UT: North Wash No Kidding: An Intro to SandTraps

My wife approved an early Christmas present and I ordered a SandTrap with plans to do No Kidding Canyon as soon as it arrived. The SandTrap arrived sooner than expected and we took off for the North Wash to try it out.

I was surprised by how accessible the canyon was, we got there ahead of schedule and were met by freezing morning winds that had scurrying for the canyon entrance.

The initial shallow slot was actually pretty good and had a couple fun downclimbs. We skipped the first rappel by traversing the slab on the left because we were worried about time, and a snow storm that was supposed to come in later that day. The first SandTrap rappel came right away and I dug out the area before lip to create better geometry. I had watched the setup and rappelled on a SandTrap when I did Tinnitus Canyon with Tom Collins, so I was familiar enough with the process to set it up correctly. We meat-anchored my wife’s two younger siblings down first and left the 3 of us to use to SandTrap. We filled up two and a half potshots with sand and dumped it into the SandTrap, placing into rappel position. We backed up Sandtrap and sent Kenna down first, it held her weight great and I followed her down. My wife Olivia went last because she is the lightest and she placed a 4ft piece of hose on the pull rope and rappelled down without incident. We were able to pull the SandTrap down without much effort and the hose did a good job at preventing rope groves and creating a smoother pull.


This process repeated many times throughout the rest of the canyon and we experimented with sand levels and different geometry to get a good feel for what the sandtrap can do. I noticed some bad rope groves developing around the canyon and it mostly seems to be a result of people placing their sandtraps far back rather than right on the edges of drops. These farther back placements would have tougher pulls, resulting in groves. There was favorable placements right at the edge of most drops so I really didn’t see why people would be setting up their SandTraps so far back from the edge.


The keeper pothole was a fun obstacle and we are able to partner assist everyone out of it. We didn't need to use any pot shots to get out of it and their were a few semi-keepers that we encountered in the canyon.


All too soon we were at the last 20ft rappel into Butler Wash and it turned out to be a the trickiest setup out of all of the drops. We didn’t have the best geometry so we put a full 3 potshots worth of sand in the SandTrap and set it for rappel. It moved a bit while Kenna was rappelling on it so we added a bit more sand and re-positioned it. Olivia made it down without incident and I did speedy rappel down followed her out. The pull took a bit effort this time around and it was cool to watch the big plume of sand go up in the air when it finally pulled.

We searched around for the Dinosaur track that is supposed to be around there and couldn’t find it, so we took off up the Kelsey exit and picked up our 200ft rope that we didn’t end up using. Once we had made it up and out of the canyon we realized that it had only taken us 4 hours to do the canyon so 4 of us opted to descend nearby East Leprechaun while Olivia would drive the car around and meet us at the bottom. This worked out great and got all the way down East Leprechaun in an hour and a half, meeting up with Olivia at the last rappel. We took off for home, hoping to get through Spanish Fork Canyon before the big storm hit.


No Kidding was an awesome, fun canyon and I highly recommend it! I will definitely be doing it again in the future. It was the perfect intro to SandTrap canyon and by the end we felt very comfortable using it. I can’t get over how cool the SandTrap is and i’ll be on the lookout for some more canyons where I can utilize it.

Nice work and thanks for the TR.

Don't get TOOOO comfortable.

Perhaps it goes without saying, but No Kidding is a good first Trap canyon partly because the Trapping in there is pretty straightforward. Safely using Traps in spots with less favorable geometry is, of course, more challenging.

Our normal procedure is to carry two SandTraps, in case one gets stuck. In this canyon in particular, if you get your single trap stuck, you could be in big trouble, as getting anchors elsewise is difficult. It would likely come down to filling a pack with sand and rapping off that.

Sometimes the trap is set back from the edge to improve the odds of it not getting stuck. For instance, if there is a constriction near the edge, it often works better to set the trap a ways back so the trap is empty of sand when it gets to the constriction.

Also, No Kidding is often people's first SandTrap canyon, therefore the wisest choices are not always made.

Tom

Nice work...

The standard for testing for a trap is 4 people. Big folks trying to make it fail, to delicate next to last going soft. Then the LAPAR. Nicely done.
Yes, you are right about the lips being good enough to trap on.
Did you back up everyone but the last person? Without weighting the line at all?
The last rap is quirky. Always seems insecure and often is a challenge to pull.
Thanks for carrying on the tradition of a Leprechaun, post No Kidding.
It is also often done by those coming out of Shenanigan's and Monkey Business too.
Cheers

Two of us would go down on the sandtrap, fully backed up without the backup line being weighted. The third person would then readjust if needed and then rappel down fast. Our weight ranged from 135 to 165 pounds and there really didn't seem to be much difference between us once the sandtrap was weighted, it sat snug in the same position.

