When the most storied franchise in sports decides to replace the most historic ballpark in baseball, challenges would be expected at every level — political, budget and schedule, fan expectation, and historical reverence. To meet these challenges, the New York Yankees and developer Tishman Speyer assembled an all-star design team. The result is a new Yankee Stadium that respects its rich history, while achieving a facility with cutting-edge design and fan amenities.
The emotional connection fans have to the original Yankee Stadium comes from the team’s rich history. The ballclub was born in 1901 as one of eight charter franchises of the American League — and was based 200 miles from the Bronx and with a very different name — as the Baltimore Orioles. In 1903, the team relocated to New York City and became the New York Highlanders. The team played at Hilltop Park in northern Manhattan between 1903 and 1912. It is here that New Yorkers’ reverence for the history of its sports franchises was born, as a plaque still marks the home plate location — now in a courtyard of the uptown campus of New York Presbyterian Hospital.
In 1913, the team changed both its name and address, becoming the New York Yankees and relocating east to share a facility with the New York Giants at the Polo Grounds in Harlem. Located on a hilltop in Coogan’s Bluff, the former stadium is within sight of the current stadium. The Yankees shared this facility with the New York Giants until 1922, when the New York Giants noticed more fans attending Yankee games than Giants games to see a new Yankee phenomenon — Babe Ruth.
Having outgrown the capacity and their welcome at the Polo Grounds, the Yankees constructed a stadium (in just 11 months) in the Bronx at 161st Street and in 1923 moved into Yankee Stadium. Despite a major renovation in 1974 that removed and altered many of the historic details, the Yankees have played in the same facility in which all the Yankee greats — Ruth, Gehrig, DiMaggio, Mantle, Jackson, and Jeter — have written their portion of an unfolding history.
The design team was engaged in January 2005 and charged with creating a facility that incorporates modern amenities within the historical context of the old stadium. Setting new roots directly across 161st Street played a significant part in capturing that history and sense of place.
The new stadium nestles between River and Jerome Avenues at 161st Street on what was formally a public park, which will be replaced and improved with new facilities occupying the footprint of the old stadium as part of a neighborhood redevelopment masterplan. This site provided the first structural challenge, as the name River Avenue implies. A former river ran directly through the site, creating conditions of shallow rock outcrops at the “river bank” on the western portion of the site and fill underlain by deep silty clay, sand, and glacial till on bedrock under the majority of the site. Rock depths varied from surface rock outcrops at grade to 125 feet below grade, with some borings unable to find competent rock. The top of the water table was a relatively shallow 12 feet below the existing surface.
To satisfy the programmatic requirement to enter the facility at the main concourse from the surrounding grade at street level, the playing field and service level would be depressed below existing grade. The playing field elevation was set to just above maximum water table elevation, requiring excavation of approximately 200,000 cubic yards of material to approximately 12 feet below existing grade.
From this elevation, a deep foundation system of 14–inch-diameter steel-cased, concrete-filled pipe piles with 150 ton/pile capacity was used to support the stadium superstructure. The site was further challenged by the location of major subway lines — on the south, the B and D subway tunnel, and on the east the elevated 6 Line. Concerns were raised about the effect of construction vibrations on the existing, old transit structures — from track misalignment caused by settlement, to spalling and cracks from transient vibrations. Vibration criteria and monitoring were developed by the project team with the NYC Transit Authority to maximize the use of efficient displacement driven piles, and limiting drilled piles to areas nearest the existing structures.
Early in design, construction strategies were explored to shorten the schedule, permit early design packages, and expedite early construction. Numerous superstructure structural systems were studied including all-concrete, all-steel, and mixed-system schemes. Ultimately, a mixed steel and concrete system was chosen for efficiency in material, schedule, and budget.
The new stadium consists of five seating zones within the bowl — the Field, Main, Suite, Terrace, and Grandstand levels. To maximize seating and unobstructed views, the Suite and Terrace levels are cantilevered approximately 50 feet beyond the support columns of the Main Level below. The most efficient structural system for these long cantilevers was steel, which utilized multi-story trusses hidden within suite walls. However, lead times for structural steel at the time of document development did not align with the project’s construction schedule.
