Mar-Mex Escapeline

Closed For Use.

Disassembled, Showing Rope Channel

The Mar-Mex Escapeline is the only commercial squeeze brake that I am familiar with. I believe it came in a number of sizes, but is no longer available. It consists of two extruded aluminum pieces that hinge together. Each piece has a straight groove where the rope runs. A swinging knob locks the plates together, and allows the user to adjust the force the plates exert on the standing line. One of the plates has a hook on the side, and the rope must be looped over this hook. There are two carabiner holes, a lower one for attaching to one's harness and an upper one for attaching other devices (e.g., a second Escapeline).

Squeeze brakes have generated a lot if interest in the caving community because they have a large contact area and do not bend the rope, and therefore appear to be appealing for long drops. Unfortunately, a simple squeeze brake does not provide adequate control because the friction is quite sensitive to the separation between the plates, and unlike snubbing, increasing the tension below the device does not effectively increase friction. In fact, it decreases it somewhat. Mar-mex got around this by adding the hook on the side. The rope is looped over the hook, which provides a snubbing action in addition to the friction from the brake itself. The knob can be adjusted so that most of the friction comes from squeezing the rope, while the snubbing provides an increase in friction as the tension below the device is increased.

My Escapeline has "MAR-MEX INTERNATIONAL" molded into the handle. A yellow sticker on one side reads:

ATTENTION
MAKE SURE ROPE IS
IN NOTCH BEFORE DESCENT
ROPE

(The last word is not my typo). The yellow sticker on the other side reads:

MAR-MEX INTL.-ATLANTA
PATENT PENDING
USA CANADA JAPAN KOREA
AUSTRALIA EUROPEAN COUNTRIES
PCT APPLICATION

I believe that the Mar-Mex Escapeline is protected by U. S. Patent 4,603,755 - at least the patent drawings match the device and the date on the patent is reasonably consistent with when I acquired my Escapeline. Similar ideas appear in older US Patents 4,448,281 and 4,056,166; each of which is referred to by the later patent.

The hook must be upright, and the rope must be draped over the hook. The Escapeline will not function properly if rigged upside-down.