Carabiner Through Belay Loop vs Rope Through Both Loops

Can anyone explain why it seems that standard practice for toproping is one of the following (figure eight knot is used in both scenarios):

1. Rope through two loops on the harness (most standard)

2. Carabiner through just the belay loop (mostly used when teaching beginners from what I can tell)

In most cases, in order to distribute wear, the belay loop is reserved for hard materials, such as carabiners, and the hard points are used for soft materials like rope and slings.

My question more is that the belay loop only provides one failure point on the harness, but using two loops with the rope provides two, but maybe it’s that the likelihood of the harness failing is so low compared to other pieces of the system?

Nathan Whitney wrote:

My question more is that the belay loop only provides one failure point on the harness, but using two loops with the rope provides two, but maybe it’s that the likelihood of the harness failing is so low compared to other pieces of the system?

A carabiner is made to be loaded at 2 points.

It’s not about the carabiner though, I’m more curious about the harness. Rope applies the same load either to one loop or two loops. I assume there is something that makes this okay, but I just can’t figure it out.

Belay loops are strong enough, like ropes, that we trust them as a single point of failure. It's no different that having your grigri on your belay loop (and only one biner)

I, like most I know, tie in to the harness loop(s) not the belay loop.  Less links in the chain and simple.

For quick top-rope a large locking carabiner seems great.  Less friction.

Could argue that beginners need to practice their tie-in anyhow so just tie in.

I used to cut off the belay loop.  It just gets in the way.  Now I am too lazy and don't bother.

Nathan Whitney wrote:

It’s not about the carabiner though, I’m more curious about the harness. Rope applies the same load either to one loop or two loops. I assume there is something that makes this okay, but I just can’t figure it out.

The two harness loops distribute the load along more rope. Loading a rope at one narrow point is bad.

The explanation is cultural: the euros are happy tying in to the belay loop rather than the two loops. Some US manufacturers have hang tags that forbid this practice, so if you do this with a US harness, you might die... 

From the harness standard/strength perspective, both (all 4) tie-in/connection methods suffice. 

As folks note, both carabiner connections may present issues with odd loading of carabiners; I'm pretty sure I can find some euro best practices that require two carabiners as a result. 

About 20 years ago, Mammut did the study of wear on the two loops--where you tie in, which connect the belay loop to the harness. The wear is a result of leg movement and has little to do with whether one is tied in with textile or clipped in with metal.

This has been covered ad nauseum on here. 

Using carabiners here triloads the carabiner, it would only be suitable to use a large and heavy quicklink or circular connection which would be bulky and heavy. 

We don't tie into belay loops for a few reasons,

1. Early sit harnesses didn't have belay loops

2. Tying into the tie in points keeps the knot lower and out of your way

3. It can be desirable to use the tie in loop as another belay loop for certain (old school) belay set ups. 

Wear on the bottom tie in loop is caused through falls not walking or moving around in your harness, this is why sport climbers can burn through a harness in a season and trad climbers a harness can see little wear in a decade, they just don't fall as much. 

Talk of redundancy is a mute point the rope and your belay loop are both plenty strong and have multiple built in safety features like the mantle on the rope or loop within a loop for belay loops.

But to actually answer the questions, we tie in when we are able to tie in well and fairly quickly, beginners take an age and it may be done wrong, a carabiner is quick, easy to check and pretty much fool proof. This is only suitable for top roping of course due to the much lower forces when (not if) the carabiner gets crossloades. 

The harness also is a single point of failure. Even though you tie in through both the belt and the leg loops, if the belt fails the leg loops are very unlikely to hold you because you would fall backwards and slide out of them. And the load-bearing part of the belt on most harnesses is only a fraction of the strength of the belay loop. But its still many times stronger than it needs to be.

I think I was taught that the climber ties in instead of clipping in usually, so that they can't accidentally unclip their rope while climbing. While it's unlikely you would accidentally remove a locking biner from your belay loop, I could see it happening if you had a bunch of junk on your harness and got confused what biner went to the PAS or your belay device or something.

Someone already mentioned triloading the biner, but I would like to expand on that. If you force a biner through both harness loops, (and it may really take some force) it will be held top and bottom, and make it almost certain that your belay device or whatever gate-loads the biner.

As for the other side, also not mentioned was that most harnesses have some protective fabric wrapped around the harness loops to protect the structural element from abrasion from the rope, while the belay loop has no such shield.

Why not really have some fun and clip one locker to the top hard point and one to your leg loops? Or even three, with one to each leg loop? If you have a harness with rated gear loops, you could even clip to those, allowing you to use 5 or 6 lockers.

Glacier travel it is common practice to clip into the belay loop with a locker or two non lockers. 

Some cavers use a quick link as a belay loop/masterpoint on the harness.

You can guess while making pizza, but don't go fancy while climbing, unless you're competing for Darwin Awards. Curious how the internet is used for giving opinions but not for researching. Where do opinions come from?

ik i'm late but may be helpful to others since there's lots of crazy/dangerous answers... "better check the manufacturer" is a good answer. Petzl has a very comprehensive explanation.

The question is about using a carabiner and in this case you MUST use the belay loop:

As explained by PETZL:

"WARNING: when the belay device is attached to the two tie-in points of a harness, the carabiner is not free to move and becomes loaded on the minor axis:"
@ petzl.com/INT/en/Sport/Bela…

Gisele Saez wrote:

You can guess while making pizza, but don't go fancy while climbing, unless you're competing for Darwin Awards. Curious how the internet is used for giving opinions but not for researching. Where do opinions come from?

ik i'm late but may be helpful to others since there's lots of crazy/dangerous answers... "better check the manufacturer" is a good answer. Petzl has a very comprehensive explanation.

The question is about using a carabiner and in this case you MUST use the belay loop:

As explained by PETZL:

"WARNING: when the belay device is attached to the two tie-in points of a harness, the carabiner is not free to move and becomes loaded on the minor axis:"
@ petzl.com/INT/en/Sport/Bela…

Nobody was talking about putting a carabiner in the tie-in points. 

Are you a real bot or a human posing as a bot?

If you look closely at your belay loop you'll notice that the tape is wrapped twice plus an overlap and sewn all the way around the ring, each wrap is sufficient for the stated strength and thus the belay loop is actually redundant.  

Dave Olsen wrote:

Glacier travel it is common practice to clip into the belay loop with a locker or two non lockers. 

Some cavers use a quick link as a belay loop/masterpoint on the harness.

I typically teach using two carabiners regardless if they are lockers or non-lockers (or a single locking carabiner with an anti crossload feature like a Gridlock) because it's very easy to end up with a single one cross loaded while walking.  The reason to use a carabiner instead of tying in directly is that a crevasse fall on a glacier will likely require a load transfer and for the rescuer to escape from the system in order to perform the rescue.  That would be terribly inconvenient if you were tied in to the middle of the rope through the hard points on the harness and the system was loaded.