Digital Baroque in the Red-Light District: Pedestrian Bridge in Amsterdam

This project was announced long ago; now it is (hopefully) ready for implementation. In the Old Town of Amsterdam, the world’s first stainless-steel bridge manufactured with 3D printing is to be erected next year. The City of Amsterdam commissioned the Joris Laarman design studios and engineering office Arup with the design of a bridge construction to span the Oudezijds Achterburgwal, a canal in the red-light district of the Dutch capital.

The bridge, which is 12 metres long, was manufactured at Amsterdam’s start-up MX3D, which specializes in a technique known as wire arc additive manufacturing. The company combines the necessary industrial robot with a welding machine that can process most weldable alloys. Metal welding wires are used as raw material. For the most part, the bridge deck consists of components around 1 m in length; these are individually extruded and subsequently welded together. However, the robot also made some longer sections, for which it was mounted directly onto the bridge deck.

In the planning phase, the geometry of the bridge had to be changed many times: originally, delicate mullions would have transferred the bridge’s load to the supports. Now, the balustrades found to either side of the bridge, which are shaped like biomorphic box girders, will bear most of the load. Furthermore, because it was not clear how the piece-by-piece welded material would respond to tensile stress, the design is such that it is primarily compressive forces that will act on the bridge.

Before the bridge in installed in situ, the banks of the canal must be restored. The engineers want to use this time to equip their structure with a large number of sensors. The measurements will serve to optimize design and calculation processes for similar bridges in future.