SYDNEY HARBOUR BRIDGE

New Zealand Herald, Volume LXIX, Issue 21279, 5 September 1932, Page 6

SYDNEY HARBOUR BRIDGE

CRACKS IN ROAD SURFACE CENTRE/jTO BE USED MORE Motorists and others using the Sydney Barbour Bridg© have been interested in the fact that, almost continually during recent months, gangs of men have been repairing the "bridge surface, owing to the number of cracks that have developed and /' to large blocKs of asphalt bulging. / Over the steel girders sustaining the roadway, as well as the railway and tramway lines, there is about six inches of specially prepared coke concrete. Tests made of this have proved that the concrete is acting up to expectations and shows no signs either of cracking or "sulphuring." Many experts asserted, before the laying of this concrete, that there v would be difficulty in removing all the sulphur from the coke content, and that it would eventually work its way either upward or downward. There is no indication of that happening so far. What is occurring is that in sections the two-inch layer of asphalt over the concrete is "sweating" in parts. This is causing bulges and cracks. Experts contend that the bulges and cracks predominate on the sections of the surface carrying the least traffic, that these arc fairly general toward the middle of the roadway, and only occiir occasionally on the sides where the traffic is heaviest. The reason .given . for this is that vehicle drivers, guided by the traffic regulation ■\ to keep as near to the left as possible, have not been using the centre tracks sufficiently to consolidate the asphalt. Recently a yhite line has been paiuted at, the centre of the bridge, and motorists and others have been informed (hat so long as they keep'to the left of that line, in either direction, they will be complying with th e/ traffic regulations. The .engineers hope/ that by this means the traffic will be more evenly distributed over fhe whole roadway, leading to consolidation of the asphalt surface and discontinuance of and cracks. The maintenance of the surface of the roadway over the bridge is still the responsibility of the contractors, Dorman, Long and Company, Limited, who do not officially hand it over to the Public Works v»' Department un|il the end of September.