THE HAWKESBURY BRIDGE.

Otago Witness, Issue 1957, 23 May 1889, Page 3 (Supplement)

THE HAWKESBURY BRIDGE.

The recently-opened bridge over the Hawkestary river in New South Wales, which forms fte connecting, link ia railway communication from Adelaide, Melbourne,' and Sydney - to Queensland, is built on the deepest foundations in the world. From the top of the piers to the k>ttom stone measures over 200f fc, , the foundations resting on a sandy base, reached after deep sinking through mud and silt. It has a clear headway of 40ft at high water. The contract price was £367,000, the Union Bridge Company, w New York, securing the contract. It has »eea an undertaking of a magnitude which few °f those not interested can comprehend, and its Successful completion has been the more wonderful when it is considered that the whole superstructure has been put together on Dangar "land and then pontooned a distance of 4000 ft Jj° its present position without any serious accioent to any of the 150 workmen employed (escept a recent fatality to a paipter) or any "^calculation in the work performed. The first *ork done was the constructing of the pontoon J}P«n which the spans were to be put together. was a task uniqne in itself, for *• pontoon is the largest in the w °rto\ it is |65ft long, eiftf wide, and

10£b deep, the hull being a continuation of watertight compartments. It was capable of* bearing 7000 tons burden. On this pontoon, trestling 35ft in height was erected, and on the trestling the seven spans of the bridge were riveted and pinned together. The bulk of the ironwork was shaped and riveted in Glasgow, and shipped out reafly for fitting. The lbngitudinal bars, however, had peculiarly-made eyes through which the pins pass. These eyes were punched by special process in New York. A substantial pier was constructed at the island, and the pontoon, which it was predicted would never be floated, was safely placed near the pier. On this jetty the ironwork was landed, and some of the parts/weighing as much as 12 tons each, were hoisted in bo position, in some instances as high as 110 ft, and then properly connected. Each span weighed 1000 tons, and when completed was borne away on the pontoon and rested in position on the stone piers as part of the railway bridge. There are six pier sin the bed of the river, and seven spans in the bridge, the latter measuring in length 416 ft, and in width 30ft, giving ample room for carrying a double line of railway built to 4ft B|in gauge. The total length of the bridge, therefore, is 2912 ft, or more than half a mile. From the rails to the highest part of each span is 58ft, and from this point the space is reduced by a broken ourve,'the minimum height being about 40ft at the extremities of every span. The spans rest on pedestals bolted into the stonework of the piers. When the sixth span was being cabled across, a strong wind proved too much, and sent the pontoon and its immensely heavy freight, notwithstanding the letting go of three tremendous anchors, in an entirely opposite direction to which it should have gone. This misfortune created delay and almost overwhelming anxiety to those concerned ; as well it might, for the destruction of a span would mean a dead loss of money to the extent of nearly £60,000. The work has proceeded with almost uninterrupted smoothness, from the date of constructing the caissons until the opening.