Data request: # kN = this injury

[Marmuzz]

Recently there’s been a lot of good safety discussion on climbing methods, ropes, gear, etc. What I’ve seen mostly discussed is how to avoid scenarios resulting in catastrophic falls, gear to decelerate falls, etc. But I want to get down to the cold hard bottom line: what will actually happen to you if you fall? With all the popularity of one sticking buzzing around YouTube, I’d like to define these risks a little more bluntly.

Does anyone have any good resources that describe the probable injuries suffered at particular kNs? I’m not talking about how to calculate fall factors or the actual kNs generated in a fall per specific inputs; there are good tools for that. Rather, I’m looking for what the injurious results will be at certain kN intervals. Ex: I see guys say on here that .5 kN will make you hurt and 8+ kN will paralyze or kill you. But I think there’s a wide ambiguity between those points that many of us (especially we newer guys who are one sticking) willingly accept in the stupid bravado that “I can endure .5 or a little more but 8-12 won’t happen to me.” But what “exactly” happens to the human body at 1, 2, 4, 6 kN?

I realize the inherent danger of such data is someone will brazenly read it and interpret “Oh, a small fall will just send me to the chiropractor. No problem.” I don’t want to embolden unsafe practices or attitudes. But I think there’s a lot of people (myself included) who will do what we can to avoid catastrophic falls (almost anyone can tell you your stick kicking out when your static tether is at your ankles will be horrible) but may still be accepting vague significant risks below that threshold without understanding that a lesser fall can still make your kidneys into jelly. I know this “sport” requires risk and everyone has to decide whether or not they’re okay with it. I’d just like to see some resources that help us more accurately grasp the various degrees of possible injury in that risk evaluation.

Feel free to refer me to previous posts and threads on here. I’m sure there’s content I’ve missed.

 

[Vtbow]

Too many variables to calculate ""Impact on body". What kind of harness? where are you tied in? Is your system dynamic at all? How much do you weigh? do you have any other prior conditions or injuries? etc....

 

[_Dario]

Getting the popcorn ready now…

so the question is, what will actually happen to you if you fall, wearing a non fall arrest device? But we need to know the other variables. Hanging from a steel chain or a bungee rope? These aren’t arbitrary details.

 

[Marmuzz]

Fair points. I can see the complexity. It’s probably why I haven’t found the answers I’m looking for.

 

[GCTerpfan]

Here is a good article that doesn't necessarily give the answers you are looking for but, does a good job of explaining some of the variables that make it difficult to answer. http://www.treemagineers.com/blog/what-forces-can-a-body-sustain/

 

[Marmuzz]

My perception is so many guys are using relatively similar setups between saddles and static ropes that we could develop a general baseline that could be used to calculate these forces or at least hold up inputs against existing data. But maybe not.

 

[_Dario]

It’s almost like you have to think about it like this…

there is a company out there (Carthrd) who invented a car that travels 0-60 in 3 seconds. There is an online forum out there with a bunch of guys figuring out the best/safest way to make their carthrd car travel upwards in the air 10 feet.

it was not designed to go 10 feet in the air, it was not designed to withstand a failure from 10 feet in the air, it has no good reason to be 10 feet in the air.

It’s just not as obvious with saddles and one-sticking because to the layman (me) a saddle looks like it would perform all the functions you are looking for that a rock climbing harness/fall arrest device would. But it doesn’t…

 

[Marmuzz]

@GCTerpfan thanks, that article moves in the direction I’m looking for.

 

[Fl Canopy Stalker]

 

[Fl Canopy Stalker]

Recently there’s been a lot of good safety discussion on climbing methods, ropes, gear, etc. What I’ve seen mostly discussed is how to avoid scenarios resulting in catastrophic falls, gear to decelerate falls, etc. But I want to get down to the cold hard bottom line: what will actually happen to you if you fall? With all the popularity of one sticking buzzing around YouTube, I’d like to define these risks a little more bluntly.

Does anyone have any good resources that describe the probable injuries suffered at particular kNs? I’m not talking about how to calculate fall factors or the actual kNs generated in a fall per specific inputs; there are good tools for that. Rather, I’m looking for what the injurious results will be at certain kN intervals. Ex: I see guys say on here that .5 kN will make you hurt and 8+ kN will paralyze or kill you. But I think there’s a wide ambiguity between those points that many of us (especially we newer guys who are one sticking) willingly accept in the stupid bravado that “I can endure .5 or a little more but 8-12 won’t happen to me.” But what “exactly” happens to the human body at 1, 2, 4, 6 kN?

I realize the inherent danger of such data is someone will brazenly read it and interpret “Oh, a small fall will just send me to the chiropractor. No problem.” I don’t want to embolden unsafe practices or attitudes. But I think there’s a lot of people (myself included) who will do what we can to avoid catastrophic falls (almost anyone can tell you your stick kicking out when your static tether is at your ankles will be horrible) but may still be accepting vague significant risks below that threshold without understanding that a lesser fall can still make your kidneys into jelly. I know this “sport” requires risk and everyone has to decide whether or not they’re okay with it. I’d just like to see some resources that help us more accurately grasp the various degrees of possible injury in that risk evaluation.

Feel free to refer me to previous posts and threads on here. I’m sure there’s content I’ve missed.

I will provide you with some resources and videos during my lunch time.

 

[Fl Canopy Stalker]

Here is a great video. It’s boring and slow but it literally shows regulations, dummy drops, and explains the injuries that would be sustained. It covers all harness types. Again it is not an action packed video though.

