The crab doesn’t have to be attached to the belay loop, even if you use one: it can go through the two hard points that you normally tie into.
If you’re using properly certified gear, and your harness isn’t worn out, I don’t see how it’s dangerous to climb on the middle of the rope? Obviously it’s even better to tie in directly, but that does require knowing how to tie a bowline properly - which is something that can be messed up. A figure of 8 on a bite, through a crab into two hard points, is surely safe enough?
for the bowline on a bight through normal tie in points for karabiners through tie in points
Karabiners go lots of places but not there. There’s a thing called cross loading which isn’t nice. Also, it’s fiddly and unnecessary. Whilst we are on the subject of tie in points, another no no is slings: they shouldn’t be there either.
A figure of eight on a bight tie through the tie in points is also good but bulky.
Tie in points are for tying into.
I tie into the middle of the doubled-over rope with a standard bowline. I then lead and bring up the seconds one on each strand. No karabiners involved. Uses my standard climbing knot. Seems simple enough.
But you can’t cross load the carabiner if it’s in through two hard points? It’s physically held in place. And with the dynamic stretch of the rope, the biner is just transmitting force through your harness’s two hard points?
I saw a couple of (what seemed to be) very experienced climbers doing this on Sunday so it seemed to be ok?
You should never clip a carabiner through the 2 hard points as you describe them, because you then load the crab in 3 directions when you clip a rope into it. Yes, you do sometimes see people doing this, but it is contrary to best practise. You also see people belaying like this, but that is wrong for the same reason. The belay loop is called that because that is what you belay from!
When I climb on a doubled rope I normally tie into the 2 ends, and get the second to tie in to the middle using a bowline (which results in a smaller knot), or a doubled figure of eight (i.e. just like when you tie into a single rope). If I have 2 seconds I’d drop the rope down again for the third person. Alternatively I tie into the middle using a bowline, and they seconds tie into the ends as normal. Tieing into the middle results in a bigger knot than tieing into 2 ends though.
@HollyP you can use your regular climbing knot, it doesn’t have to be a bowline, that just happens to be my regular knot. If you use a re-threaded figure 8 that would work just as well - might be a little bulkier is all. My general approach is to use the knot you are familiar with. It might seem different tying the knot with both strands at once but actually it is exactly the same method as doing it on a single strand.
“Whilst we are on the subject of tie in points, another no no is slings: they shouldn’t be there either.”
Does this also apply to larksfooting a sling to the harness tie in points to extend the belay plate for abseiling?
You should not larksfoot the tie in points with a sling, especially if the sling is made from dyneema. Normally the tie in points are separate i.e. a belay loop length apart. In the event of a fall (even short, which could happen when abseiling), the larks foot tightens quickly, bringing the two tie in points to meet and the friction can easily melt the sling. In practice, it wouldn’t be likely for most abseils, but it’s really not good.
for the bowline on a bight through normal tie in points
for karabiners through tie in points
