It’s an icon of Australia and a beacon to tourists around the world.
The Sydney Harbour Bridge is celebrating 90 years since it opened to the public on March 19, 1932.
See the Sydney Harbour Bridge’s history come to life in the video above
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It’s been described as a wonder of engineering, built for 6.25 million pounds in the currency of the day - nearly twice the original estimate.
Today, about 160,000 vehicles and 480 trains cross the bridge daily.
But it was some 130 years in the making before the first person crossed the bridge.
Dr Ian Hoskins is an historian and the author of the book Sydney Harbour: A History.
He has written that the “first mention of a bridge across Sydney Harbour appeared in 1789, just a year after the First Fleet arrived”.
“Governor Arthur Phillip’s description of the harbour ... in dispatches back to London inspired Erasmus Darwin to write a poem about the arrival of ‘hope’ on the other side of the world,” Dr Hoskins wrote.
“In an extraordinary bit of lucky prophecy, Darwin spoke of a ‘proud arch’ across the harbour.”
While a design for a single span bridge was drafted in 1857, there was no way it could have been achieved with the technology available at the time.
Over the next 50 years, there would be a number of different designs for a bridge.
One was from Dorman Long & Co and resembles Brisbane’s Story Bridge, while another design would have linked Balls Head, Miller’s Point and Balmain with a central tower on Goat Island.
It wasn’t until John Bradfield was appointed Chief Engineer for the Sydney Harbour Bridge and City Transit in 1912 that plans started to firm up.
“John Bradfield was the key figure in pushing for the bridge that was finally built and the key person approving its design,” Hoskins said.
“The arch bridge that was finally decided upon in 1924 was designed by Ralph Freeman who worked for Dorman Long, the winners of the Bridge tender.”
In preparation for construction, the government resumed hundreds of commercial and residential properties on both sides of the harbour, affecting thousands of people.
The first sod was turned in 1923, then tonnes of stone steel were used to complete the project.
Jeremy Hards is Director of Roads Maintenance, Sydney Harbour Bridge and Precinct, at Transport for NSW.
“About 40 per cent of the steel supply was provided by BHP, so locally Australian manufactured,” says Mr Hards.
“The other 60 per cent was serviced from the UK, so there was a lot of logistics involved there.
“The granite blocks you see on the northern and southern pylons were all sourced from Moruya on the NSW south coast.”
An important part of the design was the single span, allowing ships to cross underneath unobstructed.
At the time, perfectly calculating - and joining - the arch was considered an extraordinary achievement.
Raymond Daly is Project Engineer, Sydney Harbour Bridge and Precinct, at Transport for NSW.
“They didn’t have the computer aided technology (or) the fancy surveying tools,” Mr Daly explained.
“But they managed to get that precise, spot on.”
According to Dr Hoskins, the arch was the first part of the bridge to be built.
“It was constructed from both sides so that the arch was joined in the middle,” he said.
“Once the arch was joined, the platform which would support the road, train and tram tracks could be built.”
Over the next decade, 40,000 tonnes of steel and six million rivets would go into completing the Sydney Harbour Bridge.
But it wasn’t all smooth sailing.
“There were strikes and stop-works throughout the construction,” Hoskins remarked.
“Sixteen men died out of a workforce of 1,600 – itself remarkable given the absence of modern safety equipment.”
Then in March 1932, celebrations began in anticipation of the opening of the bridge.
Fifty-two thousand school children were the first to walk across on March 16, ahead of the big day on March 19.
“There were two ribbons,” Hoskins said.
“One on the south side, officially cut by NSW Premier Jack Lang after the right-wing protester Francis De Groot slashed it with a sword, and another on the north side, cut by the North Sydney Mayor Hubert Primrose.”
It’s estimated that 600,000 people - half of Sydney’s population at the time - turned out for one of the city’s biggest ever days.
Twenty-one thousand cars and 80,000 passengers then crossed the bridge the day after it opened, with more than 1.1 million vehicles using it in the first three months.
It also became Australia’s first toll bridge - something the then premier, Jack Lang, announced only three days before the opening.
