Z-rig safety - noob question

[Attila]

Since this is my 1st post, I can't post pictures, so I'll describe.

Using a z-rig with an ATC, I've seen illustrations where the rope feeds the ATC as usual, down through a leg-loop biner, up through 2 biners above the ATC, then finally down to the brake-hand. My question is about the 2 biners above the ATC. They are attached around the load rope and are reversed/opposed for the gates. It seems to me that they will have a large amount of torque and it is levered right on the gate of the bottom biner (it's pinched between the ATC and the top biner) setting up a possible failure of the gate.

Am I missing something here? Please educate me.

[Absolute Gravity]

I use one locker instead of the 2 reversed/opposed. Even so, I can see how this could still happen but not sure that the amount of torque is really very large even if it did. There is so much friction in the system that there shouldn't be a whole lot of weight pulling down on that top biner.

[Iceaxe]

I assume you are looking at a Z-Rig picture similar to this....

http://www.bogley.com/forum/attachment.php?attachmentid=57363&d=1344173933

I use two locking biners to complete a Z-Rig, one on the leg loop and one on the rope above the rappel device. I don't even carry non-lockers with me.

Lots of good info in this thread: http://www.bogley.com/forum/showthread.php?64958

When you attach to the lower leg loop of your harness make sure it is part of the load bearing webbing. This is not an issue with most harnesses, but it can be with a BD Alpine bod as part of the leg loops are held in place with a plastic snap link and are only meant to stop the leg loops from falling down while walking.

:popcorn:

[Attila]

That is the very picture (unable to post pix yet). I've seen the same setup in actual camera pictures also and it just seemed unsettling to me.

I also see pros/cons to 1 or 2 biners. With 2 biners, you have a backup should a gate fail. But hooking into those 2 would be tricky. Wereas with 1 biner, the hookup would be easy, but no redundancy for the gate. A failed gate wouldn't kill you, but the sudden drop would shorten your life.

[Slot Machine]

That is the very picture (unable to post pix yet). I've seen the same setup in actual camera pictures also and it just seemed unsettling to me.

I also see pros/cons to 1 or 2 biners. With 2 biners, you have a backup should a gate fail. But hooking into those 2 would be tricky. Wereas with 1 biner, the hookup would be easy, but no redundancy for the gate. A failed gate wouldn't kill you, but the sudden drop would shorten your life.

When you are in combat conditions, 200 feet off the deck, you will suddenly lose interest in placing 2 biners above your ATC. Clipping that last bit of the Z-rig is more work than you might imagine.

Trust me, just use one locking biner.

While canyoneering, we don't bring any non-locking biners. Don't want things falling onto people below. On rappel you will bump into things, and gates will open.

And like Ice said, be careful where you place your leg loop biner, if that sucker came loose... :eek2:

This thread might help a little, or at least make you laugh: http://www.bogley.com/forum/showthread.php?62272-How-to-rappel-from-300-feet

Bob

[ilipichicuma]

Failing gates on carabiners.... I'm not sure that happens very often. I feel like you don't hear stories about that. It's usually user error or the like and the biner itself is rarely to blame. I've used a z-rig before, felt totally secure on just one locking biner on the top rope.

[Scott Card]

I agree with the one locking biner. The last thing I want to do when feeling like I am going to fast mid rap is to have to try to figure how to stop and thread a rope through two opposing gates of non locking biners. It is tough enough to do one handed with one biner let alone one handed with two biners with gates opposed.

[Brian in SLC]

I dunno...I guess I wouldn't bother with locking carabiners on either end of that Z rig. They're loaded up and shouldn't really be moving around much...

[Slot Machine]

They're loaded up and shouldn't really be moving around much...

Yes, you are correct.

My opinion is somewhat a reflection of my own clumsiness. I bump into things and open biners.

I picture bumping a biner with my arm/hand/rope/wall etc and undoing part of the Z-rig. I also picture bumping them off my rack and dropping them on people. A graceful rappeller, I am not. :haha:

[oldno7]

I dunno...I guess I wouldn't bother with locking carabiners on either end of that Z rig. They're loaded up and shouldn't really be moving around much...

I agree with you in a technical aspect, Brian.

The only biners that require locking are those with a life attached.(Z-rig is a simple redirect)

I disagree from a practical standpoint--We are all striving to minimize gear. There are many things you can and should

do with locking biners that you should not do with a non locking biner.

So for the small difference in weight and price, it would be of interest for trained canyoneers to carry locking carabiners. imo

[Scott Card]

I don't carry non-locking biners into canyons. So I guess by default anything I do in a canyon is with a locking biner.

[Iceaxe]

I don't carry non-locking biners into canyons. So I guess by default anything I do in a canyon is with a locking biner.

X2

Tap'n on my Galaxy G3