Steel Project Case Study Gallery: Lexington / Bloomberg Tower, Cesar Pelli Architect, New York

Terri Meyer Boake BES BArch MArch LEED AP
Associate Professor :: Associate Director :: School of Architecture :: University of Waterloo

Lexington/Bloomberg Tower and Beacon Court

Cesar Pelli Architect

New York, New York

Project Information:

When complete the Lexington Tower will be the eighth tallest building in New York City. The height was made possible via the inclusing of a mass damping system (pictured below) that accounts for the seismic zone of NYC. The top third of the tower is residential use and formed with a concrete structural system. The bottom two thirds of the tower is commercial use, and is formed with a structural steel frame system. The punched floor pictured above is the mechanical floor. A six storey base building houses most of the offices of Bloomberg, the central focus of which is the atrium space pictured below. It uses a structural steel framework, with a curved HSS tube truss at the sixth floor level. The atrium is not only eliptical, but the exterior glazed walls also slope inward with a 7% slope. The AESS steel in this space is fire protected with intumescent paint.

For more information see Emporis. link

As well, McGraw-Hill Construction. link

Project Images:


The eliptical atrium that forms Beacon Court.	View down towards Beacon Court from the Bovis Lend Lease offices (Pelli site office) to the south.


The structural steel support system can be seen through the exterior curtain wall system.	View from the centre of Beacon court looking north/up.


Lexington Tower as viewed from Beacon Court.	The sixth floor atrium space will become a social as well as work related focus for Bloomberg employees.


The curved steel truss forms a C shaped ring around the atrium space, sloping from its high point at the north centre point, downwards on either side towards the south.	Rectangular HSS sections attach the curved members of the truss to the centre columns that form a ring around the atrium.


Horizontal round HSS sections run column to column and provide the connecting points for the curtain wall on the exterior.	The outriggers from the curved truss attach to the vertical columns around the perimeter of the elipse. The columns are WF sections with a cylindrical cover.


The mechanical floor is a 30 foot tall space. Large steel trusses are used to transfer the loads from the upper floors through this floor. Spray on fireproofing is used.	A view through the mechanical floor.


The Tuned Mass Damping system to offset seismic loads in located at the top of the building. info	The light green HSS structure below the damping system was installed simply to allow for the installation of the system. The white tubes will adjust if movement is induced in the building.


The cables run through a system that is counterbalanced by 600 tonnes of solid steel plate at the centre of the damping system.	The system must be able to absorb movement in any direction, if high sway is induced.


An exterior access stair on the mass damping level provides roof access.	View from the roof level looking north.