TSX Broadway: Structural Engineers Transform Times Square

by Benjamin Alper, PE

Projects like TSX Broadway and Palace Theater highlight Severud’s thoughtful and unique approach to redevelopment. This $2.5 billion project redefined what’s possible by combining time-tested construction with modern engineering. The result is a dynamic entertainment, retail, and hotel complex that celebrates the theater’s old-world charms and embraces the 21st century ethos of Times Square.

TSX Broadway Redevelopment: A Groundbreaking Achievement

The TSX Broadway Redevelopment project was completed in May 2023. This project involved shifting and reassembling portions of the iconic Palace Theater, requiring the application of innovative engineering solutions and intricate structural work including one of the most impressive structural engineering feats in the industry.

An Iconic Landmark, An Exceptional Challenge

The Palace Theater has remained a celebrated landmark in one of the busiest intersections of the world, New York City’s Times Square. This historic venue’s unique interior has always needed more room. This gave birth to the idea that pushed the boundaries of structural engineering to greater heights – quite literally!

Elevating the Historic Palace Theater

One of the extraordinary features of this project was raising the Palace Theater building by 30 feet. TSX Broadway structural engineers designed expansion of the original steel-framed podium and replacement of the concrete hotel tower. This was required to create the much-needed ground-floor space and improve accessibility for millions of visitors.

The Story of a Complex Transformation

The existing building, a hybrid structure occupying a significant portion of the site, required a delicate balance of demolition and reconstruction. Severud engineers addressed the complex structural requirements by extending super-columns and demolishing the hotel tower to facilitate a novel transfer system.

Three colossal post-tensioned concrete girders were installed, each 44 feet deep and 140 feet long. These concrete girders were gradually assembled in four lifts to bear the structure’s massive load, demonstrating how an incredibly complex problem can be solved using the power of modern engineering.

Foundation Strengthening

To support the increased loads from the new structure, Severud engineers upgraded the existing super-columns by reinforcing and extending them with high-strength concrete. Some of the other existing columns were replaced with entirely new, stronger concrete columns. Columns below the transfer systems were demolished and the remaining concrete slabs were reinforced to hang from the transfer girders for increased load capacity and longer span.

Accomplishing the Remarkable Palace Theater Lift

Imagine raising a 1,700-seat theater, complete with its intricate interior, 30 feet off the ground. This jaw-dropping feat was the most extraordinary part of the project. Although it seemed improbable, Severud’s structural engineers accomplished this very thing by designing concrete ring beams under the theater’s load-bearing walls, under which where 34 jacking posts were installed and anchored to bedrock. These posts were carefully synchronized, allowing the theater to be raised in small increments, enabling the construction of new floors beneath.

The transfer girder system and the lifting of the Palace Theater are significant technical accomplishments of the TSX Broadway Redevelopment project. This unprecedented undertaking underscores the ability of engineering to achieve remarkable results.

The Rise of a New Tower

Construction of a new 32-story hotel tower began from the transfer level. The sleek hotel structure was built using reinforced concrete columns, core walls, and flat plate floors. The transfer girders were post-tensioned every 10 floors to manage stresses and limit deflections. This meticulous process made sure that the tower construction proceeded smoothly. With every successful step, the effectiveness of the transfer system became more apparent.

Installation of Caissons and Sub-Cellar Excavation

The TSX Broadway structural engineering project also included excavation for a new sub-cellar. Caissons were drilled in the existing cellar, extending into bedrock. The upper portions of the caissons were designed as columns, which allowed excavation to proceed and new floor framing to be erected.

TSX Broadway: Focused on Sustainability

TSX Broadway makes a significant contribution to a sustainable future as a large-scale reuse of an existing facility. The project also incorporated advanced sustainable features such as energy recovery ventilation, energy-use monitoring, a highly-efficient boiler, and smart building management system.

Structurally, the project retained 25% of the existing structure, thus minimizing waste significantly and decreasing the demand for new materials. All concrete was substituted with supplementary cementitious materials for up to 40 percent of standard cement, and used reinforcement made from nearly 100 percent recycled steel.

This project not only set a new standard for sustainable urban redevelopment, but it also earned participation in New York City’s Zone Green program which led to incorporation of the high-performance curtain walls that make the building more energy efficient. It expands the limits of how existing structures can be repositioned and augmented to reduce environmental impacts.

Bringing Light and Live Entertainment to Times Square

As the final part of the TSX Broadway redevelopment, the podium was wrapped in 18,000 square feet of LED screens, which open to reveal the Icon Stage that projects 30 feet above Times Square, lighting up the intersection.

Collaboration and Coordination at Its Core

TSX Broadway serves as a reminder that major engineering accomplishments are often the result of collective effort. The success of TSX Broadway Redevelopment was due to the seamless collaboration between the design and construction teams, and consistent coordination over a variety of interdependent operations.

Accolades and Honors

TSX Broadway reshaped the landscape of Times Square and has garnered widespread recognition for its structural ingenuity. The project has won several awards, including ACEC 2024 Engineering Excellence Award-Grand Award, CRSI 2024 Honors, and NCSEA 2023 Structural Engineering Excellence Award-Outstanding Structure-Forensic/Renovation/Retrofit/Rehabilitation Structures > $20 Million.