A closer look
Driving beneath the ocean floor presents a terrifying suffocation hazard if you cannot rapidly vent thousands of exhaust pipes. The Aqua-Line is an engineering marvel plunging beneath Tokyo Bay, but a tunnel that long would quickly become a lethal gas chamber from trapped vehicle emissions. Engineers bypassed this nightmare by constructing the Kaze no To, a gargantuan architectural sail floating in the middle of the bay. It harnesses powerful oceanic winds to naturally drive immense subterranean turbine fans, effectively sucking toxic carbon monoxide out of the tunnel and pumping fresh ocean air straight down to the drivers.
