'belay loop'. In this way, the tie-in provides no-single-point-of failure.

A popular harness in mountaineering is the Black Diamond 'Alpine Bod' - this harness design does not have a separate belay loop. The rope must be tied through both the waist and leg loop bridge segment.

Also, I do not recommend a knot structure that is a noose/strangle/hitch form. This would induce a cinching action at the moment of impact in a free-fall arrest. Instead, I only recommend tying a connective eye-knot structure such as:
a) ABoK #1047 (figure 8 loop); or
b) A secured/locked version of ABoK #1010.

Any knot structure that suddenly cinches tight at the moment of impact creates additional risk to the user. The sudden jerk induces cinching - which in turn creates friction/rubbing. A fixed connective eye knot will not cinch tight and both legs of the eye will distribute force (ie force will be distributed across the 'eye-leg of the SPart' and the 'eye-leg of the tail side').

I would disregard any advice to the contrary - and I stand by my advice outlined in this post. This includes any published advice even from some manufacturers - who in some cases do not have vast experience or expert level knowledge themselves. Some manufacturers have little actual field experience and some are over-populated with sales staff who are good at selling but not much else (ie spin doctors).

Mark
Title: Re: Harness Tie In
Post by: Dan_Lehman on July 04, 2013, 06:02:13 PM
A popular harness in mountaineering is the Black Diamond 'Alpine Bod';
this harness design does not have a separate belay loop.  The rope must be tied
through both the waist and leg loop bridge segment.
Nice to deal with some specifics.

Quote
Also, I do not recommend a knot structure that is a noose/strangle/hitch form.
This would induce a cinching action at the moment of impact in a free-fall arrest.
  ...
Any knot structure that suddenly cinches tight at the moment of impact creates additional risk to the user.
The sudden jerk induces cinching, which in turn creates friction/rubbing.
Btw, how would a set-clinched hitch affect one's movement
in such a harness?  --i.e., in having the leg-loop/-connector
drawn up snug to the waist loop?!  This isn't asked in terms
of safety so directly but of comfort, workability/usability?

I had thought of having a *compound* tie-in in which a hitch
is a base --as a last-man-standing safeguard-- and its *ends*
are joined in an eyeknot : should the latter knot somehow
come untied, there would at least be the base hitch to hold.
But I found one use of the clove hitch to not hold, but in
a form/setting (looseness) possibly present in spanning the
two tie-in points, to just spill !!  --oops, let's not use this!
But then I came to wonder the question/issue above,
about having one's tie-in force those two connecting parts
together, and how that might impede movement.

So, I shifted from the idea of hitch-into-eyeknot tactic
to eyeknot-into-eyeknot (getting structures much like
the mirrored bowline), which is fertile with solutions.


--dl*
====
Title: Re: Harness Tie In
Post by: roo on July 04, 2013, 10:05:40 PM
The notion of 'no single point of failure' springs to mind here.
Since there are other "single points of failure", such as using only one rope (etc.), I think it maybe your sentiment might be more of a matter of "why use one when you can have two?".

Quote
This would induce a cinching action at the moment of impact in a free-fall arrest.
Cinching is part of just about any knot system.  The question becomes what part are you OK with having one part of rope/webbing stretch by other parts of rope/webbing during impact.

I'd probably be interested in trying both and seeing if the wear from bending/hitching directly to the belay loop would be more rapid than other knots in a rope-intertwined-with-rope scenario, as you'd see with a loop knot.  I suppose a hitch to carabiner to belay loop connection would avoid the issue if it turned out to produce a lot of wear.

It seems like there is a certain segment of users that distrusts the belay loop in general.  Whether that is justified or not, manufacturers might use beefier belay loops as a selling point for those people.

update: Cinching effects are not an issue:  http://igkt.net/sm/index.php?topic=6081.msg40871#msg40871

Title: Re: Harness Tie In
Post by: SS369 on July 04, 2013, 10:45:13 PM
The notion of 'no single point of failure' springs to mind here.
Since there are other "single points of failure", such as using only one rope (etc.), I think it maybe your sentiment might be more of a matter of "why use one when you can have two?".

