The ATC, or Air Traffic Control
by Black Diamond
, Is a tube belay
for the purpose of rock climbing
. Some would say THE belay for rock climbing
, as the ATC
seems to be the most common belay device used. In fact, some will refer to about any tube belay
as an ATC
, a practice likened to calling every tissue
The ATC functions by passing a loop or bight
or rope through a narrow slot (pretty much just wide enough to allow the width of the two rope strands) and then putting a carabineer
through the loop in the rope, as well as a small plastic loop attached to the ATC, for the purpose of keeping it close to the belay person, and attaching said carabineer
to the belay person
. What results is the working end of the rope (the end that goes to through whatever protection is in place and eventually terminates at the climber), enters the ATC, travels around a carabineer, and out the same slot in the ATC, becoming the Braking or loose end.
Just as with most any tube belay
, when the belay person
wishes to lock off the rope, they pull the brake end of the rope to their side, causing the device to clamp down on the loop wrapped around the carabineer
. It becomes impossible (or, very very difficult) for the rope to move, and the weight from the rope is transferred to whatever the belay
is clipped into, be it an anchor, or the belay person
. The braking hand has only to exert enough effort to hold the rope at their side.
Downsides: Constant attention MUST be paid by the Belay person, always ready to lock off the rope in case of a fall. Sometimes a climber can work a particular spot many times, falling until they get it right. This results in long periods holding the brake on, and this can be fatiguing. It is also not appropriate for certain types of belay setups.
PLEASE NOTE: This node is not a replacement for training in any climbing technique or device. It's not a replacement for the advice of the manufacture of said device, who knows best it's limitations. It's not even all the information a person would need in evaluating a decision to purchase one device or another. This node exists solely for the purpose of providing a bit of information to a non-climber as to what those little bits are hanging all over that crazy bastard who's dangling like a worm on a hook on some cliff wall.