The Hawkesbury River Railway Bridge, on the outskirts of Sydney NSW, was the third largest bridge in the world when it was built in 1889, and was the final link in the railway connection between the eastern colonies of Australia.?? Separated by a thousand kilometres of bush, the colonies could never have federated into a single nation without workable transport links between them. Henry Parkes said as much at the opening of the bridge, months before his famous Tenterfield address. The bridge was brought in sailing ships in tens of thousands of pieces from Glasgow and New York and assembled by American engineers and local workmen. Sadly the foundations were compromised and the bridge came close to collapse in 1939, at the time when Australia needed it most as a vital wartime supply line to the north. The Department of Railways of NSW continued to build a replacement bridge during the years of the war when other projects were abandoned for want of material or manpower. At the new bridge?۪s completion in 1946 it was perhaps the Railways?۪ greatest achievement, having been designed, fabricated and constructed completely within the organization.