J-Bar

The J-bar has gone out of fashion, but it once was a popular caving device. The typical J-bar consists of a frame that is similar to a rack frame, but is often bent at the top. A rope guide is welded to the top of the frame, and a large-diameter brake bar is welded at the bottom. Three standard brake bars ride above the fixed bar.

The standing line passes through the rope guide, under the fixed bar, and zig-zags upward through the moving bars, then down. Not only does this give friction by normal snubbing, but increasing the tension on the tag end squeezes the moving bars together and against the fixed bar. Using the J-bar feels like having power brakes on rope, and indeed, for drops of over 100 meters or so, the tag end must be lifted to descend, making one feel that they are pulling themselves down the pit. On shorter drops, it performs well.