I've been using a Yale XTC rope for two years without any problems, but recently my 4/2 Blake's hitch started slipping. I started using a 5/3 version instead, and thought I'd solved the problem, but today it started slipping too! What's up with that!?

I know the knots were tied right, I double and triple checked them (although I am still uncertain as to how tight one needs to keep a Blake's hitch). The rope certainly doesn't look worn, and it isn't glazed or anything. It doesn't seem to be terribly dirty, but there was a lot of dusty crud settling over me and the gear (this time, but not when the original 4/2 started slipping). Also, it seems to happen mainly on descent, not ascent or dangling.

What factors can cause this slippage, and what measures can be taken against them? Should I try washing the rope? Do something different with the knot? Help! Climbing is already thrilling enough; I definitely don't need the extra rush of adrenaline that this causes!

Brad

Hello, Brad--

I don't have an answer for you, but I do have some questions/thoughts:

1--Could moisture/humidity have anything to do with it? Has that been different?

2--How much did it slip? I assume that you grabbed the rope to stop the descent--did that take much work on your part?

3--Is it that the knot would hold you in place until you "pushed" on the top of it (to begin your descent), and then it didn't catch and hold once you took your hand off the knot?

4--How much do you and your gear weigh? And that prompts the thought, are you carrying more weight aloft now?

If #3 is true, then the answer from the engineering and physics worlds is that the dynamic coefficient of friction of the knot is too low to hold you, whereas the static coefficient of friction is high enough to hold you. What that refers to is that the frictional force may be enough to hold you *until* it begins slipping, but once the slipping has begun, it ain't gonna stop. I'm sure you've experienced that when pushing a heavy object across a floor: you have to push with a certain amount of force to get it started moving, but once it is moving, you don't have to push as hard to *keep* it moving; and once it has stopped, you have to push harder again to get it going.

Of what value is that to you in your situation? Probably none, but you did get a free physics lesson. The next time it slips, instead of screaming and grabbing for the rope, you can calmly say, "Dear me--the dynamic coefficient of my Blake's hitch is too low."

Seriously, the knot does need more friction. Why now and not before? Beats me.

You commented that you were uncertain as to how tight it should be; I snug mine down pretty tightly--no slack.

I'm looking forward to hear what some who have experience with XTC, and others with a ton more experience than I have, might have to say.

Good luck!

Jim

The only time I've had a Blake's hitch slip with XTC was when the rope was brand new. My "fix" was to tighten the hitch, producing more bend of the rope through the middle of the hitch, and thus increasing the friction/holding ability of the hitch.

Testing your hitch by going up and down once or twice just off the ground, before ascending, may help catch descent problems before they become major risks. And some kind of "stopper" knot, tied below you but sufficiently off the ground, could be the difference between you sliding all the way to the ground or coming to a hard stop still on the rope if your hitch ever does allow an uncontrolled descent.

Thanks, guys.
In answer to your suggestions:
-- the mosture/humidity wasn't extremely different that day; somewhat warmer and drier than usual.
-- once the slip started, it seemed like it simply didn't want to lock up at all. There was enough friction that it took only a little work with one hand to control, and even stop, the descent. I could come to a complete stop, and as soon as I relaxed my grip, it would slip again. I was a little too nervous to try letting it go and see what happened!
-- yes, the knot held until I pushed it down for my final descent, and then wouldn't hold again. I should point out that I wasn't on the same knot for the whole climb; I was working with both ends of my rope, and had advanced my rope four or five times, re-tying the Blake's each time. On the last knot, I checked and re-checked visually, then hung on it and bounced my weight a bit, before untying my other anchor and unclipping my Monkeytail. At that point it gripped just fine! Jim, in terms of your explanation, I guess the initial static coefficient of friction was sufficient, but the subsequent moments of static coefficient of friction weren't?
-- I weigh about 190 lbs., and was carrying maybe 15 lbs. of gear and water. This would be about normal for most of my climbs. Is 200 -- 210 lbs. too heavy for a 4/2 or 5/3 Blake's hitch?
-- yeah, I keep my knots pretty snug, too. Enough that I sometimes wonder if I'm subjecting my rope to more wear than is neccessary!
-- Bradley, your suggestions are good. Tying knots below your hitch as you climb is a good safety measure and I make my kids do it all the time. Maybe I should start practicing what I preach! As for testing, I've always limited it to testing the static position, both initially and after one or two pulls. I think I will definitely get into the habit of doing a trial descent, as well.
Thanks again for the help!
Brad

