EMFCALC is a program to calculate the magnetic field in the vicinity of a railway corridor and/or transmission line. The distribution of current in the various conductors as calculated by SIMNET, serves as the basis for the EMFCALC calculations. EMFCALC generates a graphical representation of the flux density for any cross-section of the railway corridor/transmission line under study.

Knowledge of the magnetic field in the vicinity of a railway line is of importance in the following cases:

• Assessment of the interference from overhead line systems on telecommunication wires and signalling systems.
• Investigation of interference from neighbour railway lines. This is of particular interest for AC and DC railway lines running parallel to each others.
• Compliance with environmental regulations. The increasing awareness of the impact of electromagnetic fields on health, has led to various countries setting emission thresholds for magnetic fields due to electrical installations. The railways must also adhere to these regulations. EMFCALC allows the expected magnetic fields to be calculated at design stage before the construction or electrification of a line.