Is there a reason why using a Gnat hitch or a Zeppelin loop would not be advisable when attaching rope to a harness’ carabiner (as an alternative to figure 8 loop or some form of locked bowline)?
Hi mcjtom.
I would think the first answer would be this; will your climbing partner be familiar enough to check it. (?)
Is there a particular reason why to use those knots versus time proven knots?
First and foremost, imo, security is paramount.
As always, verify all knots’ compatibility with the type of rope you are using, but I think you’d be fine. I would probably give preference to the highly secure Gnat Hitch in this scenario as it grips the carabiner and thus reduces flogging action, making it more secure in this case than more open-type connections, unless you need that openness for functionality.
The collapsed form of the Gnat Hitch would also help make it more resistant to snagging or getting hung up on protrusions or debris.
Some test results:
https://igkt.net/sm/index.php?topic=6076.msg40892#msg40892
The red-highlighted description is what most rockclimbers
will object to : tying to a 'biner, esp. if not a locking one
–regarded as verboten!
By that concern then, the noose-hitch should be the
better choice in that it gives some hope for holding
a correct position on the 'biner.
Or one might ask re the Thrun’s knot/Zep. eye knot
vs. Ashley’s #1452’s similarly made eye knot.
–dl*
Is there a reason why using a Gnat hitch or a Zeppelin loop would not be advisable when attaching rope to a harness' carabiner (as an alternative to figure 8 loop or some form of locked bowline)?
Is your question framed in the context of rock climbing / mountaineering?
Or another roped sport where the attachment of the rope to harness is life critical?
When I use the phrase ‘life critical’ - it means that failure of the attachment on the harness would lead to death or serious disabling injuries.
I’ll assume that the application is a life critical context (eg rock climbing / canyoning / caving).
Have a look at these harness use instructions from Black Diamond in the USA.
Link: https://blackdiamond-web.cdn.prismic.io/blackdiamond-web/ae89b2f8-9c74-49e5-913c-6a44904f5350_M10150_G+Harness+IS-WEB.pdf
You’ll notice that in these instructions (which are typical) the manufacturer warns against clipping a carabiner to the harness.
A direct rope tie-in is advised.
In the instructions, a #1047 F8 eye knot is illustrated (which is typical of most instructions).
Note that any of the ‘inherently secure’ Bowlines could also be used in lieu of the F8.
Special note: No manufacturer would ever recommend a noose as a tie-in knot.
This could lead to catastrophic loss of life - because obviously the noose will cinch very tight when subjected to an impact force (as would happen in a fall).
That act of cinching tight would cause textile-on-textile friction.
This friction also causes heat build up which in turn causes heat glazing and/or melting of textile fibers.
Clearly and obviously it would be unwise to subject a harness (life critical PPE) to undue wear and tear caused by a noose cinching tight.
And this reminds me of Todd Skinner who died because his harness failed (due to wear and tear over time).
Link: http://www.supertopo.com/climbers-forum/1933713/Todd-Skinners-failed-harness-update
Only a fixed eye knot is suitable as a tie-in knot for rock climbing (not a noose - which is by definition a shrinking/collapsing eye).
The point about Todd Skinner is that we know that wear and tear is not good for a harness - so the take home message is that users should care for their life critical PPE.
Be that as it may - I am only guessing your intended application of a harness… you did not state what the context is.
A Zeppelin eye knot could also be used (as a direct tie-in) - although it is rarely used by in the wild by rock climbers.
The reason why is because it is perceived to be too difficult to tie - and therefore increases the risk of human error.
Some would also tender argument that such a knot would be difficult for a partner to inspect (partner checks) - because it is largely unknown and/or obscure.
Using a connector (eg carabiner) to form an attachment interface to a harness:
For life critical applications such a lead climbing, only a direct tie-in to the harness is recommended.
There have been several incidents where a carabiner has detached from a persons harness - and resulted in serious injuries.
In 1996, Jade Francis fell to the ground when her (single) carabiner detached from her climbing harness. She was 15 years old at the time - and became a paraplegic.
Connector misalignment is always a risk, particularly when there are cyclic loads and/or slack shaking events (which was the first court case in Australia). There have been other cases -eg a 16 year old boy fell to the ground and sustained serious injuries when his carabiner detached from his harness (near Brisbane QLD - while on a giant rope swing). To some extent, misalignment can be mitigated with a noose which cinches up tight against the carabiner - which holds it in the proper alignment. However, this is still not adequate for applications such as lead climbing…
The IGKT knot tying forum is (by definition) a place where you’ll find people who are very passionate and knowledgeable about knots.
Rock climbers don’t see knots like a typical IGKT member. They see knots as simply a means to an end - and they generally shy away from any technical discussion - considering such discussion to be within the realm of academia (knot geeks).
Many thanks for this! I think I understand the debate better now.
A somewhat related question:
Ignoring the possible security differences (i.e. assuming they are both secure enough) and the perceived ease of tying or familiarity, which of these two loops is less likely to jam when subjected to high loads (or is there a difference and perhaps one is more jamming on some types of ropes)? Zeppelin loop or Scott’s Bowline (the simplest ‘woven’ version, with the working end of the initial bowline inside the loop)?
How is this related?
Perhaps search a bit more or start a new thread.