Forces (kN) placed on lanyard

[TimberNinja]

There's been several studies that show forces on TIP and basal anchors. I enjoy reviewing these and getting better insight into forces the climber inputs into the safety system.

I've never seen a study on forces on just lanyards. (Maybe I missed it?)

Just curious what kind of forces one's lanyard would experience. Example: 180lb man sitting on gaffs, lanyard around the tree. (No climbing line)

 

[evo]

There's been several studies that show forces on TIP and basal anchors. I enjoy reviewing these and getting better insight into forces the climber inputs into the safety system.

I've never seen a study on forces on just lanyards. (Maybe I missed it?)

Just curious what kind of forces one's lanyard would experience. Example: 180lb man sitting on gaffs, lanyard around the tree. (No climbing line)

Not much..
I mean if someone is just spiking up a tree one can do so with nearly no weight on the lanyard.
Leaning back into it one has the bulk of their weight on their gaffs.
Now falling is something entirely different

 

[southsoundtree]

Pushing rounds/ logs increases lanyard forces, but still of no real consequence unless you're using crap gear.

 

[Mick Dempsey]

Pushing rounds/ logs increases lanyard forces, but still of no real consequence unless you're using crap gear.

Yes, that’s the only time under normal circumstances they come under any pressure.
If everything in in decent working order ie. Krabs and stuff aligned and shut, it’s almost inconceivable anything would fail.

 

[Bart_]

If you're looking for a number, use your "leg load cells". If you're standing almost against the spar the lanyard sees way less than your body weight. If you get your legs out to about 45 degrees from vertical you'll feel the lanyard tension in your legs and on your side D's. Theoretically (and really) you could put more tension in the lanyard than your body weight by lengthening it and letting your legs get close to horizontal but the pressure and discomfort will thwart even trying. So the number is less than body weight if your legs are comfortably loaded.

yeah I'm bored

When you use your lanyard as mini-DRT it's full body weight +/- friction/acceleration forces

 

[evo]

If you're looking for a number, use your "leg load cells". If you're standing almost against the spar the lanyard sees way less than your body weight. If you get your legs out to about 45 degrees from vertical you'll feel the lanyard tension in your legs and on your side D's. Theoretically (and really) you could put more tension in the lanyard than your body weight by lengthening it and letting your legs get close to horizontal but the pressure and discomfort will thwart even trying. So the number is less than body weight if your legs are comfortably loaded.

yeah I'm bored

When you use your lanyard as mini-DRT it's full body weight +/- friction/acceleration forces

Also placement of the lanyard. Down low by your knees is probably going to see higher weights. Horizontal medium and high by ones shoulders the least.
Even if the climber is doing something to load it crazy nuts, it’s still in a basket around a wide radius.
I’ve had some crazy loads on my lanyard from accidents, never once did I question its strength. My body on the other hand was the weak link in the chain, and that was the most apparent

 

[Crimsonking]

The most load it likely sees is in scenarios where you are horizontal to your TIP, or other scenarios where you lift the lanyard anchor when you put your full weight into the system. We know from the familiar diagrams that loading a taut line (not the hitch) perpendicularly will multiply the load by 5 at the anchor points (TIP and lanyard anchor). Man, now I want to put an enforcer on the saddle and see what happens. I end up working at weird angles often and wonder what the numbers are.

When I had access to an enforcer while training full time, I used it to test forces on the TIP in different redirect scenarios. Angles are everything! Static redirects that are meant to share the load between stems can multiply forces on the main stem if installed with the redirect being pulled perpendicularly from the redirect stem prior to being loaded with climber weight. That configuration actually increases the load on both stems. The optimal redirect angle is the sling in line with the stem for compression. This really matters if you like building redirects on skinny stems that would not support you without the help of other stems. Great for reduction work. Sadly, partial knowledge misapplied often amplifies the problems climbers are trying to solve. The same goes for aerial friction in rigging, but that’s another thread.

 

[Bart_]

In my early SRT days I had a preference for dual (redundant/catch) tips at the same level (as opposed to now - a few feet fall to catch tip) and up in the skinnies this resulted in squeezing co-doms or similar leaders together.

What's your vector Victor? (Leslie Neilson Airplane)

I remember learning to cut higher on spar work so your lanyard wasn't low down punishing your hips and legs. Eureka! You also have to overcome saw to lanyard proximity fears to ease leg loading.