I've had a similar thing happen on XTC. It hasn't happened to me on 7/16" ropes like Sportline or Fly. Maybe the thicker rope isn't turning quite tightly enough around the down rope?
Anway, what I usually do before I descend is to grab the tail end of the rope (the last few inches of rope that come out of the Blake's hitch) and pull straight up. That compresses the Blake's hitch a little more and increases friction.
Patrick

Brad,

I have a 3yr old XTC, and I've just started noticing this problem. I have discovered though, that it seems to happen more after significant climbing in a tree with smooth bark. I have ben climbing a pair of willow oaks on a reguar basis, and I tend to see a little slipping while in those trees. In a white oak or a yellow poplar I've yet to have the problem. Interesting thing is that I've always just let it go, after a few inches the knot seems to remember it's job and cinches down.

As far as the blake's configuration, I always use 4-2 with my XTC. 5-3 locks solid on that rope. On my sportline either works fine, but I'm so used to the 4-2 that I don't like to use the larger knot. Interestingly, my kids have difficulty advancing the hitch on the XTC, because it grabs so well, there is a paradox for ya!

Climb Safe! See ya between the trees!
Icabod

Actually I do often use them...

The more I think about it I think that it may have to do with what is at the bottom of the tree. I've never had slipping in a wild tree, there you have leaf cover on the ground below. On the trees where I have seen the problem there is bare ground, which is constantly wet. I am starting to think that my rope is just getting grimy on the ground, and that is causing the issue. To further this theory the two times I've used the sportline in those trees I deployed from a ropebag (I was using only one end, setting a rope for the kids.)

Dietly, how's the ground under your trees in the great white north? I bet you are climbing on ground with pine needle cover, which would be similar to my nasty dirt. Either that or my theory is complete bunk!

Carelessly spouting forth poor theories, instead of getting into the trees.
Icabod (I'd rather be climbing)

I've been using XTP candy striped rope for years now. I use the slower B-53 knot because I hate sudden "skips" on my descents. I have experienced knot creep a few times. The creep is usually slow, but any creep- uh- gives me the creeps, and I respond with a vigorous upwards tug on the tail which stops that nonsense and brings my internal chemical reactions down to a tolerable level. I have never known the Blakes to create a free fall situation. A safety knot as backup down low on the rope might be a good idea until you regain trust in the knot. Like you said, we always tie a safety knot for the kids. Let's not forget that it is that same kid in a grown up body that gets us into the trees.

Thanks everyone!

I'm glad that I'm not the only one experiencing this. I guess we still don't know exactly what is causing it, but it is extremely comforting to know that many others have experienced slipping and not only survived to tell about it, but still enjoy tree climbing!

Patrick, I don't know if size has anything to do with it or not, but I can certainly second your statement that a Blake's hitch never seems to slip on a Sportline. And, I'm going to cinch up a little before descending, too.

Icabod, I agree that it likely isn't the bark; I always use a sleeve-type cambium saver or a false crotch. It could be the ground. The ground where I most recently had the problem was buried under a thick layer of leaf mulch and sword ferns, along with some rotten, moss covered logs, all covered with about 7 feet of salmonberry bush and devil's club. However, under my "practice tree" is mostly just bare dirt, and even though I use a rock-climbing-type rope tarp, the rope still gets considerable time in said dirt. It doesn't look super grimy, but it sure doesn't look pristine white anymore, either. Furthermore, the soil around here has a high clay content, so the dry stuff tends to have a texture similar to talcum powder! You may cerainly have something here; keep the theories coming!

