Gear and Carabiners
The Accessories You Need to Climb Effectively:
Harnesses make hanging from the rope comfortable by distributing your weight over a larger surface area, reducing the pressure where it contacts you.
Chalk is the chemical magnesium carbonate (MgCO3). Climbers often apply it to their hands to keep them dry so that they can grip the rock. Chalk can absorb the sweat your hands create, keeping them dry and maintaining good friction with the rock.
Climbing shoes are designed to give climbers an advantage. The rubber on the soles and around the toes is specially formulated to increase the coefficient of friction (μs) between the rock and shoes.
F = μ s × N
Note: Increasing μ s increases the frictional force that helps the climber stand on his feet and remove weight from his hands.
Carabiners are a simple and convenient means of attaching ropes, slings and other pieces of equipment to each other.
Parts of a Carabiner
Most carabiners are stamped with strength ratings that designate Major Axis, Minor Axis and Open Gate strengths.
Major Axis = 22 kN
Minor Axis = 7 kN
Open Gate = 5 kN
Why the Notch?
Carabiners have a notch or similar feature at the nose to distribute some of the load across the gate. This makes carabiners inherently stronger and allows manufacturers to use less material.
Factory of Safety.
The ratio that describes how much stronger a part or a system is than what it actually needs to be for its intended application.
Most climbing carabiners have a strength above 20 kN. Theoretically, this means they are strong enough to support a full-size pickup truck, even though forces of that magnitude are almost unattainable while climbing.
= 22 kN
~ 4,945 lb
Curb Weight = 4,930 lb
With a safety factor barely larger than 1, if a small amount of weight were added to the truck the carabiner would break.