Experience
Aitken & Partners specialise in communications engineering in the railway environment. With more than 25 years of experience, covering most Australian railways, we are very familiar with the environment.
The principal, John Aitken, is a qualified and experienced engineer with specialist training in electromagnetic compatibility engineering (EMC). He is the author of the Australian Standard for train radio communications, AS7660 and has written a number of technical papers associated with rail systems. John is a past chairman of the Institution of Railway Signal Engineers Australasia (IRSE) and has been a member of the IRSE international council. He has attended specialist training in EMC in the USA and Australia.
We are familiar with the requirements of EN50121, the international standard for EMC in railway applications and have performed analysis and tests in accordance with this standard. We have worked with the ATCS specifications for EMC and have designed and tested in accordance with those specifications.
Equipment
Aitken & Partners has a full set of measuring antennas for the frequency range 9 kHz to 6 GHz. These antennas include a rod and loop for the lower frequencies, a biconical, log-periodic and horn for the highest frequencies.
We have a Rohde & Schwarz FSL6 spectrum analyser and specialist equipment for television and AM radio measurement.
This set of equipment enables us to perform radiated emissions testing in accordance with EN50121 - Railway Applications - Electromagnetic Compatibility.
Experience
Most recently Aitken & Partners have been preparing an EMC plan for a railway operator's new freight operations. This work has required desktop analysis of sub systems and then field testing of radiation from the trains.
Much EMC work relates to investigation of problems. One of our more interesting projects was investigating EMC problems with electro-pneumatic braking systems. For this project we worked with Andrew Blakeley-Smith and Associates. The investigation revealed layers of interacting problems, most caused by equipment that complied with the relevant standards. Put together as a railway system it did not comply and problems arose.
The more successful train radio projects start with an EMC analysis. Aitken & Partners developed coverage guidelines for RailCorp electrified track through analysis and then testing of the noise contribution of the traction system. That work on DC systems established the standard for RailCorp and was followed by a similar exercise for Perth Electrification, this time for an AC system.
Desensitisation and intermodulation are important aspects of mobile communications that are often ignored. With the restricted real estate available on a locomotive careful analysis and antenna placement is essential. Aitken & Partners did this for Teknis International Railroad Systems, when we analysed the electromagnetic compatibility of the several voice and data radio systems to be installed on Australian National locomotives. This included selection of antenna locations and measurement of the coupling between the antennas. We have performed similar work for Westrail, Perth Electric, RailCorp and Pacific National.