Lead climbing is a climbing technique used to ascend a route. This technique is predominantly used in rock climbing and involves a ''lead climber'' attaching themselves to a length of ''dynamic'' (elastic) climbing rope and ascending a route while periodically attaching protection (quickdraws or traditional protection) to the face of the route and clipping into it. The ''lead climber'' must have another person acting as a belayer. The belayer has multiple roles: holding the rope in the event of a fall, and paying out or taking up rope as the climber moves.
As lead climbing does not require a pre-placed anchor at the top of the route, it is often seen as less restricted than top roping. Also, because a lead climber does not have an anchor point above them while climbing, only the limbs and body of the climber are used to affect upward progress. Protective devices are only placed to catch the climber in the event of a fall.
== Lead climbing basics ==
When lead climbing, the ''lead climber'' or ''leader'' wears a harness tied to one end of a rope. The leader's partner provides the belay, paying out rope as needed, but ready to hold the rope tightly, usually with the aid of a belay device, to catch the leader in the event of a fall. The lead climber ascends the route, periodically placing protection for safety in the event of a fall. The protection can consist of pre-placed bolts and pitons, to which the climber clips quickdraws, or removable protection such as nuts and spring-loaded camming devices, which are carefully secured by the climber into cracks or other features. Distances between pieces of protection can range from three to forty feet or more, although most often the distance is between six and twelve feet.
At any point, the leader can fall at most twice as far as the distance to the most recently placed protection. If a leader is ten feet above the last piece of protection, a fall will be a maximum of twenty feet. Realistically, the fall would likely include several more feet due to rope elasticity and slack and give in the overall mechanical system. If a lead climber, starting from the ground, approaches twice the height of the last piece of protection, there is danger of a ''ground fall'' (more commonly referred to as "decking") in which the falling climber hits the ground before the rope goes tight.
The severity of a fall arrested by the climbing rope is measured by the ''fall factor'': the ratio of the height a climber falls before his rope begins to stretch and the rope length available to absorb the energy of the fall. (A leader may reduce her fall factor by using "protection", equipment that attaches in some way to the rock, allowing the rope to pass through it.) A fall of 20 feet is much more severe (exerts more force on the climber and climbing equipment) if it occurs with 10 feet of rope out (i.e. the climber has placed no protection and falls from 10 feet above the belayer to 10 feet below—a factor 2 fall) than if it occurs 100 feet above the belayer (a fall factor of 0.2), in which case the stretch of the rope more effectively cushions the fall.
Once the leader reaches a suitable spot for anchoring, or runs out of protection (hopefully the former), two things can occur:
# The climber is lowered to the ground by the belayer or rappels to the ground, removing the pieces of protection on the way down. This is common when sport climbing or climbing short routes.
# The leader belays the lower climber (the former belayer) up to the anchors. On the way up, the climber ''cleans'' (removes) the protection placed by the leader. This is common when climbing multi-pitch routes, where this process is repeated once for each pitch.
The term ''sport climbing'' covers routes where most or all of the required protection is provided by permanently installed equipment; traditional climbing (or ''trad'') usually requires the leader to place removable protection. It is unusual but not impossible to see some pieces of permanent protection installed in the rock on some trad climbing routes. Sometimes, these pieces will be installed in spots where protection is vital but placing temporary protection would be difficult or impossible; other times, the pieces are remnants of the days before removable equipment was the standard protection method.
Lead climbing is done for several reasons. Often, placing a top-rope is not an option because the anchors are not accessible by any means other than climbing. Sport climbing and traditional climbing both utilize lead climbing techniques for practical reasons, as well as stylistic reasons.
Lead climbing also gives more of a thrill for the climber, because they know that they may fall much greater distances than if they were using a top-rope.
"Turtling" can occur if one of the climber's limbs is behind the rope and then they fall off the wall. The climber is flipped upside down, like a turtle on its back. Sometimes this can even eject the climber from the harness and is typically quite painful.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』