Carabiner Safety

A carabiner has many uses, but it is most often used for rock climbing or as a keychain. Climbing carabiners can keep a climber from falling, but it is crucial to understand how carabiners work and what their limit is to prevent failure while climbing. Carabiners are the most researched and tested piece of climbing equipment because of the stress they are placed under.

  1. History

    • Carabiners have been used for many years. The name comes from the word "karabinerhaken," a German word meaning "hook for a carbine." The first carabiner used for climbing was manufactured in 1910 by a German named Otto Herzog. Steel carabiners were used by paratroopers in World War II. Early carabiners were all made of steel, but modern ones are made of aluminum. Steel carabiners are stronger, but aluminum allows the carabiner to have a high strength with much lower weight.

    Function

    • Climbing carabiners are designed to take the force created by a short fall. When the gate of the carabiner is not closed it has much less strength, so carabiners should only be used with the gate closed. Although the force of a fall is not generally high, repeated falling can cause a carabiner to wear out, so each carabiner should be inspected prior to use.

    Types

    • There are two common shapes of carabiners and several types of gates. An oval carabiner has a gate in one of the long edges of the oval and is often used for carrying heavy items. The oval design allows the load to be distributed more evenly. A "D" shaped carabiner has the gate in the round edge of the "D" and is able to take heavier loads than the oval design. "D" carabiners are often used by the lead climber and are available in symmetrical or a-symmetrical designs. There are four types of gate closures: locking, straight, bent and wire. Locking gates have a mechanism that allows the gate to be locked closed to prevent it from opening on its own. Straight gates have wide openings and angled noses that make it easy to clip them onto rope. Bent gates have a concave curve to them and allow more room for rope. Wire gates use wire instead of a solid piece of aluminum or steel.

    Identification

    • Carabiners are marked on the spine, or long edge not broken by the gate, with how much weight they can bear. There are three different weights listed that depend on where the load is located on the carabiner. All ratings are listed in kilo Newtons; one kN equals approximately 100 kilograms or 220 pounds. The first rating is for the major axis, along the long, unbroken end opposite the gate. This is the way carabiners were designed to hold weight, so it has the highest rating. The second rating is for cross loading, along either of the short ends. This weight is significantly lower because of the pressure it puts on the gate pin. The final rating is for when the gate is open. This will also be lower than the major axis load.

    Warning

    • The carabiner is designed to take certain loads, but the marked weights should be adhered to in order to prevent failure of the carabiner. Weight should only be applied to the main axis of the carabiner, as it has more strength than any other weight distribution. Rock climbing is a dangerous sport and should only be attempted with proper instruction. Carabiners designed to be used as key chains are not able to take any significant load and should never be used as climbing equipment.