New Hampshire climber Chris Girard reported on Treebuzz that he had a partial TIP failure while on SRT ascent. He was at approx. 30' and dropped 10 ft. He was climbing on KMIII with a double-handled Ascent Tree (Petzl) up top and a Croll at his waist, the Croll (and the rope, tree, etc.) took the fall. Chris was sore but otherwise uninjured, the Croll didn't damage his rope. The rope was ground anchored over a good-sized TIP but also over a 1" diameter green (new growth) white oak branch which broke. Very glad to hear that Chris is ok.

Details here

I suspect we'll be hearing more reports like this as more work climbers switch over to SRT for tree access.
-moss

Glad the guy is OK.

Are you sure this is a true story? According to some of the math I have seen on this site the guy shoud have hit so hard that his internal organs would be ejected from his body. Or at least been broken clean in half. He was climbing on static rope you know.

Seriously though, falling is never a good thing in tree climbing.

I am not expert on falls and Internal damage BUT I'm an opinionated, So here it goes;

If you jump from say 6 ft tall fence and land on your feet does that cause Internal damage?
Well It could but not likely. I do that all the time.
So if you "fall" hanging from a rope and drop lets say 10 feet.
Does that cause Internal Damage?
Well it could but not likely! There are too many pieces of gear that reduce the impact of the fall and reduce how much force is transmitted to the body of the climber (maybe called "Faller" for this example).

It sounds to me like the rock climbing industry has exaggerated a little bit the potential damage cause by falling so that the users be afraid to death of falling from any height. ( or I'm completely wrong also!)

I have taken two good falls from a tree without any actual "damage" internal or otherwise! - well my brain may be dead but that is another problem. All that drinking and smoking in college did it!

There is a video on line of an idiot that decides to jump from a bridge on a rock climbing harness and tied to a long static line. The line is almost cut all the way across and the idiot is still hanging at the end of the drop - Looks Ok. No recommended thou. Looks very stupid and he could have been killed by the rope breaking.
Uhmmm, I wonder if that video is a fake video?
Oh, I better send it to Mythbusters to double check that one.

Anyway, just out of curiosity. How many ponds of pressure did you come out in your fall calculations Huna?

It is not the drop that kills you, it's the sudden Stop!

KMIII has stretch, more than some half inch climbing ropes. In an SRT configuration he would have a lot of rope in the system to absorb the shock.

This is conjecture...I wonder if the rope slid/rolled down the trunk which would have dissipated some energy too. I don't think that he experienced a slam-dunk stop.

This is one of the two main reasons I never, ever recommend static rope to a climbing student; arborist rope has some stretch built in. The other reason is that real arborist rope can be used for both SRT and the traditional DRT climbing. I can't think of any reason why I'd purposely purchase static rope for tree climbing unless I was working out of the back of my pickup and never hauling the stuff more than a few dozen feet to the target tree. Oldtimer's comments seem to pretty much agree with my thinking...!

Chris has high credibility. I think you have to bear in mind that he wasn't dead-dropped on to a rope suspended from a steel I-beam.

The following factors are going to absorb some percentage of shock:
1. Ground-anchored rope increases stretch/shock absorption potential, even for a static
2. Shock absorbed as the small branch broke (mileage varies, knowing white oak it probably held together enough while it was breaking to slow the drop slightly)
3. Shock absorbed by the tree when the rope hit the TIP that held (big variable here, don't know the diameter of the leader supporting the limb, could've been quite a bit of flex on loading).

Note Crazy Jimmy's report in the same thread of something similar, his organs weren't ejected either. Jimmy has high credibility as well, hey I lent the guy my 10mm static when he was in town, he's an experienced SRT climber, knows what he's doing, has no reason to fib.

I think the variability of flex in SRT anchors depending on tree structure, species etc. really throws off shock load test results conducted on non-flexing structure. It does provide a good worst case scenario baseline.
-moss

Edit: I took too long to write, the other posts came in, Tom etc. agree that the stretch in the ground anchored rope was a very important factor.

I can think of several.

Number one being that a 200' 10mm static is light and compact enough to carry long distance for woods climbs compared to a semi-static of the same length.

