Rising an historic 1,776 feet, One World Trade Center in New York City not only is the tallest skyscraper in the Western Hemisphere but also is a symbol of American pride and resilience.
Designed by David Childs of Skidmore, Owings & Merrill, the 2.6 million-square-foot building includes office space, an observation deck, world-class restaurants and broadcast and antennae facilities. Once opened, thousands of people will work inside the building, but only a few highly skilled technicians will have access to the top of the building to maintain the communication equipment and lighting fixtures on the roof.
During the final stages of construction, project coordinators and building managers assessed the roof for fall hazards and the application of a fall protection system. The last major phase of construction for One World Trade Center involved using a crane to hoist a 408-foot, 758-ton spire into position.
As the dozens of construction workers perched atop One World Trade Center looked on and applauded the historic milestone, crews installed the final two sections of the 408-foot steel spire on May 10.
"With the final section of spire now in place, One World Trade Center stands as the Western Hemisphere's tallest icon of freedom, resilience and the indomitable American spirit,” said Port Authority Vice Chairman Scott Rechler. "We could not have accomplished this momentous achievement without the thousands of men and women who have given so much over the years toward rebuilding the World Trade Center site. [This] milestone is a testament to the spirit of this great nation and a tribute to all who perished during the horrific attacks on 9/11."
Throughout the project, safety for the workers who entered the construction site was paramount. "Every day, thousands of construction workers from both sides of the Hudson come together to create a new, vibrant Lower Manhattan," said Port Authority Deputy Executive Director Bill Baroni as the spire was placed on the top of the building, adding that the completion of the building "symbolizes the ability of our nation to rebound and come back bigger and stronger than ever."
Hundreds, if not thousands, of hours of planning went on behind the scenes before the placement of those last segments of the spire. With the height of One World Trade Center, providing fall protection for the workers building the tower and installing the spire and for those who will be maintaining the communications equipment and lighting on the roof was a challenge.
When the spire was in the final stages of fabrication, DCM Erectors and the Port Authority of New York and New Jersey began consulting with Rigid Lifelines and other fall protection providers to discuss the possible system options that would meet their needs. Rather than try to install a fall protection system once the spire was in place, it was suggested that the fall protection system be installed on the spire prior to being placed on the roof.
The general consensus was that the system needed to provide continuous coverage to all work areas on and around the spire for a total of six workers simultaneously. The project coordinators decided that a rigid track system would be the best option. However, they needed a team of engineers who were capable of designing a system that completely was customized to their specifications. Rigid Lifelines was chosen to provide the fall protection system.
"We are immensely proud to be protecting America's workers and providing fall protection for the tallest building in the Western Hemisphere," said Arnold Timothy Galpin, engineering manager at Rigid Lifelines, who was the head of the design team for the entire system.
Designing a System
In order to install a fall protection system, a fall hazard analysis is a crucial first step. The analysis process helps fall protection professionals determine which system is best suited for the specific hazards at a work site. John Kemp, Rigid Lifelines' national product and sales manager, explains the importance of having several different staff members present during the planning phase of fall protection.
"Whenever you conduct any elevated work site analysis, you want all parties present who could be affected by any proposed solution(s)," says Kemp. "You need to make sure that you have all departments represented that have a stake in crafting the best solution for the application. Limiting input to perhaps only one department does not promote a team effort, which is critical for the acceptance and use of a system by the at-risk workers."
The fall hazards that maintenance crews face on top of One World Trade Center are not unique to that structure. Anyone who works on top of a skyscraper is exposed to certain hazards that could lead to an accidental loss of balance and potentially result in a fall. Lessons that were learned at One World Trade Center could serve to keep workers safe at other high-rise buildings.