Lead belay question

[rhunt]

As Shamis said it's all situational....

[pigsteak]

good way to crack a rib or hurt your back, leaving "slack" to move...think of this they... get pulled 3 feet and then slam in the anchor...talk about a hard stop.

[dustonian]

Hmmm... how to ask this. Do you guys ever tie down your partner?

We experimented with this but it made everything too hard...

[climb2core]

good way to crack a rib or hurt your back, leaving "slack" to move...think of this they... get pulled 3 feet and then slam in the anchor...talk about a hard stop.

Piggy, this is a safety mechanism that really only kicks in if the lighter belayer is getting pulled far enough to hit the wall at the first bolt. Most of the time it doesn't come into play. When it does, they have already been pulled up about 8 ft off the ground by this time, with the fall decelerated quite a bit by then and the catch is soft. Also, when the line first tightens up they are close to the ground, making an obtuse angle between the first bolt and the point of anchor, with the belayer in the middle. But as my descent continues, the angle becomes larger and larger (closer to a straight line) requiring more force to hold it. This creates a gradual yet progressive increase in the force the belayer/anchor system produces. Most importantly though, it does prevent them from getting slammed into to wall or a roof. IMO safer for the belayer and for me.

[bcombs]

By how much do you outweigh the belayer? Being a bigger climber I'm always conscious of weight difference, but I have never tied down my belayer while leading. Seems like a recipe for broken ankles to me. I outweigh my wife and a few female climbing partners by 70 lbs and they have never had an issue with the catch.

[climb2core]

By how much do you outweigh the belayer? Being a bigger climber I'm always conscious of weight difference, but I have never tied down my belayer while leading. Seems like a recipe for broken ankles to me. I outweigh my wife and a few female climbing partners by 70 lbs and they have never had an issue with the catch.

55-60 lbs depending on the day. I am surprised that you have never pulled your partner to the draw on large fall (ie 8-10 ft. above last bolt) or on fall low down low. We don't always tie down, but when we have it has always worked very well and very safely.

[dustonian]

I've got some circus-grade French bungee from my Cirque days, Ian, maybe it would be fun for you guys to play around with that...

[climb2core]

Awesome... sounds perfect Dustin!

[Brentucky]

Call me bored enough to take a break at work and think about something else, but here is how I have thought of it in basic physics terms.

Work = Force * distance = m*g*h (good old potential energy, where the h is the vertical distance of the climber above the last bolt clipped). For any who don't know m=mass of climber and g = gravitational acceleration.

When the climber falls the potential energy gets converted to kinetic energy (0.5*m*v^2), and the greater the fall distance the greater the velocity and thus "energy" of the climber at the end of it.

Well, there are a couple things that can lessen the amount of energy/speed the climber is going to end up with. There is the stretch of the rope (0.5*k*x^2, where k is the "spring constant" of the rope and x is amount it stretches), on both ends, there is friction between the rope and the quickdraws (mostly the last one clipped) where some energy is converted to heat, and there is of course the belayer who can get lifted off the ground and reduce climber falling energy by m*g*h (the distance the belayer gets pulled up).

When standing back away from the wall, the belayer leaves the climber with a much higher percentage of energy, and as pigsteak mentioned the "slingshot" effect is magnified at the climber end. With the belayer away from the wall much of the climbers kinetic energy converts to potential energy in the rope, and once the rope reaches max stretch, it then unstretches and pulls the climber accelerating him/her even faster toward the wall. At this point there is really nothing to slow the climber down other than a little wind resistance and gravity once the climber comes penduluming around into the upward part of the swing. That is until you hit the wall, and stop.

If that belayer had been a little closer to the wall, on the other hand, his/her ass could have reduced a little more of the climber energy in the form of the belayer end of the rope stretching, the belayer coming up off the ground, and thus providing that extra friction/heat/energy reduction between a sliding rope and quickdraw.

The end.

[dustonian]

No shit Einstein

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