REGISTER

John Aitken BE AMIRSE

Aitken & Partners, Consulting Engineers

In October 1877 Bell published construction details of his telephone invention. A NSW Railway engineer, Mr Cracknell built a copy and transmitted words and music by telephone over the telegraph wire from West Maitland to Sydney in December 1877. It was an era of excitement and delight in engineering. Morse code had become a mature technology, voice systems were spreading and soon de Forest's vacuum tube triode was to make amplification possible. Transmission systems were no longer limited in distance and the engineers had visions of linking the continent by telegraph and telephone.

The visions were gradually realised, though not without difficulty and dedication. The work practices of those days would not be considered now'. New engineering problems were found, analysed and solved, as communication systems grew in complexity and expanse. Some of the problems were unique to railways and a few were unique to Australia (at that stage). From these beginnings railway communications have embraced analogue carrier telephony, radio, optical fibre and digital camer systems for radio and cable. Mobrle radio has been implemented for train control, security, maintenance and administration. Some of these developments are described and discussed in this paper.