News & Press
Manhattan West Platform Reaches Major Milestone
On January 15, 2014, the first of 16 precast spans, which together will form the Manhattan West Platform, was successfully launched. The Platform is the first stage of Brookfield Properties Inc.’s Manhattan West development comprising five million square feet of premier office, mixed use and public space located in Manhattan’s expanding Midtown West district.
Post-tensioned, segmental precast box girders, typically used for bridge construction, are being used to build a 2.6-acre, state-of-the-art Platform spanning over live railroad tracks. Once completed, the Platform will serve as a street level public plaza over a parking / loading dock structure, with surrounding office and residential towers.
Brookfield retained Entuitive to design the foundations, platform support beams, and to develop the structural design of the long-span platform. One of the key project considerations is that the platform is being constructed over the tracks leading in to New York’s Penn Station, the busiest rail corridor in North America. Our team responded to this challenge by developing a design which incorporated deep post-tensioned precast box girders to span over 14 active rail tracks to avoid intrusive track-level construction and minimizing disruption of rail service. Amtrak and Long Island Railroad authorities have been significantly involved in reviewing the design and construction plans and sequences, as the platform structure comes within inches of the electrified lines that power their trains. Any impact on the electrification or any prolonged service interruption at track level were not an option, requiring a unique launching gantry and a column-free, post-tensioned structure spanning 240 feet across the tracks.
The Platform has already spurred many innovations. Entuitive designed the platform structure to meet the needs of the development and to minimize construction impact to rail service. Another innovation involves the method of lifting and placing the 2,400 ton precast spans, being launched using a one-of-a-kind launching gantry custom designed and constructed for this project by the Italian firm DEAL Equipment.
The launch of the pre-cast spans is a huge milestone in the progress of the platform’s construction and is the result of several years of careful planning and ingenuity.
For more information about the Manhattan West development, click here.
Renderings courtesy of Brookfield.