We are often asked to do the impossible. So when Meyer + Silberberg Land Architects approached us with a project that was larger than any single piece we had ever cast, heavier than any single piece we had ever lifted and with a schedule faster than what we thought we could accommodate, we, of course, said, “Yes.”
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.
The biggest part of the design problem was that we were brought in late during the building’s construction and the piece would have to be craned over the building into the courtyard. This meant designing an additional steel armature that would cage and protect the piece as it was lifted, adding close to one thousand pounds of steel that would be cut away after it was installed. All of this has to be designed, engineered, fabricated, formed, cast, flipped, de-molded, polished, sealed, delivered and craned on an accelerated schedule. We certainly had our work cut out for us.
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.
When it was finished and wrapped, we craned the piece onto a flatbed truck and drove it to San Francisco. After an overnight stay in the truck yard it was delivered to the office for the last leg of its journey. The crane picked up the piece and carried it over the five-story office building and lowered it through a narrow slot at the back of the courtyard. There was a total of three inches of clearance on either side of the armature as it slid past the glass roof of the courtyard. The whole process took close to 45 nerve-racking minutes, and we were all very relieved to see it safely back on the ground.
This was one of the most challenging pieces we had to create. We were pushed at every step of the process to think in new ways and come up with novel solutions to achieve our goals. And even though there were many late nights and difficult roadblocks to overcome, it’s projects like these that keep us coming back to work everyday. We learn new things about our material and we translate that into every piece that comes after it. The Cistern was installed in February of this year and since then we have continued to feed our appetite for complex challenges. Keep your eyes here to see what we’ve been making. We can’t wait to tell you about it.
If you have a project with a similar (or larger) scope or scale, get in touch. We’re always looking for our next big challenge. [email protected]