How do you like this tether/ rappel extension ?

Nathan Self wrote:Eric, What did you do to these people to make them act like such jerks? By the way, it's a-ok to review and experiment with your systems...just be careful and check your work!

Thank you for being a mensch. I feel a bit like Giordano Bruno, haha.

ViperScale wrote:You maybe should look up what redundant means. It basically means 2 completely different things have to fail for the system to fail.

That isn't what it means.
REDUNDANT
a : exceeding what is necessary or normal : superfluous
b : characterized by or containing an excess; specifically : using more words than necessary
c : characterized by similarity or repetition
d chiefly British : no longer needed for a job and hence laid off

Simply put a harness is not unnecessary. It is not redundant.

Eric Moss wrote: That was actually my inspiration for this. I saw the 120 mm sling setup in the AMGA Single Pitch Manual, but I didn't think it was redundant enough. Plus, this one can be detached without having to undo a girth hitch.

For what reason do you want redundancy of that sling? Especially when both ends it is attached to aren't redundant.

A solution without a problem.

patto wrote:Simply put a harness is not unnecessary.

Tell that to all the Yosemite originals putting up some of the classic lines in swami belts and swiss seats.

patto wrote: For what reason do you want redundancy of that sling? Especially when both ends it is attached to aren't redundant. A solution without a problem.

As BD has shown is, fatal manufacturing errors can happen. That's the only reason I'd want the sling to be redundant, but considering the belay device and biner aren't redundant, it wouldn't really bother me. That's the risk I choose to take when I leave the ground.

On the other hand, it is fun to fiddle with gear and systems on a rainy day so cheers to you, Eric, for thinking outside the box.

wasn't the original post talking about backing this up with a shunt?

A backup is your redundancy - every single component doesn't need to be individually redundant.

eli poss wrote: it is fun to fiddle with gear and systems on a rainy day

So fun!

Anyway, the AMGA is redundant by some definition, but not by mine. This is theirs:

Their thinking is that the overhand knot will catch you if one end of the sling fails, but if the sling fails near the knot it might not. That's why my personal definition of redundancy is that, failure of one part in the worst way possible doesn't result in system failure.

I don't think I know better than the AMGA. Their setup seems good enough.

Brandon.Phillips wrote:wasn't the original post talking about backing this up with a shunt? A backup is your redundancy - every single component doesn't need to be individually redundant.

You're exactly right.

I actually meant to say this is not necessary with a shunt because the shunt is itself a backup. If I were just backing up the rappel with a friction knot, I'd prefer redundant belay biner attachment. The difference is that a shunt can't melt if it starts slipping.

isn't that why you are backing up your rappel in the first place?

Brandon.Phillips wrote:isn't that why you are backing up your rappel in the first place?

I wouldn't count on a french prusik / autoblock to catch my weight if my attachment to my belay biner failed, but I am paranoid. Actually, every book I've read recommends a redundant belay extension when using a friction hitch backup.

Correction: Self Rescue by Fasulo presents one such extension without redundancy, alongside one with redundancy. I'm still confused by this, but I suppose it's fair to expect a single good belay biner attachment to hold in rappels.

Just curious, what situation are you imagining that your attachment to your belay biner fails?

Most people, that i know of, think of backing up a rappel as a means to back up their brake hand (primarily). In case something happens where they lose control of their brake hand (rock fall, etc.) their backup maintains the brake.

patto wrote: That isn't what it means. REDUNDANT a : exceeding what is necessary or normal : superfluous b : characterized by or containing an excess; specifically : using more words than necessary c : characterized by similarity or repetition d chiefly British : no longer needed for a job and hence laid off Simply put a harness is not unnecessary. It is not redundant. For what reason do you want redundancy of that sling? Especially when both ends it is attached to aren't redundant. A solution without a problem.

According to the google.

(of words or data) able to be omitted without loss of meaning or function.
Engineering
(of a component) not strictly necessary to functioning but included in case of failure in another component.
British
(of a person) no longer employed because there is no more work available.

It makes number 2 100%. The point of a harness is to keep you from hitting the ground if you fall. If your waist strap fails the leg straps will keep you from hitting the ground.

