By Laurie A. Shuster
Along with the twin towers, known as 1 WTC and 2 WTC, all the skyscrapers at the World Trade Center complex were destroyed or badly damaged, including 3 through 7 WTC, as was the Port Authority Trans-Hudson, known as PATH, rail terminal.
The master plan of architect Daniel Libeskind, AIA, for the redevelopment of the site called for half of the 16-acre site to be devoted to public space, including a memorial and memorial museum (see pages 48-49), and the other half to be devoted to rebuilding sustainable office towers.
About 3 WTC
- Architect: Rogers Stirk Harbour + Partners.
- Structural engineering firm: WSP.
- Most recently completed tower, June 2018.
- 1,079 ft in height (80 stories).
- 2.5 million sq ft.
- Clad in stainless steel, the exterior frame connects to load-sharing K-shaped bracing at the corners. This K bracing enables all corners of the tower to be free from columns, maximizing views.
- Ground-level podium houses retail space while tower above hosts office space.
About 4 WTC
- Architect: Maki and Associates.
- Structural engineering firm: LERA Consulting Structural Engineers.
- Completed in November 2013.
- 977 ft in height (72 stories).
- 2.3 million sq ft.
- Steel frame, including perimeter columns, erected before concrete core. Steel frame encapsulated in reinforced concrete.
- Floors plans are parallelograms from levels 15 to 54 and trapezoids from levels 57 to 72.
About 7 WTC
- Architect: SOM.
- Structural engineering firm: WSP.
- First of the World Trade Center towers to be completed, in May 2006.
- 741 ft in height (52 stories).
- 1.7 million sq ft.
- Uses ultraclear, low-iron glass and stainless steel spandrels behind the glass to help reflect sunlight.
- First New York City commercial office building to be certified in LEED; received a gold level rating. Made with recycled steel and insulation and uses captured rainwater to help cool the building.
- Although some foundation work for a planned 2 WTC tower has been completed, the final design of the tower, as well as an anticipated 5 WTC, is still in planning. The eight-story 6 WTC was damaged in the terrorist attacks and was demolished to make room for the new 1 WTC. At present, there are no plans to replace 6 WTC.
Laurie A. Shuster is the editor in chief of Civil Engineering.
This article first appeared in the September/October 2021 issue of Civil Engineering.
Read the next article in the collection: "From the ashes: The World Trade Center PATH Station."
