Quantcast
It is currently Sat Dec 20, 2014 3:07 pm

All times are UTC + 2 hours




Post new topic Reply to topic  [ 15 posts ] 
Author Message
PostPosted: Wed Aug 14, 2013 4:09 am 
Offline

Joined: Thu Aug 28, 2008 7:12 pm
Posts: 20
Real Name: Vaughn Cleminson
Hi guys

Just wondering if you backup a abseil with a Prussic cord, as a rule?
I've noticed people backup above (clipped to the belay loop), and I believe you can place the Prussic below the belay device and clip to the leg loop (which seems odd).
Seems a bit if a faf, which is why I ask.

Cheers


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 7:14 am 
Offline

Joined: Mon Jun 10, 2013 8:39 am
Posts: 46
Real Name: Mike J
autoblock on leg loop is the way to go. prusik takes too long


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 7:32 am 
Offline
User avatar

Joined: Tue Apr 10, 2007 3:39 pm
Posts: 88
Using a prussic on your leg loop is what you are meant to do. This holds the rope in the correct spot if there is a problem. but a lot of us are just lazy and don't do it properly


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 7:38 am 
Offline
User avatar

Joined: Mon Feb 01, 2010 11:23 am
Posts: 248
Location: Cape Town
Real Name: Cormac Tooze
It's for safety/redundancy
There are pro's and con's to above or below.
Personally I use below, on leg loop with belay device on belay loop extended by sling.
You can also use a shunt, It's an extra piece to carry but works very well.


Attachments:
Friction Knot Below The Descending Device.jpg
Friction Knot Below The Descending Device.jpg [ 82.62 KiB | Viewed 962 times ]
Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 7:59 am 
Offline

Joined: Tue Jan 17, 2006 1:23 pm
Posts: 124
Location: Gauteng
Like most things in climbing adding a piece of equipment may make things safer but also brings its own complications. There are very good reasons why many climbers view abseiling as the most dangerous climbing technique and would generally try and avoid it. Here are my views.

I use a prussic backup as a standard. You just need a short pendulum, a moment’s inattentiveness or a couple of wasps to make things go pear shaped VERY quickly esp. abbing down a long route at night. Helps when you need to sort out tangled ropes etc.

The prussic below and above have pros and cons:

Below: Easier to unlock when loaded. Easier to go over places where the rope pinches against the rock (e.g. over a bulge). However, it is very easy for the prussic to ride up and be positioned against the belay device and then the belay device “minds” the prussic and you have no backup. This is especially dangerous on a slanting abseil where it common for your legs to be higher up to prevent the pendulum – the higher position of your thigh means the prussic on the leg loop is also higher and in greater danger of getting in contact with the belay device. An inadvertent capsize (e.g. beginners not moving their legs down as you go are prone to this) will most likely end up in a complete failure. In general I would advise putting your belay device on a doubled 60cm sling on your belay loop when using the prussic below to protect against the belay device and prussic getting in contact. Watch out for a too long prussic (that can touch the belay device – rather get a shorter prussic or tie a figure 8 to shorten it). Be sure to use a screwgate.

Above: Much more difficult to screw this one up but one sure way to screw it up is to place the prussic too high where you cannot reach and then cannot unload it. Unloading the high up prussic once locked can be difficult (or impossible for those without the necessary skills). Absailing over bulges and overhangs where the rope tightly pinches on the rock can be very tricky.

For both setups be very careful to test the prussic beforehand and ensure that it bites on the rope. It is one thing to have it as a backup but when you let go on purpose (e.g. to sort out tangled rope) you ARE trusting your life on a piece of 6/7 mm cord that may or may not bite onto your skinny, shiny new rope. Make 100% sure you have enough prussic wraps so that it bites securely and that the knot you use (french or the true prussic) is the best one for the job.

NEVER, EVER, EVER abseil with a prussic into water. A rope and prussic tangle in water can (and has) been deadly.

Lastly: A prussic as a backup is not a very good solution to protecting a complete abseiling novice. Rather belay the person from above with a separate rope and consider putting a releasable abseil connection on the main rope (read up on this before taking your friends for a abseil and preferably have another experienced person along). The only abseil pickoff that I have witnessed was when a novice abseiler locked the prussic and then could not unlock it again - we got back to camp after dark but the lesson about novice abseilers and making things simple for them stuck with me ever since.


