The Spanish capital of Madrid boasts a rich and diverse architectural history. Its buildings and public spaces bear the influences not only of their own Spanish heritage, but of centuries of interaction with peoples, cultures, and styles from all across Europe and Africa.
Recently, Madrid undertook an enormous construction project to transform the banks of the Manzanares River into beautiful parks and promenades for its residents. The project would move a noisy highway underground and put tranquil public space in its place. At the center of this is a striking pedestrian bridge, designed by French star architect, Dominique Perrault. His firm, Dominique Perrault Architecture, had been invited by Madrid’s city council to compete for the design of the riverfront reboot.
“The competition brief proposed the landscape transformation of the 8-kilometer-long Manzanares River banks after a gigantic project to bury the King Road highway,” Perrault recalls. “We were a runner-up in the competition and one of our main proposals was to stitch both river banks together by building a series of pedestrian crossings and bridges. This proposal was judged interesting by the Madrid City Council and we got the request to build one single monumental bridge at a location designated by the city council.”
Perrault and his firm saw this as an opportunity to do something new with public space and establish an entrance to the park in its center. “The idea was to combine the features of a footbridge as a passing-through place and as a connection element with the notion of a comfortable place to stay, and also mark one of the main entrances to the park,” Perrault explains. “So we had to combine the notions of a crossing, of being stationary, and of being a landmark into a single element.”
Beyond its practical intention as a bicycle and pedestrian bridge, this structure was intended to serve as a highly visible thematic link that brings together two parts of the city separated by the river. Rather than a single structure, Perrault designed the Pasarela del Arganzuela pedestrian bridge as a self-supporting steel structure in two sections. “Technically, the foundations of the two bridges are quite complex because there are only two sets of double pylons for each bridge on top of the underground motorway tunnel walls,” Perrault says. “Structurally, that was the only possible place they could be, so it was quite challenging for the structural design.”
The tapering conical steel forms are covered in stainless steel mesh, which surrounds the bridge in a spiral design from end to end. This helix shape gleams in the sunlight and at night it is transformed by backlight into a golden spiral. The two sections, which measure 492 and 420 feet in length, extend into the park and meet in the center. This forms an entrance to the park and joins the two parts of the inner city.
“Metal mesh holds two fundamental qualities: its durability and the fact that it is adaptable and flexible as a fabric.” —Dominique Perrault, Dominique Perrault Architecture
“It’s actually two nearly identical bridges that split open when they reach the center of the park, which is the heart of the project,” Perrault says. “The entrance to the park is right there in the middle of the bridge, which is quite unique.”
Precision Panels
Perrault worked with Düren, Germany-based GKD to develop the stainless steel mesh components for the bridge. A noted enthusiast of the material, Perrault has used metal mesh on numerous high-profile projects around the world and utilized it in his design of GKD’s U.S. headquarters facility in Cambridge, Md.
The semi-transparent metal mesh that clads the Pasarela del Arganzuela bridge joins the inside to the outside and creates different impressions based on the viewer’s perspective. It is designed to be airy and to allow natural illumination during daytime hours. The spiral-shaped bridge was built so that each mesh-wrapped section is placed opposite to an open section on the other side.
The architect chose mesh for both its look and the way it works on the structure. “Metal mesh holds two fundamental qualities: its durability and the fact that it is adaptable and flexible as a fabric,” Perrault explains. “Minimal maintenance was a key design demand from the client, so not just any mesh type was suitable for this particular project. The Escale mesh [from GKD] was the right choice due to its ability to adapt to three-dimensional patterns and because it was one of the few types of mesh that allows a particular torsion.”
The flexible nature of the stainless steel spirals was able to cover the structures of the bridge seamlessly. The conical form of the structure and the curvature of the mesh did present unique design challenges. The solution was to create 64 individually formed triangular mesh sections, each adjusted to fit the substructure. The northern half used 30 sections and the southern half used 34. In total, 48,420 square feet of the stainless steel mesh was installed on the bridge.
Assembling and installing the finished mesh was a challenge that required a high level of precision, due to the size and triangular shape of the panels. Each intricately woven mesh triangle was mounted by crane with precise bending in vertical and horizontal directions to achieve the desired tension. The complex form of the bridge required a fixing technique using eye bolts.
“Each project is an evolution. We have used metal mesh for a number of years and it is an iconic material in our work, but this is the first time we actually had to use the mesh in a curved surface,” Perrault admits. “Because it was our first time, it implied certain challenges both in the design of the fixtures and the installation process on the site.”
In the end, the precision work and innovative design speak for themselves. The Pasarela del Arganzuela bridge makes a bold visual statement in Madrid’s city center while serving a practical purpose in a very efficient way. Stainless steel provides a weather-resistant, low-maintenance structure that won’t burden the city’s budget with excessive upkeep. Most of all, this elegant structure has the durability to stand the test of time in a city that has already seen the passing of many centuries.