The Kiwi Coil is a technique that is used to bring in rope, in order to shorten the distance between two climbers. This technique is commonly used for simul-climbing on easy terrain, or in glacier travel.
Check out a video on how to do it, below:
One thing to be very careful about is the use of a Kiwi Coil on a glacier. It is important to add one additional element to tie off the rope. The climber should tie an overhand knot in the line and clip it to a carabiner. The reason one does this is to ensure that if your partner falls into a crevasse and you have to untie the Kiwi, you won’t get strangled when it comes undone.
–Jason D. Martin
Advanced Skills, Knots, Hitches and Rope Work, Alpine Climbing
The Kiwi Coil
American Alpine Institute