Nick Stockton, writing for Wired Map Lab:
Hudson Yards is the largest private development project in U.S. history, and it’s being built without footings or foundations. Instead, the project is going to sit atop 300 concrete-sleeved, steel caissons jammed deep into the underlying bedrock. Work on the platform broke ground last week, and will take roughly two and a half years to complete. In that time, there’s a lot of engineering to do.