San Francisco’s California Academy of Sciences (CAS) pulled out all the stops to rebuild its Golden Gate Park facility. It won’t open until October 2008, but it already is the recipient of five major awards, including Top Overall Northern California Project by McGraw-Hill’s California Construction magazine.
Founded in 1853, CAS is not only one of the world’s preeminent natural history museums but also a center of scientific research about the natural world, with 11 fields of research and storage of more than 20 million scientific specimens. All but one wall of the former 375,000-square-foot building that houses it was torn down to make way for the new 410,000-square-foot structure that will be home to the research center, Kimball Natural History Museum, Steinhart Aquarium and Morrison Planetarium. New attractions will be a four-story rainforest, a 212,000-gallon tank with a coral reef and 4,000 fish—the deepest living coral display in the world—and a 2.5-acre living roof.
The electrical contractor, Rosendin Electric, San Jose, Calif., subcontractor to Webcor Builders, San Francisco, faced challenges from the get-go. For example, Pritzker Prize-winning architect Renzo Piano’s structural concrete and structural steel/concrete design called for hidden conduits, so the view of the park could be enhanced through floor-to-ceiling glass walls.
“It was the most unusual project I’ve done in 30 years,” said Ken Kaplan, senior project manager at Rosendin. “It was extremely architecturally sensitive, a LEED [Leadership in Energy and Environmental Design green building rating system] Platinum target project and called for a tremendous amount of coordination. We had to recycle and use recycled materials and install systems I’ve never seen before. And it had a construction schedule of two years.”
Kaplan handled coordination, power and contractual issues for the $28 million electrical package, while fellow Rosendin senior project manager Lynn Cass oversaw lighting, lighting control, fire alarm, life safety and special systems.
“Of all the projects I’ve had the opportunity to work on, this one is the pinnacle of my career,” Cass said.
On most projects, the design team—architects, engineers, lighting and acoustical designers—coordinates the design 100 percent for the construction working drawings. On this project, the general contractor came on early to assist the owner and the design team to get the drawings through the design in a more finished fashion and to provide costing advice to keep the project on track.
“When the drawings were 85 percent complete, they were issued for bid, and Rosendin was selected as the contractor,” Cass said. “From 85 percent to 100 percent, the project became a design/assist. And while the engineers were continuing to finish the design, we were on board offering them advice on constructability, and that carried through construction.”
Rosendin’s challenge was to route and embed almost 300,000 feet of PVC pipe in concrete floors and decks, taking care to retain the integrity of the concrete by routing the conduit out of specific areas where it would have been structurally detrimental.
“There was no raised floor and very few Sheetrock ceilings, only a lot of clouds, so there were not a lot of areas to hide conduit. One of the biggest challenges was to get raceway to all of the devices in a manner that would satisfy the architect, code and the structural engineer,” said Jim Millett, general foreman, Rosendin Electric.
Heavy loading was an issue due to the weight of both the water needed for some exhibits and of the scientific specimens that were stored in movable compactor systems.
“The weight was such that they wouldn’t allow us to have conduits in the concrete decks,” he said. “And since the specimens were preserved in highly flammable formaldehyde and alcohol, a Class A, four-hour wall was put in to separate the entire administration/research and collections area from the public spaces. That made those areas on all five floors almost like a separate building.”
Rosendin worked closely with Arup, San Francisco, the structural and electrical engineers, throughout the project.
“At 85 percent, working with a world-class architect, the design kept evolving. So when we were constructing, even before we had 100 percent construction designs, all the underground conduits had to be buried to meet [the] fast-track construction schedule,” said Lelet Serrano, Arup electrical engineer. “They were pouring concrete as we were designing.”
To accomplish the job, Rosendin scheduled both a day and a swing shift, used up to 75 electricians and a construction management staff of six.
“It was challenging for Rosendin to get everything right and detailed to get approval from the design team and still comply with our concrete pour schedule,” said Luis Ramos-Jurado, mechanical, electrical, planning and structural (MEPS) coordinator, project manager, Webcor. “And the schedule was pushing on them. They were working 16 hours a day for many months, finding optimal conduit routings that wouldn’t be exposed since that wouldn’t have been an option due to the fact that we have cast-in-place, Class A architectural walls throughout the building.”
The difficulties of teamwork
Rosendin’s work was complicated by unusual factors—the roof, for one. It is a living roof with seven hills of varying height that represent the seven hills of San Francisco.
“Conduit runs through all the hills and feeds power to the irrigation controllers, the architectural landscape lights, the lights over the rainforest, and fixtures and devices in the exhibit halls,” Millett said. “The structural engineer had to maintain a distance of an inch off the pan decking for the roof, so we had to maintain that throughout as we were bending it over the different radiuses,” he said.
“We had to run 60 1-inch conduits up a sheer wall and then pop out and spread them because of structural issues,” he said. “Of course, the conduits couldn’t cross because there wasn’t enough depth to handle that, so we had to re-engineer the way some of the circuits were so you could spread them.”
