Control Room Entrance

The control room entrance at Hornsby Quarry is a plain threshold: a concrete doorway, steel framing, walls marked by years of quarry dust and weather. Open in 2015, it led into what remained of the site's operational infrastructure, part of the crusher plant buildings that the Hornsby Park master plan later identified as heritage features to be retained within the redevelopment. Hornsby Quarry operated from around 1905 until 2002. The site passed through a succession of operators across nearly a century: the Higgins family in the early years, then Hornsby Shire Council from 1912, Hornsby Blue Metal Limited from 1924, Farley and Lewers from 1959, and finally CSR Construction Materials, which ran the quarry through its final decades before ceasing extraction in 2002. The primary product throughout was crushed dolerite, the hard volcanic rock of the Hornsby diatreme, quarried as blue metal for road base and aggregate across northern Sydney. The quarry sits within one of the largest volcanic necks in the Sydney area, a Jurassic diatreme formed 146 to 200 million years ago and later classified by geologists as internationally significant. Quarrying exposed more than 100 metres of cross-section through the diatreme's volcanic neck, a geological record that drew researchers long after the extraction equipment fell silent. CSR Construction Materials notified Hornsby Shire Council on 22 March 2001 that it required Council to acquire the site. Quarrying ceased in 2002. Ownership passed to Council in 2003 after the NSW Land and Environment Court determined the compensation at $26,508,771.28. The void left behind was approximately 120 metres deep at the southern face and 300 metres across. This photograph, made in 2015, records the control room entrance before the site's next transformation: the NorthConnex spoil deliveries of 2017 to 2019 and the subsequent rehabilitation into Hornsby Park. The open doorway and the concrete walls behind it are what remained of a working operation that had supplied the roads of a city for nearly a hundred years.