Quote
This would induce a cinching action at the moment of impact in a free-fall arrest.
Cinching is part of just about any knot system.  The question becomes what part are you OK with having one part of rope/webbing stretch by other parts of rope/webbing during impact.

I'd probably be interested in trying both and seeing if the wear from bending/hitching directly to the belay loop would be more rapid than other knots in a rope-intertwined-with-rope scenario, as you'd see with a loop knot.  I suppose a hitch to carabiner to belay loop connection would avoid the issue if it turned out to produce a lot of wear.

It seems like there is a certain segment of users that distrusts the belay loop in general.  Whether that is justified or not, manufacturers might use beefier belay loops as a selling point for those people.

Manufacturers of harnesses do the necessary safety testing, at their expense mind you and they all say the very same type of thing in regards to directly tying into a harness belay loop that connects the legs and belt. "The friction of the rope on the loop has the potential to make it fail and at much lower than its ultimate values".
Should we doubt this?

Quote
"I'd probably be interested in trying both and seeing if the wear from bending/hitching directly to the belay loop would be more rapid than other knots in a rope-intertwined-with-rope scenario, as you'd see with a loop knot."

Will you be sacrificing your harness and rope for this?


I personally like the knot of the loop away from that specific body region because of comfort when climbing and having that body portion firmly weighted against the rock face. This also allows the knot (loop tie in) to be advancing the climber, not in the way, while being belayed.

Certainly wouldn't want the tail of the Gnat snagged on something and lose the security.

Using the Gnat for tying to a carabiner may be fine for someone, but for me personally, I will use a hitch that is bombproof. I can always slip it off the biner to untie.

SS
Title: Re: Harness Tie In
Post by: roo on July 05, 2013, 12:50:35 AM
"The friction of the rope on the loop has the potential to make it fail and at much lower than its ultimate values".
Can you post the source and context (surrounding text) of this?

For contrast, see page 3, figure 5a of the user manual linked here:
http://www.edelrid.de/en/sports/products/harnesses/jay.html


Quote
Certainly wouldn't want the tail of the Gnat snagged on something and lose the security.
Snagging the tail shouldn't affect security in the least.

Title: Re: Harness Tie In
Post by: SS369 on July 05, 2013, 01:36:41 AM
"The friction of the rope on the loop has the potential to make it fail and at much lower than its ultimate values".
Can you post the source and context (surrounding text) of this?

For contrast, see page 3, figure 5a of the user manual linked here:
http://www.edelrid.de/en/sports/products/harnesses/jay.html


Quote
Certainly wouldn't want the tail of the Gnat snagged on something and lose the security.
Snagging the tail shouldn't affect security in the least.

One source is here http://www.outdooradventureclub.com/newsletter/belayloop.htm (http://www.outdooradventureclub.com/newsletter/belayloop.htm)\  Chip Miller for Metolius Climbing is being quoted at the bottom of the page.

Another quote, another source. http://backcountrybeacon.com/2010/10/belay-loops/ (http://backcountrybeacon.com/2010/10/belay-loops/)
"First of all, never tie your rope in to your belay loop. The friction of nylon on nylon is a very bad thing and could possibly lead to failure in a fall or even during a lower that involves a lot of swinging around to clean gear. Of course, tying in correctly also touches nylon to nylon, but it holds the rope in a much more static position, and the tie-in points are designed specifically to deal with the friction. Plus, there are two of them in case one fails."

There are other sources that plainly state how their product(s) should be safely used iterating this.
A local climbing rope/gear manufacturer (worldwide sales and trusted product history) also has said this directly to my direct inquiry.

It is called a Belay or Abseil loop for a good reason.

The tie in locations are usually made with some attention/guarding against rope friction, not so for the belay loop, since it is designed for the smooth surface of a carabiner. One should not even girth hitch slings to the belay loop. Use a carabiner and then do what you think best.

