In 2019, the Victorian Government partnered with Melbourne University to develop a digital twin for Fisherman’s Bend—the largest urban renewal project in Australia.

This was a pilot project to test the potential of wider application of digital twin technology—a digital replica of physical things such as buildings, public spaces, infrastructure assets, or entire neighbourhoods, communities, or cities.

According to the government, the project has been successful. It created an accurate and realistic model, which enables virtual and augmented reality, incorporation of real time data and data generated through artificial intelligence, and 4D modelling of a physical asset’s design and condition both above and under the ground over time. The model includes precise location and legal boundaries.

This level of data will help to track and analyse changes in the urban environment over time. It will also be used to run development scenarios with realistic outcome forecasts in areas such as traffic flow predictions, power and water usage, and shadow analysis.

In July, the government announced that it would scale this up and deliver a digital twin for the entire state. Planners, engineers, and builders will be able to use this to model different project scenarios, test the feasibility of proposals, troubleshoot potential issues, and share complex information across sectors and workplaces.

These efforts underscore growing momentum in adoption of digital twin technology both internationally and in Australia and New Zealand.

In July, the Smart Cities Council of Australia and New Zealand released the draft version of a blueprint to accelerate use of digital twins throughout Australia and New Zealand. This version outlines eighteen tasks to be undertaken by six stakeholder groups which the Council says are necessary to accelerate digital twin adoption across the two countries.

During a recent interview, Phil Christensen, vice president – digital cities, reality and spatial monitoring at engineering software provider Bentley Systems, spoke with Sourceable about blueprint and strategies to advance digital twin uptake.

At the outset, it may be useful to separate digital twins into two broad types.

First, some digital twins cover one or more specific buildings, facilities, or assets. These types are typically owned by an individual asset owner and are built for a specific purpose.

In Minnesota, for example, the Department of Transportation uses drone imagery along with digital twins to assess the condition of their bridges, along with how this has changed over time, to determine any repairs that may be needed or any bridges that may need replacing.

By contrast, other digital twins can cover entire neighbourhoods, cities, or states. These types are generally built by governments and have multiple users in mind.

The digital twin for Fishermans’ Bend and the one to be built for Victoria is one example.

Overseas, there are other examples. In Shanghai, specialists created a virtual clone of the city that is being used to help monitor everything from traffic to building operations to building maintenance. This can also be used to simulate floods or other catastrophes to plan for disasters.

Whilst both types of digital twin deliver value, this article focuses primarily on city-scale digital twins.

According to Christensen, misconceptions regarding digital twins exist across several areas.

First, there is a common view that digital twins are only for big cities. This, Christensen says, is not the case. He says digital twins have been successfully rolled out in local government municipalities as well as across cities.

Next, some view of digital twin creation as a singular project—a tool which you build and is then complete. Instead, the twin should evolve over time so that it continues to reflect the physical thing that it is representing.

Last, there can be confusion about what a digital twin really is, a point noted in the blueprint.

Commonly, a digital twin is defined as “a digital replica of a physical thing.”

Christensen agrees that this is true but adds two points. Digital twins are not fixed but rather evolve with the physical asset over time. In addition, the twin is used specifically to understand and predict the performance of an asset over time and to make decisions.

Examples of potential applications include:

• Infrastructure management applications, such as simulation, modelling, and management of flooding or air quality and planning of traffic/transport systems.
• In development and development approvals to facilitate greater understanding of the surrounding urban context for potential development sites.
• To improve transparency in community consultation in regard to potential new developments.

On this last point, Christensen says that digital twins can help to deliver a more immersive experience. It could enable, for example, users to view a digital representation of a proposed development and see how it will look from their own apartment window. Using 4D, they might see how its effects change over time. They may collaborate and discuss the proposal with others in an immersive online environment.

Christensen says that the need for digital twins is becoming greater as global warming drives a greater requirement for activities, such as flood simulations, that build a city’s resilience.

With much of the data that impacts cities existing in silos, meanwhile, a city-scale digital twin can enable greater collaboration on matters of common importance. These matters can relate to broader issues, such as climate change, COVID recovery, and others.

According to Christensen, Australia and New Zealand can draw lessons from countries overseas who are leading the digital twin rollout.

For example:

• In Scandinavia, cities, such as Helsinki and Stockholm, have undertaken extensive citizen engagement in creating their digital twin.
• Singapore has exploited digital twin capabilities to manage underground infrastructure—something which is vital but is often not afforded the attention that it deserves.
• The UK is undertaking consultation to form a broad consensus about common standards that will guide digital twin development.
• Norway has done much work to exploit digital twin capabilities at the municipality level. It shows how digital twins can be applied to cities of all sizes.

Asked about the most important actions from the blueprint, Christensen says the importance of developments at the state and regional level should not be underestimated. With record infrastructure investment underway, he says now is the time to accelerate digital investment to derive maximum value from the level of investment going into physical assets.

In addition, asset owners and operators must be engaged on this journey—either directly or through industry bodies. Whilst architecture and engineering firms have embraced digitisation, asset owners and operators are the ones who pay for digital technology and who will drive maximum value from the digital twin over its life.

Finally, Christensen said a particularly exciting facet about digital twins revolves around their ability to bring together and converge different layers of technology. These technologies include artificial intelligence and machine learning, automatic processing and drone photography, laser scanning, and others.

“I’ve seen a lot of technology transitions in my career, but I think the convergence of the different technologies, which come together to form a holistic digital twin and keep it evolving, is the most exciting thing I have seen,” Christensen said.

“Any one of the constituent parts would be exciting, but when you bring them together across layers of data, that’s an amazingly powerful combination of data to support decision making. Realising that is Bentley’s mission for infrastructure. It is a wonderfully exciting and rewarding thing to work on.

“I think it is going to be a big enhancement to the way that we build and operate cities.”