NEW BRIDGE AT WAIWERA.

New Zealand Herald, Volume LXVII, Issue 20649, 22 August 1930, Page 12

NEW BRIDGE AT WAIWERA.

DELAY IN CONSTRUCTION. HARD ROCK ENCOUNTERED. Construction of the new main highway bridge over the river estuary at Waiwera will be delayed for about two months owing to an unexpected difficulty which has been encountered in driving tho concrete piles into the sandstone strata which will form the foundation. It is not considered likely that the bridge will be open for traffic .before March. _ The construction, which is being carried out by Mr. Stirling Rogers, under the supervision of tho district Public Works engineer, commenced three months ago, when a nine months' contract was begun. The actual bridge, a steel and concrete structure, is to be only about 100 ft. in length, but the work includes the construction of a breastwork at the northern end to provide the chain and a-half of straight road required by regulation in every bridge approach, and a slight extension of the embankment at the southern end to take the new bridge. Before the steel-tipped concrete piles had penetrated the sandstone formation to a depth of five feet, as required by the Public Works Department, they splintered under the weight of the blows of the pile driver. About a dozen piles broke in this manner, and before they could bo replaced the broken stumps had to be blasted out. Up to the present no piles have been driven satisfactorily, and the work has made little progress during the past two months. It is possible that special apparatus will have to be employed before satisfactory results can be ob'tained. The old bridge which is being replaced was built over 40 years ago, and the supports have sunk unevenly, so that for some time there has been a series of Jong undulations in the decking. The bridgo has been declared unsafe for traffic of more than two and a-half tons, and this limit may have to be deduced. As mail and transport services cross the route daily, tho delay in the construction of the new bridge may cause some difficulties in the operation of these services.