System Von Roll (cable car)
The Von Roll system is a system developed by the Swiss manufacturer Von Roll in the 1940s, which can be automatically coupled single-cable gondolas . It is also known to experts under its type designation VR101 . The lifts were initially designed as two-seat chairlifts , later also as gondola lifts . The couplability made it possible to automatically detach the cabin or chair in the station from the rope, to slow it down and thus to offer passengers comfortable and safe entry without reducing the speed of the hoisting rope and thus the rest of the train.
A striking feature of the Von Roll system chairlifts are the sideways armchairs , in which the passengers sit next to each other across the direction of travel.
history
The single-seat chairlifts that appeared in Switzerland during the Second World War, with chairs firmly clamped to the hoist rope, were not satisfactory in terms of the conveying performance, as these lifts were only allowed to be operated at a maximum speed of 1.2 m / s in Switzerland. At the same time, there was a need for ever higher transport capacities for the up-and-coming alpine skiing . As a result, the Von Roll company in Bern developed a new detachable single-cable chairlift system that allowed travel speeds of 2.5 m / s and used double chairs. The chief designer Paul Zuberbühler was in charge. The first plant was opened in Flims in December 1945 . Twelve chairlifts had been built across Switzerland by 1957 and the first gondola lift based on the Von Roll system in 1963. Manufacturing licenses were granted to the companies Transporta Chrudim in Czechoslovakia and to the ABIG works in Oberstdorf . Together with the licensed buildings, over 110 systems were ultimately built worldwide. New lifts based on the VR101 system have not been built since the 1970s; it has been replaced by more modern and more efficient further developments. Some of these railways are still in operation today.
The Swiss cable car inventory published by the Federal Office of Culture attaches importance to the VR101 system as having decisively advanced the system of detachable recirculating chairlifts, which triggered a veritable boom in chairlifts in the middle of the 20th century.
technology
The heart of the VR101 system are the automatically detachable rope clamps, with which the vehicles in the stations are clamped to the continuously rotating hoisting rope. The VR101 clamps are combined spring / gravity couplings.
Since the vehicles could not drive directly on hold-down supports (e.g. when exiting the station) due to the clamp housing reaching over the rope, a pair of rails is attached to the hold-downs on both sides of the pulleys, on which the pulleys of the clamp are placed and run along.
The clamping on the rope is accomplished by two opposite, wing-like clamping jaws, the axes of rotation of which are slidably guided in elongated holes in the terminal housing. These displaceable bearings make it possible to exert clamping forces acting on the rope from both sides in the closed state. In the case of the left clamping jaw , seen in the direction of travel, this is done by a spiral spring , on the right by an eccentric mechanism that converts the weight of the vehicle hanging on it into a linear force component via a lever parallelogram to which the vehicle's suspension arm is attached.
- Coupling
The gondolas or armchairs move in the stations on the four rollers on hanging rails arranged on the coupling housing. A suspension rail inclined as an inclined plane brings the transport equipment to the speed of the hoisting rope when it leaves and this is guided from below into the open clamping jaws. Due to the weight of the vehicle, the clamping jaws are closed and stretched beyond the dead center of their pivot points, thereby taking the rope between the contact surfaces of the jaws.
- Coupled state
In the closed and coupled state, the clamping force is then maintained by the weight-loaded eccentric system (right clamping jaw) and the compression spring (left clamping jaw). The weight that is exerted on the eccentric mechanism via the hanger arm during the coupling process (and thus also the clamping force acting on the rope) is controlled by means of a support roller which is attached to the hanger arm below the coupling device. By raising (relieving) or lowering the entire vehicle relative to the rope or clamp level by means of another guide rail on which this roller runs, the clamping force generating eccentric is specifically relieved or loaded.
- Locking and locking test
A locking lever, which is operated by a control rail in the station, ensures after the clamping process by holding the spring-side clamping jaw that the mechanism remains securely locked while driving. The locking lever is also used to check the clutch every time a chair leaves the station. If the rope is not in the intended place between the clamping jaws (incorrect coupling, pinch coupling), these and thus also the locking lever will not reach their end position. The locking lever then hits a switch which stops the train and prevents the incorrectly coupled vehicle from leaving.
- Uncoupling
When uncoupling at the station entrance, the four rollers run onto a station rail that lifts the vehicle off the cable. By simultaneously opening the locking lever and relieving the weight of the vehicle from the gravity clutch, the clamping jaws open, the vehicle is braked on the inclined plane of the rails and then continues its journey at station speed. The passengers can now get off or the vehicle is transferred to a subsequent train section via the hanging rail system.
Since originally there were no station conveyors such. If, for example, chain conveyors or pneumatic conveyors were available for the vehicles, the staff had to push the chairs or gondolas manually over the hanging rails to the starting point, into the subsequent section or into the vehicle depot. Some systems were retrofitted with station conveyors (Jennerbahn, Weissensteinbahn), while manual operation was retained in others (e.g. Schneekoppe).
Existing or recently canceled plants in Europe
- Kandersteg-Oeschinen chairlift, CH (demolished in autumn 2008, replaced by a new one)
- Chairlift Oberdorf – Weissenstein , CH (discontinued in 2009, demolished in autumn 2013, replacement by new construction)
- Chairlift to Schneekoppe , CZ (discontinued in 2012, replacement by new construction)
- Chairlift to the Mückenberg , CZ (in operation)
- Gondola to the Jenner (Jennerbahn) , D (discontinued in 2017, replacement by new building)
Systems in zoos, theme parks and exhibitions
Von Roll systems have also been built around the world as exhibition and zoo cable cars and in amusement parks (selection):
- Skyfari in the San Diego Zoo , USA, four-person gondola
- Skyride at Disneyland Resort , USA, four- person gondola lift (in operation 1956–1994)
- Chairlift in the Höhenpark Killesberg , Stuttgart, D (1950–1980s)
- Interbau cable car at Interbau 57, Berlin-Hansaviertel , D (exhibition run 1957–1958)
- Hamburg, IGA 1963 , D, (exhibition track 1963)
Web links
- Information on the detachable single-cable gondola lift system Von Roll on the cable car Nostalgie
- Cable car encyclopedia - history & technology of detachable cable cars with circulating operation
- Expert opinion on the safety of a VR101 system based on the current state of technology - published in the Bieler Tagblatt, 2009 (PDF file)
- Video on youtube about a VR101 system (Schneekoppe) with detailed recordings of the coupling processes