R.A.D. srt question

robinia

robinia

Participating member
Location
Ontario, Canada
Hi folks,
first time visiting and posting-
I've gotten conflicting answers re: if the R.A.D. single rope technique system using a petzl I'D requires a backup.
This seems to be the place to get a final answer. Any thoughts? Also any ideas for a good backup if it is in fact required?
Thanks,
Rob
 
I'm running it exactly as illustrated in the Sherrill catalog: Ascender above the I'D, footloop attached to the ascender, and the tail or the rope from below the I'D up and over a micropulley. I can take a picture or scan the image out of the catalog if that helps...
 
There is no requirement to back up a friction hitch so why is there this misconception that there is a requirement to backup a friction device?

To be consistent there would be a requirement to have a second attachment while ascending a doubled rope but there isn't. Whenever I ask people about this difference there is either a blank look response or some vague answer.

Backups, or a better concept to use is, second attachment points, should be considered whenever possible. In some systems a second attachment isn't practical. RADS is one of them.

The Edelrid Eddy is a tool that works really well in the RADS in place of the I'd.
 
The short answer is: "No, you don't have to back up an i'D."

As Tom states, a second attachment point is always a good idea if possible.

I use my i'D for RADS, rappelling, and work positioning. Now, rappelling on a figure 8 should be backed up because if you let go... you hit the ground. This is not the case with the i'D.
 
you recommended that Eddy so much I went and got one, and am getting to know RADS. No backup required, but you could put one in somewhere during the ascent phase (i.e. prussik above hand ascender if you are tethered to it) No one in Canada sells the Eddy, and it seems Sherrill type suppliers don't stock it either. How come I wonder?
 
hey tom, if i am running a single ascender, with a foot loop and attachment point, and backing it up with a 6 wrap prussic above, do i need to be attached to the prussic as well, or is just clipping the prussic into the top eye of the ascender enough of a back up?
 
Kiwi,

I don't feel that having a friction hitch above the upper ascender is a safe arrangement. There are MUCH safer and more fool proof systems that are actually backups.

My opinion does run counter to accepted arbo practices I know.

Having a chest ascender or even a micrograb attached to your bridge is a MUCH safer setup.

There are so many things that can go wrong with a hitch being pushed up by an ascender. In order to have the hitch run smooth it has to be left a little loose. What happens if the ascender fails and the hitch is loose too? Ground fall or at least a slip/drop. If the hitch is attached to a biner through the upper eye of the ascender then the two are not really backing each other up. In order to have proper backups the chain of connection starts at the rope and goes to the harness. Two separate paths.

There's no arguing, using the hitch above the ascender is convenient...but is it safe? I don't think so. If you read about backups that are accepted in any other working rope profession they would not accept a system like this. In all of my reading on backups they are two separate systems.

Using a handled ascender for an upper, clip a biner through the top eye to capture the rope, attach your foot stirrup to the upper ascender not the bottom hole in the ascender. then, make a sling/tether to connect the upper biner to your harness. One attachment finished.

There are many ways to setup a lower attachment. Chest ascender is probably the best. Attaching a chest ascender to most harnesses is a chore. There aren't proper attachment points. I know some climbers who will tie a hitch with a slack tender to their bridge like a typical split tail as a lower attachment.

Look at:

http://storrick.cnchost.com/VerticalDevicesPage/VerticalHome.shtml

and pick out a 'Type 1 lever cam ascender' for a lower.
 
maybe your employer will give you more access to the computer now that he knows you can school him in a tree. So far so good with for my Eddy with the 11.7mm Poison Ivy.
 
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