Mountain Project Logo

Redirect belay in factor 2 fall


eli poss · · Durango, Co · Joined May 2014 · Points: 484
coppolillo wrote: Where’d you get the info that they intentionally let rope slip thru the Munter?

Yeah, crazy how low
A
Fall factor slams those dudes into the wall!

I got that information by reading the paper they posted with the video when it came out maybe a year or 2 ago. True about the slamming into the wall on relatively low (compared to FF2) factor falls. 

I'm not suggesting that the practice of belaying directly off the anchor is bad, just want people to know all details of the testing scenario because some of those details seem to be repeatedly obscured.

Edit since MP won't let me post again on this thread:

Here's a link, although it's in french. IIRC somebody translated part or all of it back when it originally came out but I'm not sure where to find that. Basically what happens is in a direct belay the force on the anchor is lower due to reduced momentum of a moving belayer while the force on the top piece is higher due to the lack of vertical displacement of belayer.

Belaying off the harness ought to yield the opposite results, although I haven't seen any data or numbers to confirm this.
coppolillo · · Unknown Hometown · Joined Sep 2009 · Points: 70

I never saw the paper, just the video....I'd be into checking that out---got a link?

Gloves mandatory, dude!

coppolillo · · Unknown Hometown · Joined Sep 2009 · Points: 70

ah, cool, eli, thanks for posting---i just went thru it an a) my french is frickin' rusty, 2) google translate rules and d) i'm no physics guy.....so let's call my translation half-assed at best.

at the end of the piece, they write (page 15, in the orange box): "We obtained the lowest shock force by positioning the braking device on the belay (direct belay) and letting the rope slide by increasing the braking gradually. This method is difficult to execute and should be reserved for expert climbers." Exactly as eli points out, they intentionally let the Munter (demi-cabestan) slip when catching the fall.

They add, though: "In general terms, the simplest method is to have the belayer provide a dynamic belay." (Figure 22 in the paper)

Then they add further: "If the belayer is anchored to the belay..." (they use the term "vacher" which means something like "cowboy" or "to be cowboy'd") "...the method that generates the lowest forces on the anchor is the direct belay. It's also the most comfortable for the belayer." This last part about being "comfortable" is super important, especially with a smaller/less experienced belayer---having the belayer get displaced violently is a recipe to have them lose control of the belay, and/or get injured. I've had a younger, superstrong climber use the direct belay (he was 10-11 years old at the time; I'm old and not exactly chiseled, 70lbs weight difference back then--now he's a national team ice & rock climber, killer!) and he picked it up in a pitch or two....safer for him and better peace of mind for me! 

Maybe somebody else's French is better, give another pass on it!

Thanks for the clarification, eli, interesting. We've always coached people to use gloves when using the Munter & direct belay, as there is natural slippage in the system.

Sorry for the epic rabbit hole/poaching the thread.

Anyway, thanks eli, and back to the OP: read Will's posts about clipping the anchor. Often a great idea, but recognize the drawbacks and potential problems! And always practice your French, dude. 

baldclimber · · Ottawa, Ontario, Canada · Joined Jul 2015 · Points: 1
coppolillo wrote: 
Then they add further: "If the belayer is anchored to the belay..." (they use the term "vacher" which means something like "cowboy" or "to be cowboy'd") "...

"vache" is a cow's tail in climbing lingo, ie a tether/PAS.

coppolillo · · Unknown Hometown · Joined Sep 2009 · Points: 70

ah, thanks bald.....wondered about that, but we use "cow's tail" differently in English, so didn't want to confuse.....the way it's written in the article, it'd be "cow's tail'd" into the anchor....but definitely NOT to be confused with tether/PAS, please! having the belayer attached the anchor with rope is a way, way better way to dissipate energy (as long as we're obsessing over soft catches/etc) than a PAS. not that you're advocating that...i'm just arguing my own preference/belief here....anyway, thanks dude for the clarification! 

eli poss · · Durango, Co · Joined May 2014 · Points: 484
coppolillo wrote: ah, cool, eli, thanks for posting---i just went thru it an a) my french is frickin' rusty, 2) google translate rules and d) i'm no physics guy.....so let's call my translation half-assed at best.

at the end of the piece, they write (page 15, in the orange box): "We obtained the lowest shock force by positioning the braking device on the belay (direct belay) and letting the rope slide by increasing the braking gradually. This method is difficult to execute and should be reserved for expert climbers." Exactly as eli points out, they intentionally let the Munter (demi-cabestan) slip when catching the fall.

They add, though: "In general terms, the simplest method is to have the belayer provide a dynamic belay." (Figure 22 in the paper)

Then they add further: "If the belayer is anchored to the belay..." (they use the term "vacher" which means something like "cowboy" or "to be cowboy'd") "...the method that generates the lowest forces on the anchor is the direct belay. It's also the most comfortable for the belayer." This last part about being "comfortable" is super important, especially with a smaller/less experienced belayer---having the belayer get displaced violently is a recipe to have them lose control of the belay, and/or get injured. I've had a younger, superstrong climber use the direct belay (he was 10-11 years old at the time; I'm old and not exactly chiseled, 70lbs weight difference back then--now he's a national team ice & rock climber, killer!) and he picked it up in a pitch or two....safer for him and better peace of mind for me!

Maybe somebody else's French is better, give another pass on it!

Thanks for the clarification, eli, interesting. We've always coached people to use gloves when using the Munter & direct belay, as there is natural slippage in the system.

Sorry for the epic rabbit hole/poaching the thread.

Anyway, thanks eli, and back to the OP: read Will's posts about clipping the anchor. Often a great idea, but recognize the drawbacks and potential problems! And always practice your French, dude. 

No problem. Just remember that lower forces on the belay anchor doesn't necessarily mean lower forces on the top piece. Typically my belay anchors are pretty damn bomber and I'm more concerned about my top piece failing than my anchor. 

Guideline #1: Don't be a jerk.

Trad Climbing
Post a Reply to "Redirect belay in factor 2 fall"

Log In to Reply