RADS (SRT issues)

[TC]

Been using SRT (single rope technique) for ascent only for well over 10 years now.

Never really seen or used RADS (rope ascending descending system) up close as I never liked the look of the slowness of the 3:1 system (a quick judgement made first time I saw it, could've been wrong about this?).

Recently been thinking about using SRT for working and RADS seems a logical progression into SRT working before using the Ropewrench which I'm not keen on trying straight from a doubled rope system.

I found this pic in the archives here posted by 'rescueman' in 2003.

Would this system with the Petzl ID work well and what are people using for a footloop from the ascender or would a pantin work? how is the ascender in the pic being advanced up the rope and when the time comes, how is it moved down safely?

Also could the ID be exchanged easily for a Petzl grillion or gri gri?

grateful for any thoughts or answers to any of my questions.

cheers

Tim

 

[hesanarborist]

For a foot loop i spliced one out of tenex with a large eye that I girth to my foot and a smaller eye that goes to the ascender. I have also used webbing as well. I use a petzl shunt for my top ascender because you can attach a pull cord to the back that makes it follow you on descent.

I use the Petzl RIG with my RADS system but have also used a gri-gri. they all work

as you progress upwards you will need to push the top ascender upwards with you hand. There are some you tube videos out there showing how it works.

I entered the world to SRT on a work RADS and it was a very smooth transition. I believe the idea was taken from Mr. Dunlop, showed to me by moss.

 

[hesanarborist]

close up

 

[moss]

You want the footloop off the ascender/rope clamp above the Grigri or whatever inline descent device you're using. That way you are essentially getting a 1:1 ascent rate when you stand up on the footloop. If you tried generating ascent power by using a Pantin on the tail of the rope coming out of the upper redirect you will get bored really fast, that is the 3:1 side of the system, you'll be pumping your right leg going nowhere fast. Its best to use your right arm to pull rope through the redirect on the right side.

It's tricky to spec the actual MA on a RADS. I think of it as 1:1 on the left side and 3:1 for the right arm. If you are in a tight situation getting around/over a limb with a redirected access line, it's nice to move the ascender past the limb and then pull 3:1 with both arms, it makes for a smooth move to progress.

For long straight up ascents RADS is not the most efficient.
-AJ

 

[Tom Dunlap]

RADS is a great way to enter the world of SRT.

Here are pics of the Shunt release for the upper ascender.

For the lower there are many tools that work. My favorite is the Eddy. It has an over-center panic lock like the I'd but it is about the size of a Gri Gri. The cam can be 'feathered' very smoothly for limb walking too.

 

[Tom Dunlap]

When I made that configuration DMM hadn't released the locking Revolver. Now, I would use the locker. I don't like even having any non-lockers on my harness.

The bottom...substitute an Eddy for the I'd.

The key item is the tether from the Shunt to your anchor.

 

[Tom Dunlap]

"feathering' the Eddy.

 

[SingleJack]

Been posted here, before ... still using it ... still liking it:

Work RADS

... has advantages & disadvantages ... just like everything ...

 

[TC]

Thanks so far for all the good info, pics and vid.

Will get a system set up and keep you all informed of how it's going.