GRAFTON BRIDGE.

Auckland Star, Volume LXIX, Issue 138, 14 June 1938, Page 5

GRAFTON BRIDGE.

DEATH OF DESIGNER.

CONTROVERSY RECALLED. CONFOUNDING THE CRITICS. Controversies have been manv in Auckland, nnd ■ one that greatly disturbed public opinion in the city 32 years ago is recalled by the death of jllr. R. F. Moore, the designer of the [Grafton Bridge. Originally there was a wooden fbotbridge across a lower level of the Grafton Gully, but as the years went on it became unsafe, and had to be closed. Pedestrians then had to walk down steps to the foot of. the gully, cross the small stream, and climb many steps to reach tha top level on the other side. It was then that the ratepayers of Auckland sanctioned a loan of £40,000 for acquiring the necessary land and building a high level bridge, one that it was intended should provide for Auckland's traffic for many years. The loan poll was carried in April, 1900. A year of bitter controversy followed. Then the Auckland City Council called for tenders, but insufficient time was given for the preparation of full plans and specifications.

The Ferro-Concrete Company of Australasia decided not to tender, but Mr. Moore, who was then the company's chief engineer, sent in a sketch of fl ferro-concrete bridge which it was estimated would cost £35,000. The only other design received was for a steel girder bridge which, although £3000 cheaper than the concrete structure, was estimated to cost more for annual upkeep.

Mr. Moore had to cut down a number of items to bring the cost to £32,000 before the City Council would accept

his tender, and even then many doubted whether he could build a. 320 ft arch, 147 ft high, of ferro concrete to span the gully. At that time nothing approaching such a size had been attempted anywhere in the world, and the City Council stipulated that no payments should be made until the arch was completed and tested. Mr. Moore had the fullest faith' in what he could do. The work started. Concrete was poured into the moulds until the approaches were completed to the big pylons on both sides of the gully. In the middle of the gully a latticework of timber was erected. The span was built, and finally the structure was ready for traffic, the greatest ferroconcrete span in the world. ■After extremely exhaustive tests the Grafton Bridge was officially opened on April 28, 1910, a little over two and a half years from the time that the work was started. Completed Structure. The completed bridge became Auckland's pride, and throughout the world it was regarded as a remarkable engi- ] neering achievement. Had Mr. Moore had his way he would have provided a ' structure of greater width, but the City Council of 32 years ago decided on a j limit in expenditure. a Two years ago a weakness in the f approach spans was discovered, but not even an optimistic engineer like Mr. \ Moore could have foreseen the great a weight of traffic that the bridge would i be callc-d on to carry, and the stresses r that would be added by fast-moving and heavy motor traffic. a

Since then extensive repair works have been carried out at a cost of under £2;>,000, this indicating the increased labour costs of recent years compared with the period when the bridge was built.

It is now realised that it would have been better for Auckland had designs for a wider bridge been approved in the! first place. From time to time various suggestions wer» made in connection with suggested improvements. Mr.! Moore's suggestion was that a duplicatei structure should be built and then each bridge used as a one-way traffic route.