Rack and pinion switch
Out of necessity, an idea was born. Creativity and engineering ingenuity led to the invention of a system, which at the turn of the century was the first of its kind.
ONCE A PIONEER – ALWAYS A PIONEER
Rigi Bahnen has continued to live up to its reputation as a pioneer and invented a new rack and pinion switch in 1999. The patent is registered worldwide.
One year later this was followed by the commissioning of the first flexible rack and pinion switch, which was ready to go into series production.
The system is based on a new approach. The switch consists of a flexible length of track, which resembles a closed track at each end.
The switch was developed by Rigi Bahnen in close collaboration with VT Verkehrs- und Industrietechnik AG, the Windhoff technology company (Germany), the Swiss Federal Institute of Technology in Zurich, the Institute for Transport Planning and Systems (IVT) and the Federal Office of Transport.
HOW DOES THE FLEXIBLE RACK AND PINION SWITCH WORK?
The spring switch is based on the idea of a «cut out» section of track, which acts as a kind of "spring" that is fixed at one point and bends from one end position to the other, along a precisely defined curve. In the end positions, the system operates like a "closed" track. Special construction elements prevent the movable length of track from lifting off the ground or buckling. This design offers significant advantages compared to a point or sliding switch.
The system has the following applications for cogwheel railways and adhesion railways:
- connection of two tracks (possibly more)
- wherever it is desirable to have no breaks in the track, such as points, frogs (common crossings) and other movable sliding parts
- alternative to complicated track changing systems (e.g. «British switches»)
The flexible frame (tracks + rack + mechanism for keeping the train on course) is fixed on one side and slides sideways on an upper frame. The system can be locked and monitored in the end positions.
TECHNICAL DETAILS: FLEXIBLE RACK AND PINION SWITCH
|System||RIGI - VTW|
|Track width||1435 mm / standard gauge|
|Opening||6° right / 9° left (openings can be customised)|
|Total system wight||20 tonnes|
|Track material||Standard track material (track VST36, ladder rack w=60mm, fired). Flexibility within the stress-strain curve|
|Switch motor||Hydraulic (switching torque 13'500 N)|
|Installation||Free-standing system/Embedded in gravel|
|Rack||1-piece longitudinal compensation with temperature dependent counter-movement system|
|Track stability||Horizontally with special frame reinforcement, vertically with system for holding tracks down|
|Control||Monitoring with Tiefenbach axle countre and PILZ control device|
|Installation||26. October 2000|