The largest construction project in Europe right now involves digging a new railway system, running east to west across London. Called Crossrail, the ambitious project will result in a railway that runs over 100 km, passing through 40 stations. But it's not just the size and scale of the railway that makes Crossrail so impressive; it's the advanced construction techniques that are being used. Last year, we told you about FreeFAB, a construction technique developed by Dr. James Gardiner of construction firm Laing O'Rourke. A giant robotic 3D printer, with a build volume of 30 x 3.5 x 1.5 meters, prints large molds from a specially designed wax; those molds are then used to cast concrete panels, which right now are being installed by the hundreds in the passenger tunnels of what will become the Elizabeth line when the Crossrail project is finished. Learn more at 3DPrint.com: http://3dprint.com/181956/freefab-3d...ing-crossrail/