During an episode of "SOS-Survival" Creek Stewart had occasion to tie a rope around a tree to serve as an anchor for extracting a snowmobile from a stream. He used a timber hitch, stating that this was the strongest possible knot.

This is news to me. I have always favored either a bowline, including several of its variants, or the figure of eight, which tests out quite well in this application. I could find no data on strength of a timber hitch, but I doubt it would do as well as either the bowline or figure eight.

Strength is defined as the percentage of strength retained by the knotted rope, compared to the breaking strength of the unknotted line. A degradation of close to 50% is typical for most knots, with the bowline and figure eight testing at 75-80%.

Any thoughts? None of my anchors have failed yet....

I have no idea if a Timber hitch is the strongest, but as I recall a line loses strength where the knots bend tightly and the “timber hitch” wraps around the line and uses pressure against the tree or cylindrical object to maintain its hold. This looks like it would hold very well as long as tension is maintained. I wonder how well it holds once that tension is released and then reapplied...

You can't judge a knot by looking at it. But if I had to give that a shot, I'd say the Timber hitch looks reasonably strong, but not very secure. Two different qualities. It would definitely need constant tension to hold together well.

What puzzled me was that I could find no data on testing of timber hitches for strength, although there are plenty of data for most other common knots. Anyone know of any tests?

Timber hitch would not be my choice for that use.

High angle rescue teams these days seem to favor the ”tensionless hitch” to tie a rope to a tree. The tensionless hitch is clained to retain 100% of rope strength. However, it will not stay in place without a load.

It occurs to me that the word “timber” in the name is significant. The friction of rough bark on the inside of the wrap is what keeps it secure. I’d like to see how well that hitch holds on different cylinder materials. I imagine a steel pipe would have a different value for friction and the hitch could slip. Maybe knot, but I’d be surprised if the cylinder material did not matter.

The friction of the material (tree bark in this case) certainly does matter. However, that can be dealt with. For the “tensionless hitch” I mentioned, rope rescue manuals recommend taking more wraps for smoother material such as a pipe.

The timber hitch holds fine on a pole without bark as well. It needs a fairly large cylinder though and it does not react well to changing loads and vibration. It tends to work lose under those conditions.
I was in an emergency respond team and we were not allowed to use the timber hitch for securing people or for really heavy loads. So strength did not really matter. The main use was for transporting smaller timber (a size one or two people could lift) vertically. It was always used in combination with a half hitch on the other end of the timber.

Just like a girth hitch can vary in strength depending on how much bend in the rope is created by where the intersecting rope surfaces are, so does the timber hitch.

So one would end up with a range of strengths for the same rope, hitch and anchor.

The tensionless hitch is a better way and has the bonus of being able to be released under tension. Just unclip the biner and unwind. (This can be useful in a rappel situation where someone gets their clothes or hair stuck in the rappel device and is also on a backup belay. Hold the person on the belay rope, give a few feet of rappel line, then reclip the rappel anchor. Then the person can clear their system, belayer release the belay, and continue with the rappel. Much like using a Munter/Mule system on the rappel anchor for similar screwup solutions. Cheaper than cutting the rappel rope free of the anchor and safer than trying to use a knife to cut clothes or hair away from a tensioned rope.)

The timber hitch holds better when dragging timber (imagine that) as it cinches down as the log turns, rather than unwinding, with less rope needed to make the hitch.

Hmm... reminds me of quick alpine belays/anchors; just wrap a rock once or twice.

Or if you are really ancient, you remember when bodies were for belaying....

So where did Creek Stewart get the notion that the timber hitch was the strongest possible knot for an anchor? I may have not heard correctly, of course, but I believe the WC reruns these episodes a time or two, so stay tuned.

Looks like simply a "round turn and two half hitches", an excellent knot that's been around forever but doesn't seem to get much respect. Except this fancy new one has more "round turns" and with a "figure-8-plus-carabiner" replacing the "two half hitches".

If you don't want to mess with a carabiner (like when you don't have one!), but still want something super-secure, you could just make 3 or 4 round turns and finish it off like a buntline hitch rather than with two half hitches. Slip this finishing knot if you want it to be easier to untie in an emergency (or for whatever purpose).

