Seeing the light
November 1, 2008
It’s taken almost 20 years, but Catholic residents of Oakland, Calif., are finally getting a new cathedral to replace one destroyed in a 1989 earthquake. On Oct. 17, 1989, what would come to be known as the Loma Prieta earthquake shook the San Francisco Bay area, devastating thousands of buildings and causing billions of dollars in damage.
Among the structures damaged by the quake was St. Francis de Sales, an 1893 church. It served the Oakland Diocese and had been its cathedral since the diocese’s founding in 1962. Replacing it and another area church closing due to low attendance is a 224,000-square-foot complex topped by a 136-foot-tall structure of glass, wood and architectural metal.
The $190 million Cathedral of Christ the Light, which opened in September, doesn’t look like the typical medieval-style church that many might envision when picturing a Catholic house of worship. But the very modern design of the cathedral is based on centuries-old Christian symbols.
Architects Skidmore, Owings & Merrill LLP’s San Francisco office designed the cathedral around the idea of two interlocking circles. The circles create an image of a fish, a well-known Christian symbol.
ShiningDuring the architectural phase of the project, the Oakland Diocese requested that the new cathedral be based primarily on the concept of “light,” leading to the name Christ the Light.
Attempting to maximize natural lighting, the architecture firm designed the cathedral to have extensive use of glass. Over 1,000 panes of 4.5- by 10-foot panes were installed over the wood structure. The architect used Douglas fir wood instead of steel for the cathedral’s framing to reflect more light and create a sense of warmth while in the sanctuary.
Light is also evoked from the ceiling high above the sanctuary’s altar. This glass ceiling, which was named the oculus ceiling - Latin for “eye” - provides an open look at the sky above.
The oculus ceiling is not only clad in glass, but also 140 aluminum panels. These panels were installed by San Francisco-based Ireland Interior Systems Inc., which specializes in the installation of decorative ceilings.
According to Ireland’s vice president, Michael Van Bemmel, the company worked with Linder, a German company that manufactured the panels. Both companies worked on the design and how the panels would be installed.
Van Bemmel explained that the panels are installed around the skylight. The panels along the perimeter of the skylight are flat, while the middle panels point down 10 feet. The edge panels are perforated to allow heated air from the church to escape through the ceiling.
PlatformsThe installation of the panels could have been a challenge for Ireland Interior Systems. Van Bemmel said he thought that workers might need to fabricate the ceiling on the floor of the cathedral and then use a crane to hoist up the pieces. But the company was able to use a platform in the church that reached to the top of the ceiling. A crane was then used to bring up crates of aluminum panels. The panels were then joined together and installed on the ceiling.
“I think we had the right people in the right place for the project,” Van Bemmel said.
Some panels were 8 feet by 16 feet once assembled, while others were as small as 4 feet.
The use of architectural sheet metal is clearly showcased on the walls of the cathedral, which were installed by Enclos of San Ramon, Calif.
Enclos was also responsible for the installation of most of the building’s outside features, excluding the wood framing. Enclos installed all of the metal exterior and the glass panels. The team at Enclos also installed the aluminum panels at the rear and the entrance of the church. These two walls in the church are referred to as the alpha and omega walls.
Enclos project manager John Fulton explained that the aluminum panels on the alpha wall at the entrance of the church are hanging at a 50-foot height. These panels are tipped and have small openings from the top to the bottom. This allows light to shine through the panels and hit the aluminum panels hanging at the back of the church, which makes up the omega wall.
A sun-soaked imageWhen sunlight hits the wall, a 58-foot reproduction of a sculpture called Christ in Majesty is illuminated. The image of the sculpture was taken from the Chartres Cathedral in Italy.
To create this sunbathed image, Skidmore, Owings & Merrill took a photo of the statue and pixilated it. The pixilated image was then enlarged over 50 feet. Each pixilated dot measuring a quarter inch to 3 ½ inches was then laser cut with a CNC cutting machine. A German company - one of the few with a cutting machine capable of handling such a massive project - performed the cutting. The 10-foot tall triangular panels were then shipped for installation.
Fulton said that the installation was like “a giant jigsaw puzzle.” Each panel came with a number on it. These numbers were then used to match where they would be placed on the wall.
While installing the panels was a matter of matching numbers, “the wall is not simple geometry,” Fulton said.
The omega wall reaches the top of the cathedral and then folds over at a 90-degree corner.
“We do a lot of challenging projects, but this one was unique with the geometry,” Fulton said. “On these kinds of jobs, we joke that this isn’t ‘church work’ - but this was.”
The contractors responsible for the installation of the aluminum panels weren’t the only ones challenged by the project.
Cooled by chilled waterAcco Engineered Systems of Glendale, Calif., installed a chilled water system plant for the cathedral. It also installed a displacement air-distribution system for the main sanctuary.
Gregg Holbrook, HVAC project manager, said it took the company approximately two years to finish the installation of the system. Acco officials worked with the architect to develop the under-floor air system.
An under-floor system was needed to counteract the amount of heat that could be generated by the glass-covered cathedral, Holbrook explained.
“The building has a huge glass dome with a huge solar load,” he said.
Open slots in the floor of the sanctuary pull down cool air. Rising heat is then vented out through the openings in the ceiling above.
For Holbrook, the biggest challenge was the seismic movement requirements. Since the original cathedral was severely damaged by an earthquake, the new cathedral makes use of new technology to avoid a repeat.
Under the cathedral floor are friction pendulum isolators. Holbrook said that the technology is like the church “sits on ball bearings.” The HVAC installers needed to work around these ball bearings to get the system correctly installed. But the challenge and extra work is worth the effort: In the event of an earthquake, the cathedral will move with the quake and settle back into place, he said.
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