Do most people rig Y hangs with two loops

[damian]

I don't see a problem with anything you are suggesting. The only thing to be wary of is clipping a cowstail into the rope between the last two butterflies. This is fine until you fall and the final anchor pops out, at which point your cowstail krab runs over the knot and you plummet to the base of the pitch. Fine so long as everyone you're caving with knows this (and either chooses to accept the risk, or clip into the knot itself).

 

[Jon]

I've had no formal SRT training, I'm pretty much self-taught, so if I'm overlooking anything here and this isn't best practice, then I'm keen to be enlightened.

Where would you clip in if you had to do a rescue, taking into account a potential anchor failure and resulting shock load?

 

[Cave Mapper]

The only thing to be wary of is clipping a cowstail into the rope between the last two butterflies. This is fine until you fall and the final anchor pops out, at which point your cowstail krab runs over the knot and you plummet to the base of the pitch. Fine so long as everyone you're caving with knows this (and either chooses to accept the risk, or clip into the knot itself).

Yes but there are problematic scenarios wherever you clip your cows-tail: clipping through both strands on the right is worse because a krab failure would leave you effectively detached, clipping on the left, at least there's a chance that the krab wouldn't slide over the knot, clipping through a single strand on the right also isn't ideal because an anchor failure could create a big shock loading on the system. Crucially though, if you are following the basic rule of two points of attachment, you aren't going to plummet because, either your second cows-tail is still attached, or you've got your descender on.

Maybe best practice is: never attach both cows-tails to the same side of a y-hang, and never clip both strands.

 

[ianball11]

I like your presentation there cave mapper, that is very simple to follow and I'd do exactly as you do (with much shorter knots if I could reach) though I use the triple split for as much as I can, seems sensible to me when you're clipping the rope into it anyway and I'd use a fig 8 for it too, as I see that as a stronger knot than a butterfly and although for two bolts to pop it must be a big fall or some very bouncy heavyweight prusikking.

As for connecting a cowstail, I certainly wouldn't clip between the last two bolts.  If you fell and were stopped by the karabiner you've fallen as far as clipping in to the loop of the last butterfly without the risk of the karabiners not jamming and you continuing to the bottom, so I don't see a plus point to clipping into the single strand between the last two knots, which is the place most people say is the worst, and I agree.  Easily done when you get to the top of a long pitch though.
If it were possible depending on the pitch, I'd clip into the bolts, rather than the loops, loops rather than the line and line rather than nothing.

 

[Geoff R]

Nice photos;  I rig similarly but as mentioned >>>>

.... I quite often find I add an AB free loop immediately before a pitch head Y to a) provide a clip in point for my own protection when rigging the Y hang, which can also allow minor rigging adjustment if needed and b) as a convenient unloaded easy clip-in loop for users attaching and detaching from the Y on descent and ascent, as well as an optional clip in point for follower/helper.....

 

[Cave Mapper]

Where would you clip in if you had to do a rescue, taking into account a potential anchor failure and resulting shock load?

Now you are going beyond my realm of experience. But if you compromise your rigging for the sake of a hypothetical rescue, you could end up with a self-fulfilling prophecy.

 

[Stu]

Where would you clip in if you had to do a rescue, taking into account a potential anchor failure and resulting shock load?

Now you are going beyond my realm of experience. But if you compromise your rigging for the sake of a hypothetical rescue, you could end up with a self-fulfilling prophecy.

Why would using a suitable double loop knot (so probably not the newly named Death on a Bight!) compromise your rigging?

 

[Jon]

Where would you clip in if you had to do a rescue, taking into account a potential anchor failure and resulting shock load?

Now you are going beyond my realm of experience. But if you compromise your rigging for the sake of a hypothetical rescue, you could end up with a self-fulfilling prophecy.

Why would using a suitable double loop knot (so probably not the newly named Death on a Bight!) compromise your rigging?

Exactly

 

[Stu]

Where would you clip in if you had to do a rescue, taking into account a potential anchor failure and resulting shock load?

Now you are going beyond my realm of experience. But if you compromise your rigging for the sake of a hypothetical rescue, you could end up with a self-fulfilling prophecy.

Why would using a suitable double loop knot (so probably not the newly named Death on a Bight!) compromise your rigging?

Exactly

That said Jon, you're about to embark on some training where you'll be applying rescue loads onto a single jammer! 

All scary stuff really.

 

[Cave Mapper]

Where would you clip in if you had to do a rescue, taking into account a potential anchor failure and resulting shock load?

Now you are going beyond my realm of experience. But if you compromise your rigging for the sake of a hypothetical rescue, you could end up with a self-fulfilling prophecy.

Why would using a suitable double loop knot (so probably not the newly named Death on a Bight!) compromise your rigging?

