Denis Hamill tells why there is so much union pride in building Barclays Center in Brooklyn

Construction boss Bob Sanna is behind the Nets new basketball arena

Bob Sanna, a Brooklyn native, is in charge of construction for the new Barclays Center for the Nets in Downtown Brooklyn. Also various photos of construction.

By Denis Hamill

The billion-dollar arena is 60% finished.

After all the political debates, protests, lawsuits and economic setbacks since 2003, Barclays Center is real now, rising from Brooklyn where Atlantic Ave. meets Flatbush Ave.

At long last a professional sports venue nears completion in my native Brooklyn, where there hasn’t been one — except for the minor-league Cyclones stadium in Coney Island — since the Dodgers cakewalked in 1957.

Expect the first Brooklyn Nets’ tip-off by fall, 2012.

As a sports-crazed kid who grew up 11/2 miles from here, I know this new arena will have a profound effect on Brooklyn kids, their parents and new immigrants who will unite behind a true home team, the way the Brooklyn Dodgers made my immigrant father more of a true American than his citizenship papers did.

My old man was a factory worker unionized by Local 3 of the IBEW, allowing me to work as a college helper on construction sites. Working two summers with Local 3, I formed a lasting respect for the skilled tradesmen who build this city.

Politics behind us, I want to meet the guy in charge of building Barclays Center.

I enter the loud, bustling construction site off Dean St., don a hard hat, and greet Bob Sanna, head of construction, a Park Slope native, also the son of a Local 3 worker. “I was always a tinkerer,” Sanna says, as cranes swing and power tools roar. “I liked building things. So I got a degree from CCNY in architecture.”

He signed with Forest City Ratner 22 years ago, building Metro Tech, Atlantic Terminal, 80 DeKalb Ave. and more.

“There’s a sense of pride in helping to transform Downtown Brooklyn where I’m from,” he says, leading me into the venue.

What was the first thing he had to do to erect this 18,000 seat arena?

“Demolish 52 buildings,” he says. “We did that in sections, starting at Atlantic Ave, as politics played out and tenants vacated. Then we start carving away at the land.”

Bruce Ratner, the builder, wanted Barclays Center different from Madison Square Garden where you have to scale endless escalators.

“He wants fans to enter at grade, or street level,” says Sanna. “Meaning the event level will be 25 feet below grade. This means a 25-foot-deep hole about 120-by-200 feet in dimension. But the trick is what to do with the dirt so the hole doesn’t collapse in on you.”

In March 2010, enter Dockbuilders Local 1456, drilling 25-foot deep holes every five feet, fitting in steel beams, shored by wooden planks.

“Then comes a parade of 40 trades,” Sanna says. “Local 20 guys pour concrete on the 250 steel footings, held together with metal straps, making foundation walls, forming a big fat concrete pontoon if you will, that keeps our main foundation from penetrating into the ground. The whole arena sits on this structure.”

Ironworkers of Local 580 came next.

“They started setting the structural steel columns on Atlantic and Sixth and built down the street, making a left, and circling the outside of a donut hole,” Sanna says, pointing up where crawler cranes set a steel massive roof frame. “The roof is following the same circular pattern. When the steel is finished, the ironworkers lay a corrugated metal deck.”

Then Local 46 lathers bind the iron mesh and rebar before Local 20 guys pour concrete. “There are four levels above ground, two below,” Sanna says. “With one clear span dome cap.”

Under which will perform an urban symphony of plumbers, steamfitters, painters, carpenters, electricians and all the rest of the 40 trades that Brooklyn-born Bob Sanna oversees in the construction of the first major professional sports venue in Brooklyn in 55 years.

“Office and residential buildings where people live and work are exciting,” says Sanna. “But there’s a special feeling in having a hand in building a sports and entertainment arena where memories are made and history happens in my native Brooklyn.”