11/10/2026
https://www.facebook.com/photo.php?fbid=122149108479144889&set=a.122117371473144889&type=3
"The span, unassisted, was gazed at with admiration," the Sydney Mail reported from the Hawkesbury River in 1888.
People had reason to stare. That morning the same steel span, more than 400 feet long and about 1,000 tons, had set out across the water standing on a timber trestle on a floating pontoon. Now it sat on its stone piers, and the pontoon had slipped away from underneath.
Nobody lowered it. The tide did.
That was the whole method. The pontoon was floated in with the span riding high on its trestle, brought into position over the piers, and then the men waited. As the tide fell, the pontoon sank away with the water and left the span resting on the stone. One photograph in the contractors' album is captioned simply "Span waiting for spring tide of 8'-6"".
The obvious way would have been to build each span in place, on timber scaffolding between the piers. That was the plan. But the bedrock of the Hawkesbury lay far below the water, under mostly silt and sand, and the nature and depth of the river bed changed the plan. Therefore the spans were built somewhere else and brought to the piers.
Somewhere else was Dangar Island, about a kilometre downstream. The contract had gone to an American firm, the Union Bridge Company, and the steelwork was put up by Ryland & Morse of Chicago. They landed on 7 April 1887, and their first job was the pontoon: an iron box 335 feet long, 61 feet wide and 10 feet deep, divided into 44 watertight compartments with valves so it could be made to rise or sink. The stone piers stood on foundations sunk about 180 feet below the water, the deepest bridge foundations in the world at the time.
On the trestle, about 60 men on average put the first span together. Some pieces weighed as much as 12 tons and were hoisted 110 feet by two steam engines. Almost nothing was riveted on site. The parts were joined with pins, the American way: get the pieces into position, put a pin through them, and that joint was finished.
The first float came on 25 May 1888. At half past seven in the morning the pontoon moved off from the island, hauled along a cable by a steam winch, with steam launches alongside. By half past ten the span was in position, and the men were waiting for the tide. At twelve o'clock it was down on its piers.
Six more had to follow, and the river did not always cooperate. One span was blown off course, but the anchor cables set into the river bed held fast, and it was put in place when the weather improved.
On 1 March 1889 the seventh span went onto its piers. The Hawkesbury was bridged: seven spans and six piers, 2,900 feet long.
The bridge opened on 1 May 1889, and for the first time a passenger could travel by train between Brisbane, Sydney, Melbourne and Adelaide. That afternoon 600 guests sat down to speeches and toasts in a banqueting hall built on board the same pontoon that, only weeks before, had carried the spans out from Dangar Island.
