/ Ascending rope with two knots

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humptydumpty - on 23 Sep 2013
I've tried ascending a rope (dynamic, free-hanging) with 2 knots, and it doesn't seem very easy.

The setup I tried was:

upper knot: prussik; long sling for stepping in
lower knot: prussik, french prussik (tried both); attached to belay loop of harness

Sliding the upper knot and standing in the sling is easy enough, but it's very tricky to pull rope through the lower knot. French prussik seemed slightly better, but not significantly.

Is my setup completely wrong, or is there a better knot to use at harness level?
davidbeynon - on 23 Sep 2013
In reply to humptydumpty:

Put the prusik you stand in on the bottom, then when you stand on it the one on your harness will be dragged up a rope under tension.

Then sit in the harness and move the lower knot up at leisure.
wivanov - on 23 Sep 2013
In reply to humptydumpty:

It's not easy.

Try switching tie in points: Upper knot attached to harness, lower knot for foot sling.

Try a Bachman knot.
StuDoig - on 23 Sep 2013
In reply to humptydumpty:
Prussiking is a pain. I honestly don't think there is an "easy" way to prussik up a rope, just slightly less painful ones!

I'd have put my knots the other way round (upper prussik to harness, lower extended to a footloop). I normally use a kleimheist rather than a french or classic prussik as it seems to bite better than a french and slide easier than a classic. If I'm being particularly conscientious I'll tie a clove hitch to carabiner at belay loop level as a secondary stop in case whichever prussik I'm weighting slips or fails. It is more faff though so it'd depend on the circumstances.

Cheers,

Stuart



jezb1 - on 23 Sep 2013
In reply to humptydumpty: As others have said, swap your prussics around.

To make it easier carry a small ascender on your harness, for example a Ropeman or Tibloc which would replace one of the prussics.

Worth practising these things before you need to use them in anger!

jezb1 - on 23 Sep 2013
In reply to jezb1: Oh and just to add, always do a back up by clove hitching the rope to your harness just in case...
GridNorth - on 23 Sep 2013
In reply to humptydumpty: Belay plates that can be used in "Guides Mode" like the BD and Petzl Reverso can also be used as ascenders. I've never done this in anger but would find it preferable to either a knot or a device dedicated to one purpose.
jkarran - on 23 Sep 2013
In reply to humptydumpty:

It's always a pain. You can work a krab into each Prusik, it helps with twisting to loosen it and acts as a handle for sliding it up. As others have said, experiment with the position (and winding) of the foot-loop and wait knots.

A jammer/ascender/guide-plate at the waist, a turn of rope around the foot and a back-up knot for peace of mind works nicely for one-off single-rope climbs.

That said, Prusiks improvised from slings are almost always available while climbing making them a powerful and valuable tool.

jk
wivanov - on 23 Sep 2013
In reply to jezb1:
> Worth practising these things before you need to use them in anger!

Agreed!

Another thing to practice: Instead of starting on the ground, tie into the rope and dangle off the ground as if you've fallen off an overhang and are suspended in space. From this position, get your friction knots on the rope and ascend to the lip of the overhang to get back on the rock.

Think about what to do after you get back on the rock and have a big loop of rope in the system.

GridNorth - on 23 Sep 2013
In reply to humptydumpty: Another method is to only use one prussik which attaches to the waist. When you want to move up just take a couple of wraps round the foot and stand up and slide the knot up the rope.
NottsRich on 23 Sep 2013
In reply to wivanov:
> (In reply to jezb1)
> [...]
>
> Think about what to do after you get back on the rock and have a big loop of rope in the system.

I've wondered this and decided that I would just continue up the easier ground using the prussics sliding up the rope as an 'auto-belay' as if I was soloing up a top rope with a Shunt etc. Any better ways? I guess you could anchor yourself, get the belayer above to take in the slack and put you back on belay again?

David Coley - on 23 Sep 2013
In reply to jkarran: I'm not sure a guide plate would work with a turn around the foot. With a guide plate or Grigri a foot loop is needed above the device, not below it, or the device can't be moved up
humptydumpty - on 23 Sep 2013
Thanks for all the suggestions - will swap the knots and see if kleimheist is a bit easier.

I had a bit of trouble visualising using a guide plate on harness, but there's a couple of clear photos here: http://alpineinstitute.blogspot.com/2009/07/rappel-rope-climbing-trick.html Looks simple - also worth a try, I think.
David Coley - on 23 Sep 2013
In reply to humptydumpty:
> Thanks for all the suggestions - will swap the knots and see if kleimheist is a bit easier.
>
> I had a bit of trouble visualising using a guide plate on harness, but there's a couple of clear photos here: http://alpineinstitute.blogspot.com/2009/07/rappel-rope-climbing-trick.html Looks simple - also worth a try, I think.



