'Engineering a City' walking booklet: Keith takes a stroll around some of the engineering marvels of the Adelaide City region of South Australia

The GPO is one of South Australia's most important buildings - everything is measured from there. The Post Office and lots of other city buildings stand as testament to early ingenuity and a new booklet, "Engineering a City" takes us on a tour of Adelaide and its engineering gems.

Its writer is retired engineer, and self proclaimed 'forensic heritologist', Richard Venus.

Richard Venus, 'Engineering a City': "If you want to talk about engineering history freaks you have to begin at the GPO and the story of Charles Todd. He was at the forefront and the GPO is a place of technical revolution and communication revolution."

The big one for Todd of course was the Overland Telegraph. The Engineering community is still in awe of Todd and there's a plaque on the GPO to prove it. And rightly so because in 1872, as Superintendent of Posts and Telegrams, he oversaw the completion of the link between Adelaide and Darwin. Australia was connected to the rest of the world and the first telegraph messages from overseas were received in the Chief Telegraph Office on the first floor of our GPO.

Richard also explains there's a South Australian connection every time you post a letter. "Before Federation all of the states printed their own postage stamps and in South Australia it happened down in the GPO basement." The perforating machine invented and built by local firm, Southcotts went on to process all of Australia's stamps in the early years of Federation.

Around the corner in Franklin Street another triumph of the 'can do' profession - the old telephone exchange.

Richard Venus, 'Engineering a City': "After words being sent down telegraphs we have voice. The telephone exchange was in a corner of the telegraph room but as more and more subscribers came they had to find a home for it in Franklin Street. The central exchange had 48 subscribers and within a year there was 1,000 miles of telephone line."

On Victoria square we find another example of engineering ingenuity. In 1979 the old Marine and Harbors building was jacked up, put on rollers and carefully inched 34 metres north to make way for a new building. It's another spectacular example of the engineering 'fix it' mantra.

Richard can also put to rest one of Adelaide's great myths - tunnels under the city. "The whole bit about the telegraph is that we had communication within days rather than weeks. After a while that wasn't good enough - we needed to get messages even faster and for someone to go from the Post Office to the Stock Exchange on foot took too long so they put a pneumatic tube system underneath the streets of the city. So you'd write your message - put it in a little cylinder - whoosh - it would arrive at the stock exchange."

In the corner of Victoria Square (adjacent St Francis Xavier Cathedral) Richard points out a small metal dome like protrusion from the lawn. "This is a permanent Benchmark. This one has been set at about 53 feet above low tide mark at Port Adelaide. That's the reference point it allows the pipe-layers and planners and everybody working under the ground to know exactly what level they are at. There are more than 30 of them around Adelaide - you just need to know where to look.

It's just one of the many stories included in the great little booklet, 'Engineering a City'. More than 70 sites are listed so there's something for everyone. Written by Richard Venus, it's published by Engineers Australia with the help of the Adelaide City Council. Pick up your free copy from the Visitor Centre in Rundle Mall. If you have any further questions please email info@postcards-sa.com.au

'Engineering a City' Walking tour of Adelaide
Available from Visitor Centre in Rundle Mall

Published 1st August 2010