Pull Cord - Risks of using two tied together

[mzamp]

So I finally ordered a long enough rope to do Heaps, Waterholes, etc. (Thanks Tom!) My pull cord is only 200ft. How risky is it to just tie another 120ft rope to the pull cord (say with a EDK)? I'm thinking not anymore risky than the block getting caught on something.

Opinions???

[jman]

I personally would use a double-fisherman. As I heard a long time ago, "when in doubt, double-fisherman". EDK is great, and very easy. As well as easy to mess-up if you don't set it up right. EDK also depends on knotability of the rope. IE brand new, stiff ropes is probably not the right time to use a EDK.

Tom has a tech tip about this very subject:

http://www.canyoneeringusa.com/techt...opes-together/

[Iceaxe]

"when in doubt, double-fisherman".

I believe the actual quote is "when in doubt, tie more knots".

I would have no problem using an over-hand knot (EDK) on my Heaps pull chord. In fact that is exactly what we have always done in the past with an EDK at the top and an EDK at the mid-point.

My take is a knot is either safe or it is not safe. If it's not safe it should never be used. If it's safe at 200' it's safe at 300'.

The BIG difference with a really long (300') pull is the weight of your orginal rappel line can make it really difficult to start the pull. And the extreme length of your pull cord will create a lot of streach that can make it really difficult to start the pull. And when you combine the two factors it can make it really really difficult to start the pull.



Just for giggles, here is some interesting test data on EDK, Figure 8 and Double Fisherman knots:
http://user.xmission.com/~tmoyer/testing/EDK.html

From the testing it appears the double fisherman is the gold standard.

[Deathcricket]

One problem I have with long pull cords is they tend to be super stretchy. So you start pulling on it and it just bounces like crazy. plus the rope is so thin it's hard to hold it firmly even with gloves. So if that happens just tie it to a thick stick and have your buddies help you torque on it. Never had a problem with a knot getting loose, just getting it undone after cause it is super tight!

Edit: Dammit ice beat me to it. I gotta stop opening so many tabs and answering in between work.

[ratagonia]

I believe the actual quote is "when in doubt, tie more knots".

I would have no problem using an over-hand knot (EDK) on my Heaps pull chord. In fact that is exactly what we have always done in the past with an EDK at the top and an EDK at the mid-point.

My take is a knot is either safe or it is not safe. If it's not safe it should never be used. If it's safe at 200' it's safe at 300'.

The BIG difference with a really long (300') pull is the weight of your orginal rappel line can make it really difficult to start the pull. And the extreme length of your pull cord will create a lot of streach that can make it really difficult to start the pull. And when you combine the two factors it can make it really really difficult to start the pull.



Just for giggles, here is some interesting test data on EDK, Figure 8 and Double Fisherman knots:
http://user.xmission.com/~tmoyer/testing/EDK.html

From the testing it appears the double fisherman is the gold standard.

Or: "If you don't tie knots, tie LOTS!" Personally, when my life is at stake, I think it is a good idea to actually know your knots. If not concerned about untying the knot in the field, even I would probably use a double-fisherman's.

It would be 'interesting' to end up at the bird perch in Heaps with exactly one 300' rope and one 300' pull cord, even if it has a knot in it somewhere. Except the first and second, and the second to last and last, all the raps in Heaps are less than or equal to 60 feet. So, you are likely to have more actual rope than the strand for the final.

Pull Cords longer than 200 feet are to be avoided, although Heaps is almost an ideal pulling situation. Even my 'static' 6mm pull cord still has quite a bit of spring in it, and spring makes getting a rope pull started more difficult. So use all your real static ropes first, then add your pull cord at the end.

[mzamp]

Thanks everyone…That’s the info I was looking for. Yes, my 200ft pull cord is a pain to get started with the stretch even on what should be an easy pull. So use all your static ropes first…Sounds logical!

As a side note: I have only once rapped double stranded with a EDK in a situation where there were 6 160ft raps and they were not off line enough to get out of the way of the rock fall being caused by the careless idiots above…it was crucial to get down and out of the way as quickly as possible. I know it was tied correctly because my friend who teaches rope access tied it. I would typically use the double fisherman. It was the most scared I have ever been on rappel…being showered with softball sized rocks from 400ft above and no place to hide.

[moab mark]

We regularly rappel on a double EDK. Have never seen one slip a bit. Seems to be the knot of choice now a days.

[hank moon]

In general:

- Double Fish only when knot is permanent (e.g. Prusik sling)
- Double EDK to tie pull cords/ropes together
- Flemish bend or similar to join ropes for rappel or ascent

[Iceaxe]

In general:

- Double Fish only when knot is permanent (e.g. Prusik sling)
- Double EDK to tie pull cords/ropes together
- Flemish bend or similar to join ropes for rappel or ascent

I knew there was a reason I called you MacGyver of the canyons.

[mzamp]

I'm Knot familiar with the flamish bend. I will have to look that one up.

[moab mark]

http://www.animatedknots.com/fig8join/index.php

[Iceaxe]

I'm Knot familiar with the flamish bend. I will have to look that one up.

Some call it a rethreaded figure 8.

A long time ago this was my preferred knot for tying two ropes together. It's a good knot to know.

Tap'n on my Galaxy G3