PAINTING THE BRIDGE

Hauraki Plains Gazette, Volume 47, Issue 2664, 1 September 1937, Page 6

PAINTING THE BRIDGE

QUALITY AND QUANTITY SYDNEY HARBOUR STRUCTURE. 'J’O paint completely the Sydney Harbour Bridge is a six-year’s job and keeps 42 men busy all the time. Each year it costs about £16,000 and about 42,000 gallons of paint are used.From the time it- was opened until August, 1935, the paint-work on the bridge was maintained by “patchpainting”; then it was decided to repaint the whole structure. The 10 approach spans have been painted, and later the painting of the main span began, the work commencing at the crown of the arch and the painters working downwards either side. In 1941, when the bridge has been completely painted, the work will be started all over again, and be painted in six-yearly cycles. Large Staff. The staff continuously employed on painting the bridge consists of one foreman, two leading hand painters, 13 iron-workers, seven riggers, 18 painters and one paint-mixer. In addition there are boiler-makers (employed for caulking and general maintenance), crane drivers, a fitter, carpenters and bridge attendants. Records are kept of the cost of each panel, for rigging, cleaning, time of painting and also the quantities of paint used. When the bridge was opened already 36,000 gallons of paint had been used. The employees painting the bridge are provided with washing, changing and eating accommodation in the pylons, where there is also a paint store and paint mixing room, the paint being mixed in a power driven mill. To Remove Rust. Experience has shown that rust forms more readily on and around the rivet heads than any other parts of the bridge and its removal by hand was such a laborious task that an electrically operated tool was evolved for the purpose. The qualities of different paints have been carefully investigated and various paints have been applied under similai' conditions, a complete record being kept. Up to the present the paints adopted when the bridge was constructed have proved entirely satisfactory and are still being employed. Expansion In Heat. It is also necessary periodically to lubricate the 114 extension joint slide bearings which enable the bridge to expand and contract due to temperature changes. Check measurements of the movement of the bridge during the past 12 months show that the maximum movements recorded were 9 3-8 ins. on the western truss and 9 3-16 ins. on the eastern truss over a temperature change of 38 deg. to 96 deg. There are also 55 miles of insulating cable of various sizes used in the lighting apparatus of the bridge. There are also 311 lamps to receive attendance.