Clip a chain anchor directly with a master carabiner
You're on a multi pitch route. If you come across a stout chain anchor, and if the bolts are close together and/or the chain is quite long, lucky you! You’ve got about the easiest and fastest anchor you could ever build. (Note, a vertically oriented chain anchor is also perfect for this, we're going to cover that in a new article soon.)
Why is this a sweet setup? Extremely fast to build, minimal extra gear, no slings, no knots, really easy to break down for your second.
Get the largest HMS “pearabiner” belay carabiner you have, clip the bottom two links, lock it, done. That becomes your “master carabiner”.
Note: Carabiners are strongest when loaded along the spine. When you bring up your second, that will be a larger load than just holding your body weight. So, take a moment before you clip that master point carabiner to have a look at where the rope is running down the pitch. In this example, let's say the rope is coming up from the left side of the anchor. Ideally, that means the spine of the carabiner would be on the left to take the potentially larger load, and the gate of the carabiner should face to the right.
Check out the nice diagram from Petzl to see how this works. In the diagram, the loaded rope is closest to the gate, the weakest configuration. In theory, It would be better if the load strand were on the left, closest to the spine.
(In my humble opinion, this is more of a potential issue with large loads. When bringing up your second, the load is never going to exceed 2-3 kN, so it's probably not critical if you forget to do this step. But it’s best practice, so it’s worth mentioning.)
image: Petzl.com
Add a smaller locking carabiner and clove hitch to the master point to secure yourself.
Clip your plaquette style belay device and blocking carabiner to the master carabiner. (As mentioned above, ideally clip this closest to the carabiner spine, because that's going to be taking a slightly higher load than just your bodyweight on the right.)
Finally, if you’re feeling courteous and have a spare locking carabiner, you can clip that to the master point on the far left to give your second a convenient place to clove hitch themselves when they arrive.
Possible concerns, addressed. (In some climbing situations these are valid concerns, but not necessarily here.)
Clipping multiple carabiners together!
Clipping directly into the rappel rings and possibly damaging them!
Loading the carabiner in multiple directions!
Clipping multiple non-locking carabiners together and having them flop around is a bad idea, because they can unclip themselves. However, at an anchor like this, when you use all lockers and there is no flopping movement of the carabiners, this is acceptable practice. We cover this more in this article.
Clipping into the rappel rings is totally fine with aluminum carabiners. Aluminum, being softer than the steel ring, is never going to damage the rappel hardware. (It's like using a plastic ice scraper on a car windshield; the soft plastic is never going to hurt the glass no matter how hard you scrape.) We cover this in detail here.
Loading a carabiner and three or four directions at once (known as tri-axial and quad-axial loading) can weaken a carabiner. But in this case it's not a worry, because the chains are quite long and the loads are not going to exceed 2 or 3 kN. If the loads were higher, and chains were shorter and/or the bolts farther apart, it might be a concern. Multi axis carabiner loading is an interesting and slightly complicated situation, and we cover it extensively in this article.
Detour to a toprope anchor: If you’re rigging a top rope on a chain anchor, and maybe you're short on quickdraws or other anchor material, you can clip two carabiners opposite and opposed to the bottom links. Ideally one of these is a locking carabiner.
This is generally not standard practice, it's usually a better option to use two quick draws or a mini quad, but if you're short on gear this is acceptable.
Note: if you do this on a link of the chain, you'll probably have enough room to pass the end of the rope through but probably not enough room for a bight of rope to lower from. In this case, there are large quick links at the bottom, so there's plenty of room to rig for lowering off, as shown in this article.
(I first saw this technique in a YouTube video (at 7:45) made by AGMA Rock Guide Cody Bradford.)
Here’s a nice video from Outdoor Research that shows many of these concepts in action. Important points mentioned in the video:
Avoid using smaller D shaped locking carabiners at the master point, because the carabiners become stacked on one another and the loading becomes less than ideal.
Of course, always avoid directly cross loading any carabiner gate; that’s a bad thing.
If the bolts are too far apart, and/or the chains too short, you might start to get some side loading on the top part of your carabiner. Be mindful of this, and re-rig with a sling if you don't like it. Here's an article on strength reduction from off-axis carabiner loading. (It's probably a lot stronger than you think; you'll be fine.)
