- Joined
- Apr 3, 2002
- Messages
- 6,071
- Reaction score
- 605
It has been 2 mos. since I started this thread and I still have no desire to use SRT. I embrace a lot of new tech with open arms but somehow this just doesn't get it!
OK.....Let's Get Into The Meat Of SRT !!!!
- Thread starter rahtreelimbs
- Start date
Help Support Arborist Forum:
MasterBlaster
TreeHouse Elder
+1
murphy4trees
Addicted to ArboristSite
I think its worth asking.... I checked ANSI and the best I could come up with is 4.1.2 "proper use". I would think that would better be stated proper use and according to maufacturers specifiactions... So maybe it'll be best asked to those whom make the gear.... What kind of biner is it????
Ask them how much side loading is too much... Let us know...
My mind is open...
Ask them how much side loading is too much... Let us know...
My mind is open...
NickfromWI
Addicted to ArboristSite
I've emailed petzl and am interested in what their reply is. I will surely let everyone know when I hear from them!
love
nick
love
nick
RescueMan
Rope Rescue Specialist
Side Loading
The only strength-loss figure I've ever come across for a cross-loaded biner is 40%, but there are too many variables to use any one number.
I see that Sherrill carries a lot of Petzl 'biners and every one of them will come with an instruction pamphlet that shows all the ways NOT to load a 'biner, including on the side. Some of that is they're covering their arse, but it's generally foolish to ignore manufacturer's recommendations.
And, of course, your margin of error depends on what kind of 'biner you're using. If it's aluminum, well they break all the time when misused. If it's a 65kN locking steel monster, they'll take a lot of abuse. If it's a type 2 autolocker (twist only), then the gate can open when it slides along a friction surface and that significantly weakens the 'biner.
And using it as a choker can put up to double the load on the biner, multiplied again by 2 to 4 if you bounce a lot when you climb. So, even if you weigh only 155, you could be putting as much as 1000-1200 lbs of load on that 'biner as you ascend.
If it's a 25kN (5620 lb) 'biner, and the strength has been reduced 40% by side-loading (3370 lb) and you're putting a dynamic load on it of close to 1200 lbs - the safety factor is getting kinda small.
So, can you get away with it 99% of the time? Probably. It's that 1% that's gonna hurt, though. Why take the chance?
Anyway, it's kinda like using a good screwdriver as a chisel. It might work allright, but that's not what it was made for, and a pro doesn't abuse his tools.
- Robert
The only strength-loss figure I've ever come across for a cross-loaded biner is 40%, but there are too many variables to use any one number.
I see that Sherrill carries a lot of Petzl 'biners and every one of them will come with an instruction pamphlet that shows all the ways NOT to load a 'biner, including on the side. Some of that is they're covering their arse, but it's generally foolish to ignore manufacturer's recommendations.
And, of course, your margin of error depends on what kind of 'biner you're using. If it's aluminum, well they break all the time when misused. If it's a 65kN locking steel monster, they'll take a lot of abuse. If it's a type 2 autolocker (twist only), then the gate can open when it slides along a friction surface and that significantly weakens the 'biner.
And using it as a choker can put up to double the load on the biner, multiplied again by 2 to 4 if you bounce a lot when you climb. So, even if you weigh only 155, you could be putting as much as 1000-1200 lbs of load on that 'biner as you ascend.
If it's a 25kN (5620 lb) 'biner, and the strength has been reduced 40% by side-loading (3370 lb) and you're putting a dynamic load on it of close to 1200 lbs - the safety factor is getting kinda small.
So, can you get away with it 99% of the time? Probably. It's that 1% that's gonna hurt, though. Why take the chance?
Anyway, it's kinda like using a good screwdriver as a chisel. It might work allright, but that's not what it was made for, and a pro doesn't abuse his tools.
- Robert
MasterBlaster
TreeHouse Elder
Good analogy there, Rescueman!
i go with RescueRob's view, though i still think that there is a componenet of leveraging the length of the carabiner as the body of the carbiner jams against something as a pivot; whereby the longer the carabiner, the more of this trying to 'bend' the carabiner over something can be leveraged by the carabiner's own length. i would think a screwlink/quick link(?) has a maybe heavier construction for this battle, it would suffer similar dynamics. There are a couple of differnt positions the carabiner can lay in at this point, that would place this leverage at different angles of pull against the carabiner etc. i think per strength a shackle is shorter and beefier, and more up to these challenges.
