The New Zealand Railways Magazine, Volume 3, Issue 1 (May 1, 1928)
Sydney's New Harbour Bridge
Sydney's New Harbour Bridge.
“Through the courtesy of Dr. Bradfield, the designer, and Mr. Ennis, the chief engineer of Messrs. Dorman Long, the contractors, I was afforded the opportunity of viewing what I consider is one of the most impressive features of Sydney,” continued Mr. Lynde, “namely, the new harbour bridge, which is to be the largest bridge undertaking in the world. This will provide a broad highway for railway, vehicular, and pedestrian traffic between the city proper and the northern suburbs. The great expansion which Sydney has witnessed in recent years made the provision of either a high level bridge or a subway necessary. Public opinion was greatly in favour of the high bridge idea, the high rocky foreshores on either side of the harbour facilitating this method. The clearance was fixed at 170ft. at highwater, which will enable the masts of the largest steamers trading, or likely to trade to Australia, to pass under the bridge without any obstruction from it. This headway is 35ft. greater than that provided under the Brooklyn Bridge and other viaducts across the East River, New York, and is 20ft. greater than that provided at the Forth Bridge of Scotland and the Quebec Bridge of Canada. It is estimated that when working at its maximum capacity 168 electric trains, 6000 vehicles and 40,000 pedestrians will be able to cross the bridge in an hour. The bridge provides for four lines of electric railway, roadway accommodation for six lines of vehicular traffic, and two footways each 10ft. wide. There is no provision for tramway services across the bridge. Each line of railway is designed to carry two electric locomotives weighing 160 tons each, followed by a train 1000ft. long weighing one tonper foot; four adjacent axles of the locomotives each having a load of 25 tons. The type of bridge is that of the two-hinged arch, this being the most rigid type which could be constructed. The bridge now under construction will have five steel spans at either side of the harbour, and will cost over £4,000,000. The approaches are of concrete, partly arched viaduct, and partly earthen embankment between concrete retaining walls.
The photographs included with this article give some idea of the rapid progress being made in the construction of this great viaduct which will serve to carry the railway lines emerging from the underground railway that now make Sydney's passenger traffic so much simpler than it was when surface travel was the only means available for traversing the city.”
Mr. Lynde was indebted to the railway administrations in the States visited for the splendid opportunities given him of inspecting transport development in Australia.
“I cannot say too much,” said Mr. Lynde, “in regard to the wonderful courtesy shown by the Railway Commissioners, Chief Mechanical Engineers, and other administrators towards me, as New Zealand's representative, during my recent visit.