About 20 years ago there was serious discussion in the guiding community regarding the suitability of the clove hitch as a clip in knot.
Reported, but unconfirmed, testing by the Department of Defense indicated that it was possible for the knot to slip at relatively low loads. Bluewater was contacted and they agreed to test the knot. For a more complete discussion and results from the test click here.
This device can be great if you need to belay two partners at the same time. Practice giving slack in the ropes when your partners are fully weighting the ropes. It’s not as easy as you think. See Avoiding the Touch, Self Rescue Part 1 for details on this technique. To see a video clip of this technique click here.
Many climbers choose a friction hitch based on which one they know best. Depending on the material used to make the hitch, one friction hitch may be more suitable than another in a given situation. Check out the article Comparative Testing of High Strength Cord by Tom Moyer for the holding power of various friction hitches. See the chart at the bottom of page 5 for a comparison of the holding power of various hitches. Remember the numbers given are relative only as a comparison to others in this test. In other words test conditions must be identical to compare strengths in material or knots in tests done at a different time or with different equipment.
The breaking strength or holding power of knots should only be one of many criterion in your decision making process when deciding which friction hitch is appropriate for your situation.
Friction hitches work in three ways: first by constricting the rope, second by the friction of the material around the rope, and lastly by bending the rope. If your friction hitch isn’t sticking, you may need to add more wraps and / or you may need to remove twists or crosses in the hitch. To temporarily get it to stick, try bending the rope underneath the hitch until you can add more wraps. Webbing with spectra fiber in it tends to be slippier than straight nylon. Spectra runners CAN hold friction hitches but you should check your runners with the ropes you use to be sure.
This hitch works best in cord. Typically it doesn’t work well in webbing unless you use really narrow webbing. For the common widths of webbing that climbers carry it’s better to use a klemheist.
Works in either cord or webbing.
Works well in either cord or webbing. Can have a lower holding power than the prussik or klemheist. See the Comparative Testing article.