One of 11 escalators to be installed on the site, this piece of machinery dangles high above Lower Manhattan as workers hoist it up to the 101st floor.
The escalator was lifted with a crane on top of the building.
When the building is complete, it will stand
at 1,776 feet and 104 floors, making it 408 feet taller than the twin towers before it and the largest building in New York City.
Below are several photos taken
by ThyssenKrupp Elevator of the dizzying feat of mechanics and engineering: