Osanbashi — How Many Nails Hold Up That Roof?

The answer is zero. Not a single nail was used in the roof of Osanbashi. That sweeping, organically curved structure you see below — the rooftop deck of the Osanbashi Yokohama International Passenger Terminal — was built without driving a single nail into it. So what holds that vast structure together? Welded steel plates, folded with the intricate precision of origami, form a system in which the shape itself generates the strength. No columns. Almost no beams. A single continuous field of steel lies undulating across the water. The building was designed by FOA — Foreign Office Architects — the London-based architectural partnership of Alejandro Zaera-Polo and Farshid Moussavi. Their proposal was selected in 1995 from an international competition that drew 660 entries from 41 countries, and it sent a shockwave through the architecture world. Their central idea was audacious for its time: dissolve the boundary between building and ground. The rooftop deck flows seamlessly downward, becoming a gently sloping hill that anyone can simply walk up, free and unimpeded. The people of Yokohama came to call this rooftop "the whale's back." And looking down from where you stand now, can you not see it? A great whale, resting quietly in the harbor, its back covered in natural timber decking, people strolling across it even today. The history of Osanbashi itself reaches back to 1894 — the twenty-seventh year of the Meiji era — when it was constructed as Japan's first modern iron pier. From this very place, tens of thousands of people set sail for distant shores, and just as many arrived in Japan from across the sea. The anxious hopes of emigrants boarding ships to unknown lands; the wide, curious eyes of travelers stepping off ocean liners into a new world — this pier has always stood at the threshold between Japan and the wider world. And then in 2002, on that storied ground, a work of architecture was completed — one whose organic form seems to transcend borders and cultures altogether. Tear down, and build anew. It is a cycle Yokohama has repeated many times over. And somehow, all of that history is gathered and held beneath this immense, column-free roof. Official name: Osanbashi Yokohama International Passenger Terminal Completed: 2002 Design: FOA (Foreign Office Architects) / Alejandro Zaera-Polo and Farshid Moussavi Competition: 1995 International Design Competition (selected from 660 entries across 41 countries) Structure: Integrated welded steel plate construction (nail-free) Nickname (rooftop deck): Kujira no Senaka — "The Whale's Back" Original pier: Constructed 1894 (Meiji 27)