San Francisco, CA

Brannan Cistern

Outdoor

Art

Meyer + Silberberg designed the 20-foot long, 3-ton bowl as the feature object for an office courtyard in San Francisco. The bowl was to capture rainwater funneled from a scupper above and then distributed down into surrounding planter beds. As with many of these complex projects, we initially were given a very simple form in a 3D file. It was up to us to turn the concept into a reality. Our engineering team spent weeks refining the design with the architects: studying the proportions, changing the angle to accommodate internal supports, designing a steel armature for the bowl to sit on, and changing the shape in subtle ways to maximize the strength of the concrete.

12 feet tall and 2 tons

Once we were given the green light our engineering and productions teams in tandem started straight away. Over the course of several weeks, we ran our CNC machines around the clock to create complex three-dimensional forms that would capture the shape of the finished pieces. Meanwhile, on the factory floor, orthogonal pieces were being cut from wood and a platform was erected upon which the form would be built. The form was ultimately made of hundreds of parts in wood, foam and steel. Altogether the two-part mold was over 12 feet tall and weighed almost 2 tons on its own.

Casting was accomplished in one day and involved a majority of our production staff. We used advanced concrete spraying machinery that allowed us to cast the top half of the mold upside down. When we closed the mold and filled the last bits of concrete, the real wait began. As concrete cures, it releases an enormous amount of heat. During the initial curing time we covered the mold with bags of ice and cooling blankets, in order to control the temperature, which still rose to well over 100 degrees fahrenheit.