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Upward pull on hangers


Original Post
Sam Skovgaard · · Tucson, AZ · Joined Oct 2017 · Points: 87

In lead rope soloing on a sport route, or belaying off the anchor on a multipitch route, two bolts are used to create the redundant anchor at the bottom of the route.  A lead fall places upward pull on these bolts, which obviously have their hangers oriented for downward pull.

The strength rating of hangers isn't listed for this orientation of pull; how much weaker do you think it is?

Brian in SLC · · Sandy, Utah · Joined Oct 2003 · Points: 15,692

My guess is negligible.

Also, I'd think most folks who set anchors for a downward pull, orient the hangers towards that pull.  If the anchors aren't super snug, they may move a bit in an upward pull.  That re-orientation would reduce any point load methinks.  Almost a bit of a shock absorber.  Of course a glue in...

Jim Titt · · Germany · Joined Nov 2009 · Points: 490

They just turn round, it doesn't take much force

Roy Suggett · · Unknown Hometown · Joined Jul 2009 · Points: 7,855

Of course (I think) the bolt itself is working the same.  So why not bring a small adjustable wrench (this idea is only good if the bolt has a nut on top) and realign the hanger before and after? Glue ins, another story someone else might better advise you on.

Brandon Fields · · Boulder · Joined Apr 2016 · Points: 445

There should be no meaningful short term weakening in either shear or pull-out strength so it is safe. The only real problem here is if the hanger spins and is either left spinning or goes through a repeated spin and tightening cycle, it can wear the layer of rock below the hanger or grind rock dust and debris between the hanger and bolt to such a degree that it eventually becomes a problem.

Tradiban · · Unknown Hometown · Joined Apr 2004 · Points: 11,510
Sam Skovgaard wrote: In lead rope soloing on a sport route, or belaying off the anchor on a multipitch route, two bolts are used to create the redundant anchor at the bottom of the route.  A lead fall places upward pull on these bolts, which obviously have their hangers oriented for downward pull.

The strength rating of hangers isn't listed for this orientation of pull; how much weaker do you think it is?

Depends on the hanger. 

Alot of first bolt hangers are all janked up from this, I'm sure at least one has failed but I've never heard of it.

As usual with these types of questions, Yes, it's weaker but not enough to matter.
Brandon Fields · · Boulder · Joined Apr 2016 · Points: 445
Tradiban wrote:

Depends on the hanger. 

Alot of first bolt hangers are all janked up from this, I'm sure at least one has failed but I've never heard of it.

As usual with these types of questions, Yes, it's weaker but not enough to matter.

"Depends on the hanger" is a good caveat. Depends on the bolt is also valid. If we're talking about old bolts/hangers or even new button heads (god forbid) and the like then it becomes a different animal.

Go Back to Super Topo · · Back of my truck · Joined Dec 2010 · Points: 260

2.368 kN weaker

Tradiban · · Unknown Hometown · Joined Apr 2004 · Points: 11,510
Brandon Fields wrote:

"Depends on the hanger" is a good caveat. Depends on the bolt is also valid. If we're talking about old bolts/hangers or even new button heads (god forbid) and the like then it becomes a different animal.

The bolt question is a different conversation. A bolt being pulled down and out or up and out is roughly the same. A hanger being pulled upward creates significant leverage at the "neck" of the hanger.

I would assume Mr Titt is already on the case.
Chris Hatzai · · Bend, OR · Joined Sep 2015 · Points: 646

I can add that when you lead rope solo, it’s always good to clove/figure 8 into both the first and second bolt as youre ascending. Creates a backup.. not equalized but 2 bolts are better than 1.

Andrew Poet · · Central AZ · Joined Oct 2015 · Points: 161
Chris Hatzai wrote: I can add that when you lead rope solo, it’s always good to clove/figure 8 into both the first and second bolt as youre ascending. Creates a backup.. not equalized but 2 bolts are better than 1.

Always?

eli poss · · Durango, Co · Joined May 2014 · Points: 523
apoet wrote:

Always?

always, unless you're going to fall between the 2nd and 3rd bolt, creating a high factor fall onto a single bolt, possibly ripping it out and decking. So, no not always. 

Jim Titt · · Germany · Joined Nov 2009 · Points: 490
eli poss wrote:

always, unless you're going to fall between the 2nd and 3rd bolt, creating a high factor fall onto a single bolt, possibly ripping it out and decking. So, no not always. 

If the bolts are that bad I wouldn't start up the route..... 

There are plenty of ways to stop ff2 onto the belay.
eli poss · · Durango, Co · Joined May 2014 · Points: 523
Jim Titt wrote:

If the bolts are that bad I wouldn't start up the route..... 

There are plenty of ways to stop ff2 onto the belay.

With the amount of rotting old bolts that might be fine or totally crap from the infancy of sport climbing in the US (30-40 years on bolts ranging from carbon steel to plated steel and ranging from 1/4" to 3/8") you you never really know what you mind find. Some of them look great, some look like crap, and testing and bolt removal has shown that looks can easily be deceiving. Remember that us over here in North America are always 1 or 5 steps behind y'all in Europe when it comes to bolts. 

