Lava wrote:NZcaver wrote:A rebelay? Ah, so you're not talking about caving in the US then?
Seriously, that's a good point and I was aware of it but forgot to mention the equally simple solution. Use another carabiner. Any one will do, locking or non. If you do the rappel test thing Scott's always talking about, you should not have any issues with a single carabiner through the gate of your SRTE. I never have.
Heh, there are
some places in the US where rebelays can be found.
The second carabiner method is very safe, but it adds weight and an extra step to the process of crossing a rebelay. I'd like to keep my processes as simple as possible. And how do you expect me to impress European cavers with those few added extra seconds?
I'm using a Petzl OK oval carabiner to attach my bobbin (Petzl Simple) now the oval carabiners seem much less prone to being able to trip the catch of the bobbin or stop.
and oval carabiners are the bomb when you need to strip your system to build hauls etc. From memory it is the width between the two sides of the carabiner that is important mailions and small carabiners mean it can pivot in the hole whilst the other side of the biner trips the catch, with the oval the other side of the biner is above the catch so there's nothing to trip.
Here's some pictures to hopefully illustrate, not saying an Oval can't trip the gate but I haven't been able to get it to do it.
See how the gate side of the oval contacts the catch pretty much on top of the catches hinge? this makes it unable (as far as my attempts have gone) to trip the catch, rotate the oval any which way and I can't seem to get it any closer to opening the catch than that.
With regard to the rappel check I think one of the things caving does well compared to a lot of other sports that use abseiling is that generally when you are on descent all your weight is on the abseil device, our system of checks and rigging (especially Alpine style) ensure that the descender is weighted and unlocked before removing safeties which to me ensures the user clearly knows which hand is controlling their descent before starting.
I've been doing a guiding course for abseiling and they use Prusik safeties above the rappel device and have reportedly experienced several slides while unlocking the descender (user grips the prusik and finds the prusik was at least partly holding them and not the descender), I contrast this to where I've helped instruct caving without these safeties (but we do use the rappel check although we don't call it that it's just part of getting on rope, rebelays, changeovers etc) and we've never had one, (both these cases have bottom belays in place BTW). Which similar to Gary's web post about makes me dubious about the value of Prusik safeties especially above the abseil device.