Called the ‘bathtub in the sky’, Delta Precast was responsible for the panel connection designs for a 300,000-gallon, 69 feet X 55 feet x 20.5 feet double-chambered precast concrete water tank on the roof of the Comcast Center in Philadelphia, PA.
The precast tank consisted of (64) – eighteen-inch thick panels, eight feet wide by twenty-six feet long. The panel connection designs consisted of a variety of welded embedded steel plates with studs.
The massive, sealed concrete container is the largest liquid-column damping system in North America. Its purpose is to prevent Philadelphia’s tallest building, (at 975 feet) from swaying in the wind. Though one would think the design is needed for structural integrity, its purpose is for the comfort of the occupants.
When the building begins to sway in one direction due to high winds, the water in the tank compensates by traveling in the opposite direction, actually minimizing the sway.