It's tough to be the second prettiest bridge in San Francisco.

When the Bay Bridge opened 75 years ago, Oakland and San Francisco threw a four-day party to celebrate. On that day it was the longest, most expensive, most advanced bridge in the world.

Six months later, the Golden Gate Bridge opened just a few miles away and few people have given the Bay Bridge much love — let alone a party, let alone a four day party — since. Except if there is a problem, like when part of the roadway collapsed during an earthquake in 1989. Then people talked about the bridge, but nothing nice. Nothing like the love, the songs, the poems and the books showered on the competition.

Of all the hearts that have been left in San Francisco, has one ever been lost to the Bay Bridge? A few? None?

It is a testament to the success of a monumental new work of public art on the 1.8-mile-long, 500-foot-tall suspension bridge, built in large part by IBEW members, that maybe for the first time since that four-day party in 1936, people are falling in love with the second prettiest bridge in town.

Creating a Digital Campfire

The sculpture, known as the Bay Lights, is the brainchild of Ben Davis, founder of a public relations firm hired to promote the diamond anniversary of the bridge. Back in 2011, Davis asked artist Leo Villareal to transform the bridge into the largest light sculpture in the world.

Villareal's plan was to attach thousands of white LEDs — highly-efficient and extremely bright lights — to 300 support cables that hang from the main cable as it arcs its way out of San Francisco.

The LEDs would then create vivid patterns of light and dark based on abstract images inspired by the bridge itself.

"I'm always working with the kinetic motion that I find in places and trying to integrate that into what I am doing," Villareal said in a documentary made about the project. "In the case of the bridge, obviously you have cars moving back and forth, you have traffic. There is an incredible interplay of water, air, light and the movement of birds."

His goal was to bring people who would otherwise never have met into instant communities, sharing a moment around, what he called, a "digital campfire."

"You can't see things the same way after you've seen a great piece of art," he said. "That is what my goal is: to change how people see things."

Martinez, Calif., Local 302 member Chris Berge heard about the project in 2011 when Davis, Villareal and a nonprofit arts group called Illuminate the Arts were pitching the idea to the state and local agencies responsible for the bridge. Berge was in the room because the National Electrical Contractors Association firm he co-founded, Bleyco, had been working on the bridge for close to a decade.

In the '30s, there was no way to build a single span from San Francisco to Oakland nearly five miles away to the east. Happily, right in between is Yerba Buena Island, a steep mountain of shale rock that rises hundreds of feet out of the water and a natural meeting place for two spans. The west span is the suspension bridge to San Francisco. The largest diameter tunnel in the world, according to the Guinness Book of World Records — 76 feet wide and 58 feet high — connects to the boxy east span, most famous for partially collapsing during the 1989 earthquake that interrupted game three of the World Series. All of it together is called the Bay Bridge.

Berge and Bleyco did repair and retrofitting on the both spans of the bridge after the quake. He said the $8 million privately-funded sculpture was interesting, but most of his attention was on Bleyco's contract for the electrical work on the $6.3 billion east-span replacement project.

"The whole idea was pitched before they had permits or money," he said. "But they had some unstoppable, hard-working people on their team and they got it through faster than government could have."

Caltrans, the state transportation agency, approved the project but there were significant conditions. The lights could be up for two years, but no permanent changes could be made to the bridge. All the money had to be raised privately. The project had to be fully installed by early February, in time for the anniversary celebration, but federal environmental laws prohibited work until mid-October, when the thousands of migratory birds that temporarily nest on the bridge finally moved on to warmer homes.

The thousands of feet of lights and cable (see sidebar) would have to be installed at night, during the rainy, cold, Bay Area winter with the bridge open to traffic.

"There was a not much of a window to get all the work done," Berge said drily.

Caltrans then told Davis, Villareal and Illuminate the Arts to call Bleyco.

"I needed a team with a track record, that I was comfortable with, given the short window," said Saeed Shahmirzai, who directs electrical work for Caltrans on the new East Span of the Bay Bridge and was construction manager for the Bay Lights. "It was my decision, and I wanted Bleyco."

