Hi, I am trying to find if anyone has done a study to show what percentages specific hitches reduce rope strength by. I understand that different rope constructions and manufacturers will display different results, just looking for some general information that is in addition to the 2008 Brian Kane article. Thank you!
Knot strength
- Thread starter treerxjon
- Start date
- Location
- Retired in Minneapolis
This is a common question. There are many threads in the archives that go deep into what you’re looking for
ATH
Been here much more than a while
- Location
- Findlay, Ohio
Richard (@yoyoman) has posted some videos with different hitches being broken. Search his name specifically. Hopefully he'll chime in with a link.
- Location
- Retired in Minneapolis
Climbing Innovations LLC | Tree climbing and arborist work.
climbinginnovations.com
Chaplain242
Branched out member
Don’t forget tail length. A lot of comparisons don’t include a set of figures for too short a tail length, and in some knots that could be a fatal error. Só even if you get a comparison if the knot isn’t tied properly on the day used, the comparison of strengths between knots is fairly meaningless...
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Rob Stafari
Participating member
- Location
- Cincinnasti
Courtesy of her majesty. Mostly geared towards rope access, but touches on tree climbing. Good read for the gear junky. Definitely some insight to be gleaned.
Burrapeg
Been here a while
- Location
- Puget Sound
Interesting! Thanks, Rob.
Richard Mumford-yoyoman
Been here a while
- Location
- Atlanta GA
I'm happy to chime in but I will say we are talking about the least important attribute of rope used for life support. I've watched knots on the test bench roll into themselves, roll out, break at the turn radius and on the straight, seen the core pull thru the cover all the way around the knot or I've seen core and cover break separately. I've never heard of anyone falling to the death because of a particular knot compromise the rope strength. I did almost lose a friend who fell 40 feet from a tree because the Bowline with Yosemite finish he had been using became misconfigured and he clipped back into the wrong loop.
So I'll just say that choosing a knot for its particular strength is a little misguided but makes good discussion.
- Location
- Retired in Minneapolis
Which adds to the advice to everyone tying loads down at the big box home improvement center:
If you don't know a knot...tie a lot.
If you don't know a knot...tie a lot.
*useless info*
Participating member
- Location
- usa
i think that chasing knot strength has brought us far like racing, each not as applicable to mainstream but stretches the science and understanding of the whole, and gets blood boiling to do so! Also, each is very measurable compared to other nuances.
.
Security is A#1 as stated/ as safety is to driving, but chasing strength aids to understanding proper deployment of all as a raw mechanic grooming to target. And sometimes the only way to realize theat there is a line, where it is, how bad it is etc. is by stepping across it to feel where the situation flips/takes nose dive and reveals where redline is, to then seek out power band of best usage. Also, knots are more efficient, not stronger unless add extra leg of support. So we are really talking about lacing to minimal loading of parts, rather than chancing raising forces, for unless damaged the rope itself always has same strength; just how hard are you taxing it for same job/how much we are handicapping in compromising position. In this way, it does go back to security some, as pulls on seating less and lasts longer cycles at lower loading. Especially thru dogged out, lines in dirty conditions , that sometimes don't fully relax for hours of recovery between loads for days..
.
i always watch the forces tracing thru stuff, and think if force carried in center, outer or shared thru diameter makes a difference that is not highlighted in knot strength chases.
And a lot of it has to do with grooming the structure like carving wood right when making; as a question of craftsmanship.
.
Quoted Numbers:
Rope Access doc is a classic to me ;
>> Also Life on a Line is quite a contribution by Dr.Merchant ;
>> another short classic is this Nylon Highway composition book ;
>> and later reprise ;
>> Agent Smith's efforts once again, can't go unnoticed here either even tho he too says is a lesser consideration
.
To me, a Pile HItch is hybrid mix of Clove type crossing on host(midway) for more than had deformity and Muenter crossing low/off host for worser deformity; each against the Standing Part that should be unbent IBeam. Muenter/Cow type crossing off host stabilizing backing cuts directly across line of force holding load of Standing Part (unless upgrade to Round Turn there etc.). So Pile, same trusty hitch is stronger loading from the Clove type crossing side, not Muenter. While trusty sister lacing Sailor Hitch also similair hybrid shows top crossing for least efficiency/strength robbing deformity besides 'Tensionless Hitch'.
