
Urbanisation
Lapstone Hill Tunnel and surrounding lands
RPS supports Blue Mountains project with innovative surveying solutions for complex terrain
RPS’ surveying team was commissioned by the Blue Mountains City Council to resolve complex land tenure issues and provide critical support for the design and construction of recreation facilities near the Lapstone Hill Tunnel in the challenging terrain of the Blue Mountains.
Overcoming environmental and technical obstacles through land surveying
In 2021, the NSW Government announced plans to transform the Lapstone Hill Tunnel, a historic 660-metre railway tunnel in the Blue Mountains, into a heritage tourist destination. Originally used to store mustard gas and munitions after World II, and later turned into a mushroom farm, the tunnel is now set to become a community cycleway and walking trail, connecting the villages of Glenbrook and Lapstone.
RPS was engaged at the project’s design stage to provide land surveying services and support the development of recreational facilities. However, the area posed significant environmental and technical challenges. The protected flora and fauna, heritage restrictions, and dense vegetation made it difficult to gain access for surveying. RPS also had to secure multiple approvals and navigate steep terrain with proximity to a Defence base, a national highway, and railway lines.

The land tenure issues surrounding the tunnel project were complex due to the intricate cadastral and title considerations in the area. The project required fixing boundaries from Barnet Street to Governors Drive, necessitating a full title review and assessment of road statuses. Investigations revealed diverse land types, including public, private, and stratum lands, and extensive reliance on historical and often incomplete surveys.
The western section, covered by limited titles and older acquisition plans, had issues with undefined boundaries requiring precise boundary adjustments. The tunnel section presented further complications, as historical plans conflicted with the tunnel’s actual vertical and horizontal dimensions, resulting in minor encroachments. The eastern section involved multiple unsurveyed areas, with land acquired for railway and road purposes that lacked full recent surveys.
To overcome these obstacles, RPS employed advanced surveying techniques, ensuring accurate mapping, while maintaining a strong focus on safety. This level of complexity required extensive physical surveys and boundary redeterminations, ultimately producing a detailed title review, marking maps, and boundary schedules.
Utilising UAV LiDAR, laser scanning, and expert surveying for a complex project
To tackle the rugged terrain, RPS deployed UAV LiDAR technology, which allowed the team to map the tunnel entry, exit, and surrounding steep hillsides with precision. These aerial surveys were conducted by accredited drone pilots, gathering critical data for the project. The cutting-edge technology enabled the team to accurately survey heavily vegetated areas and otherwise hard-to-reach areas.
Despite site challenges – limited space, low visibility, and scan interruptions – our specialists used laser scanning, combining two types of scanners to work around potential issues. A precise scanner was used every 50 metres to create a stable reference along the tunnel, while a faster, more portable scanner was set up every five metres to capture detailed, colourised images. This combination ensured that the data remained accurate over the tunnel’s full length, even though a full scan loop could not be completed. To handle the tunnel’s darkness, portable floodlights were used to ensure the images were well-lit and clear. Additionally, to keep the scans connected, the team set up the scanners in a zig-zag pattern, which improved image overlap and alignment. This approach allowed our surveyors to deliver a precise, colourised 3D model of the tunnel within five-millimetre accuracy, meeting the standards needed for preservation and future work.

The combination of UAV LiDAR, traditional land surveying, utilities investigations, and laser scanning provided a comprehensive view of the land. This unified approach ensured the project’s design and construction phases could proceed efficiently.
Alongside technological solutions, safety was a priority. RPS developed a thorough Safe Work Method Statement (SWMS), with extensive collaboration among the team before and during the project. Safety gear, including ankle gaiters, gloves, and protective eyewear, was worn throughout the surveying process, especially when navigating through dense, spiky vegetation and working on precarious cliff edges. This combination of advanced technology and meticulous safety planning ensured that risks were minimised without compromising on the quality of the data collected.
RPS achieves precision and safety in difficult terrain
Despite the many challenges, RPS successfully delivered accurate mapping and surveys, providing valuable data for the development of recreational facilities. UAV LiDAR, laser scanning, utilities investigations, and traditional land surveying made it possible to precisely map areas that were previously inaccessible, while rigorous safety protocols ensured the project was completed without incident.
The project’s success not only ensured environmental and heritage preservation but also set the stage for future developments in the area. Through a blend of innovative technology and careful planning, RPS effectively turned a complex project into a seamless operation, protecting both the natural landscape and the team.

Project statistics
2023 July - December
Project timeline
12 +
specialists
4200
hours worked
2.5 km
linear survey including historic rail tunnel