111 WEST 57TH STREET: TECHNICAL REVIEW AND SPECIFICATIONS

111 West 57th Street, also known as the Steinway Tower, is an engineering marvel located on Billionaires' Row in Manhattan. Rising 435 meters (1,428 feet), it is the most slender skyscraper in the world, with a width-to-height ratio of 1:24. This extreme slenderness required a complete rethinking of traditional supertall structural logic.

This technical review analyzes the towers shear-wall structural system, its integration with the historic Steinway Hall, and the heavy mass damping required to stabilize such a thin profile.



ARCHITECTURAL DESIGN AND TERRACOTTA FACADE

Designed by SHoP Architects, the tower is designed to complement the historic Steinway Hall at its base. The most striking feature is the east and west facades, which are clad in 43,000 individual terracotta pilasters. These terracotta pieces are cast in 26 different shapes and glazed in a custom white finish.

The terracotta creates a dramatic play of light and shadow, and as the tower rises, the pilasters twist and set back, creating a feathered effect at the peak. Bronze filigree accents are integrated between the terracotta and the glass, referencing the Gilded Age history of the site. The north and south facades are dominated by curtain wall glass to maximize views of Central Park and Lower Manhattan.

STRUCTURAL ENGINEERING: SHEAR WALL SYSTEM

Constructing a building this thin (only 18 meters or 60 feet wide) meant that a traditional perimeter column system would not provide enough stiffness. Instead, the engineers at WSP utilized two massive high-strength reinforced concrete shear walls running the full height of the east and west elevations.



These shear walls are up to 30 inches thick and act as the backbone of the tower. They allow for completely column-free interiors on the north and south sides, granting unobstructed views. To stiffen the structure further, a mechanical floor at the mid-height and the top of the tower houses outrigger walls that connect the east and west shear walls, forcing them to act together to resist wind loads.

THE TUNED MASS DAMPER

Due to its 1:24 slenderness ratio, 111 West 57th Street is highly susceptible to wind-induced acceleration. Without damping, the movement at the top would be uncomfortable for residents.

To solve this, an 800-ton Tuned Mass Damper (TMD) is installed at the top of the tower. This massive steel weight is suspended and tuned to the natural frequency of the building. When the wind pushes the tower one way, the damper lags behind and swings the other way, dissipating the kinetic energy and reducing the sway acceleration to acceptable levels for luxury living.

FOUNDATION AND GEOTECHNICAL SYSTEMS

The tower is built on a site with complex constraints, including the existing Steinway Hall foundation and the bedrock geology of Manhattan. The foundation utilizes approximately 200 rock anchors.

These anchors are drilled deep into the high-quality Manhattan schist bedrock. Because the tower is so tall and narrow, wind forces can actually create "uplift" (tension) on the windward side of the foundation. The rock anchors are crucial for holding the building down, preventing it from lifting off the rock during severe storms.

VERTICAL TRANSPORTATION

The building has a low unit count (only 60 condominiums), which changes the vertical transportation logic compared to an office tower. It is served by two high-speed elevators for the residents and a separate service elevator.

The elevators open directly into the residences on most floors, as the floor plate is occupied by a single unit. This required advanced security integration and destination dispatch controls to ensure privacy.

TECHNICAL DATA SHEET

Official Name: 111 West 57th Street
Also Known As: Steinway Tower
Location: 111 West 57th St, New York City, USA
Architect: SHoP Architects
Structural Engineer: WSP
Completion Year: 2021
Architectural Height: 435 meters (1,428 feet)
Width-to-Height Ratio: 1:24 (World's Most Slender)
Structural System: Concrete Shear Walls with Outriggers
Facade Material: Terracotta, Bronze, Glass

FREQUENTLY ASKED QUESTIONS

Is this the thinnest skyscraper in the world?
Yes. With a slenderness ratio of 1:24, it is the most slender building in the world. For comparison, a typical skyscraper has a ratio of 1:7.

Does the building sway?
Yes, all supertalls sway, but 111 West 57th Street would sway significantly without its damping system. The 800-ton damper at the top keeps the movement within comfortable limits.

What is at the base?
The tower rises out of the historic Steinway Hall, a landmarked building that housed the Steinway & Sons piano showroom. The interior of the hall was restored and integrated into the residential lobby and retail space.

Why use terracotta?
Terracotta was chosen to relate to the historic masonry of New York's classic skyscrapers (like the Woolworth Building) but applied in a modern, computer-generated geometry that twists and feathers as it rises.