I'll have to work on purchasing another sandtrap, or get 4 more potshots and use those. I know that using potshots for an anchor is not easy, but do you think it could be a reasonable alternative to bringing multiple sandtraps?

Great stuff. Thanks for sharing.
There are many correct ways to do things.
In our cadre....
The person that builds the anchor, generally "owns" the anchor
That person will go last or ask another to go last or ask for volunteers.
The last person will often designate who they want to go next-to-last.
The last person is in charge of adding or subtracting sand, shifting anchor etc.
Advice from others is welcome, but the last person decides
Next-to-last-person is important, as it is the last trial to see if the rig is PUUUUUR-FECT
Whoa is the next to last person who's trial rap fails, for the last person is on a "guess" then.
That is why we mostly go with 4 off the trap, not less
The next-to-last-person, in our group will rappel slowly, creating the most friction along the rap, that they can figure out.
Smearing down the drop, most often. The last person likely follows suit.
Most important is to create "bends" in the rope, before even really weighting it.
Get down as far as possible before putting any real weight on the thing.
BUT not so much that a "shocking" of the anchor is possible
While a speed rap may put less pressure on the anchor, (may, I am not sure of that) when performed successfully, it is wrought with danger.
Shocking anchors, which CAN happen for a variety of reason, is inherently dangerous. Unlikely to shock? Perhaps, but not worth the risk
With these type anchors, reducing the opportunity for that to happen, is a great long term strategy.
These are some of the shifts in form we developed as we got into triple figures, off this wonderful anchor.
You are doing great. No implied criticism at all.
Oh and a second trap is better than pots, but pots forms a reasonable back up plan.
Pots have their place. A small place, mostly, for tricky narrow spots. Or as often as objects to drag, on down climbs
And finally...Isn't watching your anchors follow you down the canyon REALLY magical?
R

Can you clarify what you mean by creating bends in the rope?

Laying rope over edges, then getting low enough before fully weighting the rope reduces the weight on anchors substantially. We call it "creating a bend" in the rope.

Jenny models here

I like to call it "soft rappelling". I often set my rappel device one level down, and make sure I move at a constant speed no stops no changes in speed like a runon sentence until you are down on the ground. Certainly involves being very careful at the top getting over the edge and weight onto the rope. Often involves sliding down the rock if it seems appropriate.

T

I always soft rappel too, unless I'm rappeling off @ratagonia as meat. Then I don't. Surely he's got me, right? (Sorry about that, you probably don't even remember, but I do.)

This is a great thread - first because I haven't ever used the SandTrap - but will soon be ordering a few. I have tried to improvise the concept a few times with a soft litter, but the time delays in rigging a soft litter to do a specific job makes little sense compared to carrying a SandTrap (or 2). It also seems like the SandTrap can easily be utilized as a soft litter to carry out an injured person (this performance parameter of rescue /evacuation may be a limited subgroup - but it is a key performance parameter for many we work with). Since it is obviously constructed to be used as an anchor - has anyone ever tried using it to lower a casualty in a diaper configuration? There is a triangular device that has been used in the urban environment and a little bit in the DoD arena to evacuate casualties vertically, but the SandTrap looks like it would work much more efficiently and may need to just add a short section of webbing to secure injured person. Obviously this usage would be considered "off-label" by manufacturer, but will try it...

Also, I have really become a fan of "soft rappelling" / "creating bends" over the years. It is pretty amazing the difference of anchor force between soft starts/raps - starting from a sitting position, weighting the rope over the edge, and a smooth rappel vs. a hard start / rap - standing and doing a "L" over the edge, and bouncing during the rap. We recently put some enforcers on our anchors and tried a variety of different edge transitions and rappel techniques - we did this in urban, mountain, and canyon environments - the numbers were amazing.

