The wagons are powered by a rope that runs under the track. They move at a constant speed of 15 km/h. To move, the wagon must grab the rope using special grips; loosening the clamps cuts it off from the rope drive and stops the wagon. Due to the high friction of the clamps, they wear out very quickly and need to be replaced every three days. The service was launched in 1878 and, at its peak, it served twenty-three lines, three of which remain to this day. The trams are one of the city's greatest tourist attractions and the only movable national historical monument. About 20.000 passengers use the cable tram daily.