Building the Largest Light Sculpture in the World

Villareal has been designing light sculpture for more than a decade and he had a specific LED system that he wanted to use. Every 12 inches, on wires up to 50-feet long, a plastic dome the size of a silver dollar, covered five snow-white LEDs. More than 500 strands were needed to complete the project.

"Our job was to figure out how to get it all up on the support cables, power it, get data to it and secure it for two years," Berge said.

Bleyco needed a clip to hold the strand of lights in place through cycles of heat and cold, wind, rain and salty spray without damaging the bridge or crushing any wires. They made extensive use of new 3D printing technology to accelerate the prototyping process and keep costs down. Similar to an inkjet printer, instead of drops of ink sprayed onto paper, a 3D printer head squirts out precise drops of quick hardening plastic, building up a model, layer by layer.

More than a dozen bridge clip prototypes were printed, tested and refined before the final design was chosen. More than 48,000 of the clips, secured with a beefy zip tie, now hold the installation in place.

Once that had been figured out, Shahmirzai said the conditions were often the challenging part of the job. Weather, traffic, wind and cold sometimes combined treacherously.

"The biggest challenge was often just getting to the work site," he said.

For 120 nights over six months, a crew of four IBEW members, two safety riggers, traffic handlers and supervisors headed out onto the bridge deck about 250 feet above the water. Two more riggers began the long climb up the main cable.

They were attached, one by one, by Martinez, Calif., Local 302 member Mike Durflinger and Sacramento Local 340 member Matt Montgomery. On support cables less than 50 feet high, they would work from a bucket truck. While they loaded up with the light strands, power cords and fiber optic cables, every one numbered and assigned to a specific part of the bridge, the two riggers on the main cable, often hundreds of feet above the work site, secured safety wires to the bridge. The safety team at road level secured Durflinger and Montgomery, the right lane was closed, and they would haul up the wires and clip them to the cable, 48,000 times.

"They spent a lot of time in that bucket," Berge said.

Down on the bridge, Martinez, Calif., Local 302 members Joel Baron and Jay Micheo worked behind a traffic barrier on the road deck, attaching the strands of lights to a control box with power and fiber optic cable. The control boxes were then connected to a computer cabinet in the center of the bridge that would instruct each LED exactly when and how brightly to shine. As the lights went up, Villareal could control the display from shore, testing new ideas or designs on a laptop connected wirelessly to the computers on the bridge, looking like just another guy checking his e-mail on a bench.

The tallest support cable is 250 feet tall, and many were beyond the reach of the cherry picker, so they used a bucket that climbed the support cables themselves. To keep the power and data wires manageable on the longest cables, only three strands of light were powered from below. One or two more wires were run from controllers on top of the main cable, sometimes 500 feet above the water.

"I've been walking the main cable on the bridge for more than a decade, but I never set foot in the bucket," Shahmirzai said, "I can't imagine letting go of the rope and holding tools, let alone focusing and doing work."

The Grand Lighting

On March 5, a driving rain did little to dim the spirits of the thousands of people who gathered on San Francisco's Embarcadero for the official lighting ceremony. There were a few sodden speeches, a countdown and the lights slowly swelled into life, dimmed out, swelled and dimmed again, like the whole bridge was taking a few deep breaths (watch videos of the opening http://youtu.be/kPY5IlxiEYk and http://youtu.be/bVKg38ynh4A)

Then a bright white star shot like a comet from the San Francisco skyline. A trail of flickering sparks drifted in its wake.

A love affair was kindled from the very first shot and the public reception has been rapturous.

"It is public art at best — temporal, contemporary and indescribably beautiful," wrote Trinity College Professor of Fine Arts Mary Tompkins Lewis in the Wall Street Journal. Christo, the artist who had Central Park draped in 1 million square feet of saffron-colored fabric in 2005, called it, "a milestone in public art."

Much of the attention has focused on Villareal, who has publicly thanked the men and women that transformed an idea into reality. Berge says they are the unsung heroes of the project.

"I take a lot of pride in the people I am fortunate enough to work with," Berge said. "They all took ownership of the project and committed themselves to a successful completion."

More than 50 million people are expected to see the Bay Lights Project before the three-month removal process begins in 2015. On opening night, San Francisco Mayor Ed Lee expressed doubt about that deadline.

"People, including myself, will want this to be ongoing," he said.