Placing protection while trad climbing is a must learn skill for every climber. Lead climber places all the gear to protect in case of a fall, gear is then removed once the climb is finished. Gear is also used for building anchors.
Gear (protection) are mechanical devices that provide safety and reduce the distance of the fall. " placing gear" is the act of setting a piece of gear into the rock face and then attaching the rope before ascending higher. In case of a fall gear acts as a catch point for the rope and preventing the climber from hitting the ground. Being "run out" refers to the situation where the distance from the climber's position to the last piece of gear is far enough that the climber will receive little or on protection from a fall.
Climbers use passive and active protection.
Passive protection such as nuts, hexagonal shaped chocks and slings
In rock climbing a nut (chock or chock stone) is a metal wedge threaded on wire, used for protection by wedging it into a crack in the rock
Hexagonal shaped chocks (hexes), Hexes are intended to be wedged by into a crack or the opening in the rock. Hexes might be placed either as a passive or active protection. When placed passively they work like a chock stones in flared cracks, like other climbing nuts, just larger and with a different shape.Active protection is achieved by orienting the webbing so that a pull causes a camming action against the rock, allowing a placement in parallel cracks They are often preferred over spring loaded camming devices because of their lack of moving parts and overall lower weight.
Sling is an item consisting of a tied or sewn loop of webbing. These can be wrapped around sections of rock. they can be used as anchors, to extend an anchor, to reduce rope drag, in anchor equalization or to climb a rope.
Spring loaded camming devices (Cams) Cams consist of three or four cams mounted on a common axle or two adjacted axles, so that pulling on the axle forces the cams to spread farther apart. Cams are place dby pulling on the trigger so the cams move together, then inserting into a crack or pocket in the rock and releasing the trigger to allow cams to expand. Now the climbing rope can be attached with carabiner on the ond of steam or sling. A pull on the rope such as in case of a fall will produce pulling force on steam and force cam to open and causes a massive amounts of friction and preventing the removal of the unit from the rock.
Placing protection on a climb.
Think carefully how you place protection while climbing. Make sure there is plenty of rock around a nut so that any load will tighten it into a crack. Seat the nut well, with few sharp pulls on it so it doesn't get lifted out of a place as you climb higher up.
Well placed and seated nut note there is plenty of contact with a rock. (actually side of the house)
Another example of well seated nut: Again good rock contact on both sides. Nut is seated deep in a crack to prevent lifting up.
Bad placements: Nut doesn't have much contact with rock and is placed in a shallow crack. Smaller size and better orientation could work much better.
Another poor placement. Crack widens up right under the nut. In case of sudden load nut can slip out of its position and won't protect the climber.
Well placed cam.
Poor placed and over cammed cam might be hard if not impossible to remove.
In this case cam is too open and might not sit well in crack. Also this cam will walk in a crack as you climb above and might walk too deep to be removed or fall out of its placement. Again different sized cam will work better.