The first crucial design decision made by Santiago Calatrava for the World Trade Center Transportation Hub was to envision the ‘Oculus’ as a freestanding structure at ground level. Strategically positioned along the southern edge of Daniel Libeskind’s ‘Wedge of Light’ plaza, this approach effectively creates a moment of architectural respite amidst the dense cluster of commercial skyscrapers. Furthermore, it establishes a vital link in the chain of green spaces stretching from City Hall Park to the serene churchyard of St. Paul’s, seamlessly transitioning through the WTC Transportation Hub plaza and extending to the tranquil gardens of the Memorial and Battery Park along the Hudson River.
The ‘Oculus’, the centerpiece of this transportation hub, is constructed from steel ribs and glass, forming a grand elliptical shape. These ribs gracefully extend to create dual canopies that shelter the north and south sections of the plaza, offering both aesthetic appeal and functional shelter.
These structural elements originate from two impressive 350-foot arches that frame the central axis of the project. Nestled between these arches is a 330-foot operable skylight. This architectural feature not only provides a framed view of the New York sky but also serves a poignant purpose, opening on pleasant days and annually on September 11th, as a symbolic gesture of remembrance and openness. While the form of the Oculus evokes various traditional motifs – from the Byzantine mandorla to the wings of cherubim and Egyptian canopic urns – Santiago Calatrava himself encapsulates its essence with the evocative image of a bird taking flight from a child’s hands. This design allows abundant natural daylight to permeate the WTC Transportation Hub, cascading through all levels and reaching as far down as the PATH train platform, situated approximately 60 feet below street level. As night falls, the illuminated structure transforms into a beacon, serving as a metaphorical lantern for the surrounding neighborhood, enhancing the urban landscape. Calatrava emphasizes the role of light as a structural element within this transportation hub, describing the building as being supported by ‘columns of light,’ highlighting the ethereal and uplifting quality of the space.
Access to this significant transportation hub is facilitated from Church and Greenwich Streets, leading through the east and west arch abutments of the Oculus. Entry stair landings project over the expansive below-grade piazza known as the Transit Hall. Within this hall, escalators, elevators, and staircases provide convenient access to the upper and lower retail concourse levels, integrating commercial spaces within the transportation infrastructure. The lower concourse lies approximately 34 feet beneath street level and extends 160 feet below the apex of the operable skylight, creating a sense of vastness and depth. This column-free elliptical space measures approximately 350 feet in length and 115 feet at its widest point, offering a spacious and open environment for commuters and visitors alike.
The site of the transportation hub is bisected by the #1 subway line running beneath Greenwich Street. To the west of this subway line, and eight feet below the lower concourse, lies the PATH Hall. This area is dedicated to ticketing, fare control, and other essential services for accessing PATH trains, streamlining the commuter experience. Mirroring the design of the Transit Hall and Oculus, the PATH Hall is characterized by a series of parallel steel ribs, which in this instance, form an undulating ceiling plane 55 feet above the floor. The clear spans within this space contribute to passenger comfort, ease of orientation, and enhanced security, crucial elements for a modern transportation hub. The PATH Hall and Transit Hall are interconnected beneath the #1 subway line, ensuring visual connectivity between the eastern and westernmost points of the WTC Transportation Hub, promoting seamless navigation. Below the PATH Hall are four PATH train platforms, providing vital rail services to Hoboken and Newark, New Jersey, connecting New York with its neighboring state. Openings in the PATH Hall floor create a spatial dialogue between the platforms below and the hall’s ceiling above, ensuring that arriving commuters are immediately welcomed into a grand and uplifting space upon detraining, enhancing their daily transit experience.
The thoughtful combination of abundant natural light and the building’s striking sculptural form imbues the lower levels and pedestrian walkways of this transportation hub with a sense of dignity and beauty. This architectural achievement provides New York City with a unique type of public space, one that elevates the everyday experience of transportation and offers a moment of architectural wonder within the bustling urban environment, setting a new standard for transportation hubs globally.
