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Mammut Smart Alpine Belay Device failure mode


Original Post
Jeremy in Inyokern · · Inyokern · Joined Jul 2012 · Points: 71

I don't know if this has been reported yet but it's new to me.

Situation: Belayer was using the device correctly with an approved rope diameter (10.5) while providing me a lead belay. the rope built up some twist on the brake side. While trying to pass some of the twist through the device the twist rolled over on itself and created a bite of rope inside the device. This resulted in the rope becoming stuck inside the device and no way of freeing it without taking me off belay. We solved the issue safely but I wanted to report it so folks would know that passing a twisted line through the device (attempting to prevent a large messy twist on the brake side)can result in a stuck rope. You will be stuck looking for a place to tie in hard with a belay that will not pay out or take up slack as you down climb. Scary. I as it turned out was close enough to a squeeze chimney to slot myself in while the situation was fixed.

edit: This happened on lower not lead. It has been proven that it can happen on lead though.

BigFeet · · Texas · Joined May 2014 · Points: 385

Jeremy,

Did the rope kink up inside the adjacent slot to the one you had the rope running through or out of the side? Was this a fast feed through the device? Was your belayer pulling the rope through on the climber's side while feeding the device on the brake side? Did the kink happen before hitting the carabiner or after?

I've never encountered this before with either Smart device I use.

Can you give a bit more detail on the sequence of how the belay was done by your belayer?

It sounds as through there was a feeding of the rope through the device without any type of tension to the climber's side causing the rope to twist over on itself.

Ken Noyce · · Layton, UT · Joined Aug 2010 · Points: 2,103
BigFeet wrote:Jeremy, Did the rope kink up inside the adjacent slot to the one you had the rope running through or out of the side? Was this a fast feed through the device? Were you pulling the rope through on the climber's side while feeding the device on the brake side? I've never encountered this before with either Smart device I've used. Can you give a bit more detail on the sequence of how the belay was done?
My guess is he was lowering, the twists built up, and the weight of the climber being lowered was enough to pull a twist into the slot that the rope was running through. I don't see how this could happen without the weight of the climber being lowered to pull a full twist into the slot, but I could be wrong.
lukeweiss · · St. Johnsbury, VT · Joined Mar 2014 · Points: 30

I'm having trouble visualizing what happened. Never had a problem with mine.
Were you using the new big alpine smart? The regular one doesn't go over 9.5 I think.

BigFeet · · Texas · Joined May 2014 · Points: 385
kennoyce wrote: My guess is he was lowering,
I believe he stated he was being given a lead belay.

I can only assume that there were twists in the rope already and that the belayer fed the device without tension on the climber's side and this caused the twist/kink after passing over the carabiner.

I think we need more detail, though.
Jeremy in Inyokern · · Inyokern · Joined Jul 2012 · Points: 71
BigFeet wrote:Jeremy, Did the rope kink up inside the adjacent slot to the one you had the rope running through or out of the side?
just behind the side being used.
BigFeet wrote: Was this a fast feed through the device? Was your belayer pulling the rope through on the climber's side while feeding the device on the brake side?
Yes.
Jeremy in Inyokern · · Inyokern · Joined Jul 2012 · Points: 71
lukeweiss wrote:I'm having trouble visualizing what happened. Never had a problem with mine. Were you using the new big alpine smart? The regular one doesn't go over 9.5 I think.
it was big. the side says max size is 11 I think.
Jeremy in Inyokern · · Inyokern · Joined Jul 2012 · Points: 71
BigFeet wrote: ...there were twists in the rope already and that the belayer feed the device without tension on the climber's side and this caused the twist/kink after passing over the carabiner.
this.
BigFeet · · Texas · Joined May 2014 · Points: 385
Jeremy in Inyokern wrote: this.
If that is the case, a bit more tension needs to be applied to the climber's side and held until the twist is passed.