My own exploration of the Gnat hitch shows that pulling the tail (snagging) is the easiest way to loosen for untying. But, you should know this already.

[/quote]I'd probably be interested in trying both and seeing if the wear from bending/hitching directly to the belay loop would be more rapid than other knots in a rope-intertwined-with-rope scenario, as you'd see with a loop knot.[/quote]

I hope to see your test of harness belay loop and rope soon.

SS
Title: Re: Harness Tie In
Post by: roo on July 05, 2013, 01:52:12 AM
A local climbing rope/gear manufacturer (worldwide sales and trusted product history) also has said this directly to my direct inquiry.
But with the German Alpine Assocation Safety Commission & Edelrid saying the opposite, it's a bit of a puzzlement.  Maybe it's a difference in the various camps' assessment of the risks.
Title: Re: Harness Tie In
Post by: SS369 on July 05, 2013, 02:39:18 AM
A local climbing rope/gear manufacturer (worldwide sales and trusted product history) also has said this directly to my direct inquiry.
But with the German Alpine Assocation Safety Commission & Edelrid saying the opposite, it's a bit of a puzzlement.  Maybe it's a difference in the various camps' assessment of the risks.

Please show me the words where they are saying the opposite. Edelrid is just showing for their harnesses that either tie in is acceptable. They only say this in their manual:
"PRODUCT ILLUSTRATIONS
Tying-in with sit harness:
1. The rope is tied directly to the tie-in loop/tie-in eyelet (A)
(fi g. 5a, 5c).
2. The rope is fed underneath the leg loop connection and then
through both the tying-in loop and the hip belt before the knot
is made (fi g. 5b)" .

Perhaps they have engineered extra abrasion resistance to these points for this as they allude to in their market words..

How about sharing what the German Alpine Assoc. Safety Comm. says? And do they say that using a hitch or noose for tying in is safe?

One of the largest sellers of climbing gear, harnesses of many brands and the place you used the (original post) harness picture from clearly states and I quote: "Belay loop: This is the strongest point on the harness and the only part that is load tested. Anything hard should attach to the belay loop (e.g., a locking carabiner while belaying or rappelling). Warning: You should not tie anything around the belay loop, including a daisy chain or sling. The belay loop will wear through quicker and is not designed to be used in this fashion. Belay loops are made of nylon webbing." http://www.rei.com/learn/expert-advice/climbing-harness.html (http://www.rei.com/learn/expert-advice/climbing-harness.html)

Black Diamond clearly shows in their user manual a pictogram indicating not to use the Belay loop for tie in. http://demandware.edgesuite.net/aakn_prd/on/demandware.static/Sites-BlackDiamond-Site/Sites-bdel/default/v1372917924868/files/M10150_B%20Harness%20IS_WEB.pdf (http://demandware.edgesuite.net/aakn_prd/on/demandware.static/Sites-BlackDiamond-Site/Sites-bdel/default/v1372917924868/files/M10150_B%20Harness%20IS_WEB.pdf)

It seems from my own research that more than not indicate this to be a place not to tie into. Perhaps the German Safety Commission is of another mindset.
I know that harness makers have to comply with Union Internationale des Associations d?Alpinisme (UIAA 105) or the European Committee for Standardization (EN 1277) I have not been able to translate enough of the limited amount I can find to see what it may say about this tie in procedure. But, I will inquire about this , in particular, from my local manufacturer next time I talk with the owner.

My hindmost is with the majority on this as I do climb, not just talk about it....

Then there is the action of a gnat noose or any noose on a soft object (webbing perhaps) and the potential infliction of damaging stresses during a fall (lots of crush and torque right there). Might cause rupture or not untie very easily at that point(?)!.

One ties off in the first place to eliminate the hardest bounce! Best to eliminate some possibilities till further notice...

SS
Title: Re: Harness Tie In
Post by: roo on July 05, 2013, 03:43:36 AM

Please show me the words where they are saying the opposite. Edelrid is just showing for their harnesses that either tie in is acceptable.
The opposite being:
Quote
"First of all, never tie your rope in to your belay loop
"Acceptable" versus "never" seems pretty opposite.

