Belay devices are mechanical friction brake devices used to control a rope when belaying. Auto-belay devices allow climbers to practice without a second person for belaying. Petzl recommends the device for lead belaying and top-rope belaying. Belaying is a critical part of the climbing system. Her running rigging consists of 140 lines secured to belaying pins and spider bands. The holes were also used for belaying mooring lines and sail sheets. This technique is a must particularly when leading a climb or belaying. Participants are provided with full-body harnesses and are connected to continuous belaying systems. At about , Schoening was belaying Gilkey down an ice slope. Belaying pins are typically made of hickory wood or steel. A belaying pin is composed of a round handle and cylindrical shaft. He also related how the first mate beat him with a belaying pin. Communication is also extremely important in belaying. This is normally not used when lead belaying. Finally the strain came onto Pete Schoening, who had been belaying Gilkey and Molenaar.