Retort Basement

The retort basement at the Bathurst Gasworks is a brick-lined chamber underneath the working levels of the plant, fitted out as the collection space for the coke that came off the retorts above. Massive brick foundations carry the load of the retort house, with the courses running deep into the floor. Surfaces are darkened by decades of industrial residue: the dark grit of coke fines, the soot of long operation, and the dust of disuse. Light from above does not reach the back of the chamber. Pipe stubs and conduit penetrations break the wall surface where service runs once connected the basement to the working floor.

Coke is the other major by-product of coal-gas production. After the volatile fraction was driven off as gas, the solid residue left in the retort was raked out, allowed to cool, and collected in the basement before sale. The Bathurst Gasworks ran coal carbonisation from 1888 until 1979 under council operation. Coke from a gasworks the size of Bathurst was a saleable product, used for domestic heating, foundry work, and industrial firing across the region. The basement is where that coke pooled before it left the site. Production ceased in 1987 when AGL stopped LPG reforming, and the coke trade had largely shifted to other fuel suppliers by then.