Treeman, thanks for your input. I feel very encouraged by your comment that you have never known a Blake's to allow a freefall. It's true that it'll take a while to trust the knot again, and I will use some safety knots for that while, but just from the feedback I've received here I'll feel more confident on my next climbs. Please tell me, though, what's a B-53 knot? Is it a 5/3 Blake's?

I thank you all, and my inner kid thanks you, too!

Brad

Originally posted by Dietley
I know the knots were tied right, I double and triple checked themI'm not ignoring your original post; I'm just sharing this experience.

I tried tying a hitch like a Blake's except instead of finishing over the bridge and under the running end I went over the bridge and over the running end. This produced a hitch that mostly belayed as expected, except when it slipped.

Are you still slipping? (Do you find your 2003-11-13 post ironic, too?)

Yeah, I find it rather ironic, too. Do you suppose if I loosen my Blake's a little, it might not slip? Having it good and tight hasn't helped!
I'm not visualizing the alternate version of the Blake's hitch you describe, but it doesn't sound like what I'm tying.....I hope.
I screwed up my back at work and haven't climbed for several weeks, so I haven't had a chance to try any changes, so, no slipping. Unless you're referring to my sanity, in which case the slippage is no worse than usual!

It took a while, but I finally got up a tree with the XTC. (It could have happened two weeks ago, but I got my new Fly and just had to try it out a couple of times, first!)

I washed the ol' XTC in a commercial front-loader washing machine, with warm water and soap flakes (not detergent). After being cleaned it was way whiter than I remembered, was a little bit fuzzier (but still pretty new looking -- you just have to love cambium savers!), and was softer and more pliable. The surface didn't seem any more "grippy" or anything, but the increased softness and pliability could certainly cause a hitch to grab better, I would imagine.

Between the encouraging words from you people and from the performance of the Blake's hitch today, it was very easy to trust it. I was up and down the tree three times, and never had the slightest bit of creep. I was using a 5/3 Blake's, but after today I will probably try a 4/2 version next time, with confidence.

Other than the laundering, nothing really changed. Same knot, same weight, same technique, similar climatic conditions. I don't know if cleaning a rope is supposed to make much difference, especially since it didn't seem terrible filthy to begin with, but based on my own experience here, I'm thinking that it might be reasonable to conclude that it makes a large difference. Is it?

Brad

VINDICATION AT LAST!

So much for my poor theories! I knew it, dirty rope is the cause!
Puts a smile on my face really. I just knew I wasn't (entirely) full of bunk!

Good to hear you are back in the trees Brad.

Climb Safe!
Icabod

I'm currently making direct contact with the rope manufacturers, surveying for cleaning methods. I hope to post the results. I'm sure the known methods are fine. Sometimes a company optimizes a method, and it takes time for it to be publicly known. I'm just shaking the trees to see what's there. Though it's curious that the XTC is the focus of conversation. Does it have a design feature more prone to slippage?

Having worked on numerous projects where a miniscule change in friction (COF - coefficent of friction) could shut down a manufacturing process, I absolutely believe washing a rope is needed where sudden unanticipated slippage occurs.

Being North of the Ohio River. the cold days of the impending winter are a good opportunity to clean rope, which is why I'm touching base with rope manufacturers.

As I think about this, I think that I'll clean 1/3 of my Fly by hand just to see if I can detect differences.

Anyone have a preferred method or technique of cleaning?

Regards,
JimK

Jim, what I'd like to know most of all is how to get pitch out of a rope, without resorting to rope-eating solvents and the like. Please let us know if any of the manufacturers have any suggestions. I live in the land of big Douglas firs and can't even appreciate it because I HATE pitch!!