To both maximize flexibility in design time and begin early construction, a concrete system was chosen for the lower levels below the main cantilevers because of both shorter lead time and structural efficiency. The cast-in-place portion of the structural bowl was constructed simultaneous with the completion of construction documents and the fabrication of surrounding steel superstructure. Additionally, the concrete system efficiently uses continuous and uniformly distributed moment frames as the primary lateral load resisting system. The vertical bracing of the main steel cantilevers and back-up spans provide the lateral stability of the bents in the radial direction and a series of continuous and discreet bracing elements provide circumferential stability. The lower Field and Main Levels are supported by steel framing and are stabilized by the concrete moment frames, and supplemented by steel moment frames in the circumferential direction.
This mixed structural system permitted an expedited construction schedule, with excavation beginning in August 2006 and concrete superstructure construction beginning November 2006. Steel bid packages were released beginning in May 2006, with steel construction beginning approximately one year later in May 2007, permitting six months of superstructure bowl construction in advance of steel erection.
The significant cantilevers supporting the Suite and Terrace Levels required a detailed evaluation of the vibration characteristics. Published design guidelines, including vibration guidelines from the American Institute of Steel Construction (AISC), do not specifically address vibration performance characteristics for long cantilevered structures supporting seating bowls, where both vertical and horizontal modes of vibration may be coupled.
Historical precedents for limiting main bowl cantilever fundamental vertical frequency to 3.5 Hz have been successful in previous sports facilities to limit perceived vibration to an acceptable level. In addition to this acceptable limit, an analysis was performed for each typical cantilever bent by applying spectator forcing functions through multiple frequencies and capturing the acceleration response at resonance. Steel tonnage was then optimized within the cantilevers to limit the vibration response of the main cantilevers to within typical AISC acceptance criteria of 5 percent of gravity.
Building information modeling
The project team committed to building information modeling (BIM) for the Yankee Stadium project at the very early stages of designs. The owner’s developer, Tishman Speyer, as well as project architect Populous, were interested in fully leveraging the benefits of BIM, especially in an open air stadium where visible structural elements are integral to the design aesthetic.
The structural elements, including steel, concrete, deck, and precast components, were modeled by Thornton Tomasetti in Tekla Structures to provide both a medium for aesthetic review of the structure, and to accelerate procurement and fabrication schedules for steel. All steel member information, including sizes, elevations, and geometry were included in the completed model and issued to erector and fabricator team Koch/CanAm in sequences that suited their fabrication and erection preferences. These models were used for advance mill orders and the basis for completed fabrication models.
The connection design of all major steel elements was completed on the structural documents for two reasons — aesthetic control of the connections and to avoid the inherent confusion that arises when issuing connection forces that envelope numerous load types and combinations. All major exposed connections were modeled in Tekla Structures to review with the project team for aesthetics, permitting connection design and geometry to be modified to suit the architectural aesthetic requirements. Fabrication models were also submitted by Koch/CanAm for review prior to detailed shop drawing submissions for approval, permitting a simplified and expedited approval process.
Frieze — The signature element of the Yankee brand is the historical frieze. The ornamental arched feature ringed the canopy of the old stadium before its renovation in the mid-1970s. However, the frieze as a branding element survived the renovation, and the new stadium would reinstate and reinterpret the frieze along the main upper canopy.
The old frieze was ornamental, constructed of copper and supported on a trussed steel structure. Initial concepts for the new frieze followed a similar approach of ornamental element with back-up structure. Thornton Tomasetti offered a different approach in which the frieze would serve both ornamental and structural functions, and be constructed as a self-supporting structural element. The frieze ringing the new stadium ties the canopy cantilevers together providing bracing support, as well as acting as the front girder to support the catwalk and the main lighting grid. The frieze is fabricated in single units between bents, fabricated from 5/8-inch continuous plate laser cut to provide the arches and openings, and curved standard tube sections. The sections are supported by built-up inverted columns at each bent and cantilevered from the main canopy girders.
