Telstra celebrates 100 years of automated exchange switching (or, why we need the NBN)

On 06/07/2012 by Ron

In 1912 the first automated telephone exchange was installed in Geelong. Australians connected to the exchange could dial one another directly, without the need for an operator to patch the call. This was amazing technology in its day, and only the second such system to be installed in the British Empire.

In its Request for Tender, the Postmaster General’s Department specified that the new equipment:

shall comprise everything necessary for a complete and efficient system of operation between the subscribers connected to this proposed switchboard at Geelong and those connected to other Exchanges in the other networks, so that intercommunication may be given between the subscribers on the different Exchanges with ease and expedition.

Telstra’s Exchange blog has an article which includes a terrific slide show of historical photographs – well worth a look.

Early relay sets

Early relay sets in an automated exchange (source: Telstra)

What’s changed in 100 years?

Obviously, lots has changed. But the answer “not much” is also valid.

It’s been a long time since we needed an operator to connect our local calls and trunk calls. We now have 4G mobile telephones, PABXs, satellite and optic fibre systems, video calling, Voice over IP and digital radio networks.

But readers with a technical background may have noticed the wire wrap, or “tag frame” distribution in some of the old photos. This was state-of-the-art technology at the time, and telephone technicians are still using tag frames today in MDFs, road-side pillars and campus distributors.

If anyone asks why we need a National Broadband Network in Australia (like this guy), the photos on the Telstra blog paint a great picture. The technology we’re using today, between our homes and our local telephone exchanges, is literally 100 years old. Copper wire was designed to carry a single analogue conversation, and in the 21st century, our need for fast, always-on internet has outgrown the Plain Old Telephone Set.

Certainly the automated telephone exchange had its naysayers in 1912: “some of the subscribers have not yet mastered the new system of turning the discs round to secure the numerical combination for each subscriber dialled…” (SMH 23/07/1912). But the visionaries of the time recognised the importance of an automated voice network, and commissioned the best technology at the time for the greater good.

Comments are closed.