Progress With New Bridge At Titoki

Northern Advocate, 13 December 1943, Page 2

Progress With New Bridge At Titoki

Estimated to cost £30,000, a new bridge, the largest and most modern structure in Northland, is being built at Titoki. This price includes approach work which will deviate the present road and eliminate three dangerous bends. Of reinforced concrete the new bridge will provide for two-way traffic on the main highway between Whangarei and Kaikohe. For the north it is a gianl structure over a total length of 630 feet, made up of three 80ft., two 60ft., and six 45ft. spans. An immense amount of work has been necessary in providing foundations which are now nearing completion. The work involves the use of 1635 cubic yards of concrete for the bridge with a further 250 cubic yards of concrete for the foundations, while 193 tonsf.of steel are provided for the reinforcing#' An immense amount of work has been necessary in providing the foundations which involve 2334 feet of piles as well as the sinking of two pairs of cylinders on which the piers for the middle span will rest. '

Use of Cylinders In all 10 piers, made up of two tapering columns joined by a thin concrete web, support the bridge, which will be 65 feet above low water level. This provision has been necessary as the rise of the stream from summer level to highest flood level is 53 feet.

With the work classed as essential more rapid progress has been mjade with the foundation work which ’has now been completed with the'exception of the sinking of the cylinder ; foundations for the middle span. yv', ' Although not a new method, the use of cylinder foundaions where work is to be done in a depth of water, is of interest 1o the layman. The cylinders, made of concrete and about 30 feet in length, are sunk in the river bed. Ah air compressor on top of the cylihder forces in air, expelling water and permitting a workman to excavate. With the release of air, which has also the effect of providing support the cylinder sinks into the excavation, the process being repeated until the requisite depth is obtained, the cylinder then being filled with concrete. When the cylinder foundations have been completed work will commence on the superstructure which it is expected will be finished in about 12 months’ time.