MEASUREMENT OF CONTACT PRESSURE BETWEEN PANTOGRAPH AND CATENARY

After a brief survey of the problems associated with current collection at high speeds and the conventional experimental methods used to study this phenomenon, the article describes a new method of measuring the contact force between the pantograph and the overhead line. The principle adopted consists of inserting dynamometers between the contact bars and the collector head in such a way that the aerodynamic behaviour of the pantograph remains unchanged. In addition, the equipment records the vertical acceleration of the head and the lateral position of the contact wire on the contact bars. Measurement noise is considerably reduced by the use of a digital telemetry system which also ensures electrical isolation between the overhead system and the laboratory. Tests carried out on a class 22200 Bo-Bo locomotive fitted with an AM 18 U pantograph are described and assessed. Other experiments have since confirmed the high reliability of this new measurement system.