Setting Up for Rappel when TR anchor is built from above

Gumby question, I'm sure, but this has come up several times for me.

Often, there are toprope anchors that are on the face of the cliff. They are easy to access from the top of the cliff by a scramble around. I can reach over the cliff edge and build a beautiful anchor, lower the rope through it, etc. But then, if I want to rappel down, how do I get me to the cliff face instead of above? I typically down-climb to the anchor while attached with a sling or PAS, hoping I don't take a painful fall onto the PAS from above while down-climbing.

Is there a smarter way to get onto the face when the anchor is several feet below the cliff edge?

Is there anything (trees, boulders) above the cliff edge that you can use to build a second (for the short rap) anchor? If not, then you're kinda stuck batmanning over the edge. But that's a really risky move. You can reduce the risk of serious outcome by tying into the end of the rope and having your partner (at the bottom) lower you rather than downclimbing above a static tether like a sling. Alternatively, if you were able to hike up there, hike back down once the TR rope is in place.

If I were in that situation would probably either do what Gunkiemike said, or would get set on rap above the edge with an “oh shit” knot before climbing over. That way if I did slip it wouldn’t be quite as jarring. 

Yes there Is. You should NEVER  be on a webbing sling (including Personal Anchor System models) level with, or above the point it’s clipped too. This is beyond ‘painful’ and into risk of total sling failure!
Lots of  info to be found on the internet about this.

In the scenario you describe, (you feel safe lying on the rim, reaching down and threading the rope; I sure wouldn’t) , where you feel confident you can scramble/slither down to get below the anchors, you could put yourself on rappel (with an extension and a prussik for safety) with a BHK tied off to your harness.

The safer scenario is setting up a rappel from way back above the edge, rapping down to the toproping anchors (with a Prussik and then tying a safety knot when you get to them), threading the rope through anchors and either swapping over to rap from them, or have your belayer lower you.

I would say, this is the sort of thing that you really should have someone teach you, preferably a professional, not a random buddy. If you haven’t learned yet, stick to routes that don’t have these set ups.

I suppose if you’re worried about it, you could buy your self a via ferrata tether. Sling length on some of those is 2 feet.
I just put myself on rappel and batman/downclimb with a brake hand on the ropes. I use a assisted braking device for rapping now (Gigajul), but even before I never found it too scary. 

Use a second rope or long bit of static to rappel down to the anchor location. There should be some trees or rock to build a natural anchor away from the cliff edge.

If you don't have a second rope, you can still do what I mentioned above by rapping to the anchor with your climbing rope, build the anchor, connect yourself to the anchor direct, pull your rope and clip it through the masterpoint you just built, then rap the rest of the way down.

If there is no opportunity for an anchor above the cliff, it probably means that anchor was never meant to be top accessed for rappel/lower.

Don't down climb with your PAS. Yea you probably won't fall any individual time but if you do it 500 times the odds add up. 

I really like tying in and having my belayer lower me. Most top roping areas I’ve been to have top and bottom access. Whoever is setting the anchor can access the top while the other person hikes to the bottom. Usually by the time I have the rope down and anchor built my partner is at the bottom. Than when moving anchors you just top out the climb move the anchor and have your partner lower you. 

I wouldn’t want to factor 1-2 on anything static. If I’m top roping with a dynamic rope and want to rappel for whatever reason I’ll rig my rappel with a back up than try to lower myself down but it always feels sketchy. 

Thanks all for the great input! This validates some of the concerns that I had while doing it (even if I ignored the concerns at the time).

Much smarter solutions for next time!

So here's what I would typically do in that scenrio: and this can happen on long adventure routes where a multi-pitch rap route might have belay stations separated by sections of ledge, 3rd class, 4th class etc, basically any time you find yourself above a rap anchor, and you're not tied in to anything.

Terrain dictates a lot here, but we'll assume a flat top and a vertical face below.

I'd rig the TR and then walk back down. Hah!

Now if I simply must rap the TR line for some reason, I would 

1. Get myself anchored to something - on the top if I can or maybe just clipping a double length shoulder sling from my harness to the anchor. Whatever I happen to have.
2. Rig the TR and get it all set, having insured both ends reach the ground or at least I'm at the middle-mark.
3. Now pre-rig my rap device on the rap rope, and snug it to the TR anchor biners as taut as the situation will allow.
4. And on the brake side of the rap device I'd tie a snug capture knot, whatever I feel like but mostly I'd use fig-8 on a bite. The knot keeps brake strand from slipping thru device plus I can clip the knot to a keeper biner on my harness, for safe keeping of the knot.
5. Make sure the backup sling (back in step 1) is longer than the rap rope rigging to my harness By this I mean should I stumble while belly flopping into position and slip off, I'll land on the rap rope not the sling. Note I might have to scootch to the edge, re-tighten the rap rigging to get my rap device closer to the anchor point, maybe even a couple of times, before its all "shorter" than my backup sling (however long that thing is, depends on what I have of course)
6. Get on down there, tighten the rap ripping again and get my weight on the rap rigging, triple check everything AFTER weighting the rope and also do a quick small "bounce" to make really sure its all right, then use non-brake hand to unclip the sling and reclip that biner to a gear loop.
7. On rappel.

Have probably done dozens of endless variations of this same procedure over the years, rapping from big routes in the mountains. The principles are simple: don't fall from above on to a sling attaching you to the anchor, and when working with rap rigging always insure you are backed up and triple check everything, always weight and brake your rap rigging prior to removing the backup sling, and bounce test that rigging a little bit, too. Bon voyage.

I spent the last year top rope soloing, and the best thing I did for myself was buy a static rope for building J-tree style anchors. Here's a relevant diagram from petzl about rigging a natural anchor above the cliff and a bolted anchor below. 

This is a great video, although he's using cams, the principle is the same if you're using trees or boulders. Make sure your trees are too big around to get your hands around.  You can search for other J-tree anchor videos, there are a ton, but I didn't learn what they were called until recently.

phylp phylp wrote:

I suppose if you’re worried about it, you could buy your self a via ferrata tether. Sling length on some of those is 2 feet.
I just put myself on rappel and batman/downclimb with a brake hand on the ropes. I use a assisted braking device for rapping now (Gigajul), but even before I never found it too scary. 

This is the most simple way and can be done with a knot below the ATC or with the belayer giving a firemans belay.

3-in-1, J-Tree with instructor tether. Learn how to do these two and using a gri gri on the instructor tether to transition down to the overhanging Master Point. Then transition from instructor tether to the climbing rope. Learn how to use an autoblok(third hand) and extend your atc away from your harness using a 48-inch sling.

Check out Blue Ridge Mountain Guide YouTube channel for the 3-in-1. 

Practice on the ground first to get dialed in and seek out a quality guide service if you want to get help with more nuanced situations. If learning stuff like this interests you, consider taking an SPI class to really learn more helpful options to add to your “climbing tool belt”. 

Trad Gumby wrote:

Gumby question, I'm sure, but this has come up several times for me.

Often, there are toprope anchors that are on the face of the cliff. They are easy to access from the top of the cliff by a scramble around. I can reach over the cliff edge and build a beautiful anchor, lower the rope through it, etc. But then, if I want to rappel down, how do I get me to the cliff face instead of above? I typically down-climb to the anchor while attached with a sling or PAS, hoping I don't take a painful fall onto the PAS from above while down-climbing.

Is there a smarter way to get onto the face when the anchor is several feet below the cliff edge?

You're doing it right, grab the anchor and use muscles to lower down. I usually plug in the rap device too. If you totally lose it, you're not going to blow through all that gear and die.