Quote
How about sharing what the German Alpine Assoc. Safety Comm. says?
See the very first post of this thread.

Title: Re: Harness Tie In
Post by: Dan_Lehman on July 05, 2013, 07:37:14 AM
Another quote, another source. http://backcountrybeacon.com/2010/10/belay-loops/ (http://backcountrybeacon.com/2010/10/belay-loops/)
"First of all, never tie your rope in to your belay loop.
The friction of nylon on nylon is a very bad thing and could possibly lead to failure in a fall or even during a lower that involves a lot of swinging around to clean gear. Of course, tying in correctly also touches nylon to nylon, but it holds the rope in a much more static position, and the tie-in points are designed specifically to deal with the friction. Plus, there are two of them in case one fails."
This sounds like imaginative rubbish : the "nylon-on-nylon"
myth (which should scare us from tying knots in nylon!),
and the failure in a fall --as though that's happened.  (The
not-so-long-ago tragedy w/a famous climber just hanging
in his belay loop (when rapping, IIRC) resulted from a badly
worn loop --quite visibly so!)

I'm moved to conceive a method that uses the 'biner snell,
with the rope so reeved through it all, that the 'biner can
fail and then, but only then one will face the dreaded
nylon-on-nylon.  (I'm tempted : let's ask that fellow about
"polyester on nylon", "rayon on nylon", "crayon on nylon"?!)
(worst case : "runs" in nylon, always a catastrophe!)


--dl*
====
Title: Re: Harness Tie In
Post by: SS369 on July 05, 2013, 03:00:06 PM

Please show me the words where they are saying the opposite. Edelrid is just showing for their harnesses that either tie in is acceptable.
The opposite being:
Quote
"First of all, never tie your rope in to your belay loop
"Acceptable" versus "never" seems pretty opposite.

Quote
How about sharing what the German Alpine Assoc. Safety Comm. says?
See the very first post of this thread.

Acceptable is not an antonym of never, at least as I can find. I feel that is semantic response.
And so far, to date, it is only Edelrid and the one person from the GAASC that was quoted in the saying the same thing. (No name to follow up with.)
The other inquiries made, from other harness manufacturers have not been posted (received?).
And nowhere in that thread http://www.8a.nu/forum/ViewForumThread.aspx?ObjectId=32418&ObjectClass=CLS_ForumGeneral&CountryCode=GLOBAL (http://www.8a.nu/forum/ViewForumThread.aspx?ObjectId=32418&ObjectClass=CLS_ForumGeneral&CountryCode=GLOBAL) is anyone asking about using a hitch/noose for tie in purpose.

I have not been able to find any advice or examples of a person advocating the use of a hitch or noose as a tie in knot to a harness at any location on a climbing harness belay loop. Just the opposite only.

Has anyone else?

I don't think this is a marketing ploy, personally, to say one should use the leg/waist tie in points versus the belay loop.

SS
Title: Re: Harness Tie In
Post by: SS369 on July 05, 2013, 03:37:21 PM
Another quote, another source. http://backcountrybeacon.com/2010/10/belay-loops/ (http://backcountrybeacon.com/2010/10/belay-loops/)
"First of all, never tie your rope in to your belay loop.
The friction of nylon on nylon is a very bad thing and could possibly lead to failure in a fall or even during a lower that involves a lot of swinging around to clean gear. Of course, tying in correctly also touches nylon to nylon, but it holds the rope in a much more static position, and the tie-in points are designed specifically to deal with the friction. Plus, there are two of them in case one fails."
This sounds like imaginative rubbish : the "nylon-on-nylon"
myth (which should scare us from tying knots in nylon!),
and the failure in a fall --as though that's happened.  (The
not-so-long-ago tragedy w/a famous climber just hanging
in his belay loop (when rapping, IIRC) resulted from a badly
worn loop --quite visibly so!)

