Advancements in unmanned aerial vehicle technology are driving smart construction in Hong Kong – and nowhere has this been more evident than in the Development Bureau’s pioneering use of drones in the management of a large construction site at Nui Po Shan.

The drones at the site – where existing sewage treatment facilities are being relocated to purpose-built underground caverns – have been deployed not only to capture photos and video, but also to record spatial data, enabling remote monitoring of progress and safety.

The deployment is one of the first pilot projects under the Low-altitude Economy Regulatory Sandbox. Deputy Financial Secretary Michael Wong, who chairs the Working Group on Developing Low-altitude Economy, commented when he inspected the project: “Low-altitude economy is a new concept in Hong Kong and the city should seize the opportunity to develop the initiative.”

High payload

Deputy Secretary for Development Tony Ho highlighted three key technological breakthroughs in the bureau’s drones, namely a high payload capacity, use of beyond-visual-line-of-sight (BVLOS) with automatic operation flight technology and cutting-edge docking stations that allow for efficient battery management.

With regard to payload, the aircraft can carry up to 6kg, meaning that they can be equipped with a laser imaging, detection and ranging (LIDAR) scanner, as well as an infrared thermal imaging camera.

Mr Ho added that the bureau’s self-developed smart platform, “SmartEye”, analyses the data collected by comparing images over time to measure soil and rock volumes, slope gradient, the verticality of structures, and more.

“For example, if we are excavating a 45-degree slope, we can use the data to verify if the excavation matches the required gradient. This allows us to detect early, follow up timely and resolve issues early.”

Enhanced efficiency

Explaining the benefits of BVLOS technology, Mr Ho said it has allowed the bureau to achieve automated operation of its drones.

“This allows unmanned aircraft to follow pre-determined flight paths and monitor construction sites at scheduled times. As a result, operators can manage multiple drones simultaneously across different sites.”

Moreover, with longer flights requiring greater endurance, the bureau’s advanced docking stations – which enable drone batteries to be replaced automatically in about a minute – make a huge difference.

“This innovation not only prevents interruptions from long charging times, but also cuts down on labour costs associated with battery management. As a result, the endurance of the drones is greatly enhanced, enabling continuous operations and broader coverage.”

Extensive applicability

The bureau aims to achieve three goals through its participation in the Government’s Low-altitude Economy Regulatory Sandbox Pilot Projects – namely to leverage drones for site management, for asset management and also for emergency response operations.

The Civil Engineering & Development Department, the Drainage Services Department, the Architectural Services Department and the Water Supplies Department will implement the technology across 12 pilot sites, including the Yuen Long Kam Tin River and reservoirs.