OUTSIDE THE HUDSON YARDS CONTEXT
, the name The Shed sounds informal, practical, and auxiliary. Sheds customarily serve larger buildings—storing tools and materials, providing workspace—and initial plans for a “culture shed” within the Yards could be read as implying that the arts were an afterthought. After city officials decided to repurpose the intended West Side Stadium/2012 Olympics site as a multiuse district, recalls Robert Katchur, principal at Diller Scofidio + Renfro (DSR) and project architect on the Shed, “they knew that to draw a full neighborhood, they would need a cultural component, but they didn’t know what it was.” Yet the Shed, a response to the city’s RFP steered by architects rather than developers, flips the script and seizes the spotlight: though arguably an appendage to the 15 Hudson Yards tower from the commercial perspective, the Shed became an instant icon when it opened in April 2019.
The Shed is dedicated to experimentation and high-culture-meets-low hybridization in the visual and performing arts, and its profile is appropriately novel as well. Its 120-foot-tall shell, a hard/soft textural combination featuring translucent ethylene tetrafluoroethylene (ETFE) cladding on a mobile structural-steel diagrid frame—rolling on six assemblies of 6-foot-long steel bogies, either to enclose a 17,000-square-foot performance space (The McCourt) or to expose the same area as a 20,000-square-foot open plaza—has no precedents in New York. In both the eye-catching kinetic component and its harbor, the fixed Bloomberg Building, which includes its own fine-tuned operable features, the Shed offers a tangible expression of the flexibility its leaders intend to foster in new artworks.
The Shed’s shapeshifting form stems partially from the anomalous conditions of its planning, Katchur observes. Since the Yards district was conceived before the 2007-08 financial collapse but designed after it, when one developer had backed away and arts endowments were at a low ebb, the Shed arose in a kind of organizational void. “We were playing architect, client, and financier for a while,” Katchur recalls, with encouragement from city development official (now Shed chairman) Dan Doctoroff and then-
Mayor Michael Bloomberg, as well as a 2010 National Endowment for the Arts grant to Hudson Yards Development Corporation, but with no major cultural institutions stepping up to occupy the city-owned site. The absence of a conventional client afforded the partnership of DSR and Rockwell Group considerable freedom to develop a performance-driven, infrastructure-based parti. Elizabeth Diller, Katchur, and others recurrently describe the organizing principle as “all muscle, no fat.”
Diller and David Rockwell teamed up to answer the city’s RFP with a proposal that responded to scaling-up trends among worldwide cultural centers, Katchur says, as well as the city’s interest in a space large enough to host major events like Fashion Week. Asking open-ended questions—”How can you make a building that will transform itself and be able to be what it needs to be for the moment, when you can’t really picture what the next 15 or 25 years are going to bring?” and “What role would it fulfill in a city that already has 1,200 cultural institutions?”—the team crafted both a design and a business plan.
In the schematic-design stage, the architects
also asked decision-makers and technical personnel from other institutions about their own experiences. Drawing on existing facilities’ input, DSR based
the Shed’s details and proportions on operational concerns. The McCourt facade’s vertical lift doors
are large enough for trucks to enter from the plaza
for direct loading onto the stage, a feature that also greatly expands fire egress capabilities, notes senior principal Scott Lomax of Thornton Tomasetti (TT). TT’s engineers are experienced with arenas and convention centers, which also rely on broad trusses to create large column-free spaces; the Shed structure, with its stiff external frame plus interior trusses and secondary members, can support 120 tons of rigging above the performance spaces, with the entire ceiling available as an occupiable theatrical deck.
Strength and flexibility are not limited to the McCourt. The eight-story fixed building stacks two double-height gallery areas on levels 2 and 4, topped by the Kenneth C. Griffin Theater on level 6, and the Tisch Skylights and Lab on the top floor. The two gallery levels have folding Bator doors, which when retracted connect space to the McCourt that can add raked balcony seating, expanding the main space’s capacity to 3,000; opening Level 2’s adjacent gallery expands the McCourt’s area to nearly 30,000 square feet. Castellated beams allow 100-foot clear spans in the double-height galleries; vibration-isolation slabs increase these spaces’ acoustic and programmatic autonomy, and strong points in the floors and ceilings allow construction of thin cantilevered walls to create more intimate spaces. While the McCourt shell’s operability is the Shed’s signature feature, the entire building is engineered for reconfiguration.
A key decision at the schematic-design stage, Lomax reports, was that “we would like to express the structure, not have a structure that would then be hidden by cladding.” The movable shell is a three-sided box (north and south walls and an east facade) “acting like a portal frame, very similar to a gantry crane”; the diagrid’s acute angles show how the structure achieves lateral stability as the vertical members carry gravity loads. The main vertical and diagonal elements are composed of curved and doubly-curved steel plates in a monocoque design, he notes, with crisp edges and flat, smooth surfaces. “It’s basically a trapezoidal section,” Lomax continues, “with the exception of the nodes, built up with plate thicknesses ranging from 5/8 of an inch to about two inches. The balance of those plate thicknesses is partly the engineering demand: obviously, it needs to stand up [and] have the right amount of stiffness, and it’s a balance between strength and stiffness … but part of it was also driven by a deep understanding of the fabrication process.”
