This past weekend I had the opportunity to witness part of the International Tree Climbing Championships held this year in Downtown Minneapolis. The ITCC was held as part of the annual International Society of Arborists convention and trade show. We caught several heats of the Men's Foot Lock climbing. These guys were ascending 50 feet of rope into the tree in just about 22 seconds!! Their method of ascent is to flip the rope up and over one foot with the other, locking the rope between the instep of the first foot and the sole of the second foot.
While I have been climbing trees for a little while, I came to it via rock climbing. I learned that the method I had been using is referred to as the Single Rope Technique (SRT). Another method of tree climbing is the Doubled Rope Technique (DRT). DRT is advantageous because it uses the mechanical advantage of a pulley. You pull down on one side of the rope and are hauled up with the other end. The photos are of some advanced equipment for this method. You'd be clipped into the lower carabiner. To climb, you'd pull down on the rope on the right, the pulley would tend the friction knot up until you stopped pulling, then you'd be held by the friction knot. While the tree climbers seem to "traditionally" use a Blake's Hitch, the one show to the right is a Distel Hitch.
DMM (Wales) was apparently showing this new pulley off, it seemed to be generating a fair amount of (heated) discussion when I found it. I haven't been able to find it in any of DMM's current online offerings.
Also note the the rope on the left has been spliced back on itself to form an eye, also the orange line has been sewn into eyes. Here is a closer look at the pulley.
I'll post some pictures of actual climbing tomorrow!