So i still see a pull at weak angle of the structure of the carabiner, that takes on a load leveraged by the choke position of the line; then that increased force could be leveraged more by the stiffness of the carabiner's length 'bent' over the obstruction.
i think that you could construe a flat surface just as long as the carabiner, so that the pulls would come perpendicular to the flat surface from the back, and give side loading without the choke or trying to bend the spine of the carabiner over a 'rock' or other obstruction elements. So as seperateable conditions, i think that the side loading, choke leverage tension in line, then bending the carabiner over an obstruction need inspected for prescence and effect seperately in a system.
Due to the shorter and beefier length design/shape i think shackles would be better for this positioning, but the soft line not incurring the problems of the stiffness of the metal devices spoken of.
Orrrrrrrrrrrrr something like that,
:alien:
So i still see a pull at weak angle of the structure of the carabiner, that takes on a load leveraged by the choke position of the line; then that increased force could be leveraged more by the stiffness of the carabiner's length 'bent' over the obstruction.
i think that you could construe a flat surface just as long as the carabiner, so that the pulls would come perpendicular to the flat surface from the back, and give side loading without the choke or trying to bend the spine of the carabiner over a 'rock' or other obstruction elements. So as seperateable conditions, i think that the side loading, choke leverage tension in line, then bending the carabiner over an obstruction need inspected for prescence and effect seperately in a system.
Due to the shorter and beefier length design/shape i think shackles would be better for this positioning, but the soft line not incurring the problems of the stiffness of the metal devices spoken of.
Orrrrrrrrrrrrr something like that,
:alien:
Kneejerk Bombas
ArboristSite King
- Joined
- Oct 7, 2001
- Messages
- 36,971
- Reaction score
- 9,980
Re: Side Loading
Robert, I think you may be underestimating the stupid factor here. Nick is not cross loading the carabiner, although there is always the chance he is doing that too. He's side loading it!
Robert, I think you may be underestimating the stupid factor here. Nick is not cross loading the carabiner, although there is always the chance he is doing that too. He's side loading it!
Dang Mike too quick fer me again, here is mine anyway! Was going to delete my post , then add this as my work around, cuz if there was no pic in original post, then ya can't edit one in the way i understand it!
Lumberjack
Banned
Spydy is right, the shortter the biner, the less leverage that can be placed against it, therefore the less side loading.
That is why Sherrills caption says for use on wood over 2'. That way the arc on the wood is flatter on larger wood, thereby sideloading less.
To me, a steel clevis, or a rapid link would be better suited to the sideloading.
But on stuff under a foot or so, most needs could be handled by a 1" nylon turbular webbing, and is cheap as dirt to make, using a beer knot.
That is why Sherrills caption says for use on wood over 2'. That way the arc on the wood is flatter on larger wood, thereby sideloading less.
To me, a steel clevis, or a rapid link would be better suited to the sideloading.
But on stuff under a foot or so, most needs could be handled by a 1" nylon turbular webbing, and is cheap as dirt to make, using a beer knot.
Lumberjack
Banned
That summed it up. Was it that hard?
But I think that the thread has moved to what is the proper usage, and what if any sideloading is acceptable?
I would say a little less than not much on aluminum, and a little more for steel.
NickfromWI
Addicted to ArboristSite
So sideloading is bad?
Yet, I am sure all of you would promote a running bowline.
Yet manufacturers reccomend at least a 4:1 bending radius, and often much higher than that. The running bowline is a lowly 1:1
So why is it wrong to disobey the "rule" to not sideload, but ok to ignore bending radius?
I'm sure there is no one here using a 2" thimble for there half inch climbing lines.
love and open mind
nick
Yet, I am sure all of you would promote a running bowline.
Yet manufacturers reccomend at least a 4:1 bending radius, and often much higher than that. The running bowline is a lowly 1:1
So why is it wrong to disobey the "rule" to not sideload, but ok to ignore bending radius?
I'm sure there is no one here using a 2" thimble for there half inch climbing lines.
love and open mind
nick
murphy4trees
Addicted to ArboristSite
the yosemite tie off puts the running bowline at 2:1
the rescue folks consider it an inferior knot... which was a surprise to me.
the rescue folks consider it an inferior knot... which was a surprise to me.
MasterBlaster
TreeHouse Elder
I bet my life on a bowline all the time.
RescueMan
Rope Rescue Specialist
That's true - they RECOMMEND a 4:1 minimum radius to maintain the full strength of the rope, but they don't REQUIRE it.
Because the manufacturers say very clearly DON'T side load biners.
I'm not sure what you mean by this, but used as a choker any loopknot will bend the choked rope around a 1:1 radius as Nick says.
This tends to be true, at least in the Fire/Rescue world where practitioners have little experience and even less hands-on time with knots. But it's not true in mountain/cave rescue with those who know their knots.
