FORT LAUDERDALE, Fla. -

Construction was moving along Friday at Fort Lauderdale-Hollywood International Airport's $791 million runway expansion project.

"We are working probably 12 to 16 hours a day right now and spending close to $750,000 to a $1 million a day on this project," said Kent George, the director of Broward County Aviation Department. "This new runway will not only add to safety but will add to capacity for the airport."

When the 8,000-foot-long runway is finished in September of 2014, FLL is expected to add 150,000 flights a year.

Construction crews have manufactured 850 steel-reinforced beams that will support the runway as it goes above U.S. 1. The beams, which were created at a concrete plant built at the airport, would stretch 13 miles if laid end to end.

Crews will also pour most of the 478,000 square yards of concrete needed for the project at night.

"It has to cool at a certain rate," said FLL spokesman Greg Meyer. "If you were to do this in the daytime with 90 or 95 degree temperatures, it would dry too quickly."

On the eastern-most portion of the runway is the mechanically-stabilized wall, which was more than halfway complete Friday.

"It is an engineering marvel, really," said Meyer.

The six tunnels that will allow cars, trains, and bicycle traffic to travel beneath the runway were also taking shape. Next April, crews will demolish the Airport Hilton and beginning expanding and remodeling the international terminal.

"We are on a very tight deadline here," said George. "September 18th, 2014, this all has to be functional."