Good friends: Tools not jewels. Edges are meant to be sharpened. On rappel in the Tetons. Vid: Adam Fabrikant

 

 

Keeping it simple in technical terrain is a mantra to make systems less complex and fail proof. Thoughts on connecting two ropes while ski mountaineering.

 

I stumbled across a video by Dave Searle this morning, a 25-minute deep dive on all the various ways to connect ropes. With no intention of throwing shade toward Dave (he seems very skilled and knowledgeable, in addition to making great videos), it prompted me to sit down and write my opinions on the subject. In short, it’s just not that complicated. Backup knots, gibbs bends, etc overcomplicate what can and should be a simple part of the overall system and rather than teaching 10 ways to make this work, let’s focus on the simplest solution and executing it well.

The flat overhand with sufficient tail length seems to be widely accepted among those “in the know,” but outside those with formal education or significant internet time, the matter seems less settled. For example, at the Grand Teton (summer) rappel station last week, I overheard something along the lines of:

“How do we tie out ropes together here?”

“I dunno. Isn’t there something called a death knot that people use?”

“That doesn’t seem right; maybe just a figure 8 or double fishermens?”

“Sure, it seems like anything will work…”

I can’t say I remember how they ended up tying their ropes, but it worked, and everyone survived the experience. That said, a quick search reveals a non-trivial number of accidents related to an offset figure 8 knot rolling and coming untied, usually resulting in fatal accidents for the rappeler.

 

Skinny Rope Flat Overhand

Our common ski rappel setup— ~6mm cords in a well dressed flat overhand with a forearm length of tail.

 

Close up different diameters.

As we see here, when the knot gets tensioned as it would on rappel, the skinny(blue) rope would need to ‘jump’ the bigger red rope to initiate a roll.

 

Among more skilled climbers, the debate seems to be less about which knot to use (most everyone I’ve encountered is using an offset flat overhand) but rather whether a “backup” second flat overhand is necessary. While there are specific cases where this is recommended, such as with a slippery Dyneema-sheathed rope like the Petzl Pur’line, I struggle to see a reason to make this standard practice. It seems like the consensus is that a well-dressed flat overhand will roll at around 4kN, around double a conservative estimate for a max rappelling force. Normally, after one roll, the flat overhand will cinch tighter and stop rolling, but that should never be an issue because we shouldn’t be anywhere near 4kN anyway.

 

skinny-fat rope flat overhand

Here we have a 6mm cord tied to a 9.1mm triple rated climbing rope. By tying the overhand with the skinny rope on the bottom, in addition to our usual good dressing and long tails, we have a robust and roll resistant connection.

 

In a skiing context, we typically use ropes of similar diameter, but in the case of different diameter ropes, there is a little more to think about. My strategy here is to tie my flat overhand such that the skinnier rope is downhill of the thicker. This way, in order to roll, the skinny rope has to “jump” the thicker rope. While I haven’t tested this, this setup seems more resistant to rolling than similar diameter ropes.

Hopefully, this will be helpful for some folks—a little KISS in an ever more complex world of technical gear.