The architect behind Penn Station’s massive timepiece had never made a major clock before. Here, he tells us how he did it—and reveals what's on his wrist.

New York's Penn Station is synonymous with poor design. Low ceilings. A general feeling of dread. The city's major rail hub exists, in its current incarnation, almost as an afterthought, buried beneath a basketball arena that doubles as a hockey rink. But it wasn't always thus.