Hawkesbury River railway bridge

On 7 April 1887, the single track section of the Main North line was opened between Hornsby and the Hawkesbury River. Passengers and goods heading north now unloaded at the River Wharf platform on the eastern end of Long Island, transferring to the double decker, rear paddled-wheeled steamer General Gordon for a three-hour trip out to Broken Bay and up Brisbane Water to Gosford where the train service recommenced. Once the 1.7-kilometre-long (1.1 mi) Woy Woy Tunnel was opened on 15 August 1887, the boat trip was considerably shortened as the boat only had to cross the river and negotiate the lower reaches of Mullet Creek to reach Mullet Creek station.[2][3]

Hawkesbury River railway bridge (first bridge)
First bridge under construction in 1888
Coordinates	33°32′2″S 151°13′42″E
Carries	Main North railway line
Crosses	Hawkesbury River
Locale	Brooklyn, New South Wales
Begins	Brooklyn (south)
Ends	Cogra Bay (north)
Characteristics
Design	Riveted truss bridge
Material	Steel
Total length	887 metres (2,910 ft)
Water depth	46 to 49 metres (150 to 160 ft)
Longest span	127 metres (416 ft)
No. of spans	Seven
Piers in water	Five
Load limit	25 Cooper's e-value
Rail characteristics
No. of tracks	1
History
Designer	John Whitton
Constructed by	Union Bridge Company, New York
Construction cost	A£367,000
Opened	1 May 1889 (1889-05-01)
Closed	1946
Replaces	General Gordon, a double decker, rear paddled-wheeled steamer
Replaced by	Hawkesbury River railway bridge (current)
Location

The Union Bridge Company of New York was awarded the contract to construct the bridge in January 1886. The railways engineer-in-chief, John Whitton, who designed and built the railway was not invited to design the bridge due to fallout from a mid 1880s enquiry into railway bridges.[1] However, subcontractors were also involved in the actual construction work. The piers consisted of concrete below water with sandstone masonry above. The spans were assembled on Dangar Island and floated 1,500 metres (4,921 ft) or so across to the bridge site on barges.

The bridge had seven spans of 127 metres (416 ft) each for a total length of 887 metres (2,910 ft). Five of the piers were sunk to then record depths of between 46 to 49 metres (150 to 160 ft) below high water. The bridge officially opened on 1 May 1889.[2]

Design and construction of a replacement bridge commenced in 1939, due to concerns that the original bridge would not hold up to extra loading and traffic caused by transport demands of World War II.[1] Work commenced on the new bridge in July 1940 and despite best efforts it was not completed until after the war finished, opening for traffic on 1 July 1946. The new bridge was positioned 60 metres (197 ft) to the west or upstream of the original bridge and consists of eight spans in three different lengths and piers sunk to depths of up to 56 metres (183 ft).[7] New tunnels were bored through Long Island to the south and Cogra Point on the northern approach.[2][8]

The design, foundation work and fabrication of the new bridge were undertaken by the New South Wales Government Railways and over 500 men worked on the project, with six dying during construction. A plaque commemorating the lives lost is at the southern end of the bridge, at the northern portal of the 1946 tunnel through Long Island.[1]

The spans for the new bridge were constructed adjacent to the bridge site on the northern side of Long Island, raised to the correct height, placed onto barges and floated out to the piers at high tide. Upon completion of the new bridge, the old bridge was removed, however the sandstone capped piers remain to this day. The construction docks remain in situ.[2]

The current and former Hawkesbury River Rail Bridges have State heritage significance. It forms part of a railway precinct of exceptional significance, with elements in an outstanding setting that represent key events in the history of railway development in NSW and demonstrate high levels of engineering achievement and the changes in railway technology in NSW in the period between the 1880s and 1970s.[1]

The completion of the 1886 Hawkesbury River Railway Bridge saw the linkage not only of the significant Sydney to Newcastle Railway link but also in effect, the railway systems of South Australia, Victoria, New South Wales and Queensland were joined by continuous rail with the opening of the bridge. The Bridge was used by Sir Henry Parkes as a powerful symbol of Federation and he gave the address at the opening of the bridge, which has been claimed by some as his first Federation speech. The abutments and piers of the bridge as well as the 1886 Long Island tunnel are tangible reminders of these significant events and the symbolic power they had for people at the time not only in NSW but throughout Australia. Both the 1889 and 1946 bridges and associated infrastructure on Long Island also demonstrate the significant investment in the railway system of NSW in the late nineteenth and early twentieth centuries. The workmanship of both bridges demonstrates the significant pride and confidence in the railways at the time.[1]

The surviving sandstone elements of the former Hawkesbury River Bridge and the current Bridge have exceptional aesthetic value in their setting on the Hawkesbury River. The contrast of the man-made bridges and tunnels with the rugged and beautiful natural landscape of Hawkesbury River allows passengers and visitors to appreciate the engineering achievements of the railway line's construction. The vantage point of the approach to Long Island and the bridge also allows passengers to appreciate views of the natural landscape. Both of these factors have made the railway journey a destination in itself for generations of rail passengers.[1]

The 1889 Hawkesbury River Bridge, Long Island Tunnel, Woy Woy Tunnel and the heavy earthworks and tunnels of the Cowan bank were the key engineering works on the Sydney to Newcastle rail link (The Short North). Together they demonstrate a high degree of engineering achievement in building a railway line in difficult and dangerous terrain. The 1889 Hawkesbury River Bridge in particular was a major technical achievement at the time: it was the fourth largest bridge constructed in the world, one of its caissons reached 49m, had the deepest bridge footing in the world and it was the longest bridge in Australia, pushing bridge design and construction techniques to the limit. The bridge was also the first of the American designed truss bridges that were introduced to Australia in the late 1880s and 1890s and thus the first to utilise the American principles of lightweight bracing, pin joints and eye bar tension members. It was the only steel trussed bridge of its type in Australia when it was built and the first major use of steel for bridges with previous examples being built in wrought iron. Its remains are tangible evidence of the change in engineering technology from British to American at this time and the decline of John Whitton's British based design influence on the NSW railway system. There is enough extant fabric in the remaining abutments, piers and the Long Island tunnel to demonstrate the engineering achievements of the original Hawkesbury River crossing.[1]

The 1946 railway bridge was also a major technical achievement at the time of its construction, its large riveted steel trusses and its footings were still among the deepest in the world. It remains the longest purpose built rail bridge in the NSW network. The bridge itself as well as the remnant construction docks, platform and power station demonstrate the technical achievements in the construction of the bridge. The docks in particular provide direct evidence for the method of construction and the challenges associated with construction in this estuarine environment.[1]

Hawkesbury River Railway Bridge was listed on the New South Wales State Heritage Register on 2 April 1999.[1]

The bridge is listed as a National Engineering Landmark by Engineers Australia as part of its Engineering Heritage Recognition Program.[10]

• 
  Original and replacement under construction, c. 1945
• 
  First and second bridges side by side
• 
  Second bridge - a pylon from the first bridge can be seen in the background

• Historic bridges of New South Wales
• List of railway bridges in New South Wales

Wikimedia Commons has media related to Hawkesbury River Railway Bridge.

• Australian Encyclopaedia Vol II and VII. Angus and Robertson. 1950.
• "Article title". Australian Railway Historical Society Bulletin. XXXIII (541). November 1982.
• "Article title". Australian Railway Historical Society Bulletin. XVI (334). August 1965.
• Nock, Oswald Stevens (1971), Railways of Australia, Adam & Charles Black, ISBN 978-0-7136-1190-8