Yes there's lots of ways to avoid high factor falls, but I was just trying to point out the complexity that makes the use of the absolutes kinda dumb in climbing (Saying that you should always clove or fig 8 into the first and second bolts)
Jim Titt · · Germany · Joined Nov 2009 · Points: 490
Tradiban wrote:

The bolt question is a different conversation. A bolt being pulled down and out or up and out is roughly the same. A hanger being pulled upward creates significant leverage at the "neck" of the hanger.

I would assume Mr Titt is already on the case.

Like i said the hanger just turns round. This is an AustriAlpin hanger (made in Austria so not some Taiwan junk) from 316 stainless in a granite block with a 10mm wedge bolt torqued to 40Nm (29.5ft lbs). 

0kN:-


2.5kN;-

5kN;-

7.5kN;-

10kN;-

20kN;-

25kN;-

35kN:-

The steel biner (rated to 30kN) failed at 35.6kN when the nose bent open and released the gate.
The hanger breaking when I´m lead rope-soloing is the least of my worries!
Jim Titt · · Germany · Joined Nov 2009 · Points: 490
eli poss wrote:

With the amount of rotting old bolts that might be fine or totally crap from the infancy of sport climbing in the US (30-40 years on bolts ranging from carbon steel to plated steel and ranging from 1/4" to 3/8") you you never really know what you mind find. Some of them look great, some look like crap, and testing and bolt removal has shown that looks can easily be deceiving. Remember that us over here in North America are always 1 or 5 steps behind y'all in Europe when it comes to bolts. 

Yes there's lots of ways to avoid high factor falls, but I was just trying to point out the complexity that makes the use of the absolutes kinda dumb in climbing (Saying that you should always clove or fig 8 into the first and second bolts)

I´ve climbed in the USA  

I just pile some stuff in my pack (rocks or whatever, about 20kg) on the ground and run the rope up through a Munter on the first or second bolt/piece. It´s just like a real belayer but doesn´t say stupid shit like YGD.
Sandy Crimp · · Unknown Hometown · Joined Jan 2013 · Points: 15
Jim Titt wrote:

Like i said the hanger just turns round. This is an AustriAlpin hanger (made in Austria so not some Taiwan junk) from 316 stainless in a granite block with a 10mm wedge bolt torqued to 40Nm (29.5ft lbs). 

0kN:-


2.5kN;-

5kN;-

7.5kN;-

10kN;-

20kN;-

25kN;-

35kN:-

The steel biner (rated to 30kN) failed at 35.6kN when the nose bent open and released the gate.
The hanger breaking when I´m lead rope-soloing is the least of my worries!

Excellent factual post </thread>

Sam Skovgaard · · Tucson, AZ · Joined Oct 2017 · Points: 87
Jim Titt wrote:

Like i said the hanger just turns round. This is an AustriAlpin hanger (made in Austria so not some Taiwan junk) from 316 stainless in a granite block with a 10mm wedge bolt torqued to 40Nm (29.5ft lbs). 

0kN:-


2.5kN;-

5kN;-

7.5kN;-

10kN;-

20kN;-

25kN;-

35kN:-

The steel biner (rated to 30kN) failed at 35.6kN when the nose bent open and released the gate.
The hanger breaking when I´m lead rope-soloing is the least of my worries!

Bravo, sir!  Thank you!

Tradiban · · Unknown Hometown · Joined Apr 2004 · Points: 11,510
Jim Titt wrote:

Like i said the hanger just turns round. This is an AustriAlpin hanger (made in Austria so not some Taiwan junk) from 316 stainless in a granite block with a 10mm wedge bolt torqued to 40Nm (29.5ft lbs)


The steel biner (rated to 30kN) failed at 35.6kN when the nose bent open and released the gate.
The hanger breaking when I´m lead rope-soloing is the least of my worries!

Maybe that type of hanger will do that, but what about a SMC etc?

And, how fast did you crank? A slow pull would allow the hanger to rotate but that's unrealistic. 
Jim Titt · · Germany · Joined Nov 2009 · Points: 490
Tradiban wrote:

Maybe that type of hanger will do that, but what about a SMC etc?

And, how fast did you crank? A slow pull would allow the hanger to rotate but that's unrealistic. 

Never seen a SMC hanger except in photos, as a rule I don't investigate uncertified stuff anyway. It was slow pulled so I could take the pictures, drop testing would normally give lower values as the frictional resistance will decrease but I doubt it's of any real interest.

Tradiban · · Unknown Hometown · Joined Apr 2004 · Points: 11,510
Jim Titt wrote:

Never seen a SMC hanger except in photos, as a rule I don't investigate uncertified stuff anyway. It was slow pulled so I could take the pictures, drop testing would normally give lower values as the frictional resistance will decrease but I doubt it's of any real interest.

Well, there's plenty of other hangers besides the one you tested that the OP might encounter.

Also, could imangine that there's plenty if cases where the hanger won't rotate because it's too tight, the rock around it won't allow it, or it's designed not to ("teeth" on the back).

How about stopping rotation and seeing what happens.
Guideline #1: Don't be a jerk.

Fixed Hardware: Bolts & Anchors
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