Brookfield Properties has broken ground on its Manhattan West project, a $680 million platform that will span above the existing rail yards. Steel Institute of New York contributing employer Metropolitan Walters LLC is doing the erection with Local 40 ironworkers. The entire project is moving forward while the tracks beneath remain active with trains traveling to and from Penn Station. Brookfield has released this video (with narration) to illustrate platform engineering, which relies on a structural steel and precast concrete design to create the structure:
From Brookfield Properties: The platform, a series of 16 bridges, completes the surface upon which the entirety of the 5-million-square-foot development will rise, envisioned as two two-million-square-foot Class A office towers, a residential tower, a 1.5-acre open public space, and retail throughout. The cores of the towers will be constructed on bedrock to the north and south of the platform. The total site comprises five acres, of which the platform will occupy 60%. The Manhattan West deck is being constructed utilizing post-tension, pre-cast segmental bridge technology which minimizes disturbance to train operations below.
The platform project is expected to generate more than 600 construction jobs for New York City and New York State.