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> "The harder and stronger the rock is, the quicker we advance."... I like how counter-intuitive is this statement. I used to live in a place where the soil w

• black_puppydog 9y ago
  I lived in Solna for half a year, then Tyreso and Lappis for my studies. Do you know if the blue line stations also used this kind of sealing, or is that something new they're doing?
• Tuna-Fish 9y ago
  Yeah, this is why there is constant talk of a tunnel connecting Helsinki and Tallinn and/or Stockholm and Turku. The distance is much more than the channel tunnel, and the population that would use it is much less, but it might still be feasible simply because it could be routed almost entirely through hard granite. In Helsinki a lot of the kind of infrastructure that is placed above ground basically everywhere else is being dug underground simply because the cost of digging is less than the cost of land, and so everything that doesn't need windows gets sunk in the rock. And when you dig, you actually get to recoup some of your expenses by selling the stone you quarry...
• bjourne 9y ago
  That's by the way the reason there are so many tunnels in Stockholm but very few in Göteborg. It is very easy (relatively speaking) to dig tunnels through granite but very hard through muddy sediment. Some tunnels are still being dug in Göteborg but they are much more expensive than in Stockholm. Nowadays, one of the main problems of digging in Stockholm is that there are already so much stuff dug out that it is hard to find room for new tunnels!