CROSS-LOADING – HOW DOES IT HAPPEN?
Unfortunately, many climbers are unaware that a crossloaded carabiner has less than half the breaking strength than it has when loaded lengthwise. So how does crossloading occur? Carabiners can rotate in a bolt and come to rest on the spine; they become cross-loaded.
This often happens during traverses. D-shaped carabiners are designed to slip back into the correct position. However, this is only possible if the loop in the quickdraw sling is wide enough to ensure that the carabiner can move freely. Again, this is why it's important to always clip the right side of the quickdraw in the bolt. In addition, avoid cross-loading when attaching your belay device to your harness, belaying, lowering and abseiling. Locking carabiners are generally used for these activities. To prevent cross-loading, some HMS carabiners have an internal positioning element for the tie-in point. This prevents the carabiner slipping and ensures that it always has correct orientation for maximum breaking strength.