By Stephanie Nestor, Assistant Editor, Infrastructure Magazine
Asset management can be highly demanding and costly, but Artificial Intelligence (AI) drones are providing new insights into the maintenance life cycles of New South Wales’ most significant infrastructure.
With maintenance work on large infrastructure, such as the Sydney Harbour Bridge, requiring regular inspections that are costly and dangerous, Transport for NSW is looking to develop and adopt new technology to find a safer and more convenient approach to asset management.
Including the Sydney Harbour Bridge, Transport for NSW maintains thousands of kilometres of roads and 6,000 bridges across New South Wales. Repairs and inspections can cause disruptions for the community, take weeks or months at a time, become expensive very quickly and even put maintenance personnel in danger.
Transport for NSW completed a three-week trial across July and August 2022 using AI drone technology to carry out inspections under the southern part of the Sydney Harbour Bridge. These drones allowed the crew to access hard-to-reach areas, capture high-resolution images, and even create digital 3D models.
The trial not only demonstrated the suite of benefits drones can offer when it comes to maintaining large infrastructure like bridges, but also what the next steps will be for adopting the technology in the future.
A powerful tool for surveying
Surveying is notoriously difficult to undertake, especially on a structure such as the Sydney Harbour Bridge. AI or autonomous aerial vehicles like drones offer maintenance crews a preventative tool for tackling inspections and repairs. For the past six years, Transport for NSW has been collaborating with companies developing AI and autonomous drones, including CSIRO, Emesent and Skydio.
These drones use AI to enable autonomous or assisted flight, meaning they don’t require someone to manually pilot them for the whole flight. Manual drones pose a higher risk of crashing and require more work from the pilot, which can impact the quality of data collected during an inspection.
Autonomous drones are equipped with sensors which prevent them from hitting objects or structures as they collect information and capture images. Using drones enabled the team on the Sydney Harbour Bridge to access hard-to-reach areas without endangering personnel and capture 4K high-resolution images.
With over 4,100 elements and 495,000m2 of steel that needs to be inspected regularly, the technology has made what used to be a time-consuming and dangerous task, convenient and comprehensive. The drones can also be used to render a 3D map of the bridge to get a better understanding of what needs to be maintained, providing detailed visualisation of every nook and cranny.
Director of Infrastructure Technology Services, Transport for NSW, Houman Hatamian, said the drone trial produced close-up and in-depth views of the bridge elements for the Sydney Harbour Bridge inspection team.
“One of the major advantages of using drones is that it simplifies the inspection process by reducing the need for special equipment and being able to access physically unreachable areas,” Mr Hatamian said. “Drones are also more time and cost efficient compared to traditional maintenance techniques.”
Navigating emerging technologies
As a relatively new technology, there are unique challenges to utilising drones for surveying. The trial may have demonstrated a game-changing method for inspecting bridges, but the uptake of drones will require more than just good technology.
Personnel must be trained up to be able to use autonomous drones. Currently, over twenty drone pilots have been trained, but rolling out the technology across the whole state will require more people with the necessary skills.
For the Sydney Harbour Bridge trial, autonomous drones were used to ensure drones could be used safely, capture high quality data and wouldn’t require pilots to undergo extensive training. Nevertheless, the team had to be familiar with regulations and public safety obligations to operate the drones, which meant planning ahead.
“The team had to familiarise themselves with the current procedures and requirements of both the Civil Aviation Safety Authority and Transport for NSW for flying drones for inspection purposes,” Mr Hatamian said. “They also had to comply with local council requirements, manage pedestrian traffic, work with other stakeholders in the same area, and most importantly, the weather.
Most of these challenges were overcome by engaging with the key stakeholders earlier in the process and finalising dates and times well in advance before submitting the job for approval.” Additionally, Harbour Bridge’s location posed another challenge. Considering the drones could potentially be damaged from rain or water, the drones had to be waterproof and durable to carry out inspections under somewhat harsh conditions.
Ensuring they used the best drones for the location and job meant the team could capture data without worrying that the drones would hit structural elements or get damaged by the weather. With the data capture and scanning processes automated, the pilot only had to set up the scan, making the work a lot easier for everyone involved.
Seeing asset management with new eyes
Apart from the Harbour Bridge trial, Transport for NSW carried out other drone demonstrations around the state, including at Gladesville Bridge over Parramatta River. But at the moment, it’s unclear whether the technology will be adopted for continued use as part of bridge maintenance.
Before it can be used extensively across the state, there needs to be more training for pilots, modelling technology that is specifically designed for monitoring and surveying large infrastructure, and planning for how often drone flights will occur to minimise disruptions to the wider community.
Nevertheless, AI and autonomous drones are quickly developing as a safer and more reliable tool for inspecting bridges. They have already been adapted to suit asset management for mining, offshore drilling, real estate and local government.
These drones can save maintenance crews time and money spent on constantly monitoring assets and putting themselves in danger while conducting inspections or repairs. Most of all, the key difference drones can offer is being able to visualise and understand how circumstances can evolve over time and impact existing structures.
Regularly scheduled drone flights and detailed 3D modelling can give maintenance teams a consistent and preventative way of protecting bridges from damage or degradation. Particularly when it comes to extreme weather events or natural disasters, having a less time-consuming and physically demanding monitoring process means crews are better prepared.
“Drones are a great tool for geotechnical inspections after natural disaster events, for example, with the Oxley Highway after heavy rainfall in 2021,” Mr Hatamian said. “Transport for NSW is also trialling water-resistant drones for post-flood assessment of impacted assets.”
The future of drone maintenance
Incorporating drones and other technologies into monitoring and asset management is part of New South Wales’ Future Transport Technology Roadmap 2021-2024.
As part of the strategy, drones and digital 3D modelling will be trialled and eventually used to assist in maintenance and repair programs. Mr Hatamian said Transport for NSW is regularly increasing its range of drone applications to many areas in both metropolitan and regional New South Wales.
“While the Digital Engineering Services branch of Transport for NSW already has 15 pilots trained in bridge maintenance, it also has a fleet of specialised drones for flying in confined spaces and GPS-denied environments,” Mr Hatamian said.
“The Transport Management Centre also uses drones for incident response, congestion monitoring and intelligence gathering, and the Network and Asset teams have been using the technology for remote site inspections.
“Our Technical Services have also been able to collect spatial data in areas that are inaccessible and as a result have created 3D models to help with further analysis. Drones have also been used for photography and videography by its production team.”
As an emerging technology that has already proven to be beneficial by saving time, costs and risks, it’s clear that drones will eventually become a regular part of asset management for infrastructure like the Harbour Bridge, it’s just a matter of planning ahead.
