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Ropes

Rope Basics

In climbing and repelling, the rope is your lifeline. Understanding rope characteristics will help you choose the right one.

Rope Types:

  • Dynamic:  has the ability to stretch when a load is applied allowing the rope to absorb some of the force during a fall. 
  • Static:  generally does not stretch when loaded; used for repelling, rescues and rope ascending.

How It's Made

Most modern climbing ropes have a kernmantle construction consisting of an interior core (kern) that is protected by a braided exterior sheath (mantle). This design optimizes strength, durability and flexibility.

  • Sheath:  protects the rope from cuts and abrasions.  
  • Core:  supports the load, bearing the climber’s weight. 

Rope parts diagram

Manufacturing Steps

  1. Fibers are spun or bunched into yarns
  2. Yarns are twisted into strands
  3. Strands are twisted forming the core
  4. Sheath is woven around the core
parts of a rope             

Percent Elongation

This is the amount a rope stretches under a specific load.
ΔL = change in rope length
L 0 = initial rope length 

Example: 
ΔL = 0.2m 
L 0 = 1.0m
percent elongation example 
Rope Setup:
Single Rope setup
Half Rope setup
Twin Rope Setup

Fall Factor

This is the ratio of fall length to the rope length. It is used to estimate the severity of a fall.

FF = fall length/ rope length
FF = 4m/ 10m = 0.4m

fall factor example 

Rope Friction

Rope friction is created any time the rope is in contact with itself, the rock, or a piece of gear and prevents the rope from elongating over its entire length. Thus, only the effective rope length (solid line) will absorb the energy of the fall.

High friction diagram
Low friction diagram

* Climbers choose a half-rope system to reduce the amount of rope friction on a wandering route.   

Common Knots.
Figure Eight on a Blight

Figure Eight on a Bight:  produces a strong loop for securing carabiners or other items.



Water knot

Water Knot:  used to join two pieces of webbing.



Figure Eight Follow Through

Figure Eight Follow Through:  a simple, reliable knot most commonly used to tie in to a climbing harness.


Double fisherman's knot

Double Fisherman’s Knot:  used to join two ends of a line to form a loop or to join two climbing ropes.


Clove Hitch

Clove Hitch:  a good binding knot when constant pressure is maintained.



Safety Knot

Safety Knot:  prevents the end of a rope from sliding through a piece of gear or another knot.