Tunnels

[Termite]

As a termite, I make some pretty long tunnels compared to my body size with twists and turns enough to satisfy the most craziest of minds, but I am interested in the longest tunnels others have been in.

Excluding the obvious Eurostar or Rail Undergrounds - who has been in a really long (or deep) tunnel during their travels?

 

[samh004]

I've been caving in Thailand and the UK but I'd imagine the transport tunnels were both deeper and longer

 

[Denali]

Although I understand at the time of it being built the Homer Tunnel at Milford Sound was an achievement but I think for today, its current condition is an embarrassment. Hated driving through it.

 

[TomVexille]

Cu Chi weren't that deep, but they were long.

Taken the train through the Seikan Tunnel to Hokkaido.

And driven the Chesapeake Bay Bridge Tunnel.

 

[JohnK]

Swiss and Italian Alps in 1994. Tunnels not quite as long as today but still some long tunnels.

 

[moa999]

Although I understand at the time of it being built the Homer Tunnel at Milford Sound was an achievement but I think for today, its current condition is an embarrassment. Hated driving through it.

Head on traffic you mean in a 2-lane tunnel.

Same with the 8km Karawanks tunnel between Austria and Slovenia which opened in 1991.
A second tunnel which will open in 2023 is now under construction.

Mind you compared to the alternative Pass routes it's OK.

 

[Boca68]

For length, driven the Gotthard Tunnel in Switzerland about 16kms long, very busy

But on the same trip, a few days later we drove the St Bernard Pass tunnel , i think about 5kms. It was much more interesting. Built in the 50's or 60's I think. A beautiful drive from Aosta in Italy to Martigny in southern Switzerland. Mostly only 2 lane and the scenery going in and coming out is wonderful, we drove from south to north.

 

[UP4014]

Underground mining, more than 3km deep. (worked for Goldfields)