AUCKLAND'S BRIDGE.

Auckland Star, Volume LXX, Issue 99, 29 April 1939, Page 7

AUCKLAND'S BRIDGE.

TRIBUTE TO ENGINEERS. *_ EXPERIMENT IN CONCRETE. An interesting review of the hiß>ry of Grafton Bridge was given assistant city engineer, Mr. A. J.'Dickson. president of the Auckland branch of the Xew Zealand Institution of Engineers, in addressing about 60 members at the branch's quarterly meeting last evening. Mr. Dickson paid a tribute to the skill and courage of the engineers "who designed and built the bridge, which, he said, at that time included the largest reinforced concrete arch in the world. The space across the gully was 320 ft wide. Spans of 80ft were formed by each of the six sections of girders. The bridge had demonstrated the excellent performance of reinforced concrete, and as a result the alterations recently carried out. including the building 'of intermediate girders, it was capable of meeting all the 'requirements of modern traffic. In a normal 10-liour day the volume of traffic carried was 8500 vehicles. Technical features of the original design, tlie causes of the structural failure which developed, and other features were explained by Mr. Dickson. He emphasised that during more than 26 years the cost of maintenance of the bridge had been exceptionally small.