The rigid catenary together with the conventional or flexible catenary are the two most widespread mechanical systems in the aerial transmission of electric current to the train. The flexible catenary is a system with three clear advantages compared to the rigid catenary. These are:
- Operating speed limits in higher trains (350 km / h).
- Minor displacements (natural fall) in the center of the span.
- Greater lengths between supports (spans of up to 60 m).
These three characteristics, among other aspects, favor the current installation of more kilometers of flexible catenary than of rigid. The design of the flexible catenary adapts perfectly to most railway infrastructure scenarios. However, the rigid catenary is a system with some very interesting advantages, which are:
- It is easy to install because of the type of supports.
- They allow the replacement of the contact wire semiautomatically.
- It has a greater section of electrical conductivity and greater possibility of evacuation of heat in the case of some point and momentary overcurrent.
- It requires smaller gauges than the flexible catenary.
- It does not require prestressing like the flexible catenary.
All the above characteristics make the rigid catenary a simple device, robust in its operation and very reliable from the point of view of safety. These aspects are fundamental in tunnel installations where the obligatory stop of a train, for reasons of a flexible catenary break or other event, would suppose a security problem, which would be aggravated in case of needing the evacuation of the passengers inside the tunnel . These are the reasons why the rigid catenary is widely used in tunnels for metropolitan and suburban railway infrastructures. This use is spreading more and more and regional infrastructure projects are being initiated, and it is even being studied to incorporate it into sections of higher speeds.
The advantages provided by the rigid catenary are making it gain ground against the flexible catenary and more and more railway administrations are opting for this option. The power of the rigid catenary seems to be still to be discovered, although it is already beginning to take off.
These expectations of growth are slowed down by the limitations in speed of operation, by the shorter lengths between supports required and by the excessive central fall when the supports are separated from each other to make the infrastructure cheaper. All these aspects are solved by Innoviria with its novel and proven device.
With the Innoviria CaDOD-100, the rigid catenary design is optimized allowing:
- regulate the damaging central fall of the rigid catenary and the center of the spans,
- increase the speed of operation by improving the dynamic behavior of the rigid catenary, and
- lower the costs of the infrastructure due to the possibility of increasing the length of the bays.
The following figure shows the difference in the contact force between the rigid catenary and the pantograph for a usual situation (Before) and its difference when incorporating the Innoviria CaDOD-100 (After). Which regulates the positioning of the catenary and controls unwanted vibrations.
Figure 1. Contact force between rigid catenary and pantograph.
The graph in the upper part of figure 1 shows three undesirable phenomena in any catenary design. The excessive oscillations of the sections between mechanical cantons generate large oscillations that lead to:
- excessive wear due to maximum force values,
- electric arcs in the values close to 0 N of contact force, and
- greater values of standard deviation in the contact forces that is related to the wear of the wire and the tables of the pantograph.
All the undesirable phenomena are reduced or disappear when the Innoviria CaDOD-100 is installed (lower graph of Figure 1), which controls the vibrations and allows, in summary, lower maintenance costs and greater operational safety. In addition, the smaller oscillations generated in the contact forces, improve the interaction between the catenary and all the pantographs for operations with multiple pantographs.
Rigid Catenary Innovation Solution 