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Structural Failure of Black Diamond Ultralight Camalot Size 0.4 Resulting in Injury


Fehim Hasecic · · Boulder, CO · Joined Jun 2013 · Points: 115

The Fall
A few seconds before falling, the climber communicated to the belayer that the fall would likely occur, which allowed the belayer to be ready to give a slightly dynamic catch.  The fall was an intentional release from about 1m above the placement with about 10m of rope out and insignificant rope drag.  The fall initiated slightly left of the cam placement but without significant pendulum risk.  Upon falling, the size 0.4 cam failed and shot into the shin of the falling climber, resulting in injury requiring medical attention including stitches.  A size 1 Black Diamond Ultralight Camalot caught the fall, keeping the climber several meters off the ground
If the climber was 3 ft above the cam and fell, in order for the cam to hit him in the shin he'd have to be perpendicular with the placement. If we was slightly left above the cam, the cam wouldn't have engaged until he passed it, hence no shin slammer. If he was way out left above the cam and falling, tension on the rope could have pulled out the cam and sent it into his shin, which means it was a bad placement. The power of the cam is never to be questioned, blasphemous thoughts will be punished with sweaty fingers.
Charlie S · · Ogden, UT · Joined Aug 2007 · Points: 1,763

I remember lobbing off of Red Zinger many years ago on a C4 0.4.  The lobe deformed similarly to the one in this picture, but without the scratches since it was in soft sandstone.  However, the piece held, and the deformation was noticed afterwards.

mike again · · Berkeley, CA · Joined Dec 2015 · Points: 40
Nick Sweeney wrote: Why buy ultralights in these small sizes when you can buy Alien-style cams? You get a super flexible stem, narrow head width, less weight, and they cost $25-30 less than ultralights at retail prices. I guess that the ULs might be nice in winter/alpine climbing, but I think aliens are the superior cam for sizes .5 and below.

This, or even better in my opinion totems.

Kevin Mokracek · · Burbank · Joined Apr 2012 · Points: 240

I wouldn’t call that equipment failure, I’d just call that climbing.   You whipped and a piece pulled.  

Dow Williams · · St. George, Utah; Canmore, AB · Joined Mar 2006 · Points: 240

Definitively simply a lack of extension, no debate.  Most common error I see as climbers start sport climbing vs alpine climbing before trad climbing.  Like maybe 90% feel it is safer to short clip a piece when faced with adversity vs "there is a high probability I am going to fall on this piece, I better extend it".  Cams are not bolts. 

Tradiban · · Unknown Hometown · Joined Apr 2004 · Points: 11,365
highaltitudeflatulentexpulsion wrote: A gear failure and it's time to blame the climber. Seems like I've heard this song before.

Gear and it's placement isn't an exact science, weird shit happens, the cam in question was placed weird and then damaged in a fall, there was no failure besides the placement.

rgold · · Poughkeepsie, NY · Joined Feb 2008 · Points: 525

It's amazing that so many people know fer sure what happened and how to fix it.

Forget about the piece pulling, there are a host of possibilities, not all of them mentioned,  the ones mentioned not decisive, and no way after the fact to know what the actual factors were.

What seems to me to be significant, whether or not the piece pulled, is the lobe deformation at a thin point (two instances cited in this thread), which raises some questions about possible under-engineering.  That said, flared placements increase the load on cams, and there is no upper limit, so that destructive forces are, at least in theory, always a possibility.  And remember that "flared" is a local condition that may not be true of the crack configuration as a whole.

SeƱor Arroz · · Unknown Hometown · Joined Jan 2016 · Points: 10

It's interesting to go to the MP page for "Neat and Cool" and look at some of the photos of people climbing that spot compared to your diagram. Seems like everyone places a piece where the #1 was that held and then moves up much higher than you did for the next piece. Maybe you just made a bad choice of placement and it pulled?





reboot · · . · Joined Jul 2006 · Points: 125
rgold wrote: What seems to me to be significant, whether or not the piece pulled, is the lobe deformation at a thin point, which raises some questions about possible under-engineering

I'd chalk it up as a weakness of the design, especially in the smaller sizes. There are a few ways to address this, each with trade-offs:

1) use harder lobe material: cam may track out more easily in smooth rock
2) increase thickness of the lobe: increases head width, making many placements harder/impossible
thickening the thin point longitudinally by:
3) decrease the axle diameter: makes the axle more susceptible to bending and side way lobe warping, which are already problems on the smaller dual axle cams
4) decrease distance between the 2 axles: decreases the range & certain stability advantage of dual axle design and may make side way lobe warping worse

Now 2) can be selectively accomplished at the thin point w/o increase the overall head width as there's already spacing allowed between lobes for the spring, though I doubt that'll add significant strength to the lobe.

I'd just use something else in the smaller sizes...
Nick Drake · · Newcastle, WA · Joined Jan 2015 · Points: 476
Señor Arroz wrote: It's interesting to go to the MP page for "Neat and Cool" and look at some of the photos of people climbing that spot compared to your diagram. Seems like everyone places a piece where the #1 was that held and then moves up much higher than you did for the next piece. Maybe you just made a bad choice of placement and it pulled?





