How laser scans and VR are preserving London's hidden 'Mail Rail'

When the Matthew Shaw and William Trossell  founded ScanLab Projects in 2011, they were a pair of freshly minted architecture school graduates who’d gotten their hands on an extraordinarily expensive commercial-grade laser scanner. Today, their London-based studio is at the forefront of large-scale 3-D laser scanning, specializing in striking, ghostly reproductions of castles, museums, ice floes and more, conjured from billions of millimeter-precise dots.

ScanLab’s latest undertaking is a sprawling scan of Mail Rail, a network of abandoned tunnels once used to transport mail beneath London. Like much of the group’s work, it sits at the intersection of utility and beauty, commerce and art. On one level, it’s an unprecedentedly detailed document of a historically significant site—a laudable bit of high-tech preservation. On another, it’s a work of art in an arresting new medium, a strange offspring of photography and computer-generated imagery. Depending on your perspective, it’s either the past seen through the lens of the future, or the future seen through the lens of the past.

Commercial scans like Mail Rail are only half of what ScanLab does. The other half—the “lab” half—is dedicated to interrogating the technology of laser scanning itself. This has been part of ScanLab’s DNA from the beginning; it’s what makes Shaw and Trossell think of pointing a $400,000 laser scanner at a cloud of fog. ScanLab has done several compelling projects in this more critical mode. Among the first, from 2011, revolved around Lidar-jamming “stealth objects.” Envisioning a future in which cities are subject to the constant scrutiny of lidar scans, Shaw and Trossell devised hypothetical devices for deceiving the lasers and distorting what they recorded. A speculative tool called the “stealth drill” was meant to dissolve scan data, “creating voids and new openings in the scanned urban landscape.” A “boundary miscommunication device” would trick scans into registering paths, tunnels and walls that didn’t exist.1

In 2012, Shaw and Trossell led a group of Bartlett architecture students on something they called “The Grand Stealth Tour.” The goal was to use laser scanning to surreptitiously steal architectural details from famous London monuments. As the students “admired the architecture” the scanner measured, captured and stored the buildings’ details, in a sense cloning the architect’s intellectual property in the process. After the scans were complete, the group used Bartlett’s CNC router to reproduce some of the architectural details in full size. It was a good-natured bit of subversion, but it had a sharp point: To consider what copyright theft might look like in a future that allows a millimeter-perfect scan of any object with the wave of a laser.

  • 1. For now, ScanLab is only loading a portion of its 3D model inside the Oculus Rift. Booting up the entire visualization, at least with their current hardware, would involve too much processing. Not that it really matters -- ScanLab's motion-tracking setup is in the middle of its office, so testers can only walk three or four steps before bumping into tables and chairs anyway. At such close quarters, the quality of the model isn't perfect either. Everything looks just a tad grainy, like an analog TV that hasn't been tuned correctly. In addition, ScanLab can only load a single LIDAR scan at once. It means that if you look in places that, at the time of capture, were blocked by other objects in front of the scanner, you'll sometimes see black "data shadows." However, this experience is only an experiment -- a version for the museum would no doubt incorporate a more complete model.