SANTA CLARA — There’s a common question around the construction site of the new San Francisco 49ers stadium: Are you sure it’s not opening until 2014?

Just six months after breaking ground, the Niners have installed about 60 percent of the stadium’s steel and are already inserting things like escalators and the upper decks. Fans stuck still watching the 49ers at dilapidated Candlestick Park may want to move to the shiny new stadium even sooner.

“It depends; do you want to be able to go to the bathroom?” said site assistant superintendent Sean Brummer. “Essentially we have to build everything you need for a city.”

Even after crews finish the outside structure in December, it’ll take 18 months to put on the finishing touches and pass inspections: six months to test all the fire alarms, two months to run the escalators, 30 days to burn in the lights, two months to grow the playing field.

The workers will test the sound system by blaring music during their final months and make sure the scoreboard is top-notch by viewing classic 49ers Super Bowl games on it during lunch breaks.

Perhaps the most death-defying act will be installing lights on the catwalks some 195 feet in the air along a commercial flight path.

Then there’s the “super flush.” Boy Scouts, volunteers and workers will flush every toilet and urinal and turn on every sink in the stadium for about a half-hour — meant to mimic halftime conditions — to see if the plumbing can handle it.

“We’re working every inch every day,” said foreman Dave Masel, whose construction team has also built stadiums for the Kansas City Chiefs, Denver Broncos and Philadelphia Eagles. “This is the fastest we’ve ever done one.”

The 49ers needed to build the stadium about six months quicker than it takes for the average NFL stadium because they had so much trouble securing the money to build it and, when the funding finally came through, were eager to hustle toward opening the $1.2 billion field by 2014. Builders Turner and Devcon lose their $35 million commission if they miss that date.

“If you miss a day — that’s not something that you can let happen,” said Devcon President Gary Filizetti.

80 percent to go

Since a glitzy groundbreaking ceremony April 19, construction is right on schedule, nearly 20 percent completed and Turner-Devcon has spent $155 million.

The entire job is planned inside “Trailer City,” a series of mobile offices next to the site that has rooms with names like “The Huddle” and “Super Bowl.” It’s separated from the construction job by a public walking and biking trail, where joggers have to be careful not be run over by massive Mack trucks entering the site or stare too intently on the sparks from the welders working nearby.

To speed up the project, the team divided the stadium into four sections — basically the two midfield sections and the two end zone regions — and is building each one simultaneously, as opposed to the traditional method of building stadiums one piece at a time. That requires extra manpower — some 2,000 workers and visitors have been through the site — and an unusually high number of cranes: five in all, one for each section and another one outside.

“There is a little competition going on” from the four teams to finish their section first, said safety chief Jim West. Standing on the “hallowed ground” where the field will be, he watched the cranes install massive steel beams. “It blows me away to watch this thing happen.”

The hardest part of the project, the construction team said, isn’t the constrained time frame but the “postage stamp”-size space builders have to work with next to streets and roller coasters from the adjacent Great America theme park. They work just a few feet from the 49ers headquarters, leaving suit-wearing front office executives to duck into a makeshift wooden tunnel to get to work every day.

With virtually no storage space, the team needs to install the steel, metal and concrete as soon as it’s shipped in, and there is only one entrance and exit point — a “logistics nightmare,” Masel said.

“Long hours and careful planning” is how we do it, said “Speedy” Clinton Horton Jr., who coordinates the truck arrivals. The trucks start lining up before dawn every morning and Horton and other workers arrive about 4:30 a.m. “I’m lucky if I can get out of here by 10 most nights.”

Steel going up fast

The installation of 16,000 pieces of steel, already visible from afar, looks methodical: Ship it, lift it and install it.

After the custom-made bars arrive from Utah, Texas and elsewhere, the four crews on the ground attach the beams to a crane. The crane lifts up to five pieces of steel at a time — called “Christmas-treeing” — into the stands where the rest of the workers are stationed. They install about 50 pieces a day, more than about 35 beams per day for the typical project.

The 500 workers on site, some of whom worked on the Bay Bridge project, toil 50-to-60-hour weeks but like the idea of being a part of the history of their favorite football team. They wear 49ers jerseys every Friday and show off their devotion to the team in some creative ways; one guy even had the team logo tattooed into his hairdo.

“It’s different than any job I’ve been on,” said ironworker Jennifer Cecil, who is still looking forward to catching a glimpse of quarterback Alex Smith practicing at the team’s adjacent training facility.

Crane operator Dan Dalton, 65, has been building stadiums and other projects for 42 years, and always goes back to check out the sports action after they’re built.

“It’s really kind of special,” Dalton said during a brief break inside the cab of his 350-ton crane. “You know a lot more about the stadium than anybody that’s been there.”

Contact Mike Rosenberg at 408-920-5705. Follow him at Twitter.com/rosenberg17.