Funifor. Image by Doppelmayr.

The funifor is a jig-back aerial cable technology patented by Doppelmayr that consists of two, independently operating, double-armed vehicles. The two arms give the system high wind stability. The independent operation (as opposed to standard single-cable aerial tram) is key for emergency evacuation (where one cabins can be used to evacuate the other) and for allowing the system to function, albeit at half capacity, with one cabin out of commission (such as for maintenance or repairs.)

Other benefits of having independent cabins is that mid-stations are easily implemented and can be located at any point en route, rather than the exact mid-point, as is most ideal for non-independently operating cabins.

To accomplish this set up, each cabin is equipped with four pulleys and supported by two support cables. End stations each have two pairs of vertical bullwheels — one pair per cabin. At one end station, each pair is powered by separate drive motors (so that the cabins operate independently.) Also for each vehicle, a much smaller diameter haul rope is looped between a pair of cabin pulleys, both end stations pairs, and the second set of cabin pulleys.