Balgray Railway Station

Story Drones were engaged during the pre-construction stage by the project team and were tasked to provide accurate ground levels of the construction area without accessing the railway corridor to better inform the tendering process.

Both photogrammetry and LIDAR techniques were used to capture the data, the flights consisted sequential flights with an 80% side and 70% front overlap to ensure enough tie points to generate an accurate 3D model aligned to the OS national grid. The results allowed the pre-construction team to perform cut and fill analysis thus providing earthwork volumes.  The goal for all was to create a design that illuminated any material leaving site during the construction phase.

Identical flights were repeated a year later, again prior to works commencing on site, to confirm ground levels hadn’t changed given another contractor had been working in the same area. The two surfaces checked by overlaying the two point clouds using known common points, this process highlighted the “before” and “after” levels of the area and subsequently confirmed the changes. Traditionally it would be very hard to get this level of accuracy however with drone capabilities this can be captured with ease.

Drone involvement on the project has been increasingly beneficial for the project team, meaning data can be collected fast, accurately and with greater density of levels due to millions of points generated from point clouds.