Kingda Huh? The Hydraulics Room that Powers Kingda Ka.

The launch cable is wound around the winch. The cable runs the length of the horizontal launch track. When the coaster is in operation, a catch car, a device that rockets the trains down the launch track, is attached to the cable. To connect the two, a "dog" drops down in the center of the train and hooks into the catch car.

To learn more about how Kingda Ka works, check out my article, Kingda Huh? Demystifying the hydraulic launch system that rockets Kingda Ka.