I suspect that the belayer fed rope into the device, but the climber's side did not move much, if at all. This gave the rope a chance to twist/kink over on itself. If there was a rest after feeding and the climber's side was slack and there was enough room for the rope to make the twist you will get what you did.
aikibujin · · Castle Rock, CO · Joined Oct 2014 · Points: 294

Sounds like the rope somehow tied itself into a slip knot inside the device and jammed. A device failure would imply that it failed to perform a function that it was designed to do, ie. catch the climber in a fall, hold a climber in a rappel, etc. Most devices are not designed to pass a knot through it directly, hence we intentionally tie stopper knots at end of ropes to prevent from dropping someone with too short of a rope. I wouldn’t call what you have a “device failure”, It’s unusual and unfortunate that rope knotted itself inside the device, but that’s not a failure of the device, more of a failure of your belayer to properly manage the rope and prevent twists.

Jeremy in Inyokern · · Inyokern · Joined Jul 2012 · Points: 71
BigFeet wrote: ...tension needs to be applied to the climber's side and held until the twist is passed...
This seems to be the mitigation step to me as well.
BigFeet · · Texas · Joined May 2014 · Points: 385
aikibujin wrote:...but that’s not a failure of the device, more of a failure of your belayer to properly manage the rope...
Agree.

Oh no, I hope this does not turn into "the deadly Grigri... er, Smart Alpine" thread.

Jeremy,

Props on you guys sorting this out in the heat of the moment without any injury. Also, thank you for informing us of potential issues people need to be aware of.
Rigggs24 · · Denver, CO · Joined Oct 2009 · Points: 45
Jeremy in Inyokern wrote: it was big. the side says max size is 11 I think.
The larger of the two smart alpine devices is rated for use on ropes at a max diameter of 10.5mm. So your rope is at the very high end of the range and if its a well used rope, it might even be thicker and outside the recommended range.

I use this device quite a bit and have never had a single issue with it. However, for the large majority of my climbing, i use a 9.5mm rope with the larger version. i can imagine that it would be a tight fit for a 10.5mm rope.
bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065
Jeremy in Inyokern wrote:I don't know if this has been reported yet but it's new to me. Situation: Belayer was using the device correctly with an approved rope diameter (10.5) while providing me a lead belay. the rope built up some twist on the brake side. While trying to pass some of the twist through the device the twist rolled over on itself and created a bite of rope inside the device. This resulted in the rope becoming stuck inside the device and no way of freeing it without taking me off belay. We solved the issue safely but I wanted to report it so folks would know that passing a twisted line through the device (attempting to prevent a large messy twist on the brake side)can result in a stuck rope. You will be stuck looking for a place to tie in hard with a belay that will not pay out or take up slack as you down climb. Scary. I as it turned out was close enough to a squeeze chimney to slot myself in while the situation was fixed.
this is a KNOWN issue with the smart ... just not very well known

it can happen with thinner ropes especially getting stuck in the central slot, but ive had it happen on up to 10mm ... ive had it happen twice in the last 5 years on "non twisted" ropes ... so it can happen anytime on basically any size rope

if it does happen you can be really screwed up if you dont know the clearing procedure which is as follows

- unweight the device ... either yr climber has to get the weight off or you need to yank hard on the climber strand while doing a bit of a jump ... at worst you may need to do a foot sling above the device and stand on it

- pull the brake strand SHARPLY upwards and to the OUTSIDE of the slot of the device ... so if yr on the right side slot pull up and to the right .... again the device needs to be unweighted

this is NOT a failure method thats in mammuts instructions ...

as you can see if you dont know this clearing method if yr partner is a on a sketchy runnout lead its potentially dangerous

and if it happens when youre lowering a climber you may need to do some fancy self rescue to remove the device if you dont know the above

this is one reason why the alpine smart should NOT be considered a beginners device ... there are various hidden "failure" modes as well as major issues lowering off the autoblock (which ive posted about)

ive been meaning to write up a comprehensive post on mammut alpine smart "failure" methods and their solutions ... but the 20+ page grigri argument thread was just too fun !!!