It works best with thinner ropes, not a big fat single.
whispering nic - on 23 Sep 2013
In reply to humptydumpty: Or put the rope through a belay plate with a French prussic just above (attached via a small screw gate to HMS)which will act as an autobloc.
GrahamD - on 24 Sep 2013
In reply to humptydumpty:

Nothing to do with the knots, but for best comfort, try using the widest webbing foot looops you can and have a loop for each foot. Thin slings and rock boots tend to cut your feet in half after not very long !
birdman - on 24 Sep 2013
In reply to humptydumpty:

a few points which can improve your system.

1. as others have pointed out, have the top prussic going to your harness and lower one to your feet.

2. For efficiency, thread the sling for your feet through your harness waist belt. This improves your position when ascending the rope for a decent distance (ie crevasse fall scenario)

3. Consider using a different prussic to French as this can slip with contact against rock or snow / ice. Classic or Kleimhiest can be released using your thumb. A Backman is also a handy development giving you a hand hold on the rope to assist.

4. Practice in a safe environment, it's amazing how quickly you deskill!
needvert on 25 Sep 2013
Cavers are the experts at this sorta stuff so poking around caving forums could be valuable. The classic method uses three prussiks.

I've found using my thumb to move that vertical strand of the prussik to loosen it made sliding it up much easier.
needvert on 25 Sep 2013
In reply to humptydumpty:

On a side knot apparently trying a klemheist upside down results in a better knot....the hedden knot
http://storrick.cnc.net/VerticalDevicesPage/Ascender/KnotPages/KnotKlemheist.html
valjean - on 25 Sep 2013
In reply to humptydumpty:

re: using belay device in guide mode

easier than using a prussic but not by much. requires you to pull up rope through the device. annoying. but this has the advantage of not taking another bit of gear. works in a pinch, but after 60 metres of this you get tired and frustrated.

i've also used a tibloc in anger -- great piece of kit. having 2 tiblocs would better as an emergency ascending system

i own a ropeman 1, yet to use in anger. rope diameter restrictions though. tested it with a 9.8mm, seems ok.

and finally, messed around with the new edelrid megajul in locking mode. amazing emergency ascender! ymmv though
ads.ukclimbing.com
tallsteve - on 25 Sep 2013
In reply to humptydumpty:

If you happen to have a ruck sack clip this to the rope with a screwgate so that as you climb it slides down and stays at the bottom of the loop of rope that extends below you. This simultaneously adds weight to the rope making sliding the second prussik up easier, and takes the weight off your back preventing a back flip.

As an added advantage the rucksack climbs at about half your speed, so you seem to be hauling half the weight. Just watch it (or indeed any dangling loop) doesn't catch on any protuberances as you climb.

Its well worth practising with a sack. People often don't try it, and it alters the dynamics markedly. Its also an essential technique for crevasse self rescue ...
humptydumpty - on 05 Oct 2013
In reply to valjean:
> re: using belay device in guide mode
>
> easier than using a prussic but not by much. requires you to pull up rope through the device. annoying.

Thanks for all the tips in this thread - things that worked out in the end:

1. top: prusik to harness, lower: prusik as foot loop (~30cm loop when on rope). Didn't need any slings at all for this, and works quite nicely.

2. top: prusik to sling for foot loop, lower: belay device in guide mode. This also works nicely; maybe a little quicker than 2 knots, but also a little more tiring? For the foot loop, needed ~90cm sling. Switching over for descent is also really simple with this setup, but not sure how important that would be in real life.

Do people tend to use backups or safety knots? Hanging directly off a prussik feels quite weird, and so does trusting a belay device no-hands.
a lakeland climber on 05 Oct 2013
In reply to humptydumpty:

Climbers get prussiking totally wrong, look at a caver's setup to see how it should be done.

The *most efficient* way is to have the foot prussik/device above the waist/body one. It's also more efficient if you have a Parisienne Baudrier (AKA chest loop) with a krab to pull your upper body closer to the rope - ideally you want your nose rubbing against the rope. The loop to your waist wants to be as short as possible (cavers have their "waist" ascender linking their sit harness and chest harness).

Rather than sitting back and having the attachment points above you you should be almost upright with them right next to you, then the motion is basically like standing up and sitting down repeatedly. You shouldn't be using any effort by your arms to pull yourself up, it should all be in the legs.

ALC

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