Japan's long-nosed bullet train stops 'tunnel boom'

This is the ultra-streamlined Hayabusa E5 and E6 series, Japan's rather striking new bullet train that was unveiled for the first time this weekend. 

It will connect Tokyo with Aomori in the far-flung north of the country with high speed rail for the first time and sports a giant nose for a very good reason.

The nose of the E5 Series, at 15 metres, is a massive 9 metres longer than the previous incarnation of the bullet train (shinkansen), the E2 Series. This, according to its designers at JR East, will help eliminate the phenomena of "tunnel boom".

Japan's rail tunnels are somewhat narrower than their European counterparts, so when the shinkansen enters a tunnel at speeds above 200 kilometres per hour, the sudden increase in air pressure can cause a loud "boom" at the other end of the tunnel. In some cases, such shock waves are thought to have damaged tunnels in Japan, ripping chunks of material from tunnel ceilings.

The shape of the front car has evolved gradually to combat this danger, and the striking "Long Nose" design of the E5 Series is the result.