The use of drones by local, municipal, state and federal governmental agencies for the inspection of non-private infrastructure has grown exponentially over the past few years. Drones mitigate the human risks associated with working at heights, over water, terrain, highways and the human traversing of inhospitable terrain or water. There is an excellent ROI as tasks are performed more quickly and efficiently by utilizing drones.
One of the more valuable uses for drones is the inspection of bridges with their varying sizes and engineering designs. Some well known designs are beam bridges, truss bridges, cantilever bridges, arch bridges, tied arch bridges, cable stayed bridges and suspension bridges (Golden Gate Bridge). The physical manned inspection process of bridges can be arduous and time consuming for many bridges due to their size, construction and elevation over terrain, roadways, bodies of water and waterways. There are some points of inspection that drones are capable of inspecting that are otherwise impossible to inspect without additional measures such as below deck scaffolding, safety harnesses and climbing gear. One drone team or a number of drone teams are able to visually capture large areas of a bridge structure in a safe and efficient manner including base or pile structures, the highest support points and the underside of the deck or movement corridor.
Other drone applications include the inspection of reservoirs, dams and spillways for spalling, cracks, movement, seepage, sediment changes and engineering assessments. Waste and water storage containment vessels and intake and diversion equipment can be inspected for corrosion, leakage and overall condition.
The types of sensors or cameras used for drone inspections would be dependent on the engineering, survey or maintenance needs of a customer. Some of the common sensors utilized capture high resolution RGB stills or video, infrared imaging, methane measuring (OGI) or LiDAR mapping with RGB overlay.