When Japan developed the incredible Shinkansen Bullet Train, it was admired around the world. Since its maiden journey in 1964, it now travels 320 kilometres (200 miles) per hour and covers almost the entire length of the country. But initially it caused huge problems for the locals.

The sounds the train created were high above environmental standards, especially when entering narrow tunnels. The rounded, bullet-shaped front of the train caused an atmospheric pressure wave to streak through the tunnel, and this surge of air pressure created a loud boom at the tunnel exit.

The sound could be heard as far away as 400 metres (1,312 feet) and attracted a multitude of complaints from members of the public living nearby. Keen birdwatcher and engineer, Eiji Nakatsu used his knowledge of the avian world to fix this serious issue. He knew that kingfishers could dive into water without creating a splash, and believed this feature could be applied to the trains to eliminate the noisy pressure waves.

The secret is in the kingfishers’ long, pointed beak, which widens nearer to the face. It helps them easily travel from the low-resistance medium of air to the medium of water, which provides a lot more drag. The shape of the beak allows water to flow past it rather than being forced away from it and creating a splash.

The front of the train was redesigned to replicate this feature, as the only other solution would have been to change the shape of the tunnel, which would have been a lengthy and costly process. The nose cone was lengthened by nine metres (30 feet) and given a gradually sloping point. This allowed the train to run at the standard noise level of 75 decibels, and also helped the service to become around ten per cent faster and use approximately 15 per cent less electricity.