Inspired by kingfisher bird, The Shinkansen Bullet Train has a streamlined forefront and structural adaptations to significantly reduce noise resulting from aerodynamics in high-speed trains, it does not only travels more quietly, it now travels 10% faster and uses 15% less electricity.
Eiji Nakatsu, an engineer with JR West and a birdwatcher, used his knowledge of the splashless water entry of kingfishers and silent flight of owls to decrease the sound generated by the trains. Kingfishers move quickly from air, a low-resistance (low drag) medium, to water, a high-resistance (high drag) medium. The kingfisher’s beak provides an almost ideal shape for such an impact. The beak is streamlined, steadily increasing in diameter from its tip to its head. This reduces the impact as the kingfisher essentially wedges its way into the water, allowing the water to flow past the beak rather than being pushed in front of it.
Nakatsu designed the forefront of the Shinkansen train based on the beak of the kingfisher. Engineers were able to reduce the pantograph’s noise by adding structures to the main part of the pantograph to create many small vortices. This is similar to the way an owl’s primary feathers have serrations that create small vortices instead of one large one.