Janet Echelman’s massive new installation in downtown Boston hovers 365 feet above the ground at its highest point and weighs 2,000 pounds. Titled As If It Were Already Here, the sculpture, suspended above Fort Point Channel Parks, is comprised of 100 miles worth of rope and exerts 100,000 pounds of force on the Intercontinental Hotel, one of the anchor points for the project, when the wind blows.

When dealing with forces of that magnitude, it’s no surprise that Echelman—who was commissioned by the Rose F. Kennedy Greenway Conservancy to build a sculpture—and Arup, the structural engineers for the project, zeroed in on this location for its robust skyscrapers. The installation could only connect with towers—such as the Intercontinental Hotel, which hosts two connections—strong enough to resist the massive forces involved. Moreover, Echelman and Arup needed at least four viable connection points: any less and the structure could only form a simple flat plane. Fort Point Channel Park “was the sweet spot,” says Clayton Binkley, a senior engineer at Arup, which has engineered four of Echelman’s public installations across the country.

Arup was responsible for the pre-stressed structural net which serves as a skeleton for the colored twine which dangles off it. This structural net is made of ultra-high-molecular-weight polyethylene, eight times stronger than steel and used in everything from body armor to ship rigging. The colored twine is standard polyester fiber. At night, the wispy sculpture is illuminated with LEDs, which are synced with gusts of wind using a software program developed by Binkley. “It’s ephemeral and ghost-like during the day, a lantern at night” says Binkley.

The engineers liken the installation to a landscape painting stretching across the sky, and much like a painter, Echelman carefully selected the colors of individual braids (e.g. red and yellow will make orange as seen from below). Says Binkley, “It’s this ephemeral painting in the sky above your head.”