NEW TRAFFIC BRIDGE.

Hauraki Plains Gazette, Volume XXXVIII, Issue 5086, 9 February 1927, Page 2

NEW TRAFFIC BRIDGE.

LARGE STRUCTURE FOR PAEROA.

DETAILS OF THE WORK.

Steady progress is being made by the Public Works Department with the new traffic bridge over the Ohinemuri River at Paeroa.

The structure, which is: being erected 30 feet down-stream from the present bridge, will have a total length o'f 300 ft, comprising four 30ft spans and three. 60ft spans. The deck level is to be 3f,t 6in higher than the existing bridge. The structure will be supported on two piers in the centre af the river, with six sets of piersi on either side. The two principal piers each consist of clusters of five piles, each pile being 14 inches in diameter and reniforced with concrete. The piles 'forming the clusters are 35ft long, and these .are driven into the river on the top of, a timber leader pile. The remaining six piers; comprise two piers, one on each edge of the river bank, consisting of two clusters each of four piles, and the four clusters each containing five piles. The work of driving the piles is a long and arduous undertaking. The clusters are driven bodily by means o'f a steam monkey, and when down to the required depth a concrete cylinder encloses the top and is filled with concrete.

The width of the bridge, consisting of two main girders with a 20ft centre line, gives a roadway of 18ft. On the down-stream side of the structure there is to be erected a pedestrian footway 4'ft 3in wide, which will be carried on cantilevers;. The piers will carry the steel girders, on which will rest the decking, comprising 9in of concrete, the top of which will be dressed with bitumen. The bridge has an approach of one in eighteen on the town side, and the approach on the Te Aretha side is one in twenty. The size of the structure can be gauged by the following details: The total number o’f permanent piles will be 53, which give an aggregate of 1860 lineal fee",. The weight of the steel girders is 106 tons, while about 26 tons of miscellaneous ironwork and steel reinforcing will be used, and approximately 468 cubic yards of reinforced concrete will be necessary. The total estimated cost of the bridge fe £12,280, of which sum the Paeroa Borough Council contributes £1650 and the Ohinemuri County Council '£1350, leaving a balance, of £9280 to be found by the Government. Of this latter amount £4030' is provided 'from the Waihou and Ohinemuri Rivers Improvement Scheme. Considerable difficulty has been experienced in driving the. piles. A hard layer of silt and sand was with fairly close to the surface overlaying softer seams. The, problem has been happily solved, however, but the preliminary work hate; been delayed as a consequence, and the driving of the remaining piles will be a slow process. The department is employing a day and a night shift of men until the pile-driving work is finished. With reasonable good fortune it is considered that 't,he structure, will be completed and ready to carry traffic witnin twelve months’ time. The existing bridge will be dismantled as soon as the new one is finished.