Crossing the bridge in 1932 cost six pence for a car (roughly equivalent to today’s $2.57), plus another six pence per adult passenger, or three pence per child.
Bikes and motorcycles were charged three pence ($1.28), while heavier vehicles had to pay between two and three shillings ($10.26 - $15.40).
For the first six months, toll collectors had no shelter - standing on the bridge in rain, hail or shine to take up money.
In June 1934, canopies were erected to help protect toll staff from the weather.
It wasn’t until 1949 that the familiar toll booths were installed.
In July 1970, one-way tolling was introduced, with tolls then collected only from southbound traffic.
In 1993, the Sydney Harbour Bridge began the first trial of electronic toll collection in Australia, using 1,000 tags and six toll lane ‘readers’.
The trial was deemed a success, more than doubling the number of cars that could pass through toll booths per hour.
Over the next six years, 30,000 electronic tags were issued.
From January 11, 2009, the bridge became cashless, leaving the imposing toll booths empty and obsolete.
“Traffic greatly improved,” Transport for NSW’s Raymond Daly said.
“So you didn’t have that constant stop, start, stop to put money in or, later on, the e-tag, but it fixed a lot of the lane-filtering issues.”
in 2017, the southern toll booths were removed, followed by the northern booths in 2020.
There’s no doubt the Sydney Harbour Bridge is an icon, so it’s no surprise it’s heritage listed.
But did you know the colour of the bridge is also heritage listed?
“Sydney Harbour Bridge grey - it’s actually called that,” said Transport’s Jeremy Hards.
“You can’t buy it anywhere, it’s not on any colour chart.
“ It’s a special paint that’s only made by one supplier.”
Repainting the iconic bridge is by no means quick.
“There’s 485,000 square metres of steel that needs painting, so it takes a bit of time - give or take about 30 odd years if we hit our meterage targets.”
About 120 people work full-time on the structure, including around 100 painters, riggers, electricians, fitters, metal fabricators and engineers.
Iconic Aussie actor Paul Hogan famously worked on the bridge in the early 1970s.
“There’s 4,500 individual elements that we we’ve broken the bridge into and each one of those elements gets inspected at least once every two years,” Mr Hards said.
So after all this time, does the bridge still have a lot of life left in it?
“It’s well and truly over-engineered,” Mr Hards said.
“The amount of traffic that it carries now - the modern trains that we have, the trucks that cross the bridge - by no means have we exceeded limits of the bridge capability.”
As well as being a vital piece of infrastructure, the Sydney Harbour Bridge has become a popular destination for domestic and international tourists.
Every year, the world watches on as Australia is one of the first cities to ring in the new year, heralded by an epic fireworks display with the bridge at the centre.
As well as taking in the water views and enjoying the restaurants and bars around the harbour, tourists can even climb the bridge to see the view from the top.
BridgeClimb was founded by Paul Cave in 1998 and more than four million people have now ascended the famous structure.
“People really do see this as the heart of Sydney,” said Deb Zimmer, CEO of BridgeClimb.
“When [people] watch the New Year’s Eve fireworks ... it’s something that you always want to see.”
Over the past 24 years, some famous faces have made their way up the bridge.
“Oprah Winfrey was one of the bigger ones (and) Prince Harry,” Zimmer said.
BridgeClimb has also recently launched the Burrawa climb, an Indigenous storytelling experience.
“We launched this with the blessing of quite a few of the key Aboriginal people in Sydney.
“They’ve been amazing, giving us all these stories, their perspective from the top of the bridge and what all these moments mean to them.”
It’s hard to know where Sydney would be today without the harbour bridge as we know it.
“The bridge defined Sydney and indeed Australia,” Ian Hoskins said.
“It changed the scale of Sydney Harbour - it made it smaller visually, simply by its sheer size.
“But it also connected north and south and thereby diminished the separation of the two parts of the city.”
For Deb Zimmer, the bridge is a way to sell Sydney and Australia to the world.
“It really is a drawcard - we are just talking about shooting the latest Tourism Australia ad,” she said.
Watch the 7NEWS special Sydney Harbour Bridge 90th Birthday now on 7plus.