Camming Devices (Active Protection)

Active protection refers to pieces of climbing protection with moveable parts: camming devices and tube chocks.

Camming Devices

Spring Loaded Camming Devices (SLCDs), commonly called cams, can adapt to a range of crack sizes, shapes, and irregularities. Apart from the mechanical action, what sets them apart is that they do not need a bottleneck or constriction in the rock to provide protection. They can be placed in parallel sided or flaring cracks where it is difficult or impossible to use a passive piece.

Basically, SLCDs are three or four lobes of milled aluminum hinged at the top of a stiff wire cable or aluminum body. Each lobe is independently spring loaded each is attached to a single trigger. The trigger retracts the lobes allowing them to be placed in a rock feature. When the trigger is released, the camming device expands. When a load is applied to the stem, the lobes are forced outwards and jam themselves into the rock.

• Stems: either single or double strands of flexible cable or rigid, aluminum bar. A flexible stem allows the unit to be placed horizontally over an edge if necessary. Although ideally any type of stem should point in the direction of anticipated pull.
• Lobes and Axles: Three cam units (TCUs) have a smaller profile and are designed to fit in thin or shallow placements. Four lobes are generally used on larger pieces. The double axle design allows a greater range of placement, although these cams tend to be heavier than single axle models.
• Size and Range: Compare cams using their placement ranges, size numbering (i.e. #2) varies among manufactures. Larger ranges mean a particular camming device can be effective in a wider selection of placements, allowing you to carry fewer pieces. However having fewer pieces may not be an advantage on a long or difficult pitch where you may appreciate having lots of pro.
• Trigger: The trigger on a U-shaped body can be manipulated with the thumb and just one finger, a single-stem unit will require your thumb and two fingers. When buying camming devices, try out several designs to find trigger action that feels comfortable to you.

Tube Chocks

These expanding spring-loaded aluminum tubes function in wide, offwidth cracks, and particularly well in uniform cracks with parallel sides. The spring action allows them to expand to the width of a crack and tightening a screw collar locks them into place. Holes at the end allow them to be slung. Tube chocks are relatively light, compact, and stable compared to spring-loaded camming devices.

See Passive Pro for more information about racking up.