The round turns give you the strength and take the load, so you don't have much tension on the finishing knot.

On a couple of occasions where we employed a tensionless hitch, we simply wrapped the tree several times and then anchored the end of the rope to yet another nearby tree,leaving some slack in the line in order to detect any movement in the system. The securing knot could be just about anything - I believe we used a bowline.

Now that's some redundancy!

This was for an overhanging descent into a sink hole near Ashfork, AZ. 248 feet hanging free...Redundancy was welcome! Besides, it worked...

What was the snowmobile doing in the stream???

Short answer - getting wet and rusty.

The show was recreating and critiquing an actual event where the driver attempted to cross a frozen stream - didn't work. They anchored a long piece of webbing to the tree and winched the snowmobile out by affixing the other end around the tread. Basically the machine self extricated, without the driver getting wet....

My choice of anchor would involve a rewoven figure 8, along with multiple wraps around the tree. I love redundancy.

If a rider keeps sufficient speed, it is possible to skim across open water on a snow machine. People sometimes do this to get over a stream or pond. This has even led to a new wave of sporting events called snowmobile skipping, snowmobile watercross, snowmobile skimming, water skipping or puddle jumping. According to Wikipedia, the current over water distance record is 212 km (131.731 miles) by the Norwegian Morten Blien.

The driver in this event was not an expert, although an Olympic Greco-Roman wrestler. In the recreation, they demonstrated that smowmobile skids could make dandy improvised snowshoes, although I would think that real snowshoes would be great EDC on a snow machine.

Would this article (pdf download) have the timber hitch info you want?
Breaking Load of Hitches and Ropes Used in Rigging
http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=3218&Type=2

Thank you very much. the article indicates that, while a properly tied timber hitch is adequately strong, it is not the very strongest knot. Somewhat surprisingly, they did not test the unknotted breaking strength of the ropes they used, and hence did not provide a measure of "efficiency," the percentage decrease in strength that occurs when the rope is knotted.

The article does indicate the importance of a properly tied and dressed knot and that there is a degree of randomness in any lash up,so don't push to the very limit of these numbers!

I would say that probably the very strongest anchor know would be a rewoven figure eight, properly tied and dressed,closely followed by the bowline and its variants. There are more variations of the bowline that there are cross ties on the railroad or stars in the sky.

More stuff on knot strength.

"A figure eight follow through, for instance, is often cited as having 80% of the strength of the rope. In our tests this ranged from 100% – it did not fail at the knot in climbing ropes in about a quarter of cases, including in a UIAA fall test that we observed – to near 50% in 5.5 Spectra/Titan cord. "

"Nor does it matter if the eight knot is “sloppy” or “neat”. In fact we tested quite a few figure eight knots, in a variety of ropes, that were improperly tied so that the last pass of the “follow-through” was not made. Did it matter? Drum roll please: sometimes it tested stronger than the “correct” eight and in a third of our tests it did not break at the knot."

http://efclimbers.net/wp-content/uploads/2013/02/Knot-and-cord-strength.pdf

Yeah, but try to untie after falling hard on a figure eight knot...

Not related to strength, but if people do not dress the knot correctly or tied is rather sloppy, I'll just tell them to redo it. Got to keep people from getting too sloppy with everything. You can often see one sloppy thing leading to another.

This statement caught my eye in this very worthwhile report:

" It would be interesting to perform a few of these “messy knot” tests on UIAA drop tests and see how they perform in dynamic loading situations."

After all, the reason we tie into a rope in the first place when climbing is so that it will catch us in a dynamic fall. Certainly a messy knot is better than no knot at all....

I've always felt that obsessive concern with knot strength is somewhat wasted effort. Modern climbing ropes have a rather large safety margin with regards to strength. People die when anchors rip out of the rock. People die when ropes get cut over sharp edges of rock. But one simply doesn't hear much about real instances of people dying because the rope broke at a knot.

I think the key factors for knots are can they be easily tied correctly, and are they easy to check? Are they secure when tied correctly, and can they be untied once they've been loaded? I once saw a climbing partner come untied from the belay in the middle of a pitch. He had somehow miss-tied his tie in knot, and it simply came untied as he was moving up the pitch. Fortunately, he didn't fall, so the incident was very scary, but not catastrophic. Note that after that he became extremely methodical in checking all of his knots!