There doesn't seem to be a suitable double loop knot:

... all three alternatives (Bowline-on-the-bight, Fusion Knot, Bunny Ears) have the same major drawback, which is that with an asymmetric hang they can easily slip sideways and leave your main hang with a rub-point.

 

[Jon]

That said Jon, you're about to embark on some training where you'll be applying rescue loads onto a single jammer! 

All scary stuff really.

It was on Sunday and I made sure not to look up when the rope was cut and that I was as close to the ground as possible!

 

[Jon]

There doesn't seem to be a suitable double loop knot:

... all three alternatives (Bowline-on-the-bight, Fusion Knot, Bunny Ears) have the same major drawback, which is that with an asymmetric hang they can easily slip sideways and leave your main hang with a rub-point.

I wouldn't say they all "easily slip sideways". Tie and use them correctly and they do the job.

 

[Stu]

Why would using a suitable double loop knot (so probably not the newly named Death on a Bight!) compromise your rigging?

There doesn't seem to be a suitable double loop knot:

... all three alternatives (Bowline-on-the-bight, Fusion Knot, Bunny Ears) have the same major drawback, which is that with an asymmetric hang they can easily slip sideways and leave your main hang with a rub-point.

Is your slippage experience that common? Was the knot actually tied right? I don't know, wasn't there, take your word for it though.

In my experience they don't slip. I'd wager the majority of cases it doesn't slip, but then who knows.

There are other double loop knots out there to try that can't slip.

I'm not advocating one rigging method over another by the way.

 

[Mike Hopley]

Perhaps worth noting that there are multiple ways in which the rigging can change during use, and it's a good habit for all cavers to watch out for this.

For example: carabiners can reorient and get cross-loaded (especially at rebelays); hangers can slowly loosen; ropes can wrap around flakes of rock; and sometimes the last caver unwittingly drags the rope up behind him, stranding those who are still in the system!

 

[Cave Mapper]

Is your slippage experience that common?

I don't know, I never use the BotB, but the following quotes suggest that it is common:

I've noticed slippage on the BotB before but isn't only when the knot isn't dressed correctly?

From PeterK's blog: " The knot [BotB] has certain shock absorbing and self equalising properties".

I stopped using them years ago as they routinely slip and deform upon loading. I still (until today) teach/taught them, though.

... as mentioned above there have been countless occasions when BotBs slip/deform on loading and due to this exasperation they don't get used in my personal rigging any longer.

 

[Jon]

I don't know, I never use the BotB, but the following quotes suggest that it is common:

I've noticed slippage on the BotB before but isn't only when the knot isn't dressed correctly?

With regards to my quote, the last part is key - "isn't it only when the know isn't dressed correctly".

By the way, thanks for putting together the cavemaps.org website. Very useful.

 

[Geoff R]

.......If it were possible depending on the pitch, I'd clip into the bolts, rather than the loops, loops rather than the line and line rather than nothing.

Slightly off topic but I would like to come back to Ian's posting. 
Personally my preference is

1) clip into the rope loops of an Alpine Butterfly (as knot slippage will limit shock loading in a fall and Im not reliant on a P design/function)

2) line, when attached to minimum 2 x P's at either end and not directly loaded in my section by another  caver

3) as a last resort, an actual P hanger of any design as this would have no redundancy and as mentioned no shock loading assistance if I slipped. 

just my thoughts 

 

[damian]

Personally my preference is
1) clip into the rope loops <snip>
2) line, <snip>
3) as a last resort, an actual P hanger <snip>

I agree with this too.

... all three alternatives (Bowline-on-the-bight, Fusion Knot, Bunny Ears) have the same major drawback, which is that with an asymmetric hang they can easily slip sideways and leave your main hang with a rub-point.

Have to say I'm not sure I agree with this, but even if it is true, the key point is surely that there are a number of ways of doing things, some of which have advantages and some of which have disadvantages. It's the job of the rigger to balance these up and decide what to do.

 

[Cave Mapper]

... the key point is surely that there are a number of ways of doing things, some of which have advantages and some of which have disadvantages. It's the job of the rigger to balance these up and decide what to do.

... its generally best to avoid the ones with disadvantages

 

[Stu]

Is your slippage experience that common?

I don't know, I never use the BotB, but the following quotes suggest that it is common:

I've noticed slippage on the BotB before but isn't only when the knot isn't dressed correctly?

From PeterK's blog: " The knot [BotB] has certain shock absorbing and self equalising properties".

I stopped using them years ago as they routinely slip and deform upon loading. I still (until today) teach/taught them, though.

... as mentioned above there have been countless occasions when BotBs slip/deform on loading and due to this exasperation they don't get used in my personal rigging any longer.

We can agree to disagree. The countless occasions seem to be just you and Chris, but maybe there are lots of occasions.

As for Peter's comment I'd say his self equalising comment isn't in the context you mean. Self equalising as easy to adjust.

You can get the loops to slip if you haven't weighted/aligned/tensioned them properly.