 Steeper, faster and longer tows require a series of pulleys to support the rope at waist height and hence require the use of some sort of "tow gripper".Several were designed and used in the 1930s and 40s, but the most successful was the "nutcracker" attached to a harness around the hips.To this is attached a clamp, much like the nutcracker from which it derives its name, which the rider attaches to the rope.