High-speed passenger trains in Japan were once a real headache, because their engineering caused a "tunnel boom," a huge boom created by air being pushed out of the tunnel ahead of a train. But the chief engineer for the West Japan Railway Company was a birder, and he’d seen Eurasian Kingfishers dive into water, creating hardly a splash. Using "biomimicry," he and his team created a shape similar to a kingfisher's bill. When fitted on the front of the engine, the nose of the train parts the air rather than compressing it. Voilà! No more boom!
Thank you, T. A. Frail and Smithsonian Magazine, for this amazing story!
Biomimicry - Japanese Trains Mimic Kingfisher
Written by Chris Peterson
This is BirdNote!
[Call of the Common Kingfisher found in Japan]
Picture the stout pointed bill of a kingfisher. Now picture a high-speed passenger train in Japan, the front of its engine the railroad equivalent of that strong, stout beak. You’ve just imagined an example of “biomimicry” — in this case, when engineers solved a problem by imitating nature.
The problem was one of physics. [Sound of a train whistle; sound of a train running at high speed]
When a train with a rounded, bullet-shaped engine would enter a tunnel, the nose of the train would compress the air. When the train reached the end of the tunnel, the air would expand so rapidly that a “tidal wave” of air would pour forth. Like a “sonic boom,” this “tunnel boom” could be heard far and wide. [Sound of “tunnel boom”] A little too far and wide! [Sound of “tunnel boom”]
Now it happened that the chief engineer for the West Japan Railway Company was a birder. And he’d seen kingfishers dive into water, creating hardly a splash. So, he and his team conducted various experiments until they created a shape that, when fitted on the front of the engine, would part the air rather than compress it. [Sound of a train running quietly at high speed]
Today, trains in Japan are known not only for their speed, safety, and comfort, but also for their quietness. You might say they operate at “beak performance.” [Call of the Common Kingfisher]
For BirdNote, I’m Michael Stein.
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Common Kingfisher #56433 recorded by Scott Connop
BirdNote's theme music was composed and played by Nancy Rumbel and produced by John Kessler.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2016 Tune In to Nature.org March 2013/2018 Narrator: Michael Stein
Special thanks to writer T.A. Frail. Review the entire story, Beak Performance, in Smithsonian Magazine Sept 2012 Vol 43. http://bit.ly/YjffSv