Converting each section of the High Line from an out-of-use railroad trestle to a public landscape entails more than two years of construction in a multi-step process. The High Line is open to the public from Gansevoort Street to West 30th Street. However, the third and final section of the park – the High Line at the Rail Yards – is under construction.
For more images of the High Line's construction process, visit our construction gallery.
Before the new landscape on the High Line can take shape, everything on the structure, including steel rails, gravel ballast, soil, debris and a layer of concrete, must be removed. This is necessary in order to test and make and needed repairs to the structural layer of concrete that sits inside the steel frame of the High Line. The High Line is structurally sound - it was built to carry two fully-loaded freight trains - but minor repairs and waterproofing must be done to the steel and concrete, and drainage systems must be installed.
During removals, each section of railroad track is marked, mapped for its location, and stored. Later, many of the rails and other steel railroad artifacts are returned to their original locations, integrated into the plantings.
After removals, the steel elements of the High Line structure must be sandblasted to remove the original lead paint. Sandblasting is done in a containment tent, which is moved along the structure, enveloping one 25-foot section at a time. Once the steel has been treated, it is repainted in three layers. The top layer closely matches the original color of the High Line.
Repairs are also made to the High Line's Art-Deco railings. The steel is treated, and missing parts are fabricated to restore the railings to their original design.
Site preparation also includes the installation of pigeon-proofing (slanted strips of metal that prevent pigeons from roosting) in the beams on the underside of the structure, and the installation of a new drainage system and a layer of waterproofing on the exposed concrete.
The final phase in the High Line’s transition to a public park is the construction of the park landscape. The High Line's pathways, created from a series of smooth, tapered concrete planks, are laid into place above the lower layer of waterproofed concrete, leaving space in between for drainage and electrical conduits.
In many places, the High Line's railroad tracks are returned to their original locations, integrated into the planting beds. Seating elements include the park's signature "peel-up" benches and riverview sundeck chaise lounges.
Construction of stairs and elevators allow visitors to access the High Line from street level. In some locations, beams are removed from the structure to allow stairs to rise up from the sidewalk, cutting through the center of the High Line structure and allowing visitors to come face-to-face with the steel beams and girders on their way up.
Energy-efficient LED lighting elements, integrated into the High Line's railings, illuminate the park's pathways at night. Lights are placed below eye level on the pathways, to create a safe condition for walking, while allowing the eyes to adjust to the ambient light of the surrounding city sky. Lights are also installed between the beams on the underside of the High Line, to gently illuminate the sidewalk below.
Soil is delivered and distributed to the planting areas on the High Line. Plants, which have been selected from nurseries up and down the East Coast, are planted by the High Line's team of horticulturists to match the plans created by landscape architects James Corner Field Operations and planting designer Piet Oudolf. Read more about the Planting Design
Visit our Construction Gallery.