Organizer:
Gordon Wing-Lun
Date/Time:
Date(s) - Saturday 18 April, 2020
4:00 am - 5:30 am
climbing
Date and time is tentative, depending upon interest and your feedback. Daytime as it’ll be outside in my backyard.
Disclaimer
These are just a few discussion notes and do not claim to be perfect or even correct. You need to do your own research, get professional training and learn to evaluate the best risk decision.
This discussion and others can never be complete and cover every aspect and every situation.
Climbing is a dangerous activity!
The Trip
We are getting ready for that planned trip to Mt Boyce to do a few grade 10’s m 12’s. Of course with Covid19, it may not happen in 2020.
Participants for the trip itself would have robust multi pitch sport climbing experience too say grade 16. And have some knowledge/experience of trad,
To introduce there’ll be series of trips :
1. Interactive discussion/demo Building a trad anchor – on Zoom (This trip)
Next possible trips, if there is interest.
2. Gear – what it is, choices, racking, what to take.
3. Planning a trip – trip notes, The Crag and Guidebooks, what gear to take
4. Working with your partner
5. Anything else ?
This trip will also cover, inter alia, matters raised in feedback to my recent Club FB post:
Why as simple tube atc for belaying the second? I left my guide mode atc at home.
Is the anchor equalised? It’s in the direction of force, for my photo I stood to one side.
Cam placements – sometimes you have to use what nature gives you. The cams would be better deeper in a slot, but the slot wasn’t any deeper.
The nut – it was an almost bomber placement , whilst slightly flaring outwards, it was a constricting taper with more than 2/3 solid side contact. A perfect fit for a DMM offset nut.
The sandstone rock was for the cams a bit soft, but then that’s all I had in my backyard. On a hard pull though, still looked solid;though I wouldn’t rely on this rock in real life.
Finally if I’d been carrying my nylon 240cm sling, I’d have used that rather my dyneema sling, given the better stretch characterictics of nylon. In the event of my second falling the dynamic force should be less on nylon.
On the other hand tests (DMM video, I think) show that the decelerating forces are comparable for nylon and dyneema, IF there is a knot (or two?, I can’t remember) in the system; it seems that as the falling force cinches the knot tighter, then lower deceleration forces result.
Having nylon is a no brainer in my view as it is cheaper and the cost is a few grams extra to carry. No downside and possible upside.
Finally many discussions on trad anchor building include noting that it is pretty impossible to achieve perfect equalisation. So thinking about the above may be useful.
And in our Session we might discuss why in a three gear placement anchor system, a sliding X may not be the best risk mitigant. Noting that in trad, anything less than three gear points of protection is , in my view high risk; exceptions being that 15cm tree with deep roots, that very solid rock pillar or similar etc. BTW be careful sllnging a rock pillar, a chockstone, etc! (do you know how?)