The steel fabricator, Lomax notes, chosen after the team compared three test mockups of a challenging full-scale node, was closely involved with the design team in determining measures that would safeguard the design vision without soaring expenses. “It’s very high-end steel work,” he says; “it’s exposed plate work. It does come with a premium—it’s not the same as doing standard conventional plate work— but it doesn’t mean that you cannot still control the economy of that process.” One risk with monocoque designs, he explains, is “you go so thin on the external plate, and then you have a welding behind it, that sometimes you see the effect of that welding; it’s called the hungry-horse effect, where you see that ribbing.” Conferring closely within the team about procedures and dimensions, “we’ve reduced welding by not having internal stiffeners, or reduced the number of internal stiffeners, and we’ve made their life easier, because during the fabrication process they do not need to worry so much about distortion during the welding process.” The idea “that the lightest structure is always the cheapest structure,” Lomax says, is a misconception; “by understanding the craftsmanship of how something is going to be built, and understanding what a fabricator needs to go through to control that process, we can actually add material, reduce complexity, and get a better-quality product.”
The shell’s four single-axle and two double-axle bogies are made of 8-inch-thick plates totaling 25 tons of steel, supporting the whole mobile shell on eight points. (In detailed negotiations with the Department of Buildings, Lomax reports, TT demonstrated that “any one of those supports could deflect, and it wouldn’t impact the building’s ability to stand up.”) The bogies roll on MRS 221 rail, the largest gauge commercially available, assembled in transportable-length pieces and thermite-welded onsite into two continuous 273foot tracks. “The whole idea was to have the plaza as clean as we possibly could,” Lomax notes, “which meant that up on the top of the fixed building we have these rack-and-pinion drive systems, and on those drives runs this rack and pinion that is connected to the trusses up in the roof.” The sled drive that moves the shell comprises twelve 15-horsepower motors (the resulting 180-hp system has been loosely compared to a 134-hp Toyota Prius engine, though its output is closer to that of a Jeep Compass or a Mazda 6, a few horsepower below a Mini Cooper). A centering device atop the assembly absorbs horizontal stresses, helping stabilize the system under wind loads.
ETFE cladding, Katchur says, was a logical selection as a thermal insulator with 1/100th the weight of glass. Considering “the movements that we would induce by making a moving building,” he says, “if you did that out of glass, you would be really wrestling with the size of the joints and the way in which the components were going to fit together.” Panels of ETFE (up to 70 feet long, some of the largest ever manufactured, arranged as 146 three-layer cushions and two with four layers) clip onto structural members with aluminum-framed extrusions and are inflated by four air-supply units with variable-speed main and backup fans; sensors adjust the air pressure to weather conditions. The shell’s distinctive soft-white tone results from variation in the layers’ colors: a print pattern for the top layer, a white middle layer with 29% opacity, and a transparent bottom layer.
ETFE, Katchur adds, allowed “a terrific embodiedenergy savings, in a sense that it performs equitably to glass” thermally while sparing the load burden. “It’s impossible for us to have an entirely reliable statistic without designing a glass version of this thing, but I would wager that we probably saved 25% of this raw steel tonnage on the project by selecting ETFE.”
The gains in lightness and thermal control with ETFE come with an acoustic downside. To help keep street noise out and music in, the team specified blackout shades massive enough to absorb sound as well as darken the interior. They also borrowed from sailing technology, applying an acoustic mass onto a carbon fiber sail. “It could roll up onto a mandrel motor, much like you’d find in the marine world for a jib on a sailboat,” says Katchur. “A furling motor is inside of a steel tube, and then the shade wraps around it, so we have a 3/4-inch ABS [acrylonitrile butadiene styrene] plastic hat attached to a carbon-fiber tail, connected by about 5 or 6 pounds a square foot of acoustic mat.” The Shed is too new a typology for most local fire and safety codes to apply. “There are not codes written for moving buildings,” Katchur notes; “you have cranes’ and derricks’ and bridges’ codes, and you have building codes…. How do you fire-rate a wheel?” The team “developed a great working relationship with the City of New York,” he says, hashing out new applicable standards in detailed negotiations. Since ETFE, although fire-retardant, would disappear quickly in the event of a fire a performance based design (PBD) approach was developed with the Department of Buildings. “This approach combined the inherent redundancy of the structure with detailed fire modeling and recognizing that, sans ETFE, we have an outdoor structure,” says Lomax. “Using this methodology we determined that the fire protection could be simplified with intumescent coating only applied up to the door headers and spray-on protection in the mechanical deck. This was a significant savings in terms of time and money and preserved the appearance of the exposed steel diagrids.”
As the Shed—its official title trimmed after Poots came on board and noted that the word “culture” seemed redundant—evolves to define itself in mission and form, perhaps its punchy name works best as a verb. Musicians refer to solitary practice, learning material and developing chops, as “woodshedding” or simply “shedding.” This building—perhaps the one part of Hudson Yards that invites the whole public in, the one with a chance to overcome the wider project’s cycle of hype and blowback—sheds preconceptions on multiple levels (programmatic, structural, material, civic) and gives New Yorkers more than another cultural playground. It’s built to give us things to think about.