IS THE SYDNEY HARBOUR BRIDGE HAUNTED?
Sydney Harbour Bridge has a "ghost." Engineers say that they have a simple explanation for eerie wails, which are heard at irregular intervals, but workmen still call the phenomenon the "bridge ghost."
The uncanny sounds were heard first on the approach spans. They began faintly, then rose in volume and finally died away. They were first attributed to the siren of a vessel passing underneath the arch, but the persistence of the sounds soon attracted close attention. Engineers were informed, and endeavoured to explain the phenomenon.
Several theories were advanced and as quickly rejected. It was suggested that riveting machines were reacting upon certain steel members, causing them to take up vibrations in sympathy, in the same manner as a tuning fork. This was soon discounted, for the sounds came on as strongly as ever when there were no riveters at work in the vicinity.
It was then suggested that gusts of winds were responsible. On the roadway section there are several vertical pipes for drainage purposes and it was thought that, under the wind's influence, they were acting like the pipes of an organ. The recurrences of the sound on a perfectly still day exploded this theory.
A very simple solution of the problem has now been found. It has been observed that the wailing is heard only during which the temperature varies greatly. On a cloudy day, broken by short periods of strong sunshine, the wails are particularly noticeable. On such days there is considerable movement at the expansion joints of each steel truss. Due to the weight of steel bearing., on the plates on which each truss slides, friction is considerable. Movement then takes place in a series of backward and forward jerks. This irregular movement sets up vibrations in the members constituting the framework of each truss, which acts as an enormous tuning fork.
Nevertheless, there are some persons of an incurably romantic turn of mind who prefer to retain the supernatural explanation of a ghost.
Published by The Kyogle Examiner, NSW, Fri 6 Feb 1931
To be continued
Kanacki.