173 space on a concourse wall, trying and testing different ideas virtually before they finalize the design and build it. The Digital Twin Expands to Capture All of Brisbane Cross River’s commitment to the common data environment (step one of the three-point plan recommended by the Brits) signaled a shift in the usual relationship between GIS and BIM on this kind of large infrastructure project. In the past, GIS would have served as a crucial support player, a context-adding host for the 3D architectural BIM renderings. But considering the mandate to document economic development around the train stations, Cross River elevated the importance of GIS. To depict those aboveground areas, Cross River required skillful 3D maps, including data gathered by lidar sensors to capture engineering-grade measurements. That, in turn, led to another requirement. The aboveground data would also require context. If the goal was to understand how the stations would affect economic development in the CBD, it didn’t make sense to map just the area around them. You needed a map of the entire CBD. And everything had to be layered perfectly, so that anything underground (stations, tracks, tunnels, cables, and pipes) lined up in every respect with what was above it. The result is a 3D land layer that shows lots, utilities, and other pertinent visual information. Cross River’s use of 3D even includes material designed in consultation with Brett Leavy, a self-described “cultural heritage digital Jedi” who uses advanced VR technology to re-create precolonial Brisbane. Leavy’s input, Vine explained, has helped ensure that the project honors and remains respectful of a First Nations perspective. “We went from ‘it’s all about building a railway’ to ‘ah, it’s also about rebuilding the city,’” he said. “We ended up making a 3D model of Brisbane, because it was impossible to do one without doing the other.” A Twin without End The Cross River digital twin is a continuous work in progress. As designs are finalized and construction proceeds, a staircase or tunnel that existed as a single item in a contractor’s initial BIM submission becomes one with thousands of individual components in the federated BIM model. Beyond just the Cross River project, there’s no reason the digital twin can’t continue to grow in perpetuity, evolving with Brisbane itself. “We have a running joke about Cross River Rail, that the more you look at it, the bigger it gets,” Vine said, noting that after the project began, the city was selected to host the 2032 Summer Olympic Games. “We have an opportunity to take what we’ve done here as part of building a railway line and stretch it to include everything we’re going to need to build for the Olympics.” Vine even foresees the twin being a tool for operating the system in addition to its value in design, construction, and project management. “We realized we’ve built a digital twin that will help run the railway,” he said. “So there’s almost a whole second chapter waiting to be written.” Infrastructure Cross River Rail project map, with four new stations: Roma Street, Albert Street, Wooloongabba, and Boggo Road.
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