Temperature variations occurring in the contact wires and other conductors (e.g. catenary wires, feeders, auxiliary and supply wires, earthing wires, etc.) during operation, can be investigated via simulation using the software tool CONTHERM. The following is used as input data:

• The geometrical and material properties of each individual wire
• The relevant environmental parameters (such as ambient temperature, wind speed, etc.), and
• The variations of load against time for each conductor, as calculated by FABEL and SIMNET.

CONTHERM provides a numerical solution for the non-linear equations of heat transfer. The variations of the electrical resistance of the wires with temperature are taken into consideration, as are the variations of the system time constant with temperature.  Environmental factors such as ambient temperature, wind speed and exposure to sunshine are also taken into consideration.

CONTHERM has been extensively validated against measurements on numerous occasions. It has been successfully used for network investigations on AC and DC railways