The Spiral

One of a Kind.
Sixty Six Times.

Viewable for miles across the Hudson River, each of The Spiral’s 66 floors is uniquely designed to support the structure’s signature spiral exterior, which features a reflective glass façade.

“The name really says it all,” said Patrick Chan, Senior Vice President of Building Structures at WSP USA. “Most commercial buildings tend to be the same footprint all the way up the building. Sixty-six Hudson, with the spiral being one of the feature elements of the architecture, has a different floor footprint on every single floor, and that created a lot of structural challenges. [We] dealt with it by coming up with innovative structural systems.”

The structure’s signature cascading spiral is a connected system of outdoor terraces, each supporting ample greenery and extending usable floor space. The Spiral’s terraces and their supporting plate sizes shrink with each increment in elevation.

“The spiraling terraces work [their] way up the building and spiral inward as we rise through the spiral system, and the footprint gets smaller and smaller by small amounts,” explained Jeffrey Smilow, Director of Building Structures for WSP’s Property and Buildings division. “That's what makes this very unique. The net result is that every single floor is framed differently.”

The completed design provides tenants with terrace access and 360-degree views of Manhattan from wherever they are in the building’s outer regions. While a traditional office experience is often limited by the constraints of standard commercial architecture, The Spiral provides a dramatic upgrade by offering the work-life harmony office workers yearn for post-pandemic.

Aeos: Reduced Weld Preheat & Domestic Availability

Of the 31,000 tons of structural steel used in the project, approximately 4,900 tons were Nucor’s Aeos ASTM A913 high-strength structural steel. Aeos also played a key role in reducing overall time and construction costs on the project, particularly during the welding process.

“When we're working with heavy welds, it's always a complicated process,” said Smilow. “Anything that could be done to reduce the thickness of flanges by any amount. And in this case, we're talking 30 percent less material. [That’s] is a big help.”

But Aeos’s utility in the project extended even further, down to the fabrication and erection phases. Due to its low preheat requirements and enhanced weldability, Aeos saved stakeholders time when it mattered most: during the pandemic.

“Back in March 2020, when we all went into the COVID pandemic, New York state law determined that we had to shut down the project,” said Barry King, President of NYC Constructors. “That turned out to be two months of idle, no construction going on. When we came back, our workforce was able to get aligned with the safety protocols of COVID and bring the job within schedule, on time, and within two months of the original schedule.”

Despite a two-month delay, construction teams were able to fast-track the rest of the project due in part to a material that could flex with their schedule. The most significant time savings with Aeos occurred during fabrication, but the material saved valuable hours and manpower on the field as well.

“We did recognize some of that in the field as well, through the winter months, so A913 did save time,” said King. “I believe that Aeos helped the developer through . . . overall cost and budget savings, [which] allowed them to proceed and continue with the project. It will be a factor going forward for future buildings.”

The reduced welding preheat requirement also contributed to being able to stay on schedule. John Grafrath, General Superintendent for Turner Construction, observed this benefit at 66 Hudson: “The welding time dropped dramatically on this project when we were doing our field welds, because [using Aeos] reduced the preheat time that you had to do to complete the weld. And the welding application was also reduced as far as the duration.”

Additionally, as the only domestic A913 steel, Aeos was readily available in a time of major global supply chain issues. Grafrath explained, “Using American-made steel benefited this project because we had zero scheduled delays. We ordered the steel, we fabbed the steel; the steel always came on time.”

Aeos and The Future
of Building Construction

The path to innovation is hardly linear, but it never ceases to deliver world-class results. With Aeos high strength structural steel, the 66 Hudson Boulevard project stayed on schedule while avoiding major construction issues.

“Having used Aeos at 66 Hudson and the benefits that we've learned from using it, we would definitely recommend using Aeos for new projects [and] future projects,” said Chan. “High-grade steel is going to be the future of the industry.”

Looking toward the future means choosing sustainable solutions today. Nucor’s Aeos, with a recycled content exceeding 95 percent, provides a sustainable structural steel material that project stakeholders can trust. Smilow noted, “The benefit from having higher-strength, lighter material, [is] less effort in the fabrication process and less impact on the environment.”

Construction professionals observed all aspects of the 66 Hudson build and supported their decision to use Aeos. “I would use [Aeos] on my next project,” said Grafrath. “It raised the safety level, which is the number one thing for us, and it decreased the cost and decreased the schedule for us.”

As new tenants flood into The Spiral’s 66 floors of forward-thinking office space, the structural accomplishments enabled by Aeos nod toward a future of endless possibilities for steel construction.