Overhead line geometry – contacting system (pantograph)

Overhead line geometry – contacting system (pantograph)

This product accurately measures the pantograph interaction with the overhead lines.

Monitoring overhead lines using a pantograph or contacting system is useful if the measurement parameters you require include the contact force, as this is the only way to achieve this. This product is used in addition to an acceleration-based system, which will measure impacts between the pantograph and the overhead lines. Measuring the contact force can indicate where the tension in the overhead lines is incorrect and where little or no contact force is measured and areas where there is potential for an electric arc to be created between the two.

How it works


Each pantograph is different and fitting a series of load cells to the pantograph can be an engineering challenge, particularly as the aerodynamic performance cannot be altered. Traditionally, measurement devices are fitted to each end of the pantograph carbon although a series of fibre optic strain gauges can be fitted underneath the pantograph carbon and are less intrusive.

Irrespective of the design, the measurement devices react to the force applied to them; this is a combination of the pantograph uplift force, the tension in the overhead lines and the aerodynamic force acting on the pantograph aerofoils. Mathematical processing of the output can also be used to determine the lateral position of the overhead lines with respect to the pantograph.

Key features


  • Measures the interaction between the pantograph and the overhead lines
  • Also can produce overhead line stagger measurements
  • Additional overhead line height measurements can be added
  • Can identify low tension in the overhead lines and potential electric arc issues



  • Only means of continuously assessing the pantograph/overhead line interaction
  • Only a small number of vehicles need to be fitted to cover the network