Effects of Metal Climbing Gear and Lightning Safety Position During Simulated Lightning

Introduction When trapped in a climbing route during a thunderstorm, it is generally recommended that climbers should maintain a maximum distance from rock formations and water accumulations. It is common practice for climbers to untie themselves from the rope and deposit metal equipment a few meters away. Methods In an experimental study, the formation of upward leaders from metal gear attached to a climbing harness and the number of lightning strikes to rope, metal gear, and subject were evaluated. A lightning impulse generator was used to simulate high-voltage discharges of up to 2500 kV. Results When the subject was suspended from a conducting rope, no upward leaders were observed, and no lightning strikes hit the subject. Ungrounded metal gear kept on the climbing harness did not increase the risk of a direct impact, even in the presence of upward leaders. When the metal gear was in contact with the ground, upward leaders were seen to occur and downward discharges to even hit the head of the subject. Conclusions The findings of this experimental study indicate that unless grounded, metal gear on a climbing harness does not increase the risk of a direct lightning impact. The authors recommend that when caught in a thunderstorm, climbers should refrain from unnecessary touching of the rope. Furthermore, climbers should ensure that they do not untie from the rope.