“I think heroic deeds were all conceived in the open air.”

WALT WHITMAN “Song of the Open Road,” 1856

Constructing the World Trade Center depended first on the configuration of the below- and above-ground transportation network. That network determined where the stores and restaurants along the transit corridors would go. Next, the mechanical systems and foundations shared by the site’s nine structures had to be integrated, both vertically and horizontally. Eight acres (3.2 ha) are devoted to the 9/11 Memorial, the plaza of which serves as a massive green roof, a fully constructed ecosystem, above multiple subterranean structures, including mass transit passageways and tracks, the 9/11 Memorial Museum, and the central chiller plant.

Ordinarily, a building has its own owner and sits on its own plot. Next door is another building, another owner. That situation didn’t exist at the Trade Center, where multiple buildings that were owned or controlled by multiple parties were stacked on top of each other. Moreover, each structure had its own schedule and managers, each of whom was answerable to multiple masters. “Everyone had to dance together or it wouldn’t work. Reaching that level of collaboration took time,” said Craig Dykers of Snøhetta, designers of the museum’s entrance pavilion. “It was like threading the needle through a concrete block.”

The ensuing scrum was an atypical but unavoidable means of construction, given the site’s interconnected nature. Every conversation about this unusual way of sharing space and resources started with “Huh?” Steven Plate, who directed World Trade Center construction for the Port Authority, said, but “we slowly and methodically broke it down into the finest elements and attacked that problem.” Plate’s office allocated a percentage of shared infrastructure costs to each structure, basing it primarily on square footage but also on other parameters, such as the structure’s load, weight, or the amount of water or air conditioning it needed. Building owners are billed separately for maintenance and direct energy use.

Michael Kraft, who coordinated construction for the Port Authority, unfurled a complicated diagram in a rainbow of colors to show me the specific responsibilities of each entity on the site. “We use this as a tool, not just to represent where stakeholders reside in the site, but also as a working document to resolve conflicts,” he said. Project areas yet to be reconciled in color were readily apparent. Pointing out one multicolored block, he said, “That’s where we need to bring the architects and engineers together and work that conflict out.” In every instance, during meetings held weekly since 2005, owners saw the entire site, not just their small piece of it, enabling this remarkable collaboration to unfold.

BUILDING STRATEGIES

My father, who has a knack for coining apt new turns of phrase, speaks of events marked with the “asterisk of sorrow” to describe circumstances whose outcome has been influenced by grief. The rebuilding of the Trade Center was so asterisked, prompting an unprecedented outpouring of ingenuity and hard work. A state-of-the-art enterprise, it required the skills and brawn of thousands, many of them union members. Their numbers include riggers, painters, drywall tapers, plumbers, waterproofers, electricians, and others. All told, forty-nine unions were represented; these estimable brotherhoods are listed at the end of this book. A discussion of the union workers who handled the tower’s primary building materials—steel, concrete, and glass—is shorthand for the extreme talent and determination that so many trades invested in the tower. A timeline of historic construction photographs, shot by the Port Authority over the past decade, documents the heroic business of building a skyscraper.

The Central Chiller Plant is a key element of shared infrastructure. It cools the 9/11 Memorial Museum and other low-rise public buildings, as well as the Transportation Hub, No. 1 subway platforms, and retail stores. The office towers have independent cooling systems. Energy efficiencies include using water from the Hudson River, about 30,000 gallons (113,562.4 L) per minute, to cool the chillers. The water is filtered before being discharged back into the river, and its impact on marine life is monitored in accordance with New York State Department of Environmental Conservation requirements.

The construction site is a noisy place. There are many voices here, all of them speaking at once: the hushed voices of the dead, the barked orders from the project’s many timekeepers, the laborers’ mutterings and jokes, boom boxes blaring hip-hop. They mix with the sounds of jackhammers, welders’ arcs, concrete spreaders, and lumbering trucks. It’s a jumbled cacophony of political perspectives and contradictions, a Rachmaninoff concerto, intense and sublime, all of it gathered into the ever-present existential roar of the memorial’s waterfalls.

Inside too is a glorious collage—exhaust pipes, heating ducts, aluminum tiebacks, glass panels, and steel pulleys that hang down like beads, glinting silver and platinum in the light. There are piles of strange loveliness: slabs of sheetrock, wooden spools of red and blue wire, plastic buckets, cinder blocks. Some pieces are spray-painted “Save.” Dense hieroglyphics—the signatures, thoughts, and drawings of those lucky enough to be inside with a few minutes and a Sharpie—cover the walls. One reads, “Te Amo Tres Metros Sobre el Cielo,” meaning, “I love you three meters above heaven.” Scissor lifts are poised to rise. Orange netting hangs like celebratory bunting from the ceilings. Over everything is a fine pale dust that makes what is material seem immaterial, transporting the visitor to another realm that exists not entirely on earth. I will save this.

Steven Plate is an engineer from a union family. Hands-on, and as dedicated as he is demanding, he created a climate of cooperation at the congested site, negotiating daily who-has-access-first issues among the myriad building teams there. Plate was joined in his efforts by Dan Tishman, chairman and executive of Tishman/AECOM, who would visit the original site with his father, the pioneering contractor who managed the Twin Towers’ construction. Tishman/AECOM managed construction for the Port Authority on a number of the Trade Center’s major structures and portions of the underground infrastructure. A Tishman/Turner joint venture built the Transportation Hub, along with the Downtown Design Partnership. Liberty Security Partners developed the Vehicle Security Center.

Raising the tower was not a linear process. Everything—design, engineering, and construction—was developed concurrently and collaboratively. Because of the economics of large-scale construction, the foundations and underground portion of One World Trade were under way long before the design of the building was complete, shaving at least three years off the schedule. “We had a footprint, we had a layout of the building, we had the beginning of a structural system. We knew where the columns were going to come down. It was unusually informed,” Tishman said. “It’s like a big game of chess. No one move is a move unto itself. Everything you do has a domino effect on many, many other things.”

Before construction of the superstructure began in 2006, months were spent crafting scheduling strategies that ultimately allowed the construction of two floors every two weeks. One such tactic involved building a structure made of thirty-six shipping containers that was hoisted to the tower’s upper levels. Dubbed “the hotel,” it contained a Subway sandwich shop, so workers could avoid making a slow trip to street level for lunch, as well as lockers and restrooms. But it provided much more than $5 foot-longs. The hotel stabilized the tower’s steel frame and reduced the amount of steel that had to be erected before the concrete core, ten floors behind steel erection, caught up. Placed inside the core void, the hotel acted as a roof, protecting workers below from the ironworkers above and from rain, allowing concrete work to continue regardless of the weather. The hotel was dismantled in 2012, when it reached the ninetieth floor, the level at which the tower was too slender to support its size.