The soil that surrounds railroad tracks shifts and erodes slowly over time from moisture changes, jostling, and the wear and tear of use. So, remediating them requires an acute understanding of the existing conditions including the track limitations, fixed points, and immovable constraints.
Surveying Techniques
Engineers must balance the desire to stay true to the original positioning while accepting some conditional changes. Numerous surveying techniques are available. So, railroad authorities have various forms of data to assist in the design effort for specific projects. One way of measuring what exists is using the Amberg Trolley system. Track surveyors can perform detailed mapping of track geometry and wayside clearance with a lightweight trolley. Further, surveyors can remove the trolley easily from the tracks as needed. As their website says, Amberg Technologies provide measurement systems for railway surveying. They offer high quality, reliable, economical measurement performance for many projects. Project types include construction and maintenance of slab track and ballast track, as-built survey of existing lines, and clearance analysis.
Surveyors can also acquire data with LiDAR or mobile mapping. This is done by attaching equipment to aerial platforms, hi-rail trucks or the trains themselves. Other methods to collect track data include the usage of GPS/RTK systems or terrestrial 3D scanners. To use these, we set the instrument up at strategic locations on a project site. The scanners collect over a million points per second for the development of a 3D point cloud.
Next Steps
We are experienced utilizing these survey methodologies to collect precise track and corridor data and providing this information in a convenient and functional format to our internal designers and external clients. One possible use of the collected data is Track Optimization. This can help get the rails back to the intended geometry; thereby allowing rolling stock to run at maximize speeds and reduce the wear and tear on both the cars and the rails.
Want to learn about the benefits and limitations of different surveying methods being currently deployed? Contact Tom Reed, PLS at thomas.reed@colliersengineering.com with your specific questions, and to find out how our team can help you execute your next project!