I actually don't think of it in terms of specific scenarios. I know there are many factors such as manufacturing mistakes, rope burn, chemical contamination, or overloading that can occur in unpredictable ways. I abstract these together as a possibility of failure for every piece of gear.

Eric Moss wrote: but I am paranoid.

Yes.

Technically belay loop is redundant because there are 2 of them wrapped around (given I say that is questionable redundancy since you are taking 2 pieces that are singly strong enough and basically melting them together into 1 piece and means a single rock fall on it could destroy both).

There is the redundant definitions you can find in the dictionary and wiki ad infinitum. In climbing, the term is simply meant that if this piece of gear fails is there another piece of gear that can save your life. If the belay loop fails, someone is going to get hurt or die.

Calling the belay loop redundant because it has two or three wraps, hundreds of stitches or thousands of fibers misses the climbers use of the term redundant. It would be similar to calling the rope redundant because it's made of thousands of fibers or a biner redundant because it's made of millions of molecules.

All of these components are very strong when in good condition. But all do fail from time to time. Perhaps we should focus on the spirit of the climbers definition of redundant, not some literal Google wikki bull shit.

Greg D wrote:Perhaps we should focus on the spirit of the climbers definition of redundant, not some literal Google wikki bull shit.

And wile we're at it, perhaps we should do a better job of ignoring forum trolls desperately seeking attention.

ViperScale wrote: According to the google. (of words or data) able to be omitted without loss of meaning or function. Engineering (of a component) not strictly necessary to functioning but included in case of failure in another component. British (of a person) no longer employed because there is no more work available. It makes number 2 100%. The point of a harness is to keep you from hitting the ground if you fall. If your waist strap fails the leg straps will keep you from hitting the ground.

Even with your chosen definition a "harness" is not redundant. Because if the harness fails there is no other component to back it up.

Your use of the word redundant is incorrect. Trying to distort the english language to fix you mistake is just sad.

ViperScale wrote:Technically belay loop is redundant because there are 2 of them wrapped around (given I say that is questionable redundancy since you are taking 2 pieces that are singly strong enough and basically melting them together into 1 piece and means a single rock fall on it could destroy both).

No it isn't.

Greg D wrote:There is the redundant definitions you can find in the dictionary and wiki ad infinitum. In climbing, the term is simply meant that if this piece of gear fails is there another piece of gear that can save your life.

Exactly. And that ties in pretty damn closely to dictionary definitions.

Now if we used the word "redundant strength" then arguably most climbing equipment has redundant strength for general use. However this is a deliberate choice to cater for extreme circumstances.

Eric Moss wrote:I actually don't think of it in terms of specific scenarios. I know there are many factors such as manufacturing mistakes, rope burn, chemical contamination, or overloading that can occur in unpredictable ways. I abstract these together as a possibility of failure for every piece of gear.

I'm not sure that climbing is for you.

p.s. I'm not trolling you

p.p.s. Really, you if you can't trust a bar stock carabiner and a back-up prussik then you either need more experience or climbing isn't the sport for you.

Eric Moss wrote:manufacturing mistakes

These are so few and far between that the probability of them being an issue for you is effectively 0%
Just check your gear when you buy it and you'll be fine

Eric Moss wrote:rope burn

The only way rope burn is going to be an issue for your gear is if you allow your rappel extension to wrap around the rope. Pay attention that your extension is not twisted and this won't be an issue.
If you are worried about the rope "burning" through your rappel biner then you apparently need to be replacing your biners much sooner than you do. Carry a steel biner if you are really that worried about it

Eric Moss wrote:chemical contamination

Don't store your gear next to cleaning supplies or in your garage and don't climb at cartoony chemical plants

Eric Moss wrote:overloading

Apparently you do not understand just how strong climbing gear is. Do you really think you are going to apply 2 tons of force on your rappel extension? Make sure that you are not cross loading or triaxially loading your biners and they'll be fine. There are several biners from several manufacturers that make biners specifically designed to prevent cross loading for belaying/rappelling (not sure how you would manage it while rappelling) if you are really worried about that.

All and all, just make sure you are using your gear correctly and retire it at the appropriate time or find a different sport.

This thread is still happening?