A handcar (also known as a pump trolley, pump car, jigger, Kalamazoo, velocipede, or draisine (powered or unpowered)) is a railroad car powered by its passengers, or by people pushing the car from behind. It is mostly used as a maintenance of way or mining car, but it was also used for passenger service in some cases. A typical design consists of an arm, called the walking beam, that pivots, seesaw-like, on a base, which the passengers alternately push down and pull up to move the car.