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 8:21 am 
Offline

Joined: Mon May 25, 2009 10:29 pm
Posts: 26
Just to add on to what Dean said, getting your prussic up against your belay/abseil device or even into it can really ruin your day. I would be carefull of using the french prussic in this case as any pressure, against the rock or your leg, could cause a french prussic to slip. Rigging the abseil using a sling or cow's tail as Dean suggests is probably the best idea if you want to use a french prussic as the above would then be less likely to happen. Of course the advantage of a french prussic is that when it is properly made(enough wraps and dressed) it will bite, even if not properly minded and it can be released under tension. Use a locking biner at all times, ESPECIALLY ON A FRENCH PRUSSIC!...sure I won't have to explain why :thumright

Be carefull of how you attach your prussic to your leg loop if you choose to do so. Auto-locking or 'ziplock' buckles on a leg loop can become undone when a prussic pulls on the 'outside' of the buckle effectively unlocking it. Make sure the prussic is on the inside of you leg from the buckle as this failure can then not happen.

:thumleft: Happy climbing!


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 10:29 am 
Offline

Joined: Thu Jul 12, 2012 12:09 pm
Posts: 16
Real Name: Immo Bartens
I've only used a prussik on very precarious abseils. Another safety precaution that can be taken when more than one person abseils off the same line is a "dead man's belay"(not sure if that's the correct term).

Most experienced abseils first(prussik or no prussik). Once at the bottom, he then just holds onto the abseil line(or keeps the line in his abseil device) for the next(less experienced abseiler's) descents. If something goes wrong, he just loads the line to lock the descending abseiler's belay device causing him to stop automatically.

kyknoordfokvoord


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 10:51 am 
Offline

Joined: Tue Jan 17, 2006 1:23 pm
Posts: 124
Location: Gauteng
immortality wrote:
"dead man's belay"(not sure if that's the correct term)


I know it as a Fireman's Belay (which sounds a bit safer :lol: )


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 11:03 am 
Offline

Joined: Mon Apr 02, 2007 9:40 am
Posts: 787
Location: Stellenbosch
Real Name: Nic Le Maitre
Hi there

I also regard it as rather a faf and consequently use it rather less than I probably should when out climbing. That said I also generally try to avoid abbing in when I can walk around simply because in most cases it is faster, safer and causes less grief down below (if you have ever had a rope/rock dropped on you you'll understand).

As Hendrik, Cormac and Dean have said, the prussik on the leg loop is easier but some what less safe in some situations. The best advice is learn the 3 major prussik types (3-wrap/Klemheist/French) and their respective advantages and disadvantages and use what suits the situation best.

If you need to stop on an abseil and don't have a prussik, wrap the rope around your leg several times, that will hold you easily.

_________________
Happy climbing
Nic


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 12:06 pm 
Offline

Joined: Fri Dec 15, 2006 12:32 pm
Posts: 1173
Location: Cape Town
Real Name: Willem Boshoff
extending your belay loop (as per Cormac's picture) works really well because:
your center of gravity is now below the abseil device
causing less strain on your core to stay in an upright position (especially with a backpack on)
and your hand that's on the prussic helps keen you upright & from spinning.

i prefer to attach the prussic to my belay loop with a small biner, running right below the belaly device - keeps everything aligned; easy to hang "hands free" if you need to rest / take pictures / clean gear. works like a charm.


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 1:37 pm 
Offline
User avatar

Joined: Fri Sep 25, 2009 11:21 am
Posts: 277
Real Name: Henk Grobler
Agreed with Mok. Most of the time I extend like that and clip the prussik to the belay loop, making sure that at full extension it does not run into the device.

_________________
You may still be here tomorrow, but your dreams may not. Cat Stevens


Top
 Profile  
 
PostPosted: Wed Aug 14, 2013 6:41 pm 
Offline

Joined: Wed Jan 31, 2007 8:09 pm
Posts: 253
Once you've mastered a skill, its really not a faf anymore.
Dean's summary is a good one. Try both and pick your favourite.

Wondering when you're going to die when you're trying to have a good time is a faf.
Medical bills and funerals are a faf.


