The second stage of works to repair erosion damage and stabilise the cliffs at Fremantle's historic Arthur Head is underway.
Since 2018 the severely eroded limestone cliffs at Arthur Head, the site of Fremantle's heritage-listed Round House, have been fenced off due to the safety risk from falling rocks.
Last year the City of Fremantle and the state government committed matching funding of $500,000 each for urgent works to stabilise and repair the cliffs.
The first stage to repair and repoint the imposing limestone wall to the north of the Whalers Tunnel was successfully completed in January.
Fremantle Deputy Mayor Andrew Sullivan said the second stage would involve extending the limestone retaining wall adjacent to the railway line to the south of the Whalers Tunnel.
"Arthur Head and the Round House is one of Western Australia's most significant heritage sites, so it's tremendous to be progressing with the next stage of these important conservation works," Cr Sullivan said.
"Over the past week our contractors have been scraping away any loose or suspect material in the stage two project area in preparation for the extension of the retaining wall.
"The exposed cliff face will then be covered with plastic fibre reinforcement and concrete will be poured to stabilise the wall.
"The finish of that section of the cliff face will be limestone blocks matching the existing ones, apart from a couple of areas where the natural limestone features that are still considered structurally sound will show through and form part of the retaining wall."
The footpath running parallel to the railway line will be closed and detours will be in place while the second stage works are underway. The second stage is due to be completed by late May.
The third stage of the Arthur Head conservation project, scheduled to begin in June, will involve stabilising the cliff face above the western entrance to the Whalers Tunnel, reinforcing the entrance to the tunnel and building a new rockfall canopy.
The new canopy will be clad in corten steel and have Aboriginal artworks incorporated into the design. It will be supported on custom-made hydraulic buffers to cushion the impact in the event of a rockfall.
The project also includes the removal and restoration of the steel gates at the western end of the Whalers Tunnel and additional fencing around the site.
Planned future stages that are subject to further grant allocations include repairing the limestone walls around the top of Arthur Head, restoring the stairs and the eastern entrance to the Whalers Tunnel and works to repair and conserve the Round House itself.
A multi-disciplinary team led by Hocking Heritage Architects investigated and designed the solutions to stabilise the cliff faces. The team included structural engineers, historians and geotechnical engineers.
The Round House was the first permanent building in the Swan River Colony and is the oldest public building still standing in Western Australia.
It was built as a jail and opened in 1831, with the Whalers Tunnel added in 1838.
Between 1833 and the 1960s Arthur Head was extensively quarried to provide building material and to facilitate works on Fremantle Port and the railway.
The quarrying left the cliff faces exposed to the harsh coastal environment and has contributed to ongoing issues with cliff instability and erosion.
