The VT Prusik
Watch this video to learn several hitches you can tie with your VT Prusik, including the autoblock (French Prusik), French braid, Valdotain (a combination of French Prusik and French braid), Schwabish Prusik (asymetrical Prusik) and Distel Prusik (clove hitch Prusik).
Several of these hitches have similar uses. The autoblock is commonly rigged below the rappel device and used as a self-belay while rappelling. The Valdotain is the easiest to release when loaded. In fact, it can be used to descend a tensioned rope and as a self-belay rigged above the rappel device. You wouldn’t want to rig a self-belay above the rappel device with a normal Prusik hitch as it would be difficult to release after loading.
I use the Valdotain for ascending ONLY when I know I will transition to rappelling as it makes the transition very simple. Downside is that the distance between compressing to move and stretching to hold results in some lost efficiency. When I ascend to top out without transitioning, I prefer using the Schwabish or Distel. They each hold as well as a symmetrical Prusik, but are easier to move up the rope after loading.
Note that the VT Prusik is made with an 8mm cord with Technora sheath. Technora is an aramid fiber with a very high melting point. Well, actually, it doesn’t even melt; it chars at around 950 degrees F. This high heat resistance is important when your cord is moving on a rope. The friction point on the rope is constantly changing, but the friction point on the cord is constant. A cord made with nylon or polyester may melt through and suffer catastrophic failure if used for the same applications.
Kevlar is another aramid fiber used in some cords. Like Technora, it has a very high heat resistance, but it is prone to flex fatigue. Repeated bending and knotting will break the fibers and weaken the cord. Technora is a much better choice for our applications.