The problem is that (as some of you have said) the bowline is not an easy knot to learn or remember for newbies, it tends to be insecure when not under continuous load and hence needs a backup, and it can capsize and turn into a slipknot.
So do I - and I use it in rescue as well as in recreational climbing and caving.
- Robert
murphy4trees
Addicted to ArboristSite
it can capsize and turn into a slipknot...
I've heard that before but do not recall seeing it happen....
If set properly what would cause it to capsize???
Would making a second loop make a differnce....
Spydy PMed me about the yosemite tie off not changing the strength of the knot.... I liked it because the tightest bend in the rope goes around a single line.... Add the yosemite and that bend goes around two lines.... but Spidy pointed out that that is not where the knot is loaded....
I've heard that before but do not recall seeing it happen....
If set properly what would cause it to capsize???
Would making a second loop make a differnce....
Spydy PMed me about the yosemite tie off not changing the strength of the knot.... I liked it because the tightest bend in the rope goes around a single line.... Add the yosemite and that bend goes around two lines.... but Spidy pointed out that that is not where the knot is loaded....
From the lore of shipping docks comes the warning of inverting the bowline from the tail/'toggle' sticking outside the eye the bowline forms. In this position, the tail can snag on a moving load, inverting the knot. The bowline was used for centuries like this, availing to the fairly friction free transport of water connecting many places.
The half hitch/'bunny hole' ring of the bowline is the primary loaded arc/curve, and dictates the knot strength, and making this termed properly a knot. A hitch, needs a host, to wrap on; it is this host/post/another line etc. that have varying sizes, that sets the primary arc for a hitch. Therefore a 'knot' will have pretty much a set strength; but a 'hitch' (that needs a mount or host to be complete) can have varying strengths depending on the primary arc that the host it mounts to imposes. Whereby, slapping a bowline around 3 different size posts, will yield the same size primary arc in the half hitch that forms it. A clove to the same 3 posts, will have 3 different primary arcs, thereby strengths; as i understand the differance betwixt 'knot' and 'hitch'; though as ya go real small (fishline etc.), they call everything a knot, as i understand it.
So the Y tieoff affects the size of the loop around the standing part, not the size of the primary loaded arc of the half hitch, so does not give more releif/strength to the loading. A double/round turn/mountaineer bowline, gets a slight strength boost spreading out stress a bit by doubling the choking ring in number, not size IMLHO.
i'd been talking to Daniel about making the DBY (Double Bowline w/ Yosemite tie off); being stronger, so PM'd him to edit if he'd like; being kinda my fault perhaps. i make the DBY with the slipknot method, kinda a backwierds/counterintuitive approach (surprize, surprize ); that gives a view of how the knot could invert in it's simplest form, with 1 ring, tail outside, no stopper knot (that the Y tie off satisfies as well as 'cleaning' out the temporary eye formed by the bowline).
Working the 2 rings to form to knot is easier, with the slipknot method IMLHO; it also breaks the making of the knot into 2 stages, one that can wait on hold; then the 2nd stage can be whipped on quickly, precisely when needed. The slip knot method was used for rescue of a concious victim on the side of a cliff that could only have 1 hand free, especially if they were afraid to lift legs to draw a roundsling etc. up to seat. Under arms is a good place for this short term, otherwise the arms can go numb/ get lazy from the bite of the thin line, and victim can fall.
i think that the bending radius strength loss is more for lines the increased dynamics of being drawn/cranked across a surface, not in a standstill inside of a knot/hitch. Really for braids that aren't reel stiff 8x is prefferable (10x for twisted, aramids/kevlar almost to that of wire at about 24x); but the 4x is accepted as more workable, with strength loss in the knot ranges ; so is 'matched' componenets. But a spliced eye on a 4x diameter pulley wouldn't be 100% strength IMLHO. Another factor is how the sheave/pully supports the 'belly' of the line (not just a deep groove, giving no support here). With aramaids real picky (as is cable) about this part of the design, regular rope pulleys not fitting the bill here for kevlar and cable.
The half hitch/'bunny hole' ring of the bowline is the primary loaded arc/curve, and dictates the knot strength, and making this termed properly a knot. A hitch, needs a host, to wrap on; it is this host/post/another line etc. that have varying sizes, that sets the primary arc for a hitch. Therefore a 'knot' will have pretty much a set strength; but a 'hitch' (that needs a mount or host to be complete) can have varying strengths depending on the primary arc that the host it mounts to imposes. Whereby, slapping a bowline around 3 different size posts, will yield the same size primary arc in the half hitch that forms it. A clove to the same 3 posts, will have 3 different primary arcs, thereby strengths; as i understand the differance betwixt 'knot' and 'hitch'; though as ya go real small (fishline etc.), they call everything a knot, as i understand it.