Since the frieze is self-supporting, requiring no back-up support structure, the visual appearance is the same from both the field view and the view from the upper seating. The connections were detailed such that there are no visible connections from the field side of the frieze, creating continuously clean lines. These critical details were modeled in Tekla Structures, allowing the team to visualize and modify the connection shape and geometry, such as adding chamfers to end plates to lessen their visual impact. Attention to this level of detail, and fully leveraging these visualization tools, resulted in a signature element seamlessly connected to the main structure.
Y-Column — The upper seating bowl emerges as a modern structure set against the classical Yankee limestone appearance of the precast facade. The upper bowl presented an opportunity to create a unique look. The back supporting column of the upper seating bowl was offset from the front support column by half a grid line. With the rear column positioned between radial bents, diagonals extend up circumferentially to support the upper seating raker, creating a “Y-column.” In addition to a signature look, the Y-column creates a lateral stiffness and load path without the need of additional bracing, and as the columns are offset in plan, the appearance of a wider concourse is achieved. Attention to detail was again critical, and Tekla Structures was used to model the connection of the node of the “Y” to create a compact connection to the supporting box column.
Topping slabs — The design team spent significant time culling lessons learned and best practices from previously constructed sports facilities. One common theme in many stadiums is the performance of exposed concourse topping slabs and their tendency for extensive cracking. Thornton Tomasetti challenged the conventional approach to topping slabs, from mix designs, construction techniques, and quality control. A project-specific topping slab specification was developed, including specifying acceptable mix proportions, admixtures, high-performance structural fibers, jointing details, placement and finishing techniques, quality control, and mockups. Attention to detail addressed many of the challenges faced when placing high-performance topping slabs.
Soaring entry — The main entry portal to the stadium is the Great Hall. The area is a curved space 500 feet long and 70 feet high, clad in architectural precast and an opaque Kalwall roof system, containing the major spectator distribution elements of the stadium. The perimeter wall is supported by box columns acting as a perimeter moment frame, with the perimeter frame tied back to the main structure with built-up exposed box girders.
The New York Yankees have one of the most educated and critical fan bases in sports. As a consequence, attention to quality, detail, and brand identity were ever-present themes throughout the structural design work — from the innovative formula for the slabs, to the Y-columns that foreshadow the Yankee name, to the signature frieze. The challenge of designing a stadium against a backdrop of rich history was met through attention to details and a highly collaborative approach of all members of the design team. Yankee Stadium opened on April 16, 2009, to widely received praise for appealing to an honored past, while firmly pressing into the future.
By the numbers: Yankee Stadium
Physical size and shape of project
Number of stories: 7
Structural system types: cast-in-place concrete; composite steel framing; composite metal deck; and prestressed-precast seating bowl
Foundation type: driven steel-pipe piles, concrete filled
Unique project aspects
Construction materials — amounts
Total tons of structural steel: 12,000
Tons of rebar: 3,600
Cubic yards of concrete: 45,000
Square feet of: Slab-on-grade: 362,000 Metal deck: 485,000
Canopy deck: 51,000 Concession roof deck: 105,000
Precast seating bowl: 290,000 CIP concrete: 225,000
Number of piles: 1,700
Unique construction aspects
Timeframe for design completion: 18 months (and approximately 45,000 man-hours)
Timeframe for construction completion: 32 months
Thornton Tomasetti, Inc.
Firm leader: Thomas Z. Scarangello, chairman
Headquarters: New York City
Year firm established: 1956
Number of employees: 600
Number of branch offices: 19
Areas of practice: structural design, building skin, building performance, building forensics, analysis, and investigation.
Markets served: aviation and transportation; commercial; cultural and institutional; education; healthcare; hospitality and gaming; residential; special structures; sports and entertainment.
Firm awards: 2008 Engineering News-Record Top 500 Design Firms (#98) and Top 100 “Pure” Designers (#68).
Q&A with the SE
JG: What is your role on the project?
