Below is the key excerpt which discusses some important thoughts on more advanced abseiling rigging techniques and their usefulness in Blue Mountains canyons.
There has been much talk about using Single Rope Techniques (SRTs) on the ozcanyons group over the last few years and they seems to be gaining more momentum, especially in the newer generation of canyoners. It’s the norm in most other countries. Those other countries also tend to have either much higher water flows or much less prevalent anchor options.
Though I trained in their use and used SRT way back in my brief stint as a guide and it made sense to me in that situation for private groups I’ve always preferred the simplicity of throw and go, loop the rope through the anchor and every one abseil on double ropes.
When heading out with Tim’s group I’m happy to fit in with their SRT method of isolating the stands with a butterfly knot and people abseiling on alternate stands.
Last weekend I attended a training day with the Upper Blue Mountains Club where we practised setting SRT with a releasable anchor. I.e. isolating the abseil strand with the Munter/mule.
The advantage of this is if someone gets stuck on rope for whatever reason you can undo the mule under load and use the munter hitch as a belay to lower them to the ground.
Now in mumblecoughmumble years of canyoning I’ve never come across a situation where I needed to do that but it got me thinking (must be getting old or the weekday job of Safety Coordinator is rubbing off on my weekend self): what if that 1 in 100000 case came along. Sure there are other methods to preform a rescue but are they as safe and as quick and if they didn’t work would I be kicking myself for not using the “Rigging for Rescue” technique?
Anyhoo Anna is pretty keen to put this technique to use in every canyon trip she leads and I thought it might be a good idea to run this trip that way for practice (Ev had done the training day too, so it’s a shame she missed it.)
So I rig the first drop. I really had to think about it as it was a long abseil requiring 2 ropes working out where to put the munter so the knot would not impede it took more thought than it should have. It’s pretty bloody obvious but I guess that's why you practice these thing is relative benign situations so these it becomes second nature.
3/4 of the way down the last abseil I run into the spot of bother and think maybe I’ll need Anna to put the lowering me down method into practice. There is a knot in the rope below me. Usually no big deal. Just stop pull the rope up and undo it (tip for young players. Stop early and pull the knot up to you. The closer you get to the knot the harder it can be to get slack and if you abseil down onto the knot you’ve got buckleys of getting it undone).
Usually when the rope knots itself it's just a few loops caught on themselves and a bit of a shake gets it clear. This had somehow done a proper job on itself and I had trouble getting it undone while hanging in space. I was nearly ready to call out for Anna to pull the mule and lower me when I got it sorted and continued down.
Now what if I hadn’t been able to undo the knot or hadn’t been on a lowerable system?
I hadn’t yet locked off properly and was trying to undo the knot left handed so I could lock off to get both hands free as my first option. Second option would be to prusik back up to the ledge or top and sort it out there so I’m confident I could get myself out of that situation. But what if it happened to someone less experienced or without those skill sets? (Other than the obvious everyone on a private group should get themselves those skills sets. Good point but we were all beginners once.)
Those at the top could deploy the spare rope, someone could even abseil down to me to help out. That all takes time and hang syndrome becomes a factor. Abseiling down to help out puts the rescuer at risk too. So much to consider.
Anyhoo I clear the knot and continue down.
How much did the rigging for rescue slow us down? Last year with a slightly bigger group the trip took us 6hrs 23min car to car. Today, practicing what’s still fairly new to us took us 6hrs 49min. Though there is probably a bunch of other factors in there as well.
So what are my thoughts? I’m still undecided.
Anna was keen to only lock off one side of the rope and keep the other stand at the top to avoid confusion.
I prefer to do a munter/mule in both strands to allow people to rig up alternate strands and quicken things up. If you then need to lower then the person on the spare strand gets off and it’s quick to undo that one altogether and lower the other. Which is fine until you have 2 ropes joined with a knot at the top and then it’s not possible.
So here what I see as the pros and cons. Feel free to comment if you have other ideas.
Pros of releasable SRT using Munter/mule:
- Simple to set up and fairly quick to tie once you practice a bit
- Ability to quickly and safely lower a stuck abseiler down to the ground.
- Ability set the end of the abseil strand just on ground/water level to make getting off the rope at the bottom quick and easy
- It does take longer to tie and untie (not to mention it’s a ugly looking knot)
- Rope wear and tear. A single strand taking full weight obviously is under more strain than if you were abseiling on double strand.
- Chardie pointed out abseiling on double rope with an isolating knot at the top gives you some back up if you cut one strand on a sharp edge. Not an advantage if you use throw and go with out isolating.
- Only possible to use one strand if the abseil involves joining ropes.
- Can be tricky if the anchor is close to/below the edge but not too much more than normal.
If the stuck person is unconcious I’d say yes.
What is the liklihood of that happening though? And does that likelihood justify the slightly longer more complicated set up of each and every abseil?
I don’t know.
Being able to set the end of the rope just to water hieght is a big advantage in highwater but we don’t tend to have that in Australia.