Excellent points, but some of us (I won't name names) began climbing before modern climbing ropes were in vogue. my first use of a rope was a 1/2"manila rope fixed by our leader who free climbed the pitch (today rated at 5.6) and we clambered up hand over hand. Belay, what's a belay? I have no idea how the rope was fastened to the stout tree that anchored our ascent.

Fortunately, someone arrived in town with nylon ropes, pitons, carabiners, and the knowledge to use them correctly and we lived to tell tales.

I do think it is useful to be aware of the changes in strength wrought by knotting, running sharply over a carabiner, wear and tear, etc., and be mindful of these factors when climbing or rigging.

I have receeently had occasion to apply my knowledge of rope craft to rigging large paleontological specimens of unknown weight (but estimated to reach around 1200 pounds) for extrication. The work is much more methodical than the usual rock climbing situation, but care is needed. Failure would b embarrassing, to say the least....

Sounds like a mammoth job! Especially for an old fossil such as yourself. I hope you were able to channel the forces correctly? Just remember, no man is an island.

But many are atolls.

A lot of what passes for gospel in climbing is based on the untested or anecdotal.

Things like connecting two loops of cord. In the old days we did a strop hitch or girth hitch and thought no more about it. We just figured any knot would reduce the strength of the cord by up to half. Since we overbuilt everything in the first place, no problem.

Now, I get told when connecting two loops of cord or web to use a carabiner, that it is much stronger. (Bull pucky, it is one more thing that can go wrong, either by the added chance the biner is damaged or by getting cross loaded, and it uses up one piece of gear you might need later on the climb.)

All that because John Sherman reported a girth hitched sling broke at low load.
Suddenly girth hitches are only for connecting a leash to your harness. (If they are not strong enough on one piece of an anchor system, how in heck are they okay as your ONLY connection as a leash?)

This supposed new safety rule is still being passed about years after tests showed Mr Sherman's broken sling had been badly damaged beforehand.

There's always someone who didn't get the memo. At a minimum,that would be me and those who wrote the latest edition of Mountaineering: Freedom of the Hills. The girth hitch is conspired legitimate and its use is advocated for several applications, such as tying off short on a piton, etc. Realizing that a girth hitch does cut down on the overall strength, think as you rig. Again, per AKSAR, things rarely, if ever break down at the knots, despite Sherman's experience.

It's always a good idea to retire equipment, especially ropes and slings, before they get too old. i'm thinking that might apply to climbers, too....

They can always find something else knotty to do.

I remember climbing on, what as it called, "Gold Line"? Something like that. Better used for rappelling or top roping. If you were foolish enough to lead climb on it, and fell, with it's 15-20% stretch you'd hit bottom and then get flung the rest of the way of the rock you were trying to climb!

Goldline was a fairly evolved climbing rope. That manila rope, I later learned, came from a rope spool that had been condemned by the telephone company. My first real climbing rope was 7/16 white laid nylon. Goldline was the next evolution, and, although elastic, as you noticed, at least it didn't break.

When I price today's full featured ropes, and their stratospheric prices, I recall my first real climbing rope cost all of $20 from REI. Yes, I am ancient...

My first rope was a 120 ft Goldline, the soft hand version that you could lead with using clean pro. The hard finished versions were only good for pitons as the kinks and coils of the stiffer rope would pull your chocks right out of their placements.

The stretch was pretty bad, but the whole point was not to fall anyway (unlike sport climbing where the gear is more tried and trusted.)

I also remember Greenline (vets probably used this), SKYline (not blue line like if first said) (solid pale blue or white with blue tracers), as other inexpensive laid climbing ropes.

My father in law still has his white laid rope, soft pitons, and steel carabiners shaped like a B from the 50's. They reside on his wall.

Goldline was in common use in the early to mid sixties, when I started climbing. Back in that era before kernmantle rope was common, lots of hard routes were climbed, and lots of bad falls were successfully held on goldline. Modern ropes are definitely better, but goldline worked.

We used Skyline at Outward Bound in the mid 80's. It was much cheaper, but heavier, stretchier, and pulled pro out on lead. But we were usually on top rope or 3rd class climbs (Allen Steck 3rd class climbs).