UKC

At an indoor climbing wall wanting to use a sandbag as an anchor....  If using the rope (not a sling), would you attach your belay device to the belay loop or the rope loop? Bearing in mind the sandbag is heavy but is not fixed to the ground and is movable.

It doesn't much matter as long as you, the belay krab and the sandbag are all snugly and safely linked together. Experiment, if the straps are the right length to clip it to your belay loop there's no point messing about with the rope. Unless there's a big weight differential or you're doing fall practice sandbags are mostly just a pain in the arse.

jk

thanks for the reply. so would this be ok if anchored to a sandbag? 

http://howtoclimbharder.com/wp-content/uploads/2016/01/5041502954_2c7d91e4f...

Why not connect the belay device to the 'belay loop'?

This is why I’m asking. Belay loop or rope loop. Westway video shows rope loop but that’s with a fixed ground anchor. I wasn’t sure with a sandbag which isn’t ‘fixed’ to the ground so to say. 

Ground rope tied through harness tie ins, if a carabiner on ground rope, clip to belay loop. Belay device should always be in the belay loop. It is what it is designed for. Because some else does it wrong does not make it right. Putting the belay device in the rope tie in loop cross loads the knot! Rope manufacturers and safety people advise against cross loading knots.

Really? I'm amazed that someone with your apparent experience thinks that.

Edited because I though "Absolute bollocks" was probably a bit too blunt...

Your talk of cross loading knots is total cock, figure of 8s are bomb proof.  If cross loading  a knot is a problem, then you're using the wrong knot!

Clipping into the rope loop lets you escape the system.  On multi pitch climbs and some sea cliffs I even go one further and tie a second figure of 8 on the bite close to my loops, and belay on that extra loop.  Then I can just untie my loops with minimal faff, and I still have my harness to go rescue you.  Together with an upwards belay anchor, it enabled me to go get a rope above a stuck leader while leaving them tied on, and nominally still on belay (they dropped one rope and stayed protected by the other).  I was inspired by the dude that rescued Caff off Master's Wall).

If I did it your way we'd both still be stuck on that mountain to this day.

So going back to my original question, is this ok (attaching to rope loop) when attached to a sandbag anchor in an indoor climbing wall, as the sandbag is not fixed to the ground. 

Yes, it's okay.

The most important thing is that the belay device is attached to you too, through either your rope loop or belay loop.  This wasn't clear at first. 

Clipping both the belay device and ground anchor to the rope loop would be best in my opinion, to avoid anything weird going on like crushing the waist loop and leg loop, and minimising extra links in the system, and giving a bit of redundancy if it was a decent anchor.

Doesn't the wall have ground bolts by the way?  If you get catapulted in the air as you stop a lead fall, do you really want a sand bag swinging around below you that cut potentially hit another belayer, or just something unnecessary that you could trip over while you're walking around looking upwards?

No it only has sandbags and it’s not for lead. Just a top roping anchor. 

You'll be fine then, it's just to keep you on the ground however you clip to it.  Just make sure there's not too much slack and the forces are all really small compared to what the equipment is rated to.

As an aside, it's not actually true that the figure of 8 is bomb proof when cross loaded.  Otherwise, it would be the ideal knot for joining ropes for abseiling...

I've thought that too but I suppose if one uses a stopper knot (obviously too bulky for joining ab ropes) then there is no problem. I seem to remember UKC did an article about using belay loops vs tie in loops and concluded either was OK generally.

https://www.ukclimbing.com/articles/skills/belaying_-_rope_loop_or_belay_lo...

That's totally fine

That'd be fine (though overly fussy for indoor use). The bag could be clipped to the rope loops (good), or the belay loop (ok) or one of the belayer's tie-in ropes can be clove hitched to the bag (best). It's all fine. The key is getting it snugly connected so you aren't lifted off your feet with a big bag swinging about between your feet but also so you aren't crouching over it with aching knees.

If it's not essential for safety don't bother with sandbags, they mostly just get in the way.

jk