On August 26 my partner Sean (27) and I (28) were climbing Transporter Crack (5.6). Sean set up a Black Diamond ATC-Guide device in guide mode to belay me from above. When I was ready to lower, instead of taking me off belay and switching to a more practical lowering system, Sean decided to practice lowering using the autoblock device. Sean threaded a thin sling through the small “release hole” of the device and redirected it through a carabiner clipped to one of the anchor bolts.

As he began to lower me the tension released slowly, then when the device finally opened all the way it inverted, creating a pulley and causing me to gain momentum. Realizing that I was falling, Sean attempted to brake but couldn’t hold my weight due to the increasing momentum. I experienced a virtual free fall for about 30 feet until I landed at the base of the climb.

Luckily, because of the relatively short distance of the fall and the fact that I landed on my butt, I was able to hike out under my own power after my group cleared my spine and checked my vitals. They contacted 911 and the Park Service. A ranger arrived on the scene to help coordinate local EMS and hiked out with the group. I was checked out and cleared by the EMS personnel, and driven out by fellow group members.

Analysis

There were several oversights that caused the accident. First, Sean had used the lowering technique before, but never in a situation where a climber was being lowered from the top of a route. He had only used the technique for climbers that needed to be lowered a few feet while on belay. To the best of his knowledge, he believed the system would be adequate as a lowering technique in this situation. Not so. I should have clipped into the anchor as soon as I completed the route, and a more practical lowering system should have been implemented.

The primary cause of the fall was that Sean neglected to redirect the brake strand into a carabiner connected to the anchor above. In addition, Sean did not back up the brake strand with a friction knot made with webbing or cordelette, which should have been clipped back to his belay loop. (Source: Daniel Kessler.)

(Editor’s note: Black Diamond recommends that belayers use a back-up belay when lowering a second climber with the ATC-Guide in autoblock mode. For example, the belayer can use a Munter hitch on a locking carabiner clipped to the belay loop on his or her harness. Black Diamond has produced a helpful video demonstrating lowering and other techniques using this device; search “ATC Guide” at YouTube.)