The viaduct is not sandstone, it is concrete and brick and it was built when
the line was duplicated and deviated around 1915 (I think). The problem with
the viaduct is not caused by the viaduct itself, but with the ground around
there subsiding and damaging the viaduct. One arch of the viaduct was taken
out in 1985 and replaced with a steel span. The work on the viaduct delayed
the opening of the electrification to Wollongong until February 1986.
Regards,
Chris Stratton
Wollongong, NSW, Australia
stratton.chris.cp@bhp.com.au