‘Camming chocks’ and tapers are what make up most of the climbing gear referred to as passive protection. They are also commonly known as hexes, stoppers and nuts. These heavy chunks of aluminium, which vary in terms of shape and size, all share one characteristic – they do not have any moving parts and consequently, are always attached to either a webbing sling, a cord or a wire cable.
Tapers and micro nuts
As the name suggests, these pieces of aluminium are narrow at one end and larger at the other. Their function is to slide into cracks on rocks which taper and wedge themselves in. They usually are most effective when used in cracks with narrow to medium widths. Due to their wedge shape, they are as suitable for parallel sided rock cracks. Tapers normally have faces that are slightly curved, with one side being concave and the other convex. The latter will lock against the two contact points located on the concave side, which helps to create a stable triangle of forces.
Micro nuts are essentially just a smaller form of the taper and are reserved for old piton scars or thinner cracks, where no other protection climbing piece is likely to fit. They are typically about seventy five percent smaller than a normal sized taper.
Camming chocks and tri cams
Camming chocks do not have moving parts, however, unlike a taper, a camming chock can to twist or rock itself into a locked position in a cliff face’s pocket. These tend to be useful when a crack in a cliff face is either too straight sided or large for a taper to fit into. Camming chocks are usually placed within horizontal, round pocket and parallel sided cracks.
Tri cams are uniquely shaped pieces that are pointed on one side and rounded on the opposite side. Like a taper, they can be placed directly into a crack, or alternatively, they can be placed with a sling running along the edge of a curved rock and ‘cammed’ into place. The placement of tri cams is a little tricky and thus requires practice. However, once a climber has mastered this technique, tri cams can be very useful.
Is passive protection equipment necessary?
Some climbers might wonder if it’s worth purchasing passive protection, when there are SLCDs, or spring loaded camming devices, that are easy to place and very secure. There are in fact a number of reasons why passive protection could be a good investment. Firstly, SLCDs, when placed in flaring cracks (that is, those that get increasingly wider), have been known to gradually ‘walk’ their way out, in which case a taper would be a much safer option. Secondly, a climbing equipment rack that has a full set of tapers is not only less bulky than the same volume of SLCDs, but is also significantly lighter. Last, but not least, when a climber is in a position where they have to leave behind a couple of pieces of protection gear so that they can do an unexpected rappel, the majority would rather leave a few inexpensive tapers instead of a very pricey SLCD.