Top
 Profile  
 
PostPosted: Thu Aug 15, 2013 8:44 am 
Offline

Joined: Mon Oct 16, 2006 8:53 am
Posts: 899
Location: Cape Town
Real Name: Charles Edelstein
Any system that adds complexity to an otherwise simple system is not worthwhile. Experienced climbers that I mostly climb with rarely if ever use prussics. It is not only more faf but more clutter. As I tell my son, I cannot get much stronger at my age and probably not even smarter so all I can focus on is efficiency.

Anything that affects your efficiency is going to affect your chance of success and also endanger you.

I always ensure I have two thin slings or 2 5mm bits of rope with me when doing mutlipitch climbs.

I occasionally put knots in the end of the rope.

But mostly, as Nic indicates, I wrap the rope a few times round my leg if I need to take a hand or hands off the rope.

Cormac, I don't like your system at all. Too many things can go wrong with it. Especially in the dark. The tape through your belay loop is not a good idea and if your are going to do it that way then the tape should be a hitch through both the waste band and the leg loop band of you harness in the same way you would tie a rope.

When abseiling, the only person who is in real danger is the first person down. He then must tie of the end of the ropes or slow the next person by loading the rope to whatever degree is necessary to control the descent of the next person if needed. Much better than faffing with backup systems.

Abseils fail due to anchor failure far more frequently than abseiling off the end of the rope although that does happen but more often because the rope ends are unequal lengths!


Top
 Profile  
 
PostPosted: Thu Aug 15, 2013 10:57 am 
Offline
User avatar

Joined: Mon Feb 01, 2010 11:23 am
Posts: 248
Location: Cape Town
Real Name: Cormac Tooze
SNORT wrote:
Any system that adds complexity to an otherwise simple system is not worthwhile. Experienced climbers that I mostly climb with rarely if ever use prussics. It is not only more faf but more clutter. As I tell my son, I cannot get much stronger at my age and probably not even smarter so all I can focus on is efficiency.

Anything that affects your efficiency is going to affect your chance of success and also endanger you.

I always ensure I have two thin slings or 2 bits of rope with me when doing mutlipitch climbs.

I occasionally put knots in the end of the rope.

But mostly, as Nic indicates, I wrap the rope a few times round my leg if I need to take a hand or hands off the rope.

Cormac, I don't like your system at all. Too many things can go wrong with it. Especially in the dark. The tape through your belay loop is not a good idea and if your are going to do it that way then the tape should be a hitch through both the waste band and the leg loop band of you harness in the same way you would tie a rope.

When abseiling, the only person who is in real danger is the first person down. He then must tie of the end of the ropes or slow the next person by loading the rope to whatever degree is necessary to control the descent of the next person if needed. Much better than faffing with backup systems.

Abseils fail due to anchor failure far more frequently than abseiling off the end of the rope although that does happen but more often because the rope ends are unequal lengths!

@ Snort, that is not the exact way I do it. I got that picture off the web for illustration purposes. I girth hitch sling thru belay loop.

Sometimes I use a shunt or pussik or neither!
The nice thing about the back up is that, if you were rendered unconscious, some one would still be able to come to your rescue instead of sliding further down/off the rope!


Top
 Profile  
 
PostPosted: Thu Aug 15, 2013 12:12 pm 
Offline

Joined: Fri Dec 15, 2006 12:32 pm
Posts: 1173
Location: Cape Town
Real Name: Willem Boshoff
i extend my belay loop with two 30cm slings and a locking biner. gear i carry in any case when trad climbing. in fact, for other than the prussic cord it does not add any clutter to my rack. big abseils, especially free-hanging ones, without a prussic is downright irresponsible for beginners, unless there's a fireman's belay from the bottom. i still think it is worthwhile the practice though and a small time & weight price to pay for the significant safety margin added.

having a prussic securing the brake-rope, you can swing around; use both hands; lean in all directions - all things made more difficult with a rope-around-the-leg. i have had to kick 5-6m sideways in many occasions to go and dislodge stuck ropes etc. a prussic is great on those occasions.

i concur if you're a dinosaur like snort, is vastly experienced and climb in really rad places you can do as you please :thumright


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 15 posts ] 

All times are UTC + 2 hours


Who is online

Registered users: Baidu [Spider], Bing [Bot], Exabot [Bot], Google [Bot], Majestic-12 [Bot], Yahoo [Bot]


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group