I'm moved to conceive a method that uses the 'biner snell,
with the rope so reeved through it all, that the 'biner can
fail and then, but only then one will face the dreaded
nylon-on-nylon.  (I'm tempted : let's ask that fellow about
"polyester on nylon", "rayon on nylon", "crayon on nylon"?!)
(worst case : "runs" in nylon, always a catastrophe!)


--dl*
====

As far as the "imaginative rubbish" is concerned:"Nylon fiber is very abrasive from the moment it changes from a liquid polymer to solid fiber, air quenched.   At this point everything the fiber touches has to be wear resistant or turning roll guides plus the immediate application of a finish to enhance it?s processing qualities. The finish also protects the Nylon fiber from surface damage.   Guides, surface finish of the guide, finish solutions on the fiber, and line speed are very critical to Nylon fiber as the fiber has to drawn, stretched or reduced in diameter,  to be very useful.  This draw ratio, based on length, can be from less than 1 to over 4.  In every case the fiber or guide is moving relative to each other.  Nylon fibers have a propensity to be more abrasive/agressive as the diameter decreases and the relative speed between the guide and threadline increases.   There have been numerous studies, more unpublished than published, on this effect mainly dealing with what could you do to mitigate the damage.  I seen Thermography, High Speed Photography, IR, Mechanical, and numerous other testing done on fiber thread lines.  I?ve never seen much changed from what was known by empirically derived improvements.
An older process for Nylon used a modified machine from the cotton mills to do a secondary operation on Nylon.  The only thing changed on the machine was that the guides were chrome plated, or changed to chrome plated or ceramic coated rollers. "  Quoted from http://www.eng-tips.com/viewthread.cfm?qid=92753 (http://www.eng-tips.com/viewthread.cfm?qid=92753) They are talking about nylon fibers, not solids.

If you know someone in the Applied Polymer Science field perhaps you can inquire about this "rubbish".

I am interested on your take in the case of "crayon on nylon". :-))

But seriously, the rope manufacturers do spend a bit of time and money researching best combinations of materials for purpose based use. If nylon on nylon was not an issue of any kind, in regards to safety/product life, then I don't think they would necessarily have gone to the expenses incurred to provide better products addressing this. Do you?

I am moved to ask about your "'biner snell", will you elaborate please?
 
Would you Dan advocate the use of a hitch/noose as a tie in knot using the belay loop as the hitch to location, as asked in the OP?

SS
Title: Re: Harness Tie In
Post by: roo on July 05, 2013, 05:10:19 PM
I have not been able to find any advice or examples of a person advocating the use of a hitch or noose as a tie in knot to a harness at any location on a climbing harness belay loop.
You're getting ahead of yourself and ignoring the opposing advice on using the belay loop for tie in.  For this point I realize that no source is touching directly on using a hitch, but it doesn't make sense to deny or downplay ("not an antonym"???) the opposing advice being given on tying into the belay loop.
Title: Re: Harness Tie In
Post by: SS369 on July 05, 2013, 05:42:15 PM
I have not been able to find any advice or examples of a person advocating the use of a hitch or noose as a tie in knot to a harness at any location on a climbing harness belay loop.
You're getting ahead of yourself and ignoring the opposing advice on using the belay loop for tie in.  For this point I realize that no source is touching directly on using a hitch, but it doesn't make sense to deny or downplay ("not an antonym"???) the opposing advice being given on tying into the belay loop.

No, I am not getting ahead of myself, I am trying to stay on point of the original post.
I did not ignore, as you put it, I am attempting to give reason(s) for my personal opposition (evolving more so) to using the belay loop as a tie point using a hitch as you asked with example "http://notableknotindex.webs.com/gnathitch.html".

I'll refrain from  the ongoing word games you seem to want to play and stay with the thrust of your original question: "Would any of you out there be willing to tie a loop or hitch directly to the belay loop and forgo using the tie-in loops?"

Perhaps a loop if a abnormal situation warranted it and I was convinced that any other way would more dangerous.
Till I have read data that allays my concern of hitching to or noose-ing to the belay loop attachment method I'll pass.

