Anchor Bolts: Clip Above or Below Chain/QuickLink?

You have a lot to learn.

They really should make some kinda human body model to do proper drop testing with sensors to tell what kinda force is really being exerted on the human body. Seems like alot of this is just guess work they are making cause I doubt they really know the forces climbers falling have taken when they get hurt, not like all climbers are doing this with sensors for real data. And I highly doubt they did enough real drop test with live humans to figure out what kinda force the body really has to take in a fall to damage it and figure out all the variables.

Jim Titt wrote: You have a lot to learn.

I agree. We all do. Do you have primary resource that explains why you would accept it? Or any quality control organization that accepted this notion and reasons why? I'd be happy to read it. 

What would Bearbreader do?

ViperScale . wrote: They really should make some kinda human body model to do proper drop testing with sensors to tell what kinda force is really being exerted on the human body. Seems like alot of this is just guess work they are making cause I doubt they really know the forces climbers falling have taken when they get hurt, not like all climbers are doing this with sensors for real data. And I highly doubt they did enough real drop test with live humans to figure out what kinda force the body really has to take in a fall to damage it and figure out all the variables.

I'm pretty sure "they" do. His/its name is rescue randy IIRC. IIRC, it is a 100kg body that is designed to replicate a squishy human body and how a squishy human body will react to a fall. Unfortunately I don't have time right now to dig up all the studies and data related to rescue randy. This is was bearbreeder would do.

I ALWAYS will clip below the ring or link. The hangers are designed for loading closet to the plane of pull closest to the rock. So what if it takes you an extra minute to unclog from the belay station.

Gotta love the idiot responses and smart ass reply’s. You guys are quite the bosses, right?  NOT

Tim Stich wrote: What would Bearbreader do?

PAS FIGHT BRO WTF ELSE? 

Leo Gokovski wrote:

I agree. We all do. Do you have primary resource that explains why you would accept it? Or any quality control organization that accepted this notion and reasons why? I'd be happy to read it. 

The value of 80kg solid mass to replace a 100kg human body (from memory it´s actually a 102kg human) was decided upon by the UIAA and the test laboratory in Munich based on tests done using live volounteers and weights by Troll who were the pioneers of climbing harnesses. This was some time ago so that "reviewing the literature" is not a question of ten minutes with Google but visiting the UIAA archives and reading the minutes of the meetings. Or just talk to Paul Seddon who was involved as one of the founders of Troll who sits on the BMC Technical Commitee along with myself  

There is plenty of work done on the forces humans can survive in harnesses mostly starting from the 2nd WW with parachutes and when ejector seats became common. The replacement of live humans with solid weights or articulated dummies has been extensively studied by the safety industry and there are seemingly endless discussions available online debating whether the correction factor should be 1.4, 1.1 or something else as harnesses and their application change and the weight and fitness of the users alters.

That something isn´t on the internet doesn´t mean it doesn´t exist!

They should start using people who have been sentenced to death as the test dummies for stuff. That way they can do test on them and when they die o well.

Jim Titt wrote:

The value of 80kg solid mass to replace a 100kg human body (from memory it´s actually a 102kg human) was decided upon by the UIAA and the test laboratory in Munich based on tests done using live volounteers and weights by Troll who were the pioneers of climbing harnesses. This was some time ago so that "reviewing the literature" is not a question of ten minutes with Google but visiting the UIAA archives and reading the minutes of the meetings. Or just talk to Paul Seddon who was involved as one of the founders of Troll who sits on the BMC Technical Commitee along with myself  

There is plenty of work done on the forces humans can survive in harnesses mostly starting from the 2nd WW with parachutes and when ejector seats became common. The replacement of live humans with solid weights or articulated dummies has been extensively studied by the safety industry and there are seemingly endless discussions available online debating whether the correction factor should be 1.4, 1.1 or something else as harnesses and their application change and the weight and fitness of the users alters.

That something isn´t on the internet doesn´t mean it doesn´t exist!

I actually provided a link to an article that refers to the forces of parachute deployment in my previous post. I also agree that there is a massive amount of data on the forces humans can tolerate, and that this information is used both by climbing/rescue industries, car manufacturers and others. No Contention whatsoever. 

The assertion that something can exist and not be mentioned on the internet - also agree, quite true.

As you yourself suggest, the debate is ongoing regarding how well an (effectively) incompressible mass correlate with the human body. My point was that "widely accepted" is  an inaccurate description of the role 80 kg steel mass test in the industry.

I'm glad to see we have a contributor here with inside knowledge of the interworks of UIAA.
 
Regarding the test: Are you suggesting that a 100kg of a mass as deformable as the human body would provide a pulse of force equal to that of an 80 kg mass of undeformable material? (that was the context of discussion here). From my understanding, this test and the 12kN parachute standard was accepted based on HUMAN tolerance for forces. The discussion in which the 80kg was mentioned considered the forces under which a dyneema daisy chain would "pop" its intermediate stitches. Entirely different pulse is generated under this scenarios.

To be clear: I am not suggesting that the test is meaningless. I'm suggesting that the correlation between the 80kg mass and the human body is accepted under a narrow set of conditions, and that the pulse of force by an 80kg steel mass is very different than a mass of 100kg that deforms and absorb the force over greater span of time. Incidentally, BD who performed the experiment, mentions that the correlation between what happens in a drop tower with an 80kg mass is HARSHER than a force that could be generated by a climber.