CABLE SYSTEMS
The track of the modern cable systems is constituted by a series of stations, each one connected to next one by a cable ring. These systems (with many analogies with the classical funiculars) are constituded by the following main elements:
cable
motorized station
return station
tensioning station
vehicle.
The cable is moved by an electric winch and it's set from a return to a tensioning station; intermediate stations are located between these terminals, along a route that allows different types of sections (straight, curved, inclined), thanks to specific mechanical rollers (straight rollers for straight or vertically convex segments, inclined rollers for horizontal curved segments, other rollers for vertically concave segments). The winch generates the cable motion, which is transmitted to the vehicles by some plyers which lock them to the cable.
In the return station (mostly coinciding to the motorized station), a pulley mantenins the cable in the correct configuration. In the tensioning station (at the opposite side of the track) possible imbalances of the cable are recovered thanks to a hydraulic system. The rubber tyred vehicles, linked to the cable by a fixed or temporary grip, are guided by horizontal wheels which runs along horizontal guide beams, on each side of the running platform; thanks to the absence of on-board engines, vehicles have low noise emissions and a low weigth. The latter factor, combined with the cable traction, allows to overtake strong vertical gradients (in same cases more than 15%).
In "temporary grip" cable systems a turning platform allows the vehicle inversion at the terminals, so that they can return in the opposite direction with the doors located in the external part of the track.
Single track option (if adopted) needs some vehicle crossing sections (with double track), with the same train or metro principle.
Nowadays most of the applications are characterized by total automation, so that system supervision is managed by a central control place, often located in the maintenance area. Cable systems control is based on the classical ATO, ATP, ATS architecture (APM), managed automatically by a specifical software that works on the informations provided by a signalling system located along the track (track circuits, transponders); this allows the train detection on the track and the speed control in order to warrant the safety conditions and the respect of the timetables. No fixed staff operates in the stations; safety and communications (on board and at the stops) are provided by video and audio systems that allow each moment to exchange infos between passengers and the central control place.


Links to the producers sites:
DOPPELMAYR
LEITNER
POMA