Sand was another factor. The museum is only a few miles from the ocean, and salt water is needed for the tanks, so one of Rosendin’s tasks was to renovate and rebuild an underground pumping station—operated by telemetry controls—that connects through an existing underground pipeline to the CAS for transport of the water. When the ground below the museum was excavated to two floors below street level, however, Rosendin and Arup discovered sand.
“It was a challenge for us to excavate 1,600 feet of duct bank trenches in the sand and install 50,000 feet of feeder PVC raceway and the large utility vaults that distribute the power throughout the project to the 18 electrical rooms,” said Tom Bales, general foreman, Rosendin Electric. Unique spread footings and grade beams were needed to support the building.
Implementation of the lighting design, by Florence Lam of Arup Lighting, London, called for Rosendin to install more than 8,500 fixtures, many of them custom, designed by the architect and imported from Europe. The plan incorporated the use of daylighting integrated by a Lutron Graphic Eye 7000 system, which was chosen since it could not only manage the daylighting controls, but also interact effectively with the motorized shades used to protect against rain and sun and for acoustics.
“There were over 100 fixture types of which over 25 were dead custom or modified custom,” Cass said.
Installation of fixtures in the rainforest was a particular challenge.
“Picture a geometric dome with the fixtures on the flat steel structure less than four feet above it,” Kaplan said. “We could not put the fixtures up until after the glass was in place, and we could not put scaffolding above the glass since it was too precarious an incline for an electrician to stand.” Special beam clamps were installed for the mounting of the 104 1,000W and 36 2,000W metal halide fixtures by se’lux (Highland, N.Y.), which have a flat beam and a spreader beam to support growth of the trees. To handle the installation, theatrical electricians rigged up with harnesses were lowered down through operable skylights or worked off special boom lifts. The fixtures, with remote ballast/transformer trays, weighed between 50 and 80 pounds.
As with the rainforest, the Coral Reef and California Coast exhibits required lights that would not only provide illumination but also support growth. For the latter two exhibits, the final lighting design and fixture selection were done by Bart Sheperd, curator, Steinhart Aquarium, based on experiments he did at CAS’s temporary facility.
“The fixture was designed to be able to penetrate deep in the water and achieve a very high foot-candle level to maintain the growth of the coral. It took time and detail to coordinate the installation,” Cass said. The 154,000W of grow lights—1,000W metal halide fixtures with remote ballasts (approximately 200 feet away in three different locations)—were mounted on specially built catwalks installed a few feet above the water. All electrical equipment in the areas with salt water had to be stainless steel or fiberglass because of the corrosive environment.
Accomodating the inhabitants
For the African Hall, Rosendin provided power and lighting for many large and small dioramas, some of which will house live animals. The installation for the museum’s most popular inhabitants, the penguins, required special lights that mimic the sunrise/sunset cycle, a special air conditioning system and a filtration system. Rosendin also installed (but didn’t commission or program) the automated control system, called the dedicated control system (DCS), a low-voltage control system for all the motor-operated valves and level and temperature transmitters for the life-support systems for the various animals.
“The challenge was that there already was a life support system for the building, which was in the utility plant,” Kaplan said. “But a separate life-support system on emergency power was needed for life support for the animals.”
Edwards Systems Technology’s EST3 fire alarm system, selected from a short list of acceptable vendors because of Rosendin’s confidence in the product and because the distributor, Sabah International, Pleasanton, Calif., also handled other selected fire alarm products, was interfaced by Rosendin with other specialized fire alarm systems and controls. Hi-Fog, a system from Finland-based Marioff Corp., provided added fire protection in the research and collections area, where millions of specimens—some already extinct and others rare—are stored, some in the flammable materials. Hi-Fog has its own motors and power source, and it comes directly off a constant water feed and uses hydraulic pressures and small amounts of water to produce fine water mist. The CAS installation is the first in California.
In case of emergency ...
“You can put out a fire with tens of gallons instead of hundreds or thousands of gallons of water,” Kaplan said.
A very early smoke detection system (VESDA), which incorporates tubes with tiny holes that constantly sample the air and is less likely to trigger false alarms, was installed in the rainforest, a high-humidity environment. For the public areas of the piazza and planetarium, a UVIR fire alarm system, which uses an ultraviolet reader that detects fire and sends a signal to a fire control panel, was chosen over a typical smoke detector system.
“Lots of tests were done in order to successfully commission these three systems, and we received help and direct involvement of city inspectors and the fire department alongside Rosendin and their distributor, Sabah International, to help the process along,” Ramos-Jurado said. Rosendin interfaced with Webcor’s fire-protection subcontractor, Northstar Fire Protection of Minnesota on the installation of the VESDA tubes.
While major construction was completed at the end of 2007, Rosendin is continuing to work on the tenant build-out.
“Excellent job by Rosendin,” said Phil Williams, vice president of systems engineering, Webcor Builders. “It’s what we expect from them on every project.”
CASEY, author of “Kids Inventing! A Handbook for Young Inventors” and “Women Invent! Two Centuries of Discoveries that have Changed Our World,” can be reached at www.susancaseybooks.com or firstname.lastname@example.org.