DMM XSRE micro biners for anchors?

Karl Henize wrote:

Other options worth considering are the Revolver (51g) Axiom (66g), which is a 22kN carabiner with an integrated pulley. 

DMM Revolver is probably not what you want.  https://www.mountainproject.com/forum/topic/116586082/dmm-revolver-carabiners-dont-work-very-well-as-pulleys

Karl Henize wrote:

I am glad you pointed this out.  I can see how people might get confused.  My goal was mainly just to give people a comparison to another piece of climbing equipment with a 4 kN load rating that is commonly used for hauling.  

I guess I'm confused because you said you were considering "incorporating the XSRE carabiner into my crevasse rescue / hauling kit," showed photos of the XSRE being used with 2 different progress capture pulleys, and said "Then let's consider that it is standard practice to backup all friction hitches, ascenders, and progress capture pulleys" (which I took to mean that it was ok to use the XSRE with with the aforementioned applications, since they will be backed up).

Kyle Tarry wrote:

You said you were going to "incorporating the XSRE carabiner into my crevasse rescue / hauling kit," showed photos of the XSRE being used with 2 different popular progress capture pulleys, and said "Then let's consider that it is standard practice to backup all friction hitches, ascenders, and progress capture pulleys" (which I took to mean that it was ok to use with with the aforementioned applications, since they will be backed up).  If you're not actually using it with those, what are you planning on doing with it?

I was mainly considering using it for use to connect a tractor and pulleys.  I don’t currently own any pulleys that are not progress capture pulleys, which is why all the photos were with progress capture pulleys.  

That being said, I estimated the max load on both pulley locations for a 3:1 direct haul system.  I estimated that the maximum dead weight I would conceivably want to haul with the XSRE attached to a pulley would be about 1 kN or 225 lbs (assuming there would be an added 0.5 kN of resistance due to friction for a total force on the load line of 1.5 kN while hauling).  The resulting force on each pulley and attached carabiner would be well under the 4 kN load rating of the carabiner.  My usual partners weigh less than 225 lbs, with gear.  So, I certainly don’t think it is crazy to consider using it on either pulley for a typical crevasse rescue hauling system.  

My preferred crevasse rescue method is a 2:1 drop loop hauling system that requires 5 carabiners and one progress capture pulley, so any other equipment I bring to set up additional mechanical advantage doesn’t normally get used.

I normally carry enough additional equipment to set up a 6:1 mechanical advantage system, just in case I need to.  However, I have never actually needed that much mechanical advantage.    

The XSRE can also be used for other lower applications, like:

- rigging a chest harness

- attaching a pack to a rope or anchor

- attaching the ice axe used to dress the lip of a crevasse to the rope

Karl Henize wrote:

I am glad you pointed this out.  I can see how people might get confused.  My goal was mainly just to give people a comparison to another piece of climbing equipment with a 4 kN load rating that is commonly used for hauling.  

Not good enough, Karl.  You said earlier:

The 4kN load rating of 5e XSRE matches the load rating for the most common progress capture pulleys 

Load rating of some climbing pulleys:

NanoTrax 22kN

Micro Trax 15kN

Pro Trax 22kN

Rescue Pulley 36kN

Partner Pulley 15kN

Oscillante 15kN

Spock 15kN

Any rated biner 22kN or better

These are not matched by the 4kN of the XSRE.

Latro wrote:

Not good enough, Karl.  You said earlier:

The 4kN load rating of 5e XSRE matches the load rating for the most common progress capture pulleys 

Load rating of some climbing pulleys:

NanoTrax 22kN

Micro Trax 15kN

Pro Trax 22kN

Rescue Pulley 36kN

Partner Pulley 15kN

Oscillante 15kN

Spock 15kN

Any rated biner 22kN or better

These are not matched by the 4kN of the XSRE.

The progress capture function is limited 4kN for the Micro-traxion and other toothed progress capture pulleys to avoid damaging the rope.  I wasn't trying to imply that the 4kN load rating of the XSRE matches the 15 kN load rating of the pulley function, but I realize that my statement could have been interpreted that way.  Mea culpa.  

