And while a bridge can inexplicably fail, we tend to assume all the structures are usually magnificent engineering triumphs.

Often they are achieved in the face of what initially might seem like impossible obstacles.

Take the first bridge over the Hawkesbury River, for example.

I’m not talking about the familiar old Pacific Highway road traffic bridge from 1945 (now duplicated), which thousands of motorists rely on daily.

The first bridge was actually an impressive rail bridge back in the 1880s, downstream of the present old and new road bridges stretching between Mooney Mooney Point on the northern bank of the river and Kangaroo Point on the southern shore.

However, the first rail bridge, although ornate, still pales in comparison with modern bridges, many of which exhibit beautiful symmetry, even classical beauty, built worldwide.

But when the Hawkesbury River’s first rail bridge was opened in May 1889, it was a 19th century wonder and hailed as being the third largest in the world.

Five of the bridge piers reached record depths of up to 160ft (48.7m) to enable the structure to span almost 3000ft (890m). 

More than 100 years have passed, and this bridge no long exists (well, only in part).

After finally detecting problems, a second rail bridge had to be erected and it was finally opened 72 years ago next month, on July 1, 1946.

So, what happened?

Rail passengers travelling to Sydney from Newcastle today can still glimpse the original, impressive, tall sandstone pillars parallel to the existing line. They will see them if they glance out the window while crossing the serpentine waterway to Long Island before entering a tunnel to soon whiz by the sleepy hamlet beside Hawkesbury River Station (Brooklyn).

And why is the riverside village called Brooklyn, anyway?

The clue lies in the fact that the first rail bridge was built by the Union Bridge Company of Brooklyn, New York.

While now long stripped of a metal framework, this first bridge’s graceful, now orphan, stone pillars march across the mighty Hawkesbury River. Seeing them, often causes people to ponder, “Why was it replaced?”

Rail historian Bill Phippen OAM knows the story well.

He has just released a 350-page, coffee-table book explaining that, despite the apparent solid nature of the elaborate 1889 bridge, “it proved to be badly built and its complete replacement became necessary by 1939”.

With fast-flowing currents, a deceptive river bottom hiding bedrock far beneath, it’s a treacherous area to build any bridge, let alone one that must provide a reliable lifeline for goods and people to the north and vice versa.

It’s also vital to the Australian economy.

The Hawkesbury River 1889 connection was the final link in the rail connection between Brisbane, Sydney, Melbourne and Adelaide.

Phippen reveals that the deep foundations for the new second rail bridge in the flooded river valley “took the greater part of nearly seven years the bridge took to build”.

His book for the Australian Railway Historical Society (ARHS) reveals that the two rail bridges, however, never operated together, despite the impression from some 1940s photographs.

Phippen reveals the last train running over the old bridge was from Sydney. It then reversed at the northern end and came back as the first train over the new bridge.

Writing in a book preview in the May issue of Australian Railway History magazine, Phippen said amazing results were achieved during construction.

Foundations were thrust deep into the hard river silt before 1500-tonne steel spans were floated out by barge from shore to mid-river in only and hour, or two, ready to be lifted into position.

Dismantling of the old bridge then began in 1947. Six workers died constructing the new bridge.

For the record, we also tend to overlook the potential hazards of such a major undertaking in wartime. In this case, World War II.

At the opening of the second Hawkesbury River rail bridge in July 1946 (after WWII had ended), the then NSW premier William McKell made some interesting remarks.

McKell said the body of the captain of one of the Japanese midget submarines, who died attacking Sydney Harbour in May 1942, was found carrying a map of the Hawkesbury rail bridge, presumably to destroy it.

Meanwhile, NSW railways bosses also had prepared their own plan a year earlier in case the Japanese invaded. 

Luckily, they didn’t. 

WHILE on the subject of the Hawkesbury River, an important new book on a well-known, yet almost unknown site near the twin road bridges has been published.

The book, Peat Island, Dreaming and Desecration (Wakefield Press), by retired academic Adrian Mitchell tells what he calls the “sorry story” of little Peat Island, an institution for the mentally ill for more than 100 years.

The author writes of the now abandoned site still looking dark and brooding. Over the years, while still operating, it had become “almost a parody of institutional awfulness”.

To the public, the place always seemed secretive, sinister almost, and the subject of occasional lurid press reports.

Rather bizarrely, however, Peat Island’s prime location enjoys one of the most beautiful vistas along the Hawkesbury.

Mitchell writes: “It was decommissioned in 2010; quite empty now, it remains a locked facility just as it had always been”.

And eerie.

“The last residents were dispersed into the wider community. In this, they echoed the fate of the Darkinjung people, original custodians of this country – their community was scattered just as intentionally and effectively, if not quite so brutally.

“It is not one of the NSW government’s finest accomplishments,” Mitchell says.

Yet, he relates, for all the unhappiness, Peat Island was once home to more than 3000 residents and gradually became a happier place, even as it rapidly aged to become “a bureaucratic nightmare and a political football”.

It’s a well-written and researched book, but one suspects that had more people been willing to tell their tales, it would have be an even greater, more insightful, work.

Mitchell himself questions whether the book project should have even been attempted, with the topic being so acutely painful and distressing for many.

“But then, its complicated story ought to be told,” Mitchell concludes.