The Real Deal New York

Hudson Yards’ green space presents unusual challenges

The 4.5-acre Public Square may look like a garden but it’s a feat of engineering
July 26, 2015 04:00PM

Large portions of Hudson Yards will sit over the 26-acre West Side Storage Yard – where hundreds of LIRR cars are stored – and that has presented an unusual challenge for the designers of the project’s green space.

Hudson Yards’ 4.5-acre Public Square will look like a garden when it is finally finished in late 2018, but in fact it will actually be the roof of a working rail yard. And that means soil and roots, the cooling system for the roots, the water supply and storage, storm drainage, ventilation for the rail yard, and the utilities and sewage lines must fit into a layer of the roof ranging from just 18 inches to seven feet, according to the New York Times.

“All the things we put into the ground without thinking, we have to sandwich here,” Thomas Woltz, principal of Nelson Byrd Woltz Landscape Architects, designers of the square, told the Times. “We went through a lot of acrobatics to get a healthy, long-living horticulture.”

One solution was to build a plenum – a six-foot high empty space for ventilation. Above the plenum, a 60,000-gallon collection tank will store rainwater, which will irrigate 225 trees and 28,000 plants.

The beds for the trees and plants will be just 18 inches to four feet deep, and saved from the heat below by “concrete slabs threaded with conduits carrying glycol coolant.”

The takeaway: building a green space atop a train yard ain’t easy. [NYT] Christopher Cameron