Heritage-Listed Gasholder Restoration
From the late 1800s until the mid-1900s, gasholders were commonly found in Australian cities and in cities across the world. These vessels were used to store gas created from coal, with the gas being used for street lighting and other purposes prior to the introduction of electricity. The gasholder located in the south-west of the site is the only intact ‘telescopic’ gasholder remaining in NSW. It once stored gas created by the Macdonaldtown Gasworks for lighting railway carriages and workshops.
To restore the ‘southern gasholder’, the project team engaged a consultant with the relevant expertise for assessing its structural integrity. The original plan for repair of the gasholder involved full restoration onsite, however detailed assessment of the structure by the project team engineers and the consultant revealed that a better outcome would be achieved by temporarily dismantling the gasholder’s superstructure (the above-ground structure), restoring it offsite and then returning it to its original location at project completion.
Offsite restoration significantly reduced impacts for nearby residents and dismantling the superstructure produced the best restoration outcome for the gasholder i.e. the dismantling allowed protective treatment of all surfaces of the superstructure, not just the exterior, and enabled the reuse of original fastenings after their restoration.
The sequential method of dismantling the gasholder’s superstructure involved removal of the gasholder’s horizontal trusses, cross-bracing and columns using a large crane. These elements were individually labelled and following inspection, delivered to an offsite facility. At this facility, the elements were cleaned and blasted to remove old paint and corrosion, and a protective coat of grey-coloured paint, which matches the original colour of the structure, was applied.
When the project’s remediation works were finished, all of the gasholder’s superstructure elements were returned to the site and the gasholder was reconstructed. Each element that was removed was carefully replaced in its original position.
The change to the restoration plan was approved by the Department of Planning and Environment, and consent was also received from the Heritage Council of New South Wales.
The steel bell of the gasholder, where gas was contained when the gasholder was operational, remained onsite during the superstructure’s offsite restoration. The top of the steel bell was cleaned, blasted and painted before the full reassembly of the gasholder in July 2016. The surrounding environment was monitored and protected during the bell restoration.
Heritage specialists have undertaken archival recording of another gasholder, the ‘northern gasholder’, which was only present as remains below-ground, and other important below-ground infrastructure at the site. Archival recording is the capture of information which describes the configuration and condition of a heritage item, building or site. The archival recording has been detailed in a report that is publicly available from RailCorp upon request.