So the Y tieoff affects the size of the loop around the standing part, not the size of the primary loaded arc of the half hitch, so does not give more releif/strength to the loading. A double/round turn/mountaineer bowline, gets a slight strength boost spreading out stress a bit by doubling the choking ring in number, not size IMLHO.
i'd been talking to Daniel about making the DBY (Double Bowline w/ Yosemite tie off); being stronger, so PM'd him to edit if he'd like; being kinda my fault perhaps. i make the DBY with the slipknot method, kinda a backwierds/counterintuitive approach (surprize, surprize
); that gives a view of how the knot could invert in it's simplest form, with 1 ring, tail outside, no stopper knot (that the Y tie off satisfies as well as 'cleaning' out the temporary eye formed by the bowline). Working the 2 rings to form to knot is easier, with the slipknot method IMLHO; it also breaks the making of the knot into 2 stages, one that can wait on hold; then the 2nd stage can be whipped on quickly, precisely when needed. The slip knot method was used for rescue of a concious victim on the side of a cliff that could only have 1 hand free, especially if they were afraid to lift legs to draw a roundsling etc. up to seat. Under arms is a good place for this short term, otherwise the arms can go numb/ get lazy from the bite of the thin line, and victim can fall.
i think that the bending radius strength loss is more for lines the increased dynamics of being drawn/cranked across a surface, not in a standstill inside of a knot/hitch. Really for braids that aren't reel stiff 8x is prefferable (10x for twisted, aramids/kevlar almost to that of wire at about 24x); but the 4x is accepted as more workable, with strength loss in the knot ranges ; so is 'matched' componenets. But a spliced eye on a 4x diameter pulley wouldn't be 100% strength IMLHO. Another factor is how the sheave/pully supports the 'belly' of the line (not just a deep groove, giving no support here). With aramaids real picky (as is cable) about this part of the design, regular rope pulleys not fitting the bill here for kevlar and cable.
Last edited:
Kneejerk Bombas
ArboristSite King
- Joined
- Oct 7, 2001
- Messages
- 36,971
- Reaction score
- 9,980
Side loaded biners
Look at the sheet of paper that comes attached to the carabiner when new. It warns of side loading.
They are tested by pulling two ways, along the axsis and across it. They are not tested by pulling sideways as to bend the tool. They do not test them this way for obvious reasons, they would break at very low pressures. It would also be dependant on wether or not pressure was on the gate or parts of the gate. Using a biner this way could also damage it without you noticing it, only to have it fail when you need it.
If you want proof, clamp a binner in a vice with the jaws at what looks like the most vulnerable spot on the biner (right at the lower gate axis), tie a rope to it's top, and pull sideways. I doubt you'll need any more than your hands to pull it to breaking. This is not exactly the way the forces work in your set up, but it would establish an approximate sideload strength.
I think we all agree the biner would be damaged at far below 5400 pounds, and even if you don't think it would be damaged at that point, it's not rated or intended for this use, therefore it doesn't meet ANSI's requirements when used this way.
Look at the sheet of paper that comes attached to the carabiner when new. It warns of side loading.
They are tested by pulling two ways, along the axsis and across it. They are not tested by pulling sideways as to bend the tool. They do not test them this way for obvious reasons, they would break at very low pressures. It would also be dependant on wether or not pressure was on the gate or parts of the gate. Using a biner this way could also damage it without you noticing it, only to have it fail when you need it.
If you want proof, clamp a binner in a vice with the jaws at what looks like the most vulnerable spot on the biner (right at the lower gate axis), tie a rope to it's top, and pull sideways. I doubt you'll need any more than your hands to pull it to breaking. This is not exactly the way the forces work in your set up, but it would establish an approximate sideload strength.
I think we all agree the biner would be damaged at far below 5400 pounds, and even if you don't think it would be damaged at that point, it's not rated or intended for this use, therefore it doesn't meet ANSI's requirements when used this way.
NickfromWI
Addicted to ArboristSite
Mike, look at the sheet of paper that comes with many climbing lines....the part where it reccomend (usually at least) a 4:1 bend radius. Then get back to me on why you can break that rule, but not the carabiner rule.
love
nick
love
nick
Similar threads
Latest posts
-
-
-
-
-
-
Please recommend a small chipper- Boxer x7 vs Vermeer bc700xl or....
- Latest: clydesdale6
-
