Kilonewton, Forces, & Rock Climbing

1 Kilonewton = 224.8 Pounds

A kilonewton is a measurement of force. It is important to understand the kilonewtons in top rope climbing

Evaluating and managing risk. We always climb with the intention of protecting ourselves and eliminating as much risk as reasonably possible. To get a sense of how much force a person can generate, we use this example: A man weighing 225 pounds who steps off a cliff generates 2,200 pounds (roughly 10 kN) of force in his fall. The belayer’s upward movement and the slack in the rope adds another 1,450 pounds. This increases the total potential weight of the climber about 3,650 pounds! Neither you nor I can handle this weight alone–understanding that is key.  At most, our bodies can only withstand 12 kN. Therefore, we must remember to build our anchors, as a benchmark, double what our bodies can withstand, 25 kN.

Protecting ourselves:  In order to protect ourselves from all of the forces generated in rock climbing, we can first think about how friction is added to the system. As the climber climbs up on one side of the rope, friction is generated from the rope passing through the carabiners.  Additional friction is generated by the belay device and the belayer. When used properly, the belay device creates friction by looping the rope under the device.

rock protection

The second way we protect ourselves from the forces created in rock climbing is by using “protection” or  nuts, hexes, tri-cams, cams, and naturals (trees and boulders). Each of these has its own kN value and we want the value to add up to at least 25 kN.. To find the value, look on the piece of gear or make note when you purchase (cord and webbing). This is the amount of kilonewtons that the piece of gear will hold, if placed correctly. Remember though, the strength of your gear is only as good as the quality of your placement.

These are  just a few considerations you need to know before building anchors and climbing systems.  If this is confusing or you want to learn more, join us for a two-day anchors course. We discuss this topic and many other anchoring principles and considerations. After all, it’s your life at stake!

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Spring Cleaning: Climbing Rope Care

A strong climbing rope is essential to climbing! To keep you safe, here are a few tips for care and maintenance. Don’t let a dirty climbing rope get you down.

Did you know that besides the act of climbing and belaying, nothing wears out ropes faster than stepping on them?  Sand and other particles from the ground are particularly hard on ropes.  Rocks underfoot can cut the sheath (colorful outside) and compromise the core (white inside).  And dirt and dust can also work their way into the core, making the length of life of the rock climbing rope much shorter.


A simple fix is to remind your rock climber friends to stay off the climbing rope and to use a rope bag. (We like the Black Diamond Super Chute Rope Bag).

Another factor that affects rope wear is placement. Make sure the climbing rope runs freely whenever possible.  If you’re leading a pitch, use slings that are appropriate length to decrease rope drag and keep the rope away from the cliff face. If you’re top-rope climbing, make sure your master point is extended over the edge of the cliff. Also remember that a fall onto a sharp edge can seriously damage or slice through a climbing rope.  Finally, at the end of the day, while enjoying time socializing in the parking lot, keep the rope off the pavement. Oil, battery acid, and Freon that has leaked onto the asphalt can destroy climbing ropes.

At Apex Adventure Alliance, we wash our ropes frequently.  Washing ropes increases their life by getting the dirt and grime and aluminum oxide (from the carabiners) off.  If you want to wash your ropes, it is best done on a cloudy, windy day to protect the rope from harmful UV rays. First daisy chain (See Here) the ropes and stick it in the washer with cold water.  We use Woolite, but you can use a special rope detergent.  Hang to dry and your ropes will be like new!

Now get out and climb!