Finding Solid Ground

The 1.2 metre diameter rock core samples were cut and extracted using a Calyx drill as part of the extensive geological investigations that began in 1942 to find the most stable ground for Warragamba Dam. A total of 525 metres of large core samples were taken.

The geological survey also involved cutting thousands of 76 millimetre diameter cores from the rock in a 15 metre X 15 metre grid along a 3.2 kilometre length of the Warragamba River gorge.

Approximately 1.7 kilometres of these cores were extracted and reassembled piece by piece above ground to create an accurate map of the rock strata below.

The core survey on the intended site of the dam revealed a thick bed of shale, too unstable for a dam. In 1946, the final site was chosen further upstream where the most suitable geology was located.