The massive construction project to revamp the USTA National Tennis Center is in full swing, but the clock is ticking on phase two of the project, as crews get ready for one of the city's biggest events. NY1's Ruschell Boone filed this report. 

The harsh winter almost knocked them off schedule but tennis officials say construction at the USTA Bille Jean King National Tennis Center will wind down in a few weeks to start the preparation for this year's U.S. Open.

"We had to bring a third crane in in March to get it back up to speed after a really rough January and February," says Chief Operating Officer Daniel Zausner.

Crews are building a retractable roof over Authur Ashe Stadium, a new grandstand court and other facilities. 

"The iron workers are getting ready to demobilize over the next couple of weeks so we can spend the balance of this summer getting ready to have the site ready to have the site in perfect condition for this years U.S. Open," Zausner says. 

That means removing all the cranes and other construction equipment from the center. No work will be done during the Open which is set to start on August 31. 

One hundred and fifty tractor trailers will come on site and take all these crane pieces out of here and they won't show back up again until after this years open.

The construction is part of a five-year $500 million renovation plan. The biggest part of the project is the retractable roof which is being built to protect fans from the elements. That's slated to be completed in time for the 2016 Open. 

"One of the two retractable portions will sit on the far east side and one will sit on this far west side over here and they will move from east and west to the center and closing that whole gap here. The rest of the time this will all be wide open and as you can see by how large, this opening is the stadium will still feel like an out door stadium," Zausner explains.

The new grandstand court will expand capacity to 8,000 from 6,000 seats. Construction on the new Louis Armstrong Stadium will begin in the fall of 2016 and that will add 5,000 seats, bringing its capacity to 15,000. 

Fans of the U.S. Open know that the existing Grandstand Court is attached to the Louis Armstrong Stadium. A structure that dates back to the 1964 World's Fair believe it or not. So at over 50 years old it's kinda outlived its useful life. 

The court is being built on the the Southwest corner of the tennis center to make more room for fans who will see significant changes in 2016. 

"All new grandstands, all new restrooms, concession stands, merchandise, fan activation. Everything fun will be improved tremendously for 2016," Zausner says.