The Port Authority and the Durst Organization will be testing the spire and beacon on top of the Freedom Tower at 5:30 p.m. on Friday.
The Durst Organization is responsible for operating the spire, which is intended to be a broadcast facility.
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The spire and beacon are 408 feet tall. The beacon is the top portion of the spire and holds 288 50-watt LEDs. The spire will be visible from as far as 50 miles on a clear night.
Ironworkers installed the last portion of the spire on May 10. With the spire, One World Trade Center stands a symbolic 1,776 feet tall.
The spire and beacon will be visible throughout the city Friday evening from 5:30 p.m. onward, the Port Authority said.
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