There is a reason we stamp three ratings on each and every carabiner certified for climbing. It is important that climbers understand the limits of their gear. A carabiner engaged in a cross-loaded position is far weaker than a carabiner engaged along its major axis. This weakness is amplified if and when a sling, hanger, or wire pulls directly at the nose of the carabiner with a force that pulls the nose out and away from the gate. Of course, lockers offer a distinct advantage in this regard by helping to keep the nose and gate aligned, but the risk of cross-loading remains, especially in the case of a belay biner as it is the only biner standing between the climber and ground.
Gear manufacturers have tinkered with this problem for years and the results have been solid with systems ranging in complexity from basic rubber keepers and extra loops in belay loops (CAMP’s patented No-Twist) to help prevent carabiners from rotating, to multiple gates built into a single carabiner. The latter solution is a good idea, but implementation has been left wanting in most cases. The question is; how can we simplify this system to make it as safe as we want to make it without making it a total pain to use? Enter the new HMS Belay Lock. This patented carabiner features a small inner gate that closes over the belay loop once the biner is in its optimal position for belaying or rappelling. The inner gate prevents the biner from rotating and voila! The potential for cross-loading is virtually eliminated.
The magic is in the patent. We use the same spring for both the main gate and the small inner gate. This allows us to shave weight and makes the two gates work in unison for fast and easy attachment. First, attach the biner to the belay loop and let it close. Second, open the small gate and insert the belay loop. Third, open the main gate to its full position to fully compress the small inner gate and insert your belay device and rope at the same time. Tighten the screw gate. On belay!