SS

 
Title: Re: Harness Tie In
Post by: Dan_Lehman on July 05, 2013, 05:53:24 PM
Another quote, another source. http://backcountrybeacon.com/2010/10/belay-loops/ (http://backcountrybeacon.com/2010/10/belay-loops/)
"First of all, never tie your rope in to your belay loop.
The friction of nylon on nylon is a very bad thing and could possibly lead to failure in a fall or even during a lower that involves a lot of swinging around to clean gear ... ."
This sounds like imaginative rubbish : the "nylon-on-nylon"
myth (which should scare us from tying knots in nylon!),
and the failure in a fall --as though that's happened.
...
 (I'm tempted : let's ask that fellow about
"polyester on nylon", "rayon on nylon", "crayon on nylon"?!)
(worst case : "runs" in nylon, always a catastrophe!)

--dl*
====

As far as the "imaginative rubbish" is concerned:
| "Nylon fiber is very abrasive from the moment it changes
| ...
|  I've never seen much changed from what was known by empirically derived improvements.
| ...

If you know someone in the Applied Polymer Science field perhaps you can inquire about this "rubbish".

But seriously,  ...
... we do have some considerable in-the-field-*lab*, practical
experience to look at : do we see the rumored catastrophes?
(no)

Quote
Would you Dan advocate the use of a hitch/noose as a tie in knot
using the belay loop as the hitch to location, as asked in the OP?
Now, I'm not saying that the hitching's rope movement might
not be significantly worse than an eye's movement; but I am
suggesting that the movement got from (merely) swinging
around is probably pretty minimal --though it occurs to me
that the through-the-leg-loop point is lower and more loaded
than would be desired for such things (esp. in looking at how
these leg loops are built, IMO) --vs being more supported by
the waist loop, and leg movement rendered irrelevant. 

(Todd Skinner's --the tragically lost rockclimber, of note--
belay loop was said to have been in visibly BAD shape.)

So, no, I'm not keen to hitch to tie in.  And note my earlier
concern about having such a joint set tight --so to lessen
the amount of movement got by heavy loading--, about
how that might *crimp one's style*, so to speak, in bringing
the loops together where they need to have more space
for ease of movement.

Quote
I am moved to ask about your "'biner snell", will you elaborate please?

<patent pending>

Run the line down the 'biner axis in a gentle turn,
then wrap back over this, which should take 3-5 wraps;
now, that's the *effective* part, delivering force where
you want it, and with a gentle curve around smooth
metal, and what remains is how to tie off this business
part --there are various ways to do this (e.g., one could
tie a strangle knot to the SPart).

But the 'biner-snelled tie-in I think will have the same
problem of bringing the two tie-in points together, making
for awkward movements!?  Could one have two such
'biners, maybe feeding into a common eyeknot, and so
that the connecting part of rope ran though the tie-in
points (so that if 'biners opened, there'd still be the rope).


--dl*
====
Title: Re: Harness Tie In
Post by: roo on July 05, 2013, 06:19:03 PM
I'll refrain from  the ongoing word games you seem to want to play and stay with the thrust of your original question: "Would any of you out there be willing to tie a loop or hitch directly to the belay loop and forgo using the tie-in loops?"
There is no word game involved.  This diversion started by asking the context of this:
Quote
Manufacturers of harnesses do the necessary safety testing, at their expense mind you and they all say the very same type of thing in regards to directly tying into a harness belay loop that connects the legs and belt. "The friction of the rope on the loop has the potential to make it fail and at much lower than its ultimate values".
Should we doubt this?
When I mentioned that a manufacturer didn't share this view, I did not say a thing about hitching options.

I'm not sure who exactly Sales Manager Chip Miller is, but it seems pretty clear that your statement about the unanimity of manufacturers' advice against tying into the belay loop is flatly false.

Title: Re: Harness Tie In
Post by: SS369 on July 05, 2013, 06:33:11 PM
Quote
... we do have some considerable in-the-field-*lab*, practical
experience to look at : do we see the rumored catastrophes?
(no)

I can take some peoples words on faith (somewhat), but I can't disregard the scientific communities findings.

