Directional for bringing up second

[jimmyleg66]

So, when I'm bringing up someone on a pitch, if there isn't much space I like to flake the rope over whatever I've used to tie in to the anchor with. This is usually made easier by running the rope through a directional, most often above me, depending on my stance. However, its not always possible or convenient to have the directional go through an equalized point on the anchor, so I'll just attatch it to a single piece.

 

For bringing up the second, is this a grevious error or common practice?

[catbirdseat]

Common Practice. If the piece blows, the load goes directly onto your belay device. Better to have the rope lead to the directional on the opposite side of your body from your brake hand. This would make it easier to maintain the belay if it blows.

[iain]

You could also just belay off the anchor completely. Less force on the pieces if someone falls, and you can get out of the situation easily if there is a problem. An autolocking device makes this easier.

[bonathanjarrett]

If you are redirecting through a single piece of the anchor then you are putting you, your partner, and the anchor in danger. If the piece rips, you have just weakened the anchor. If you redirect, either bringing up a second, or as the leader heads out of the belay, it is best to clip into the master point.

Belaying off the anchor for bringing up the second is the best idea as it does not multiply the force created. Either rock and Ice or Climbing just recently did an article on this topic. Check it out.

[catbirdseat]

Placing a redirect on the master point still multiplies the tension in the rope (although it does equalize the force among all the pieces comprising the anchor to the extent that is possible). If the angle is 180 degrees and assuming zero friction on the biner, the force is doubled. In reality friction reduces the force by about 35% so it would be about 1.3. The only way to avoid applying this force multiplier to your belay anchor is to either belay directly from your harness, or use a piece that is independent of your anchor system.

[iain]

...awaiting the free body diagrams taking into account friction etc and every possible hypothetical situation

 

Just belay off the anchors and keep your life simple, knowing it works well. If the anchor is sketchy, well, sucks to be you! Keep the gear stuff simple so you can focus on the fun of climbing, and safely at that

[thelawgoddess]

i've belayed lots of seconds. and plenty of seconds and thirds at the same time. both of which i generally do directly off of the anchor. this also frees up your hands to do whatever flaking or other nonsense you might want to take care of ...

[selkirk]

...awaiting the free body diagrams taking into account friction etc and every possible hypothetical situation

 

Just belay off the anchors and keep your life simple, knowing it works well. If the anchor is sketchy, well, sucks to be you! Keep the gear stuff simple so you can focus on the fun of climbing, and safely at that

 

Time to avoid my research for a moment

 

As someone who's taught statics I'd say belay directly off the anchor with an auto-locking settup or a munter. If it's a hanging belay you won't really be able to get your weight off the anchor regardless, but with this settup, the magnitude of the tension due to the second isn't multiplied (or for the Munter is only very weakly multiplied) since the tension on the brake strand is small or negligible. I can draw up the FBD's if you'd really like.

 

Of course if your belaying off of a redirect through the powerpoint from a hanging belay my instinct says it doesn't matter. The anchor is initially holding the belayers entire weight, when/if your second falls, their line comes under tension, your pulled up, and in the end it's your weight plus the weight of the second, though your weight is distributed differently (either all on the redirect, or partially on the redirect and partially on however your tied in to the anchor).

 

If your on a ledge or otherwise don't have the belayers weight on the anchor initially, using the redirect will increase the load on the anchor. If this is the case, the least possible load on the anchor if your footing is good is to belay off your harness (part of the load will be supported by your footing), and part by the anchor. Next lowest load is using an autolock or munter, where the anchor only supports the seconds weight. The redirect has the highest load where it will support both the second, and a portion of the belayers weight.

 

However the maximum load on the anchor is probably only 400 lbs? (Remember this isn't a leader fall but an effectively static load being applied by the second)

 

Of course the other option is to place the first piece on the next lead a few feet out and redirect through that. It gives you a nice high redirect to keep the belay clean, and protects the anchor much more effectively than anything else. If the second falls, you both load the high piece, and the anchor unloads as your weight equalizes the seconds. In addition as your swinging leads, if the your partner takes a fall shortly out from the anchor you've protected against a factor 2 directly onto the anchor. It is a little more awkward if your using an auto-lock settup though.

 

Of course i'm ignoring the dynamic aspect of the system, since that would actually involve real math, and is much more appropriate to a leader fall unway, unless you second has some serious penalty slack.

 

I never quite understood why people get so worked up about redirects. The maximum load the redirect could possibly have (assuming there isn't a ton of slack out) when a follower falls is maybe 400 or 500lbs if your both fat, which is almost negligible unless your pro really sucks. (for reference this is roughly 2Kn). The real threat is a leader fall or a fall onto a personal anchor directly onto the power point. High factor fall's, even short ones are where the real loads are at.