 

[Marmuzz]

@Fl Canopy Stalker
Thanks I’ll have to check those out later after work.

@_Dario
I hear what you’re saying. I get that saddle hunting greatly borrows from arborists, rock climbing, etc. and we are not simulating apples to apples. Ultimately, everything we’re doing is probably out of spec compared to safety test data that does actually exist or how products were intended to be used. The trouble for me is that ambiguity creates the specter of a huge margin of risk which I don’t understand. (I’m not saying that for everyone. I’m pretty new to saddle hunting, and don’t profess to be an expert, physics major, or engineer. But I suspect a lot of newbs like myself are leaping into this headlong without knowing just how shallow the bottom of the pool is.) I’m just trying to gather more understanding of the most probable, most similar injury data that we do know of because short of that info, one sticking (or other climbing methods for that matter) begins to seem willingly reckless.

 

[Weldabeast]

.0003 kn and I usually bust a nut

 

[Jtaylor]

.0003 kn and I usually bust a nut

Those things need work hardened! Seems like they should take a bit more.

 

[Fl Canopy Stalker]

Here is a great video. It’s boring and slow but it literally shows regulations, dummy drops, and explains the injuries that would be sustained. It covers all harness types. Again it is not an action packed video though.

@philsanchez76 watch this video. The third drop uses a rock climbing harness with a dynamic lanyard (these are even better than screamers) the drop is worse case scenario, but check out the forces applied and tell me you still think you’d generate less than 1kn. Again this is worse case scenario, however I don’t want you thinking I was lying to you either. If you look at the graph associated with each drop, if your saddle bridge failed, it would snap during the peak force. Meaning that the next peak following the max force peak would be the minimum force applied to your linesman loop or d ring after your system suffered shock and failed. It’s still going to be way more than your body weight. That’s all I was saying man. Not being a know it all or anything, I just want people to have more realistic understanding of forces being applied and what might happen if you feel especially given that we are so confident in our back up systems.

 

[Vtbow]

@philsanchez76 watch this video. The third drop uses a rock climbing harness with a dynamic lanyard (these are even better than screamers) the drop is worse case scenario, but check out the forces applied and tell me you still think you’d generate less than 1kn. Again this is worse case scenario, however I don’t want you thinking I was lying to you either. If you look at the graph associated with each drop, if your saddle bridge failed, it would snap during the peak force. Meaning that the next peak following the max force peak would be the minimum force applied to your linesman loop or d ring after your system suffered shock and failed. It’s still going to be way more than your body weight. That’s all I was saying man. Not being a know it all or anything, I just want people to have more realistic understanding of forces being applied and what might happen if you feel especially given that we are so confident in our back up systems.

... And something people dont take into consideration is slack in the backup system. Shock loading a backup can be a major issue as well and potentially even cause it to fail. Sure there may not be any slack in your tether system to start, but if your backup is simply clipping the end of your tether into a LB or other anchor point and there is slack between that and your primary anchor point, you've introduced slack into your "system"...

Technically all anchors should be solid, redundant, equalized(meaning the redundant anchor points/backups should share the load at all times) and non-extending should one of those anchor points fail....

Very few, if any systems I see people using in a saddle meet all these criteria.

 

[Red Beard]

Great video. Our folks need to see more like these.

 

[Red Beard]

Here is a great video. It’s boring and slow but it literally shows regulations, dummy drops, and explains the injuries that would be sustained. It covers all harness types. Again it is not an action packed video though.

So basically what I got out of this GREAT VIDEO is that any fall where your connection points are placed at the hips only is going to break your back. Mods, suggest this video be a sticky in the Saddle Information for New Users section.

 

[enkriss]

I remember reading somewhere that it takes ~4kn of force to break a human femur

http://eknygos.lsmuni.lt/springer/659/279-310.pdf

 

[Fl Canopy Stalker]

So basically what I got out of this GREAT VIDEO is that any fall where your connection points are placed at the hips only is going to break your back. Mods, suggest this video be a sticky in the Saddle Information for New Users section.

I agree. However this video’s falls are generated on a 1.25:1 fall factor and a drop of 6’. For work positioning harnesses (which by definition, is what a saddle is) you should never climb above your connection point (which would be a 1:1 fall factor) you should also keep your system tight enough so that it never generates a fall of 24” or more. So many people have marketed these to sell as the safest option. That helps with sales but it’s only a true statement if you keep your system tight. Any force over 900 lbs which is about 4 KN can hurt you badly. That could be a sprained back. It could be a herniated disc. It could be a broken back/hips. This is not suggestion, this is factual and well documented. Any forces generated over 1800 lbs or 8 KN can and most likely will cause life threatening/altering injuries. Can you come out of a fall like that alive? Absolutely. But remember people have fell from 20’ up with no harness hit the ground and lived, it doesn’t mean that they had a great life afterwards and were able to hunt or walk again. Just because the saddle catches you, doesn’t mean your injuries will be any less severe than falling to the ground. This is me giving it straight to everyone, no hype marketing products, no magic cure all, and I am completely unfiltered. With that said if you use the system as intended, and you inspect your equipment, you will be safe on most saddles (there are many out there who never truly test). If they have tested their, they get a report of certification that they passed tests. It tells details of the tests. It tells what tests were taken. If a company markets that they are safe or tested, ask for videos or reports. If they say they aren’t approved, and you choose to use it, you should be very familiar with the risks involved and you should also be sure to keep the system tight because if you fall (1 in 3 elevated hunters, eventually suffer a fall) then there can be severe life altering consequences. Again I love saddles. I hunt exclusively in them. But I am also realistic about the dangers involved.