In reply to DubyaJamesDubya:
It's a lot more than braking-hand force that can be applied, they are effectively tied into that little web. If it fails or cuts the rope they fall.
Your braking hand is somewhat isolated from the live rope tension by the U bend around the krab and a sharp V bend in the rope (plus any teeth the device has), the latter is no longer present in the scenario we're discussing.
As I've said before it's not certain death by any means but there are plenty of devices out there where it's a very poor choice in order to save a few seconds.
Sorry, I'm not trying to browbeat someone that probably knows perfectly well what they're doing and the risk they're taking with a device that is plenty strong enough (as my Sticht is). What I am trying to do is prevent someone who doesn't know what they're doing adopting this technique with something like a Generation 1 Reverso which has a die-stamped center web with quite sharp edges even in finished form. Again, it's probably not immediately deadly but if you had the choice between threading a stamped bolt hanger or a smooth staple to ab off which would you go for?
There's another device I remember from starting out 15 years ago, I thought it was called a Tuba but google doesn't turn anything familiar up. That had the ropes separated by a thin alloy tube pressed into a much larger ribbed tube. Loading the thin tube in this way would be a very bad idea. Seems perhaps they're rarer than I realised though.
jk