New Personal Escape Descender - Petzl Exo

[adleedy]

I just picked up this very one myself - brand new and really cheap (like 90% off retail).

OK...where did you get it?

eBay of course. It was still sealed in the packet - probably came out of an army surplus lot.

The guy's listing said buy-it-now, so what's a gear junkie to do? Like a moth to the flame...

yes i seen this on ebay, almost bidded on it but decided i had no use for it.

[NZcaver]

yes i seen this on ebay, almost bidded on it but decided i had no use for it.

Yeah - me too! (No use for it, that is.) The instructions say absolutely not to attempt ascending on it, so maybe I'll give that a try some time...

[adleedy]

NZCAVER-- how much rope did that kit come with?

[NZcaver]

NZCAVER-- how much rope did that kit come with?

82 feet of 5mm Tech Cord - which retails for $1 a foot, by the way. Further details here.

[Stridergdm]

I just picked up this very one myself - brand new and really cheap (like 90% off retail).

OK...where did you get it?

eBay of course. It was still sealed in the packet - probably came out of an army surplus lot.

The guy's listing said buy-it-now, so what's a gear junkie to do? Like a moth to the flame...

yes i seen this on ebay, almost bidded on it but decided i had no use for it.

What does actually NEED for use have to do with acquiring gear?

Hmm, gotta go find a ferno for sale cheap...

[Stridergdm]

NZCAVER-- how much rope did that kit come with?

82 feet of 5mm Tech Cord - which retails for $1 a foot, by the way. Further details here.

5mm huh.. Yeah that's definitely a "the alternative will be worse" type situations before I'd really really want to use that.

[adleedy]

NZCAVER-- how much rope did that kit come with?

82 feet of 5mm Tech Cord - which retails for $1 a foot, by the way. Further details here.

5mm huh.. Yeah that's definitely a "the alternative will be worse" type situations before I'd really really want to use that.

I whole heartedly agree

[NZcaver]

5mm huh.. Yeah that's definitely a "the alternative will be worse" type situations before I'd really really want to use that.

Oh, I dunno...

I remember when I was first introduced to a similar cord all those years ago - 5.5mm Spectra. The guy in the shop said it was "a bit fast" through his rack, even threaded back and forth a couple of times. But then he said the real freaky thing was hearing the Spectra "creak" as he climbed it on his Jumars!

I figured he tried all this out at a local 60-foot high quarry where climbers practice. Nope - he apparently tried it here... or so he said.



Lost World, Waitomo, New Zealand. A 300 foot free rappel. You can even pay to do it - but you'll have to use full size rope.

By the way, at the time that guy was the president of the New Zealand Speleological Society.

[adleedy]

5mm huh.. Yeah that's definitely a "the alternative will be worse" type situations before I'd really really want to use that.

Oh, I dunno...

I remember when I was first introduced to a similar cord all those years ago - 5.5mm Spectra. The guy in the shop said it was "a bit fast" through his rack, even threaded back and forth a couple of times. But then he said the real freaky thing was hearing the Spectra "creak" as he climbed it on his Jumars!

I figured he tried all this out at a local 60-foot high quarry where climbers practice. Nope - he apparently tried it here... or so he said.



Lost World, Waitomo, New Zealand. A 300 foot free rappel. You can even pay to do it - but you'll have to use full size rope.

By the way, at the time that guy was the president of the New Zealand Speleological Society.

DO WHAT??

[Stridergdm]

5mm huh.. Yeah that's definitely a "the alternative will be worse" type situations before I'd really really want to use that.

Oh, I dunno...

I remember when I was first introduced to a similar cord all those years ago - 5.5mm Spectra. The guy in the shop said it was "a bit fast" through his rack, even threaded back and forth a couple of times. But then he said the real freaky thing was hearing the Spectra "creak" as he climbed it on his Jumars!

I figured he tried all this out at a local 60-foot high quarry where climbers practice. Nope - he apparently tried it here... or so he said.


By the way, at the time that guy was the president of the New Zealand Speleological Society.

Wow.. I'd be real interested to see what the breaking strength on the Spectra would be after a few passes through a rack. Those tight bends can't have been good for the fibers.

[NZcaver]

Wow.. I'd be real interested to see what the breaking strength on the Spectra would be after a few passes through a rack. Those tight bends can't have been good for the fibers.

Interesting thought... but unless you have a big tree for a tensionless hitch, you'll be tying a figure 8 or figure 9 on the bight to rig the Spectra anyway. The bends in those knots are a little tighter than rack bars, even if they are relatively stationary.

