Liberty Industrial was engaged by TransGrid to undertake the demolition and remediation works to the Mount Carroll Radio Repeater Site located 22km south-west of the country town of Yass, New South Wales. The project comprised of the decommissioning of the Mt Carroll Radio Repeater Site which had been identified as being no longer required for future use. A need was identified to completely decommission the Mt Carroll RS and remediate the site under the terms of the lease.
The steel lattice radio tower structure was located within farm land and only accessed via 3km of unsealed road which was severely undermined in areas, the unsealed road was upgraded prior demolition and remediation works commencing in order to facilitate delivery trucks to access the site with plant and equipment and haulage trucks to remove demolition materials post demolition works. Prior demolition works commencing services technicians ensured all live services were removed from the structure.
The structure was assessed for demolition methods and deemed suitable for an induced collapse in order to bring it safely to ground level for processing and shearing. Oxy cutting methods were utilised to remove hold down bolts at the base of the structure and also to create holes in the legs to attach shackles and cables for pulling. Additional birds mouth cuts were created in the legs of the structure to guide the direction of fall and the shackles and cables were attached to the structure. Under the control of the demolition site supervisor the excavator operator was directed to walk the machine backwards and pull the cables inducing the collapse of the tower. The structure was brought safely to ground level and was processed with a shear attachment to the excavator, loading the steel material onto trucks for transfer and recycling offsite.
The concrete footings and inground infrastructure was also demolished and transported to a nearby concrete recycling facility.
The remaining scope of work tasks included the importation of clean compatible fill material which was spread across the footprint of the demolition site and machine tracked with the excavator. Native grass seed was imported and spread across the area to regrow and return site to natural condition.