Quote
Would you Dan advocate the use of a hitch/noose as a tie in knot
using the belay loop as the hitch to location, as asked in the OP?
Now, I'm not saying that the hitching's rope movement might
not be significantly worse than an eye's movement; but I am
suggesting that the movement got from (merely) swinging
around is probably pretty minimal --though it occurs to me
that the through-the-leg-loop point is lower and more loaded
than would be desired for such things (esp. in looking at how
these leg loops are built, IMO) --vs being more supported by
the waist loop, and leg movement rendered irrelevant. 

(Todd Skinner's --the tragically lost rockclimber, of note--
belay loop was said to have been in visibly BAD shape.)

So, no, I'm not keen to hitch to tie in.  And note my earlier
concern about having such a joint set tight --so to lessen
the amount of movement got by heavy loading--, about
how that might *crimp one's style*, so to speak, in bringing
the loops together where they need to have more space
for ease of movement.

Quote
I am moved to ask about your "'biner snell", will you elaborate please?


Quote
<patent pending>

LOL

Run the line down the 'biner axis in a gentle turn,
then wrap back over this, which should take 3-5 wraps;
now, that's the *effective* part, delivering force where
you want it, and with a gentle curve around smooth
metal, and what remains is how to tie off this business
part --there are various ways to do this (e.g., one could
tie a strangle knot to the SPart).

But the 'biner-snelled tie-in I think will have the same
problem of bringing the two tie-in points together, making
for awkward movements!?  Could one have two such
'biners, maybe feeding into a common eyeknot, and so
that the connecting part of rope ran though the tie-in
points (so that if 'biners opened, there'd still be the rope).


--dl*
====

I didn't want to snip out all of the above, but the thrust of this original post was not about hitching to the waist and eye loops, but to The Belay loop (only).

Wear is a concern,  but not the only one.

Most climbers will take a fall of some kind during their days of doing climbing and it is the fall's stress on that singular point of the belay loop imparted by a tightened hitch or noose that we (I) am responding to.

There will be considerable friction generated at the moment of maximum tightness and I personally have seen fusing of rope materials when this type of force has been encountered.
My weight doing a fall factor of 1.5 = 1500 lbs. (approx.) This is pretty considerable being concentrated in a noose (as the gnat hitch is). I see the force being concentrated towards one side, primarily, when it is tightening up. Not like a loop necessarily. That one-sided inducement of friction at that level of force would/could have thermal properties of high intensity, besides and including that the smaller diameter rope (to belay loop's size) acting like a saw/knife.

So I am asking, again, would You tie in into the belay loop using a hitch/noose. This is the original question.

SS
Title: Re: Harness Tie In
Post by: SS369 on July 05, 2013, 06:47:46 PM
I'll refrain from  the ongoing word games you seem to want to play and stay with the thrust of your original question: "Would any of you out there be willing to tie a loop or hitch directly to the belay loop and forgo using the tie-in loops?"
There is no word game involved.  This diversion started by asking the context of this:
Quote
Manufacturers of harnesses do the necessary safety testing, at their expense mind you and they all say the very same type of thing in regards to directly tying into a harness belay loop that connects the legs and belt. "The friction of the rope on the loop has the potential to make it fail and at much lower than its ultimate values".
Should we doubt this?
When I mentioned that a manufacturer didn't share this view, I did not say a thing about hitching options.

I'm not sure who exactly Sales Manager Chip Miller is, but it seems pretty clear that your statement about the unanimity of manufacturers' advice against tying into the belay loop is flatly false.

Chip Miller, the Global Sales Manager for Metolius Climbing as you may read in the link I gave previously.

Hitching to the belay loop options is the thrust of this original post. I'll leave that be.

"unanimity": the quality or state of being unanimous (definition).
I did say All manufacturers, yes, but that is in context with my research and experience. Better put , a majority.
It seems word games are being played to me.

I've made my personal contributions and opinions known and that is what you asked for roo.....

Good day.

SS