Freedom Tower Redesigned to Be World’s Safest Skyscraper

Wed July 13, 2005
Aggregate Equipment Guide

NEW YORK (AP) Hurriedly redesigned to make it less vulnerable to a truck bomb, ground zero’s Freedom Tower will lose its distinctive, twisting look but will be the safest skyscraper in the world, officials said June 29.

The redrawn tower will be slimmer, straighter and more conventional, it will be set farther back from the street, and it will be placed atop a mammoth, 200-ft. (61 m) concrete-and-metal pedestal designed to repel explosions.

The changes will require the relocation of the 20-ton granite cornerstone that was laid with great fanfare by Gov. George Pataki last Fourth of July.

The original design for the tower that will rise on the site of the destroyed World Trade Center was sent back to the drawing board in May after the police department raised concerns that it would be too vulnerable to truck bombs.

The new design is intended to meet the security standards set for U.S. embassies, making it the world’s safest high-rise building, said lead architect David Childs.

“This building is as robust and as strong as any I’ve ever been in,” he said.

The original design had a twisting, asymmetrical shape that was meant to evoke the outstretched arm of the Statue of Liberty it will overlook. The new design will be a more rectangular shape with some of the square edges shaved off, resembling a faceted version of one of the twin towers.

“In a subtle but important way, this building recalls … those buildings that we lost,” Childs said.

Construction is expected to begin next year, with steel rising above ground level in 2007 and completion scheduled for 2010.

Like the World Trade Center, the tower will reach 1,362 ft. (415 m) into the sky. But an illuminated spire, meant to evoke the Statue of Liberty’s torch, will stretch the building to the symbolic 1,776 ft. (541 m) envisioned in the original Freedom Tower design. The spire will change color and cast alternating beams of light to the sky and to the horizon.

The base will be constructed of 3-ft. (.91 m) thick concrete, clad in a shimmering metal curtain that will afford additional blast protection and also give the impression of movement and light. Above the 20-story concrete base, the building will be sheathed in plastic-laminated glass for increased resistance to explosions.

The building will be set back an average of 90 ft. (27 m) from West Street, the major thoroughfare along the Hudson River. The original design placed the building just 25 ft. (7.6 m) from the six-lane highway.

“The new Freedom Tower design incorporates standards the police department had sought to protect the building against bomb blasts, which our counterterrorism experts agree present one of the greatest threats to such iconic structures,” Police Commissioner Raymond Kelly said in a statement.

The need to set the building farther back from the street forced the architect to reshape the base and abandon the asymmetrical design.

As in the original design, stairwells, elevators, communications systems and water mains will be protected in a concrete and steel core. It will have extra fireproofing, biological and chemical air filters, extra-wide emergency stairs, a dedicated staircase for firefighters and “areas of refuge” on each floor.

The new design also retains plans for 2.6 million sq. ft. (240,000 sq m) of office space on 70 floors, a restaurant and observation decks.

This story also appears on Construction Equipment Guide.