Thing you never knew about iconic Harbour Bridge
THEY say you learn something new every day.
But if you were to take a look at one of Australia's most revered and photographed landmarks - the Sydney Harbour Bridge - you might be called crazy if you said the 85-year-old Goliath did the same.
It turns out the iconic mass of concrete and metal has its own digital version of a brain and it is learning information every day to keep the millions of Aussies who use it safe.
That's because it is lined with more than 3000 sensors which feed into an Artificial Intelligence (AI) system.
One of those who is part of the operation to install and monitor the sensors, Doctor Fang Chen - who is a thought leader in AI and Human-Machine Interaction - told news.com.au they are essential if our beloved treasure is to survive.
She said there are a number of different sensors feeding into the system and there are plans to keep adding them all the time, but the most important ones detect vibrations.
"These essentially measure movement," she said.
"When cars, buses or trains drive through it triggers the bridge to move and shake a little bit.
"What these sensors do is record all this movement and then they will determine whether this movement is within a healthy range.
"This AI system has learned a lot in terms of what type of movement is a healthy movement. So, they will indicate whether there is some sort of crack or something which needs to be checked."
Since the bridge first opened to allow awe-struck Sydneysiders to walk, drive, cycle and ride across it in 1932, it has stood strong despite everything its evolving host city has thrown at it.
And, as tragic events in Italy have recently shown, the safety and maintenance of such a major structure cannot be underestimated.
That's why, five years ago, Dr Chen and a her team of AI boffins began loading it up with these sensors, which she compared to a medical device which checks on the health of an ageing person.
She says the tourist attraction has been learning ever since and it now knows whether the bridge's movement is cause for concern or not.
It now knows that certain vibrations mean something is wrong and it sends an alarm to a Roads and Maritime Services team who can either close lanes, send workers to check on the issue or, if it is dangerous, close the bridge altogether.
Despite it being something thousands of us stare at, take pictures of and travel across every day, Dr Chen says there are many mysterious elements to the bridge which nobody yet understands.
One of these is the effect of the sometimes harsh, sometimes beautiful Aussie weather on its health and that's why there are hundreds of weather sensors which feed into the AI system too.
"In the short-term, it is very hard to see whether hot weather will have a significant impact," Dr Chen said.
"Over a longer time, for example when the environment is getting hotter and hotter - we can see what this is doing and we can change our response.
"But we really don't know how weather is impacting the bridge yet. It is a long term monitoring issue."
There are plans to keep adding sensors to the bridge as the iconic structure approaches its 90th birthday and Dr Chen says we should look after its health like we would an ageing person.
"It's like we're giving the bridge a blood test and checking what the health of the bridge looks like," she said.
"85 is old for a man or woman now, but by then we will have learned a lot about our health condition and deterioration in our 20s, 30s, 40s and 50s.
"But, in terms of bridges, the Sydney Harbour Bridge is relatively new and undiscovered.
"So what should an 80-year-old bridge's health should look like? This should be a fundamental question for our society.
"But at least with these sensors you know, with the current loading, how the bridge is responding now."