Shrouded in foreboding black safety netting, the former Deutsche Bank building near ground zero has loomed over Lower Manhattan as a jagged reminder of both the 9/11 terrorist attack and the lengthy delays in rebuilding the neighborhood.
Now, three and a half years after demolition of the 41-story tower began, workers next week will start the arduous job of dismantling its 26 remaining stories and removing 15,750 tons of concrete and 11,000 tons of steel.
Crews have already replaced the black plastic netting shrouding the building with blue, fire-retardant netting; removed all the walls, glass, plumbing and work sheds from the interior; and erected a plywood perimeter around the top three floors. The construction manager, Bovis Lend Lease, expects to get a permit from the city's Buildings Department early next week to resume demolition.
In the coming months, ironworkers, operating engineers and laborers will go floor by floor, smashing the concrete into rubble, cutting the steel beams and lowering the debris to the ground under the watch of a small army of fire guards, inspectors and regulators. Sometime next spring, the star-crossed building will cease to exist.
"We believe we have developed a plan utilizing the latest techniques and best practices to safely and efficiently deconstruct 130 Liberty Street," Steven H. Sommer, a senior vice president of Bovis Lend Lease, said in an interview on Tuesday.
It has been a long time coming. In 2001, steel from the falling south tower of the World Trade Center tore a 24-story-long gash across the northern facade of the skyscraper. Deutsche Bank squabbled with its insurers for nearly three years over what to do with the building.
In 2004, the bank, the state and insurers reached an agreement in which the Lower Manhattan Development Corporation would buy the tower for $90 million, and two insurers - AXA and Allianz - would be responsible for most of the demolition costs.
Since then, the demolition has been plagued by delays, regulatory failures by city agencies, criminal investigations of contractors and the death of two firefighters in a 2007 blaze.
After the fire, the development corporation and Bovis abandoned their plan to strip the building of hazardous materials and demolish the structure simultaneously. Decontamination of the remaining 26 floors resumed in January 2008 and was completed in August.
While it took 250 workers to decontaminate the building, demolition will require only 50. Starting on the 26th floor, crews will use three Brokks - remote jackhammers mounted on mechanical arms that extend from motorized bases - to smash the floors into basketball-size chunks of concrete, which will be allowed to fall to the floor below.
Once the concrete is stripped away, ironworkers will mount scissor lifts and use acetylene torches to cut the steel beams. At any one time, there will be four to eight cutting teams. The work site will be surrounded by fire blankets and fire guards armed with water hoses or extinguishers to put out any flames from molten steel, or slag.
The cut beams will be lifted to the floor by minicranes, which will place the steel into specially designed containers. A tower crane will move the containers to the ground, where the steel will be unloaded and trucked away.
The concrete will be crushed and used to fill the basement cavity of the building.
In the early days of the project, workers demolished one floor a week. At that rate, 26 floors would take six months. Because they have revised their demolition plan, Bovis executives were reluctant to say exactly how long the last stage would take.
"Demolition is inherently dangerous," said David Emil, president of the Lower Manhattan Development Corporation. "The city and Bovis have worked on a plan to minimize the risks to the greatest extent possible. We're happy to be approaching the final stage, but we remain vigilant on the safety issues."