Tag Archives: Smith Rock State Park

Girth Hitch Insanity

Sling to sling to sling girth hitch insanity: a climbing anchor.

Sling to sling to sling girth hitch insanity: a climbing anchor.

Justin Rotherham took this shot at Smith Rock a few weeks back. A seemingly infinite chain of girth hitched webbing. We’ve discussed the whole girth hitching webbing thing in the past here and here. This one isn’t necessarily all that dangerous, for the simple reason that the girth hitched monstrosity is a ‘back up’ for a presumably more proper climbing anchor. But it definitely qualifies as Jive-Ass (in this case, of the ‘overkill’ variety).

In Justin’s words [emphasis is mine], “This sling to sling to sling girth hitch insanity was a back up to a 2 quickdraw top rope set up.  The sling ‘back up’ was attached to the anchor for the next route over with another non-locking biner.  The other end of the sling had a quicklink that they had threaded the rope through after clipping the draws.”

Yeah, some times people go a little overboard with their redundancy. Apparently two bolts (two bolts!) weren’t enough for top roping (top roping!). And thus jive-assery was required.

Parting words or wisdom from Justin: “These are bolted anchors people!  Quit trying to make it harder than it needs to be.”

Location: Smith Rock State Park, Oregon, USA

Hot Spectra-on-Spectra Action!

Spectra girth hitched to Spectra

Hot Spectra-on-Spectra Action

I see soft goods girth hitched to other soft goods in anchors all the time. In this case a spectra/dyneema sling is girth hitched to a spectra/nylon mix runner on a hex.

Location: Smith Rock State Park, Oregon

Spectra-on-Spectra Close Up

Spectra-on-Spectra Close Up

I’ve posted more than one “soft goods girth hitched to soft goods” anchor (see Girth Hitch Death Wish), so let’s discuss this knots issue. Any knot in cordage or webbing decreases its strength. These girth hitches reduce the strength of the slings to only 60 – 65% of their original strength. Had a carabiner been placed between the slings, there would be no knots, and the slings would still be full strength.

And how about the webbing material? HMPE (High Modulus Polyethelyne) fiber, sold under the brand names Spectra and Dyneema, is stronger than steel, light weight, and offers minimal elongation (i.e., it doesn’t stretch far before breaking). It also has a relatively low melting point: 147°C. That’s not a lot hotter than the temperature of boiling water. Friction, at enough pressure and speed, can generate enough heat to melt this fiber. An example of this pressure and speed would be if, for example, you girth hitched a Spectra runner to another Spectra runner and then had a climber fall on it. Those girth hitches would immediately tighten very tight, a great pressure and speed, and…well you get the idea. This isn’t just ‘theory’. There are examples from the field of Spectra slings melting and failing at knot points in this way, so it’s just not a good practice to tie Spectra webbing together like this.

If you care to geek out, here’s some testing from Black Diamond and the folks at Caves.org, and here’s a recent article on the pros and cons of Spectra v. Nylon from Rock and Ice. Finally, Here’s an interesting video testing knotted Dyneema from DMM. They don’t test slings girth hitched together, but the basic idea from the results are instructive just the same.

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Update: Todd Eddie offers the following link to tests from Black Diamond testing just what we’re addressing: webbing girth hitched to webbing.