MS: [I was the] principal in charge and project executive.
JG: Who were the other team leaders and their titles and roles?
MS: Thomas Z. Scarangello, P.E., was managing principal and Steve Hofmeister, who is a principal in our Kansas City office, managed the development of portions of the design, the development of the Tekla model, and design of major project connections.
JG: What was the first task you needed to do to get started on the design?
MS: Evaluate the structural system options to determine the most efficient structural system. This included the evaluation of all-steel, all-concrete and hybrid solutions that best suited the project schedule and budget.
JG: What was the most challenging aspect of the structural design?
MS: The thought process from the very beginning of the project combined structural performance with the highest level of aesthetics. The most challenging aspect of any structural design in a sports facility is that the structural elements become the design aesthetic and are fully exposed to view. The design, and even shape, of the structural members can be driven by the connection concepts, requiring one to think ahead to the aesthetic of a connection before the design is complete.
JG: Were there any surprises?
MS: Although not a surprise, one element that exceeded expectations was how successful and widely used the BIM process became for the Yankee project. At the early stages of design, BIM was at its early stages of industry acceptance. The design team, led by Tishman Speyer, wanted to push the boundaries of BIM and leverage its benefits further than any previous projects. The first push was the development in-house of the Tekla model, which Thornton Tomasetti was at the forefront of with our in-house capabilities.
The BIM extension went well beyond design, requiring all contractors to develop their fabrication drawings in a 3D model that could be coordinated within Navisworks instead of the traditional methods of drawing overlays between contractors. All coordination on the Yankees was done virtually and before shop drawings. There were more laptops than drawings at coordination sessions.
JG: What software did the design team use for design?
MS: Tekla Structures was used to develop a full steel and concrete model that was given to the steel fabricator for use in steel procurement, and to provide the base for a full fabrication Tekla model. Representative connections were also modeled in Tekla and given to steel contractors at bid to assist in clarifying the connection complexity and scope. Additional software used includes Computers & Structures SAP, Structure Point PCA, Microsoft Excel, and Autodesk AutoCAD.
JG:To what extent was the BIM process used?
MS: [In addition to the explanation above,] a full 3D AutoCAD model was used for coordination with the design team during design development. All design models were incorporated in Navisworks by Turner Construction for clash detection during design. Contractor scope documents required that all contractors develop 3D models for fabrication, which were incorporated and replaced design models in the Navisworks BIM as construction coordination and shop drawings proceeded. Construction coordination was performed using Navisworks in real-time using the latest design and fabrication models.
JG: What owner requirements affected the way you managed the project?
MS: The owner and design architect Populous had a vision of a highly detailed stadium, with attention to and control over every detail. Thornton Tomasetti designs all non-typical connections on our construction documents as standard practice, which helps to control the design intent and aesthetic on a project with exposed-to-view elements. The complicated connections required early discussion with potential steel fabricators to incorporate preferences that would enable details to be developed that would be accepted widely across multiple bidders.
JG: What engineering ideas did you implement to save project costs?
MS: An engineering process that saved time and cost was the development of a Tekla model by the design team that was given to the fabricator as a deliverable. This allowed early mill orders and early detailing to begin, shortening the fabrication schedule.
JG: What lessons did you learn from this project that you will apply toward future projects?
MS: Make sure in a BIM platform that all contractors are working within a 3D format. The BIM for coordination is only as good at the information that it contains. If a fabrication element is not included within the model, the same possibility of coordination mistakes can occur as with traditional methods of coordination.
Thomas Z. Scarangello, P.E., is managing principal of Thornton Tomasetti and located in the firm’s New York City office. He has more than 25 years of experience in structural engineering and is experienced in the application of state-of-the-art engineering technologies for building analysis, design, and construction, including 3D modeling and interoperability. Michael J. Squarzini, P.E., is a principal in the same office. He has extensive experience in the structural analysis, design, and review of a variety of building types, including sports facilities, commercial buildings, transportation, and educational buildings, in both steel and concrete. They can be reached at firstname.lastname@example.org and email@example.com, respectively.