There is nothing wrong with placing where the OP did, actually I'd recommend it. If you do not place a finger size piece above the area that they had a #1 in you face very real deck potential during hard the left and right traverse. For reference you end up at that brighter white triangular rock (if you aren't antsy there is a no hand rest over there). You can get a larger piece in as the traverse starts going right, but the rock is a bit funky (irregular) and you're running the pump clock to get it in (rather shitty steep stance), better to finish going right and get the feet up before plugging more gear. 

kendallt · · Tahoe · Joined Aug 2012 · Points: 113
rgold wroteWhat seems to me to be significant, whether or not the piece pulled, is the lobe deformation at a thin point (two instances cited in this thread)

I don't think there would be any lobe deformation if the piece *didn't* pull.

I've seen deformations that are on the outside of the lobe in my own cams when they pull (grind aluminum against granite, and granite will win) but I've never been able to deform the inner part of the lobe. I can't tell if it's actually deformed inside, but the picture of it not fully open seems to imply that it is.

They're tested when they're placed solidly in a controlled environment, not when they're getting ripped out. I don't think there's really any expectation for a cam remaining in one piece once it's in motion and being spit out of a crack. This of course assumes the 'deformation' is the effect, not the cause. But it should show up in testing if it was the cause.
reboot · · . · Joined Jul 2006 · Points: 125
kendallt wrote:

I don't think there would be any lobe deformation if the piece *didn't* pull.

Pretty sure you have the cause and effect backwards here...

kendallt · · Tahoe · Joined Aug 2012 · Points: 113
reboot wrote:

Pretty sure you have the cause and effect backwards here...

If the deformation is the cause of the fall, I don't know why everyone who's falling on their cams isn't deforming them. Or why they don't get deformed in tests.


Most placements don't pull (or get pushed past their strength ratings), which explains why you don't hear about deformed cams much.
patto · · Unknown Hometown · Joined Jul 2012 · Points: 25
reboot wrote:
Pretty sure you have the cause and effect backwards here...
Exactly.

kendallt wrote: 

If the deformation is the cause of the fall, I don't know why everyone who's falling on their cams isn't deforming them. Or why they don't get deformed in tests.


Most placements don't pull (or get pushed past their strength ratings), which explains why you don't hear about deformed cams much.

Lets get this straight:

-this cam was not pulled by a force greater than its strength rating

-this cam DID suffer deformation of the cam lobe which very likely precipitated the failure

-the lobe itself might have been under higher than usual loads due to the cam at an angle to the fall AND/OR localised flaring.  This is all speculation but perfectly valid.
reboot · · . · Joined Jul 2006 · Points: 125
kendallt wrote:

If the deformation is the cause of the fall, I don't know why everyone who's falling on their cams isn't deforming them. Or why they don't get deformed in tests.


Most placements don't pull (or get pushed past their strength ratings), which explains why you don't hear about deformed cams much.

You said: I don't think there would be any lobe deformation if the piece *didn't* pull.

Pieces get pulled w/o lobe deformation all the time, and a piece can deform and fail beyond reuse but still holds a fall (has happened to me more than once). But a piece w/ enough load to cause deformation can track out of a placement. So how exactly does having a piece pull cause the lobe deformation???
reboot · · . · Joined Jul 2006 · Points: 125
Dow Williams wrote:

Cams are not meant to function correctly and hold up structurally if the weight and point of the fall and direction of force is not optimum. This is not hard to achieve, but is not being regularly practiced or taught.

Cams are not strength rated in sub-optimum placements. But if a cam can't function (within a reasonable % of its rated strength) in often encountered real world placements, it just isn't a very good cam.

Short Fall Sean · · Flagstaff, AZ · Joined Sep 2012 · Points: 5

Trad climbing has got to be so damn casual for all these engineering-wizard-never-made-a-marginal-placement crushers! Y'all should go daisy solo Reticent wall or something. I'm sure it'd be pretty mellow with your skillzzzzz!

NateGfunk · · Unknown Hometown · Joined Apr 2013 · Points: 50

This all begs the question, why were you cragging with ultralights? They are lightweight tools for specific use cases. Small cams sometimes get weird and fail, we dont climb in a lab... 

Jake Jones · · Richmond, VA · Joined Jul 2011 · Points: 1,639
NateGfunk wrote: This all begs the question, why were you cragging with ultralights?  

In general I agree, but BD touts that they're as durable as their counterparts.  Regardless of the myriad of opinions that have been stated here, I still maintain that I'd like to see a pull test- static as it's done in the "lab" and dynamic- when the cam is placed on the contact point with the thinnest amount of material.  A dynamic test in a parallel placement may be even more telling.  May be that it holds fine and goes to past the stated failure strength limit like it does in the "optimal placment" which usually means around mid-lobe- where the lobe material is almost twice as thick.

I don't know for sure, because I don't own either, but IMO, the "ultralight" nature of the cam has little to do with it, unless you're placing emphasis on the stiffer stem.  IIRC, the lobe machining is roughly the same as the C4.  So theoretically, this would have happened with the non UL version of the same cam in the same placement.
patto · · Unknown Hometown · Joined Jul 2012 · Points: 25
NateGfunk wrote: They are lightweight tools for specific use cases. 
Aren't they for climbing?

NateGfunk wrote:Small cams sometimes get weird and fail, we dont climb in a lab... 

How is this a small cam?   Seriously I get sick of this notion that cams in this size are "small".   There is more than enough size to make a strong, functioning cam,  DMM cams of this size are rated to 14kN. Metolius to 10kN...  But that is besides the point.  The cam wasn't loaded anywhere near this amount.

And no, small cams just don't get weird and fail.  Place a cam appropriately whether small or large and it should hold.  You should have to find yourself asking whether a cam lobe is going to compress on itself.

Guideline #1: Don't be a jerk.

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