Cranes install base of spire on roof of 1 WTC

Cranes install base of spire on 104th floor roof of 1 World Trade Center

The first piece of the spire for One World Trade Center is lowered by construction cranes into position on the roof of the tower, Tuesday, Jan. 15, 2013 in New York. When the spire is completed the building will top off at 1776 feet (541 meters), making it the tallest building in North America. (AP Photo/Mark Lennihan)

NEW YORK (AP) -- Workers at the rising 1 World Trade Center on Tuesday installed the first piece of the spire that will make the 104-floor skyscraper the tallest in the Western Hemisphere.

Dozens of construction workers were on hand as two giant cranes on the roof slowly lowered the massive, round piece of steel into its socket — the base of the 800-ton, 408-foot spire that will also serve as a world-class broadcast antenna.

"Its function is incredibly important to the region," said Anthony Hayes, spokesman for the Port Authority of New York and New Jersey, which owns the 16-acre trade center site. "We're bringing broadcast back down to lower Manhattan on top of the World Trade Center."

With a beacon at its peak to ward off aircraft, the spire will provide public transmission services for television and radio broadcast channels that were destroyed on Sept. 11, 2001, along with the twin towers.

The nearly 70-ton piece floated into Manhattan last month on a barge. It's the heaviest of 18 parts that will top the 1,776-foot skyscraper symbolizing America's freedom

Overlooking the Statue of Liberty and Ellis Island, the high-rise is scheduled to open for business in 2014.

Major tenants include the magazine publisher Conde Nast, the government's General Services Administration and Vantone Holdings China Center, which will provide business space for high-profile international companies.

The new tower is at the northwest corner of the site, which is well on its way to reconstruction, with the 72-story 4 World Trade Center and other buildings also going up.

The tower's crowning spire is a joint venture between the ADF Group Inc. engineering firm in Terrebonne, Quebec, and New York-based DCM Erectors Inc., the prime steel contractor for the tower.