Like I said - that's the story he told me. Knowing him, it's probably true.

[Stridergdm]

Wow.. I'd be real interested to see what the breaking strength on the Spectra would be after a few passes through a rack. Those tight bends can't have been good for the fibers.

Interesting thought... but unless you have a big tree for a tensionless hitch, you'll be tying a figure 8 or figure 9 on the bight to rig the Spectra anyway. The bends in those knots are a little tighter than rack bars, even if they are relatively stationary.

Like I said - that's the story he told me. Knowing him, it's probably true.

True, but those knots are probably pretty static. I'm thinking repeated use of a rack here.

A mutual friend had a piece of his spectra tested... failed at about 1/2 its original rated strength. This was from use on his cowstail I believe for 4-5 years. Good old Nylon is still my favorite.

[NZcaver]

A mutual friend had a piece of his spectra tested... failed at about 1/2 its original rated strength. This was from use on his cowstail I believe for 4-5 years. Good old Nylon is still my favorite.

Using Spectra for a cowstail? Yikes!!!

[ek]

Well umm... yeah.. it's pretty cool alright... but how do we get back UP... we're cavers we go DOWN first then go back up!

There are many ways that doing what I am about to suggest with the Exo could lead to death, and I am not recommending it, but as a thought experiment...

Assuming that the descender works like a Gri-Gri, if you have an upper ascender that is safe for use on a 7.5mm rope, you could hang a small pulley (a carabiner would work but not be ideal) from the upper ascender and run the braking end of the rope through it. At this angle, the rope will feed freely backwards through the descender, but lock when the descender is weighted. So you can stand up into your foot loop and, if there is insufficient rope weight below, pull the rope down through the pulley. Then sit down and lift the upper ascender (thereby lifting the weight of the rope below plus friction in the pulley...but that wouldn't be too bad since it's 7.5mm rope!). When you're done frogging up, the system is reset to its initial configuration, with the descender at the top of the rope. And a changeover is extremely easy.

It looks like the Exo is designed for a single use, though. The rope might not be sufficiently abrasion-resistant for caving. Plus I don't think it's designed for rescue loads--it is a personal escape system.

Hmm...the rope is fire-resistant. Perhaps that would be good for preventing disasters arising from carbide-related buffoonery on rope.

Big problem: Rebelays are required much more often with thin, non-abrasion-resistant ropes. How are you going to pass them? And if you notice an weakened point in the rope and tie it off, how are you going to pass the knot? Plus each caver using the system must rig the cave separately.

Solution to the rebelay problem: Say there are N rebelays. Bring N+1 Exo's down with you (one of them rigged at the top). When you get to the first rebelay, clip into the anchor, unclip your descender, rig your second Exo, clip into it, unclip from the anchor, rappel down to the second rebelay...

Solution to the knot-passing problem: Don't worry about passing the knot. Bring a big sack of backup Exo's (rope and attached descender, you can leave out the hook) and deploy as needed. Remember your sheet bend.

[NZcaver]

Solution to the rebelay problem: Say there are N rebelays. Bring N+1 Exo's down with you (one of them rigged at the top). When you get to the first rebelay, clip into the anchor, unclip your descender, rig your second Exo, clip into it, unclip from the anchor, rappel down to the second rebelay...

Solution to the knot-passing problem: Don't worry about passing the knot. Bring a big sack of backup Exo's (rope and attached descender, you can leave out the hook) and deploy as needed. Remember your sheet bend.

Solution to both situations - think outside the box.

Instead of rigging normal rebelays with knots in the rope, rig them with Prusik loops instead. Of course on 5mm Tech Cord you'd have to use something like 3mm parachute cord for the Prusiks - but that should be fine, right?

Then all you do is rappel down to just above the rebelay, remove the Prusik, place it back on the rope (cord) above you, and descend a little further bringing the Prusik down with you. Then comes the fun part - attach a micro-sized 5:1 haul jigger between the bolt and your Prusik, use it to drag the Prusik (and your own body weight) back up, and clip the Prusik back into the bolt directly. You'll find this quite easy if you use your own weight as a partial counterbalance for the jigger.

With this method, your (one and only) descender stays on the rope at all times - brilliant! For the climbing phase, transfer your weight to your upper ascender above the bolt as you pass each rebelay, and then simply remove the Prusik and re-attach it back on the rope below your lower ascender/device. Easy!

[Legal disclaimer - don't mistake this for good technical advice...]