;)
Mammut smart "failure" mode
Jeremy in Inyokern · · Inyokern · Joined Jul 2012 · Points: 71

yep, that's it BB, just like the photo.

eli poss · · Durango, Co · Joined May 2014 · Points: 442

I've experienced this once with the thick rope version of the smart and never with the thin rope version and only when the rope wasn't tensioned. luckily the leader was standing on a ledge I told him to stay on the ledge for a second. This has also happened multiple times when feeding my 9.2 into the slot before clipping the carabiner.

It isn't difficult to deal with unless the rope is tensioned or if using really fat ropes. Although I'd consider it closer to user error than device failure, I think Mammut should cover this in their instructions. I'm glad this didn't result in injury and I hope this experience doesn't discourage you from using the smart as it as a very useful tool in a wide range of scenarios.

BB I'd be interested in seeing a thread listing all the "failure modes" for the smart because I'm sure there are still some that I haven't discovered yet.

bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065
eli poss wrote:I've experienced this once with the thick rope version of the smart and never with the thin rope version and only when the rope wasn't tensioned. luckily the leader was standing on a ledge I told him to stay on the ledge for a second. This has also happened multiple times when feeding my 9.2 into the slot before clipping the carabiner. It isn't difficult to deal with unless the rope is tensioned or if using really fat ropes. Although I'd consider it closer to user error than device failure, I think Mammut should cover this in their instructions. I'm glad this didn't result in injury and I hope this experience doesn't discourage you from using the smart as it as a very useful tool in a wide range of scenarios. BB I'd be interested in seeing a thread listing all the "failure modes" for the smart because I'm sure there are still some that I haven't discovered yet.
ill write it up by the news years i promise (like ive been promising for the last 2 years!!!)

i just need a dry spell this month and some victims ... ahem .. "partners" i mean to take some photos

as to this particular "failure' mode ... IMO its a design issue as even with the "normal approved" belay method the rope can get stuck

note this is a quite rare occurrence ... ive probably had over 1000+ days easily on my smarts and say at an average of 10+ pitches a day ... its occurred twice in the last 10000+ pitches

often when the rope gets in the grove it can "self clear" under body weight ... though i wouldnt count on it always happening

however when it does it can be a show stopperr ... particularly if you dont know hot to clear the jam

-----

imagine a highly experienced belayer giving their buddy a belay on a runnout sketchy climb on the smart ... youre all confident as the belayer is solid and has an assisted locking device ...

you get up 15 feet above that black alien and suddenly you get short roped ... your belay shouts out "THE DEVICE IS STUCK" ... its too hard to downclimb and yr belayer doesnt know what to do

theres also a bit of a ledge below you


------

now imagine yr a fairly new belayer or one who hasnt used the smart much ... your partner just finished the climb and your lowering him the "approved" way ....

suddenly the rope no longer feeds out anymore no matter how hard you pull or lift the handle ... yr climber is stuck in mid air

now if yr lucky you might be at a gym or popular crag where eventually enough experienced folks should be able to figure out something

if yr unlucky you guys might be all alone and your more experienced partner shouting out instructions on how to unweight the device via a friction hitch from above

if yr REALLY unlucky you might need to call those fine folks in orange to rescue you from dead elephants evil belay device !!!


-----

ive had variations of the (somewhat exaggerated) scenarios happen on the alpine smart

i strongly urge every alpine smart user thats reading this thread to "get the strand stuck" right now and practice the clearing method i listed above ... practice it with and without tension (hand a bike or tire if need be)

unlike the grigri 2 "stuck rope" scenario which usually only happens on whippers and isnt "dangerous"

this particular smart "failure" mode can be quite dangerous if one is not prepared for it as it can happen on lead, on single strand rap or on lower ....

the OP essentially had to go off belay

;)

Edit some more photos

Stuck in grove

To clear UNWEIGHT the device and JERK hard up and to the outside

Multiple hard jerks or using both hands to jerk (insert joke here) may be needed of the rope is really stuck .... Using both hands usually does the trick even in the worst jams

Ive had someone tell me they use their finger to push the struck strand out ... I dont need to tell MPer what a bad idea that is if your climber decides to fall at that particular point =P

Which brings up another issue with the smart ... But thats for next time
BigFeet · · Texas · Joined May 2014 · Points: 385

At the house messing around with Jeremy's originally posted issue, I found that I could replicate the problem.