I trust mechanical gear on statics more than semi-statics (cover is much more durable)

I'd rather do a plus 80-90' SRT ascent on a static any day compared to semi-static.
-moss

And lastly I'd be interested in seeing a comparison of the destructive effects of a Croll shock loading on a semi-static vs. a static rope. Is the semi-static more or less likely to be shredded? Lots of testing has been done on statics, we know that with sufficient load the cover strips but the core holds.
-moss

KMIII is not really a 'static' rope...for that matter...what makes a rope 'static'? The term semi-static has been tossed around.

There is more stretch in a ground anchored setup using KMIII or another semi-static or even static line, than a traditional doubled rope system using half inch or even 11mm arbo rope.

Sweeping away any rope without looking at the specs requires a pretty broad brush.

I think "static" is a relative (not absolute) term.

The commonly used definitions as rope manufacturers and retailers categorize and describe them:

Static - low stretch kernmantle construction, cover is tightly braided and durable, the core is not a braid (described by Sterling Ropes as "twisted parallel"), the core takes most of the load, the cover protects the core.

Arborist rope or semi-static - Typically a double braid but there are variations, cover and core are braided, the cover braid is not especially tight (what makes it supple) both cover and core braids share the load, low stretch but typically has more stretch than a kernmantle construction static.

There are static ropes that have more stretch than the lowest stretch arborist semi-static ropes, stretch rating is not the defining characteristic.
-moss

I think it's worth mentioning a little discussed inherent fact about SRT. Perhaps it's too obvious because I haven't seen it posted. And, it's NOT "the double load problem".

If a ground anchored SRT TIP fails and catches the next limb five feet down, then, suddenly there is ten feet of slack in the rope. So, a five foot drop in TIP equals a ten foot fall. Right?

Don't get me wrong! I'm an avid proponent of the gound anchored SRT - just and observation. I keep a tiny monocular in my throwline kit - always available to examine the TIP. If I can't SEE the quality of the TIP from the ground, I'll reset it.

Good observation. If a climber reports a fall of say 10' on a ground or trunk anchored SRT system caused by partial TIP failure, then it's fair to say that the TIP moved down 5' before a branch caught it.
-moss

That's a sound safety practice but real world experience is that many rec and pro climbers get on SRT settings where they cannot see the TIP. The climber can verify that the rope is over sound branches even though they can't see the exact location of the rope. The iffy part is that the climber can't tell if the rope is also over dead or small live branches above the strong branches. That's where load testing becomes critical. Even then it's not a guarantee, then again nothing in tree climbing is guaranteed. Best case is that the climber has narrowed down the chances of a partial TIP failure to a minimum. I think most SRT climbers have plenty of experience doing a "gentle" first ascent on a hidden SRT pitch.
-moss

TIP safety could be a wonderful subject for general debate ... even if, already debated. It's certainly agreed that "nothing in tree climbing is guaranteed." That's probably part of the attraction. And, I don't doubt for a minute that many in the "real world" successfully climb a "hidden SRT pitch".

However, I've always wondered about "load testing" - specifically the 'bounce-test'. When a TIP does not fail the "bounce test", does it really verify it's strength? Or, does it simply weaken a marginal TIP so it fails after the fifth stride ... or tenth stride ... whatever?

It's all about risk management ... or risk tolerance. Granted, visually verifying a TIP is no guarantee, either. But, a "hidden SRT pitch" exceeds my risk tolerance. Perhaps that means more time to set a better TIP or maybe even, not to climb at all. It's simply a matter of personal choice.

It would be really interesting to have others weigh-in on the question this thread raises about TIP safety/verification.

I'm no engineer, but I don't know if it's possible that a TIP could pass a bounce test with a higher load than an ascending climber, yet be weakened enough that it would subsequently fail at the lesser load. My intuition tells me that this would be like in Hollywood movies when a rope holding the hero is fraying. As more and more strands break, the rate of failure decreases, until only one strand is left and it holds for a long time until the plot calls for it to break, which is exactly opposite to how a rope actually fails. Okay, so maybe this isn't the most precise analogy.....

At any rate, if I had to choose between a visual inspection from the ground OR a bounce test (not both), I would feel safer with only the bounce test. With a visual inspection you are only seeing the underside of the TIP, and all experienced climbers have stories, some funny and some scary, about things they've discovered once they've arrived at the TIP.

Having said that, however, don't mistake me for someone more courageous than I am! I still prefer to see AND bounce test my TIPs, and climbing to an unseen TIP makes me climb really smooth!