Kingfisher Shinkansen

The Shinkansen was fast. That was the point. But speed brought a problem nobody could ignore. When a high speed train rushed into a tunnel, it shoved the air ahead of it like a piston. That squeezed air had to go somewhere. It burst out the far end with a loud boom. People living near the tunnels heard it. The sound would not go away.

The trouble was the change of medium. Open air is easy to move through. Air trapped in a tunnel pushes back hard. A blunt nose hit that wall of air all at once. Engineers could not simply slow the train. Speed was the product. They needed a shape that could enter tighter air without slamming into it.

That is where the kingfisher came in. The bird hunts by diving from open air into water, a far denser medium. It does this with almost no splash. An engineer noticed the bird and saw the same problem in miniature. The answer was the beak. It was long and wedge shaped, widening gradually rather than all at once. It parted the water instead of hitting it.

So the train nose was redesigned to mimic the kingfisher's beak. The goal was simple. Cut the noise from high speed trains. The new front eased into tunnels the way the bird eased into a pond. Years later, the National Inventors Hall of Fame would hold it up as a lesson in biomimicry, the practice of copying designs from nature.

The boom had a fix. It had been diving into ponds all along.