.
Also some deformity from rear end of knot carriage not held square is lesser consideration, un-noted nuance i think, where by in old pics the finish with 2 Half Hitches then sewn seizing that then holds the Halfs off the rear end of knot more like preceding halfs in Timber, rather than no Stopper Knot to keep from deforming or Stopper that deforms by ramming the rear, the seizing maintains a straight line into rear of knot and tends to hold that end of the knot carriage squarely to purpose, then allows Standing Part to do its best. i think that is a nuance they were trying to hand down in those pics, and Anchor Hitch seized etc. There is the IBeam support quantity, and the squareness of the rest of the carriage to it, as like rigids of wood or metal that can be easier to imagine matching forces and considerations in sometimes. Rope forms so easily, without heating or pounding etc.; so doesn't remind of these complications when sculpting form, like wood and metal do.
.
Security is A#1 as stated/ as safety is to driving, but chasing strength aids to understanding proper deployment of all as a raw mechanic grooming to target. And sometimes the only way to realize theat there is a line, where it is, how bad it is etc. is by stepping across it to feel where the situation flips/takes nose dive and reveals where redline is, to then seek out power band of best usage. Also, knots are more efficient, not stronger unless add extra leg of support. So we are really talking about lacing to minimal loading of parts, rather than chancing raising forces, for unless damaged the rope itself always has same strength; just how hard are you taxing it for same job/how much we are handicapping in compromising position. In this way, it does go back to security some, as pulls on seating less and lasts longer cycles at lower loading. Especially thru dogged out, lines in dirty conditions , that sometimes don't fully relax for hours of recovery between loads for days..
.
i always watch the forces tracing thru stuff, and think if force carried in center, outer or shared thru diameter makes a difference that is not highlighted in knot strength chases.
And a lot of it has to do with grooming the structure like carving wood right when making; as a question of craftsmanship.
.
Quoted Numbers:
Rope Access doc is a classic to me ;
>> Also Life on a Line is quite a contribution by Dr.Merchant ;
>> another short classic is this Nylon Highway composition book ;
>> and later reprise ;
>> Agent Smith's efforts once again, can't go unnoticed here either even tho he too says is a lesser consideration
.
To me, a Pile HItch is hybrid mix of Clove type crossing on host(midway) for more than had deformity and Muenter crossing low/off host for worser deformity; each against the Standing Part that should be unbent IBeam. Muenter/Cow type crossing off host stabilizing backing cuts directly across line of force holding load of Standing Part (unless upgrade to Round Turn there etc.). So Pile, same trusty hitch is stronger loading from the Clove type crossing side, not Muenter. While trusty sister lacing Sailor Hitch also similair hybrid shows top crossing for least efficiency/strength robbing deformity besides 'Tensionless Hitch'.
.
Also some deformity from rear end of knot carriage not held square is lesser consideration, un-noted nuance i think, where by in old pics the finish with 2 Half Hitches then sewn seizing that then holds the Halfs off the rear end of knot more like preceding halfs in Timber, rather than no Stopper Knot to keep from deforming or Stopper that deforms by ramming the rear, the seizing maintains a straight line into rear of knot and tends to hold that end of the knot carriage squarely to purpose, then allows Standing Part to do its best. i think that is a nuance they were trying to hand down in those pics, and Anchor Hitch seized etc. There is the IBeam support quantity, and the squareness of the rest of the carriage to it, as like rigids of wood or metal that can be easier to imagine matching forces and considerations in sometimes. Rope forms so easily, without heating or pounding etc.; so doesn't remind of these complications when sculpting form, like wood and metal do.
Last edited:
ATH
Been here much more than a while
- Location
- Findlay, Ohio
Story on new technology to study knots:
www.npr.org
A Knotty Problem Solved
We know that some knots hold better than others, but the why of it hasn't been so clear. Special fibers that change color under strain are providing some answers.
www.npr.org
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