It appears that there is a sweet spot of multiple components within the belay system being in the correct orientation, and the Smart to be manipulated in the right fashion for the rope to become compromised in the way bearbreeder shows.

I found that I could create this issue whether or not the rope is twisted. The twist may cause the rope to want to move in the direction of the adjacent slot more easily, depending on the rope's twisted direction, but the issue could be reproduced without a twist in the rope.

If the carabiner is just above the wide central curve which is the widest part of the grooved carabiner slot, and the rope feeds before the carabiner with the carabiner then turning and coming down through the slot from the applied pressure on the Smart up and slightly away, there is plenty of room for my 10mm rope to slide through to the adjacent rope slot passage. The carabiner actually forces the rope through to the other side.

When trying to repeat this multiple times the rope usually only ended up half way on the center plate edge and cleared itself with no problem, but with the correct conditions it ended up in the pictured position bearbreeder shows.

Interested to see your write up, bearbreeder.

rob.calm · · Loveland, CO · Joined May 2002 · Points: 630

Accidents from rope bunching can even occur with an ATC. A couple of months ago, a friend of mine had an incident because of the rope coiling up on the brake side of an ATC. He was lowering his partner when the rope on his side of the ATC formed a lump, which he didn’t notice as he was watching the climber he was lowering. When the lump hit his brake hand, it knocked it loose from the rope and the climber began to fall. The belayer looked to grab the rope on his side of the ATC, but the rope was twisting around so fast he didn’t know where to grab. In desperation, he grabbed the rope on the climber’s side of the ATC and was able to arrest the fall a few feet off the ground. The belayer suffered severe rope burn on his hands.

Rob.calm

bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065
rob.calm wrote:Accidents from rope bunching can even occur with an ATC. A couple of months ago, a friend of mine had an incident because of the rope coiling up on the brake side of an ATC. He was lowering his partner when the rope on his side of the ATC formed a lump, which he didn’t notice as he was watching the climber he was lowering. When the lump hit his brake hand, it knocked it loose from the rope and the climber began to fall. The belayer looked to grab the rope on his side of the ATC, but the rope was twisting around so fast he didn’t know where to grab. In desperation, he grabbed the rope on the climber’s side of the ATC and was able to arrest the fall a few feet off the ground. The belayer suffered severe rope burn on his hands. Rob.calm
the situation the OP mentioned can happen even with a non bunched up rope with "regular belaying"

with an ATC its good "modern" practice to use BOTH hands under the device ... with one hand feeding and straightening the rope while the other forms a solid "O" around the strand

this minimizes the chance of loosing control on lower and rappel

for lead you obviously cant do this but the brake hand should be constantly shaking out the rope if its twisted with a SOLID grip ... again a solid "O" around the strand should basically never come off when belaying

in those spots when not feeding the rope the non brake hand should also be shaking out any twists in the rope

with an assisted locking device this also makes the feeding smoother

when cragging flaking out the rope before every lead is not a bad idea ... or at minimum use a rope "bucket" like an ikea bag with the rope stacked in properly

personally i cringe when folks just toss down the rope sloppily before a lead

;)
mbk · · Unknown Hometown · Joined Jul 2013 · Points: 0

I have only used a smart for lead belay on one day of cragging.

The reason I only used it once was that (despite flaking the rope prior to each climb), I experienced severe twisting of the rope.

I am sure that this is due to "user error", since clearly it was the user incorporating the twists.

However, I have belayed with many other devices over the years and have never experienced such twisting with other devices.

I suspect that my "feed" operation was incorporating a small bit of twist with each pull. I haven't bothered to try to reproduce the situation, but I was not surprised to see someone complain of extreme twisting on the brake side with a smart.

Guideline #1: Don't be a jerk.

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