The Longest Tunnels In The World
Tunnels; the less appreciated but just as impressive sibling of our famous bridges. Following last week’s attempt at discovering the world’s longest bridges, this week I’ll be giving the longest tunnels in the world a go. (Ed. I realised half way through this post that it’s much harder to find pictures of tunnels!)
Unlike bridges the ‘length’ of a tunnel is pretty easy to define, it’s the length that the tunnel tube runs. However, finding the longest is a bit harder. You see, the absolute longest tunnels in the world are effectively pipes; often similar in diameter, but, when it comes down to it, pipes. Similarly, pipes aside, metro systems are massive underground networks and so comfortably take the lead against your traditional ‘tunnel’.
So for today’s article I’m going to take a less abstract definition of a tunnel: A tunnel is a piece of infrastructure that allow traffic to pass under or through an obstacle. And with that heavily caveated description under our belt, here are the five longest “tunnels” in the world:
New Guanjiao Tunnel
I’m going to just go ahead and apologise for the photo now. But it seems that the passengers along this 32.6km rail tunnel between Qinghai and Tibet are curiously uninterested. Completed at the end of 2014 this is the longest rail tunnel in China, and at at 3300m above sea level- definitely a candidate for the highest tunnel in the world!
Lötschberg Base Tunnel
At 34.6km the Lötschberg Base Tunnel is not the only tunnel in this list to cut through the Swiss Alps. Despite being open since 2007 this tunnel is not, in fact, complete. Spiralling construction costs of the network means that the original intention for the whole tunnel to be double track was never realised. Phases 2 and 3 to promote the other two thirds of the tunnel from single track remain in political limbo.
The Channel Tunnel
With its seeds in an 1802 proposal, it wasn’t until 1994 that England was linked to France by this 50.5km engineering achievement. Possibly my favourite piece of trivia about the channel tunnel is that while the English TBMs were given dull alphanumeric names, the French TBMs were all named after women!
The Seikan Tunnel
The Seikan Tunnel is a 53.9km beauty that connects the north and central islands of Japan. Because I’m a civil engineer, I actually had a tour of this when I was on holiday. While it’s close to losing its distinction as the longest tunnel in the world, it’s still the deepest rail tunnel at 240m below sea level.
Gotthard Base Tunnel
At an amazing 57km km the Gotthard Base Tunnel takes the railway through the Swiss Alps. Although it won’t be open to commercial services until June, the structure is complete and so I’m giving it it’s rightful position on this list. That, and it has a gold sleeper laid to celebrate the completion of the track!