Tram and railway industry

Online contact line measuring system OVHWizard for monitoring the contact line position during travel

The OVHWizard is a non tactile contact line measuring system for determining the contact line height and stagger with and without uplift. The system operates with ultrasound according to the runtime measurement principle.

This measuring principle offers the advantage over optical systems that it also works in direct sunlight, light rainfall or fog. Thanks to its weight of only about 4 kg it is easy to handle and can be installed on any vehicle roof with a few actions. A simple RS232 link to the PC or laptop enables communication with the measuring software.

A special evaluation software which was developed in co-operation with SIEMENS AG allows the measured data to be compared with the given line data and types of catenary.

The system is approved by the DB, the SBB, the ÖBB Network rail and the Turkish Railways TCCD.

OVHWizard measuring system

Two specially developed high-performance ultrasonic distance sensors form the core of the OVHWizard contact wire position measuring system. These sensors are installed respectively at an optimum angle at the ends of the measuring instrument.

The entire processing electronics are located in the connecting tube between the sensors. The system operates on batteries or on the mains and can therefore be used on every vehicle.

FMA Evaluation Software

The FMA software was developed by SIEMENS for post-evaluation of height and stagger measurements. We then developed it further to offer the OVHWizard system user the following possibilities by direct interaction with the OVHWizard software:

  • Checking the specified basic data of the line
  • Combining the measured data with existing measured basic data of the measuring line
  • Synchronisation of the measured data with existing line data
  • Automatic determination of pole and dropper positions
  • Determination of the tolerances for the measurement by design types from the railway regulations (e.g. Re 160, Re 200, Sicat etc.)
  • Monitoring of the permissible wind deflection
  • Monitoring of the span length steps and the gradients
  • Creation of a report according to railway specifications
  • Comparison of the measurements with and without uplift and determination of elasticity
  • Creation of a list of necessary corrections with values for the correction

After recording a measurement with the OVHWizard software, the FMA software is started with it and the measurement file is read in. The project data such as line designation, track, measured section, type of contact line, rated contact wire height, wind velocity and data for the later output format for this measurement file are then loaded. Then the previously tested basic data for track and contact line are loaded. The basic data can be viewed together with the measured data in a preview. Then the basic data and measured data are shifted manually over each other at significant points at the beginning and end of the measurement and then synchronised automatically. This eliminates any differences in the distance measurement by measuring wheel slip or inaccurate specification of the wheel diameter.

The software then automatically determines the deviations from the specifications at the pole and dropper locations and writes this deviation as an error code in different colours to the pole locations or the span length step according to whether a warning or tolerance value is exceeded.