Backup system in DdRT

Hi guys !

This idea is purely theorical for now so don't try it at home. Even if it works it is more about having some kind of "secured laboratory of tests" than a easy safety system, so even if it's OK i guess that it will allways be for advanced climbers rather than beginners.

I show that to you to have your thoughts, it's kind of experimental so maybe i should have post that on the canopy chatter but one more time i've lost my member password and i can't get it back.

But if it works that could save a lifes, or wrists...

I had it for two reasons :
1 Andy's accident, it touched me and i can't stop thinking about how to be sure that couldn't happen again, even if something is wrong like a knut.
2 In France we have to respect european standardizations and to use non standard gear like an Unicender, or a Hitch Hiker, whatever, is prohibited in clubs and associative events. To use them anyway we must bypass the ascender by a standardized system.


There it is, in red the life line, what is'nt red can be disconnected without security issue :




1 : Bridge
2 : Climbing system primary carabiner
3 : Life line primary carabiner
4 : Bat Plate large
5 : Carabiners for the three connecting points.
6 : Belly climbing system (prusik, unicender, hitch hiker, whatever)
7 : Ascender holding the life line to make it adjsutable (a Duck should do the trick)

8 : Sliding side of the climbing rope
9 : Life line
10 : Fixed side of the climbing rope

11 : Fall arrester (like Petzl's ASAP)
12 : Fall arrester connection (linking ASAP + life line + arrest prusik)
13 : Arrest prusik avoiding the ASAP to fall and the fixed side of the climbing line to go away.


I got some ideas for the Y connection it needs a lot of tests to find the good simple solution i guess.


Do you know if it had been ever tryed (don't want to invent again the wheel...) ?
What do you think about that ?

Hey bradypus, That's interesting, but I'll have to study it further. By the way, I thought maybe Canopy Chatter was defunct, but I was able to log in this evening! My first impression is it looks like a lot of gear.

Hi Walter

Yes it is a lot of gear and i guess it will be even bigger than i hoped. Lot of gear = weight, bulk and more handling troubles, so it's a really bad point.

It is defenetly not a minimalist system, i hope tests will show that it can be reduced but ASAP + bate plate + duck + line... it should make something like 500g (one pound), reducing weight and volume is a challenge.

But it will allways be more bulky and heavy than nothing, it adds a fall arrest system so. And it is quite expensive...

An ASAP is on its way and i should be able to test that soon. Fall arresters are not made to follow a fast descent like with a spiderjack or an unicender, so that would be the end of "bombing to the ground". But the ASAP should be good with normal speeds, and its design is pretty handy for that kind of configuration where the arrester is so close from the fixing point.

For now anyway it is just in purpus to have fun testing a lot of exotic systems without being in danger. Question is : will it be functional ? I'm sure it is safe but i'm not sure it will work well, the connection 12 is the critical point. If it's ok there the rest will be good and safe. If it is next question will be : does it worth money, weight, volume and extra handling ?

http://www.treebuzz.com/forum/threads/tandem-hitch-sddrt.27377/

Hey Hugo, I thought you might want to check this out. Let me know what you think.

You sure have put a lot of thought into that, but it looks to be very complicated and confusing
Having a set procedure for system change over has worked for me, costs nothing, and is easy to carry.
Always weight test a system before you commit your life to it, weather that be on the ground or in the canopy.

Be safe up there

I agree with the above post. Simplicity is a key element of a safe system. Simplicity, and a keen awareness of your situation.

dogwood wrote: Simplicity is a key element of a safe system. Simplicity, and a keen awareness of your situation.

+1

That being said, a system called DRT is gaining acceptance in the arborist community. Essentially it entails being tied in on two separate rope systems, with two bridges on the harness, at the same time. There has been quite a discussion of this topic on treebuzz. When you boil it down, it's a matter of being able to come home safe and sound at the end of the day.

Hugo, what is your intended use scenario? For designing and evaluating anything I like to start with a "use case", ie: what is my goal, what is the scenario where this would be used?

Theoretically there should be no use for fall arrest in tree climbing since we are "work positioning" climbing (minimal to zero slack while on rope) and there is no fall on to the system.

From there I would ask is it really a back up system (like the double rope system Dogwood referred to) or a true fall arrest system you're looking to develop?
-AJ

Hey guys, didn't saw your answers, sorry.

It was above all to see if it would work, and it does well in fact.
One use i thought about was for recreational instruction with kids and psychologicaly unsecure adults when they do their own knots for the first time for exemple. It's a tiny use indeed. I've seen some of them going down too fast and being arrested by a magic knot, it can be used to avoid that and not have to stop because of each magic knot. I thought also to some experimenters making holes into some expensive ascenders (we all know at least one don't we ), or playing with homemade splices and sewn eyes (hu we know an other one ) especially when it is for the first time.

It is a backup system, i've changed the title of the topic, my bad sorry.
But the ASAP can also be used in a DRT system as a fall arrester, that's its first purpose. Every industrial cordist use it that way here.

As you say guys it is not a simple system. It is not too complex neither, it is fast to set and requires no additional manipulation during the climb as long as no trouble occurs. It is not the kind of complexity that add more possible breacking points in a line as it just bypass the basic setup to add a security. But for sure it is bulky, heavy, expensive and to be really effective it needs a mobile false crotch as it adds lot of boring manupilations using a ropesleeve.


My ASAP was deficient when i received it, fortunatly a friend had one and we tryed with it. I've seen it was working, but the bulkyness and heavyness bugged me. I had no need to use it since and i forgot about it. I've just send back my broke ASAP, as i'm kind of broke too and that the seller proposed it i guess that i'll keep the bucks to earn other toys cause i've a more interesting plan in mind : making a rope walk system on a frenchy. This strange system we got here set like a DdRT but used like a SRT climbing on both sides of the rope at the same time. It is really efficient, pretty versatile, but it lacks the hability to be used with a rope walk as the rope is sliding in the anchor point like a DdRT. I've found a solution and i need to make it.


I feel it was a good exercise, but that's it. So unless i feel a real need to go back on this idea, as i know now that it works, i'll keep going on other, more usefull, stuffs i got in that nerdy mind.

dogwood wrote: http://www.treebuzz.com/forum/threads/tandem-hitch-sddrt.27377/

Hey Hugo, I thought you might want to check this out. Let me know what you think.

Hi Walt

That's a version of what some of american climbers call the frenchy, and for sure we use it a lot here. I love the efficiency of the knot lifting. That's really a good thing and many of us would enjoy it because we usually don't use pulleys, pushing the prusiks up with hands. That's why adjustable bridges are really loved around here, thanks to them we can adjust the position of prusiks in this system, making them away when climbing and close when moving around.

The bad thing of the system shown here is that it is complex to use each rope side independently, wich is imho the big strengh of that system. You get at the top where the rope is looped thanks of a carbiner, ropes ends are indeed at the anchor point, not on the ground, you secure yourself, fastly change to a DdRT with one side of the rope, then you can untie the lanyard, move away and as soon as you need it you use the other end of the rope to make a second DdRT system.

With the system shown here it's a bit longer and you may drop a carabiner or a pulley manipulating it. That's impossible if you have two independent attachment points.
So pulleys have to be seperated to facilitate a double DdRT system in any situation.

That's one of my goals for making a rope walk on that setting, funny you're talking about it here as i sent back the ASAP planning to go for that !