I am not an engineer or a physics professor, but we all deal with physics whenever we are on rope... so some of the findings we have had will probably be better explained by others in this group than myself. The capstan problem is typically used to explain the friction we achieve in our DCD, but is also used when discussing the friction over edges when on rope, as Attaway has done on some ITRS presentations. Although this gives us some understanding of how angles and coefficient of friction play a role, the equation never comes out perfect, and not many of us walk around memorizing the COF of an aramid over sandstone vs polyester over granite. I recently read an article nonlinear frictional behavior - which basically stated that;

- Frictional Law = Inverse Power Law relationship - (nonlinear)
- The behavior of friction in a system is nonlinear but is not always noticed
- The "capstan problem" is theoretical and can give a rough estimate to your system
- The capstan doesn't take into account... bending rigidity or nonlinear friction behavior.

The point of me spewing his out is -
Looking at just how much force a ~90 degree angle takes off your anchor if loaded correctly, like what Tom refers to as a Soft Rappel - makes a big difference. Out of every measurement we got from the enforcers, it seemed that sandstone as a whole took less weight off, while an urban 90 degree edge over brick or a concrete parapet took slightly more weight off the anchor. When doing a "bail-out" from a window with a wood sill - it took less weight than sandstone. All of these were done with 100% aramid 7.5mm ropes. But I assume all of the different numbers between surfaces had to do with the various coefficient of friction between material. I know there were potential variances in the exact angles we were going over, but.. this really was not meant to be "scientific"...more just to try and get better fidelity on technique selection.

We then tried the above with different ropes - comparing various manufacturing techniques - and how the morphology changed with weight. The cliff's notes - a rope like Sterling's RIT Response is listed as a 9.5mm, but flattens out quite a bit by design, but it seemed to take more force off the anchor - maybe because there was greater surface area over the edge - and because it flattened out more than many other ropes - it's angle over the edge was sharper...?(Tom- maybe?) - while stiffer ropes took less weight off of anchor - and their morphology over the edge was rounder - maybe this has to do with the "bending rigidity". Also...the weight of the rappeller - the greater the weight - there seemed to be a tipping point in some ropes, where the rope would flatten out more. These don't even add the additional variables of wet vs dry, ice / snow, etc.

It seems like there is no shortage of variables in any system we use in rescue, canyons, urban, or wherever - making much of what we do vertically nonlinear physics and less newtonian. Knowing principles definitely trumps learning just one way of doing it - what worked in this place may not work in that place, which I believe is what (tom) was saying in his earlier post.

This tipping point between the anchor holding - the friction gained between anchor and load (rappeller) & technique over edge and smooth rappelling, reminds me of a technique we used to teach in the fire service many years ago, when you clipped your 8mm rope around the neck of your SCBA bottle, and used the bottle as your anchor to go out a window (window sill needed to be at least 24" off ground)...picture attached - The first couple times I was positive the bottle was going to flip right out of the window and beat me to the ground...

I should of paid more attention to physics in school....

A couple years ago Luke (Bluu on this site) put together an awesome practice session with a dozen canyoneers to see who could
be the best 'soft rappeller'.
We met at our local sandstone craig with a fairly sharp (1" radius?) edge and every canyoneer got three rappels rigged to a load cell
to see who could creep over the edge and keep the LOWEST possible peak load on the rope throughout the whole drop.
Participants ranged in weight from 115 to 195 lbs, and ranged in experience from newbie to canyon-guide-fire-recue professional.
The winners?
1st Parker (195 lb canyon guide fire-rescue pro)
2nd Desiree (115 lb rappel device developer)
3rd Me (flabby old climber type)

As I recall the winning (lowest) values were in the 50 - 60 LB range of maximum weight on the rope.
Lessons learned?
As per Tom and Ram: slow and SMOOTH wins the day!

We have done this very thing as well with similar results. 65 lbs was the lowest. Were easily able to generate loads over 500 pounds with careless starts.

That is awesome... it would be great if folks in the traditional rescue world (which I sometimes work with) could learn some of these techniques, showing that they can increase their SSSF by just altering their techniques, instead of going for gear with higher kN's.

There's a story about that.

.....Story???????

I'd love to see that one repeated with Ram competing. That dude is soft and smooth.

........that was maybe not the story we were hoping for....

I ended up doing No Kidding for the second time yesterday with a member of our group weighing 210 pounds. I was surprised by how much it changed the amount of sand needed and the pulls after. It definitely wasn't as graceful as the first time through, but was a good learning experience

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AH, the "bends," thought I studied that in SCUBA diving. The physics people will like these: http://rope-work-101.wikidot.com/rappelling-faster-reduces-anchor-load, https://en.wikipedia.org/wiki/Normal_force. A second person standing on the rope as it goes over a "bend" takes some of the force off the anchor and places it on the rock.