What does it mean to cross load a carabiner? The guide to using a carabiner safely!

What it means to cross load a carabiner – detailed explanation

Now lets discuss a cross load. The middle picture shows a cross load. Any force in this direction is marked on the carabiner with a left right arrow. A carabiner can usually  take a considerably smaller load in this rotated direction than in the main loading direction. It comes down to the   design of the carabiner: In this direction, there is less material to support the load.

The gate of the carabiner takes some load too, even if you load the carabiner in the main direction. And that’s why you will find another symbol on the carabiner for this. It indicates the possible load when the gate is open. It’s usually much less than with a closed gate, as an open gate cannot load force.

The gate is also part of the reason why the maximum loading force for a a crossload is so low. For the case that the force pulls inwards, the gate is only held in place by the locking sleeve and nothing else. And as a carabiner is only as strong as it’s weakest part, it means you have a low strength when load goes in this direction. It’s higher when you load outwards, as the locking sleeve and the gate itself pushes against the rest of the carabiner in this case.

Other bad loading scenarios: Tri-Axial loading and nose-hooked carabiners

Another weak point of a carabiner is when you load in directions completely away from the spine. You can find this scenario in the right picture. It’s described in more depth here. The load a carabiner takes in this direction can be even weaker than a cross load. The same applies to the so called nose-hooked carabiner.

What’s a nose-hoked carabiner?

A nose-hooked carabiner happens when your contact point squeezes open the gate at the nose of the carabiner. It’s a really bad situation, which can result inf carabiners failing at less then 10% of their rated closed gate strength. For our example this is around 227 kg of a load hanging in free air. Source here. This amount of force can happen if you have even just a small fall or bounce test

Why is a nose-hooked carabiner so bad?

Why is the carabiner’s breaking strength all of a sudden so low when nose-hooking it? It’s because this scenario combines an open gate with the design of the carabiner and a weird position for the force to attack. By putting load on it now, you basically create a cantilever that pulls the carabiner basket off of the bolt hanger.

As the load is not in line with the spine axis, which is the main direction to load the carabiner, the carabiner becomes excessively twisted and torque builds up in the material. It then breaks at the weakest point, which is the upper part like shown in the picture.