The $2.1 billion Sunbury Line Upgrade between Sunbury and Footscray will enable more modern trains to run on the line once completed. The upgrades will create an end-to-end Sunbury to Pakenham/Cranbourne rail line linked by the Metro Tunnel.

Power upgrades are required along the line to support the movement of 113,000 extra passengers every week. New traction power substation locations were proposed to supply more power to the rail network.


Middleton Group were asked to determine whether the electromagnetic fields emitted from the new traction power substations posed a risk to public health or to equipment sensitive to magnetic fields.


To solve the challenge at hand, Middleton Group measured the electromagnetic fields at two existing substation locations and six proposed substation locations. Advanced testing instruments were used to provide accurate and reliable results across an extensive frequency range.

In particular, magnetic field readings were measured for the static magnetic field. Time-varying magnetic fields ranged from 1 Hz – 400 kHz, while electric field readings were measured for time varying fields from 1 Hz to 40 GHz.


Our results provided Metro Trains Melbourne (MTM) with an overview of the maximum electric and magnetic field readings against the recommended exposure limits set out in the guidelines by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These readings provide a baseline that will be used for future measurements once the proposed traction substations are entirely constructed.