I am open to being corrected, but I still don't see how one would expect to exceed 4kN in a normal crevasse rescue hauling application, as long as you don't try to use the as a master point for the anchor.  

Karl Henize wrote:

I was mainly considering using it for use to connect a tractor and pulleys.  I don’t currently own any pulleys that are not progress capture pulleys, which is why all the photos were with progress capture pulleys.

That is cause for confusion.

My preferred crevasse rescue method is a 2:1 drop loop hauling system that requires 5 carabiners and one progress capture pulley, so any other equipment I bring to set up additional mechanical advantage doesn’t normally get used.

See, this reads like you are thinking of attaching the "one progress capture pulley" at the bottom of the drop loop using the XSRE which is plainly madness.

If the XSRE is only a redirect or compound to help pull up the running strand of the drop loop, and you have an actual PPE backup at the bottom of the drop loop like the rescuee sliding a Prusik or ascender up the standing strand to assist in the rescue, you should make this clear IMO.

Karl

please read this quote of you from yesterday again:

The 4kN load rating of 5e XSRE matches the load rating for the most common progress capture pulleys 

You were stating that the load rating of the XSRE matches common pulleys, rather than not trying to imply it. That's just plain wrong, and highly dangerous for anyone reading it who doesn't know what the load rating of pulleys should be. And 4kN is an insufficient load rating. Any 1 kN type person jumping on a haul line to free a stuck bag can generate over 4kN on the pulley, and therefore on whatever the pulley is attached to.

Karl Henize wrote:

The XSRE can also be used for other lower applications, like:

- rigging a chest harness

- attaching a pack to a rope or anchor

- attaching the ice axe used to dress the lip of a crevasse to the rope

Why not just use a standard light wiregate (that you probably already have on your alpine draws or whatever) for these tasks?.  Compared to something like a nano or 19g, so this little toy carabiner is only saving you like 10 grams each.  Also, if this was your intended use of the XSRE, one wonders why you bought the locking version, and why you attached a bunch of photos of how it fit with progress capture pulleys...

I was mainly considering using it for use to connect a tractor and pulleys.  I don’t currently own any pulleys that are not progress capture pulleys

If you want to shave some weight, only carrying one microtrax (and using carabiners, or lighter pulleys) is a really easy way to do that.

@OP What does your partner think about this setup?   Do they know/endorse the lightweight plan?  How about both your significant others/family?   

Pete S wrote:

@OP What does your partner think about this setup?   Do they know/endorse the lightweight plan?  How about both your significant others/family?   

OP hasn't posted since 2017.

Even the manufacturer states that the XRSE is for non PPE purposes. Progress capturing pulleys are rated for ascending and as such can be used for life support.

Also the pulley won't break at 3kN if it gets twisted, but cantilever or crossloading will mess the xrse up way before that. The 4kN limit is an MBS, not a WLL.

Also someone mentioned that they'd trust it with a backup, but I think that  a legit system to have 2 ppe rated connections.eg. I wouldn't prusik a rope with a 5mm and 2mm cords, if two 5mm's were available.

Another comparison is that you don't usually build a sport anchor to two crappy bolts or a crappy + good one.

Wow, if one of my partners racked up with these in their glacier kit, I'd probably bail and never climb/ski with them again. Why would anyone think this is a good idea.

Alec Baker wrote:

XSRE locker = 10g

Petzl Sm'd Screwlock = 46g

The difference is 36ml of water, or 1/27th of a liter of water.

That better be some good water to make a difference...

Considering we now have 19g carabiners that will be without a doubt stronger than the 4kn of the XSRE I no longer see how this conversion is relavent, the progress capture device may not sit perfectly losing a little bit of efficiency but this is negligible. The trade of for a small amount of efficiency loss and 9g of weight is 5x strength increase gate closed and still 3kn more with the gate open compared to XSRE closed. 

And as pointed out, soft shackles may be another potential option. 

I do seem to remember seeing a pull test though where the XSRE broke around 10kn but I can't remember where I saw it or if its accurate. 

The omega pacific doval is the lightest oval biner I know. 37g and 25 kn rating.