The Atlanta Falcons tested the retractable* roof on their new stadium which is due to host its first exhibition game at the end of the month.

The Mercedes Benz Stadium, which cost an estimated US$1.6 billion, closed its roof for the first time in advance of the new season. The revolutionary mechanism opens like the aperture* on a camera lens.

Once fully operation, the roof should be able to open or retract in just 15 minutes, protecting the 70,000 fans the elements.

However, despite the imminent* start of the season, the roof will not be fully operational on day one. The project was hit by a number of delays which will impede* the operation of the roof. While the roof might seem to rotate during its operation, this is an optical illusion. The eight petals are moved by giant mechanized bogies which cantilever the structure into place. Once the roof is closed, air inflated pillows are deployed to form a waterproof seal. The lightweight fabric is translucent* and allows light to pass through.

Contractors have begun the process of permanently attaching the mechanism to the roof structure, although it could be a number of months before the system is fully operational.

Work on attaching the mechanism will take longer than planned due to the stadium’s busy schedule.(SD-Agencies)