22kn Loop Runner Redirects

As I learned it, the angle referenced is the angle that is created by and imaginary line drawn straight through the block, opposite to the entering of the line, and the line that exits the block. I guess we can all agree on 90*? /forum/images/graemlins/wink.gif
 
Hi folks,
I'm a bit at odds with 22kn endless loop thread.People have remarked that in a choked config it would not be accepted????????
Ok in the states I can understand that the sling is 20 newtons shy of industry standard which is as far as I know is 5000lbs(22.2kn) but in europe it is industry norm.Ok in a choked config your going to lose approx 20% of your strength.So your sling is going to be down to around 17Kn.If you some how you have your PTIP lower than your redirect you can have problems with double load on the redirect!!!!!!!!,Though I think that the limb your tyed into will break before 17kn unless of course it is round some big limb close into the stem which makes it a pretty useless redirect.The reason we use equipment that takes such large loads when only holding so little is partly to allow for configuration of systems(choked slings) In the States for example If you are using 12.5mm XTC-12 it exceeds the industrial standard but tie a knot in it and its down to around 14kn(3200lbs) less than the sling!!!!!!!!!.Tensile strength never allows for configuration so for this reason something that is weakest link in the chain may not be when the whole system is configured..A climber in a fall factor 1 swing will generate 2g if the climber weighs 100kg that will make 200kg + climbers weight 300kg.If your redirect is higher than than your PTIP then this will double the load on the redirect and branch. = 300kg+ 300kg= 600kg force
6 kn into 17kn configured sling.HHHHHmmm.I think that allows enough for for wear and tear of gear..As For TCC as the rules on gear were changed on the 2004 draft
of 5400lbs(24kn) to(shall meet min industry standards) for Euro comps would mean 22kn is acceptible and 22.2kn/OSHA for the US.

Well I had my rant, Its good to have minimum standards and SWL and MBS and WLL and factor of safety but its also good to understand how they all work.Then you can decide if your system is strong enough.At the end of the day Nearly everytime the stem or branch you are tyed into will be the weakest link.So it sort of opens a whole other can of worms

Didj

P.s I'm not encouraging anyone to break regulations
 
Everthing that you say is correct. When the breaking strength standard is written all of the things that lead to loss of effeciency are accounted for. It makes for a common measuring point. The difference between 5,000# and 22kN is pretty insignificant in the big picture but that's the starting point.

The only time that I've ever heard of the difference being an issue is in a competition. In the real world I've never heard of anyone getting a fine for having an under rated piece of gear. It's hard to imagine that the difference in strength would be the only key factor in a rigging failure. We all know how little it takes to generate 50 pounds of load.
 
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22kN is a more common rating for other rope access industries. The 5k# rating has a lot of history, it's going to take a while to change.

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Tom, you are undoubtably correct but I wish the ANSI comitteee would take the lead and write 22kn in as acceptable. As you and I both know-practically alll 22kn rated equipment would actually pass a 5000lb ratings test-and the 5000lb was just a nice round number anyway-22kn is double a "maximum survivable" fall rating and entirely adequate for breaking the tree at our TIP in many cases. I respect the idea of establishing safe standards but I despise stupidity and arbitrary numbers in the rulemaking process. /forum/images/graemlins/crazy.gif
 
Agreed, Greg. This has come up at Z meetings before. Maybe when 2005 is put to print we can make the change. Infact, this would be an opertune time to prime the pump and let the committee know what issues are important.

That said, after witnessing some of the discussions over simple wordsmithing it will be a challenge to make a substantial change like this.

My concern about people using 22kN gear is that in the case that someone is hurt, that could be used to show negligence. It's much easier to have gear that's all in compliance.
 
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My concern about people using 22kN gear is that in the case that someone is hurt, that could be used to show negligence. It's much easier to have gear that's all in compliance.

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Sorry Tom, but this stinks.

22kN is the industry standard in MORE than the Netherlands, in fact probably everywhere but the US of A.

To help the industry is to accept one others industry standard and not to keep knit picking over a couple of kilograms.
If someone gets hurt because of using 22 kN gear is that it did the job, but the climber broke in two.

I think (and with me, everyone in the rest of the world using the 22 kN standard), that if there is anyone in the committee that even thinks about not to certifie 22 kN gear he or she HAS A HIDDEN AGENDA. /forum/images/graemlins/headpop.gif
 
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I think (and with me, everyone in the rest of the world using the 22 kN standard), that if there is anyone in the committee that even thinks about not to certifie 22 kN gear he or she HAS A HIDDEN AGENDA. /forum/images/graemlins/headpop.gif

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I think so too.
 
Agreed!!! It does stink. This is an issue that will be getting more attention in the next Z revision. I'll be talking with people on the Z committee to see what needs to be done to realign our standards with the rest of the working rope industries. Sitting on tradition is no reason to stick with 5k#. If that were true, we would still allow natural fiber rope :)
 
I heard this last revision. now is the time for the change.
there are more things never done because they were put off till the next day or the next revision etc... The committie has the ability to change this now. The revision is in the public comment period, so if enough of us request the change then it should change.
So how many need to file for the change for it to occour this revision Tom? or is it already set in stone to not touch the 5k# till next revision?
If this sounds mean or harsh it's not supposed to, just curious (like what killed the cat (it wasn't the 22Kn))
 
The more comments that are recieved the more likely the issue will get the attention of the committee. Look at this like a grass-roots referendum. build a groundswell so large that the power structure can't ignore the issue. With enough volume we can bring attention to this issue. Maybe not for the 2005 revision but it would tee-up the talks for the next round.

It's past time for our industry to align it's standards with other working rope industries I think. There are plenty of unique things about treework but to think that we should have standards that are close, but just a teenie tiny bit different because of the differences is silly. I've talked with other rope industry folks and they can't understand the 5,400# breaking strength rule, even given the historical context. Heck, he made the jump from manila to Arboplex close to 30 years ago, isn't it about time to change the standard?

Get your comments in and let anyone else in the arbo industry know that they need to get involved too.
 
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