Monday, April 28, 2008

Belay technique reviews

Petzl had recently started posting video tutorials. The first covers belaying a leader as well as the second and rappelling using the Reverso (applies equally well to most tube-style devices like the BD ATC). The second deals with belaying using the self-braking Gri-Gri. Definitely worth watching if you've ever wondered how to safely belay a leader using a Gri-Gri.


2 comments:

kenny g said...

Great videos...

The key is that the GriGri is an autolocking device, relying on a speed-dependent moving cam to grab the rope in the case of a fall. Feed out slack slowly and the cam remains unactivated, allowing rope through; feed out or pull rope quickly - as when the leader falls - and the cam *should* engage and lock off the leader.

So how do you feed out rope quickly , as when the leader is clipping, and not engage the cam? You can actively hold the cam in the open position, which is what the 2nd video shows for two different belaying styles.

***When the cam is held like this, the autolocking mechanism is disengaged*** The inherent danger is the leader falling and the belayer automatically grabbing with his hand, thus disengaging the autolock and allowing the leader to fall freely. However, it is impossible to feed out slack to a leader without this kind of trade-off.

Remember the GriGri can still function as a tube-style belay device if you hold the brake end of the rope down, creating friction through the piece (this is how you lower a leader: using the lever to disengage the cam and controlling the descent with brake-hand friction). What makes the quick-feed tricks for giving slack dangerous is that you disengage the cam with your brake hand, reducing the ability to brake in this manner should a fall occur.

I think the GriGri has its time and place, you have to understand its benefits and drawbacks and really know what you're doing.

kenny g said...

Note there's a redesigned reverso.

It's now essentially the ATC guide that a lot of us carry. The old reverso and the ATC guide were topologically equivalent, but the new design is less likely to develop a sharpened edge.