Quantcast
It is currently Thu Oct 30, 2014 6:48 pm

All times are UTC + 2 hours




Post new topic Reply to topic  [ 7 posts ] 
Author Message
PostPosted: Thu Nov 23, 2006 10:05 am 
Offline
User avatar

Joined: Sat Apr 30, 2005 8:31 am
Posts: 3037
Location: Montagu
Real Name: Justin Lawson
The other day I belayed someone (roughly 80 kilo's) on an 8.9mm single rope. The leader took a fall about 6 bolts up (he fell from +- 1m above the bolt) - the Grigri held the fall dropping him only +-2 meters (to me the fall was standard and what I expected)

I was wondering... is there any significance that certain ropes slide through certain belay devices quicker than others? (I’m referring to the Grigri in particular). Most rope manufactures offer some type of rope treatment that is applied either to the interior or exterior (sometimes both) of the rope. These can be: Dry treatments and special coating finishes (to enhance strength / reduce friction, etc).
Another factor that comes to mind is how the rope (sheath & kernel) is designed, does the belay device squash it completely flat or does the rope stay relatively firm allowing the Grigri to grab it quickly (with minimal slippage).

It would be interesting to know what brand of ropes where being used at the time of past 'Grigri' related accidents and find out if certain ropes slide through certain belay devices faster / with less friction.

Is it possible that the accidents could be a rope problem more over than a belay device problem?

I'm not a rope expert, but what’da you think?

_________________
Climb ZA - Administrator
justin@climbing.co.za


Top
 Profile  
 
 Post subject:
PostPosted: Thu Nov 23, 2006 10:21 am 
Offline

Joined: Wed Sep 07, 2005 12:12 pm
Posts: 22
In my experience, beware of new ropes, as they go through a grigri that much easier, and are more likely to give issues, especially with a novice belayer. (Don't know about the various treatments). When your rope is nice and frayed (ie thicker maybe) it locks a lot easier.

Holding on to the other end of the rope, and not using the \"hands-free\" approach to belaying also has a significant effect on much rope goes through a grigri.

Finally, how sharp the fall is affects it too. If its a good sharp fall, then grigris lock nicely, if the climber grabs the rope and slowly releases his weight onto the rope its more likely to slip through slowly and not lock.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Nov 23, 2006 12:12 pm 
Offline

Joined: Wed Jun 08, 2005 8:49 pm
Posts: 293
Probably the only people who know the answers for sure are the rope manufacturers, none of whom are likely to admit their ropes dont work in certain devices.New ropes most certainly slide super easily. Use only devices designed for the rope thickness you are using (so 8.9 = mini bug or possibly a sum [although even this is below the recommended min. thickness]).

Wear leather fingerless gloves for belaying, nobody does this but it will prevent you letting go of the rope from a burnt palm in the case of sever rope slippage, this is especially true when using thin ropes which are generally below a diameter that ergonomically can be gripped by the hand. Gloves also spare your hands that polished look at the end of the day.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Nov 23, 2006 3:40 pm 
Offline

Joined: Tue May 03, 2005 12:48 pm
Posts: 265
Location: Cape Town
Real Name: Guy Holwill
New ropes do make a difference - for sure. But there are two things that are more significant (and three are inter-related)

Use the right tool for the job

The Gri-gri is designed for rope 10mm and thicker (it says this on the gri-gri). It will work with a 9.7mm and with a 9.5mm etc - but obviously not with 6mm cord.

Learn to belay properly

Most people assume that this only means keeping your hand on the rope below the device. Whilst this is the most important piece of belay technique, factors like watching the climber, positioning yourself correctly, NOT LYING DOWN, belaying dynamically, staying focused etc all play an important role.

The truth is that the gri-gri is probably the best belay device that has been produced - the problem is that people like to think that it is idiot proof...

_________________
There's no point being pessimistic, because it probably won't work


Top
 Profile  
 
 Post subject: Foolproof
PostPosted: Thu Nov 23, 2006 4:35 pm 
Offline

Joined: Tue Jan 17, 2006 1:23 pm
Posts: 120
Location: Gauteng
“A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools” – Douglas Adams


Top
 Profile  
 
 Post subject:
PostPosted: Thu Nov 23, 2006 10:47 pm 
Offline

Joined: Wed May 04, 2005 7:39 am
Posts: 57
Well said Guy. The problem is a people problem, great peice of equipment in the right hands, works like a charm on my Mammut 8.9mm single rope. An idiot can mess anything up.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Nov 24, 2006 9:49 am 
Offline
User avatar

Joined: Sat Apr 30, 2005 8:31 am
Posts: 3037
Location: Montagu
Real Name: Justin Lawson
Petzl have introduced something called the Freino http://en.petzl.com/petzl/SportProduits?Produit=578 – a carabiner like device – to add friction for skinny /slippery ropes. They would probably go for around R300+.
While this seems like an effective method, maybe there is a simpler solution?

Image
Image courtesy of http://Petzl.com

I reckon that statistically the Grigri must be the most used belay device (in SA and around the world). Therefore, belay accidents that do occur would understandably happen more often with Grigri’s.
Pilot error is a big problem too, but I’m sure the Grigri has saved a lot of people as well e.g. when the belayer falls asleep, while using both hands to take a picture of the climber they are belaying, etc

Whatever the case I trust and will continue using my 'G' 8)

_________________
Climb ZA - Administrator
justin@climbing.co.za


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 posts ] 

All times are UTC + 2 hours


Who is online

Registered users: Bing [Bot], Google [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