Arch Street Presbyterian Church

Posted by Ellen

The 199-year-old dome of the Arch Street Presbyterian Church is reflected at the base of the four-year-old Comcast Center office tower, tallest building in Philadelphia and fifteenth-tallest in the United States.

The black cube-like structure at the top of the blue-glass tower is said to be a water tank containing 300,000 gallons of water. The weight of the water–thirteen hundred tons–helps keep the building from swaying in high winds. The Comcast Center's Tuned Liquid Column Damper is touted as the largest watery building-stabilization system in the world.

The 58-story tower is 974 feet high. The cable company uses about 90 percent of the building's one million square feet of office space and leases out the rest.

Comcast touts numerous energy-saving features of the tower, notably including waterless urinals, which were opposed by the plumbers' union. The dispute was resolved by an agreement that included installation of plumbing to all the waterless urinals in case they didn't work out and had to be replaced by conventional urinals.