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What makes this project incredible is how it is dug at the base of the mountain, instead of higher up. That makes it the deepest tunnel, dug under 2,500m of roc

by SeoxyS 11y ago

What makes this project incredible is how it is dug at the base of the mountain, instead of higher up. That makes it the deepest tunnel, dug under 2,500m of rock at its max. When you have almost two miles of mountain weighing down on you… pressure is intense. The rock has different compositions along the way, some parts have to be dug with boring machines, some parts with explosives. The project has been in construction for 20 years. For comparison: the Golden Gate Bridge took 4 years. The Hoover Dam, 5 years. The Burj Khalifa, 5 years.

jo909 11y ago
There are deeper mines than that. The long time the project is taking is also an indicator that it is mostly about repeating a certain set of tasks over and over and over again. Certainly there were big challenges, but I imagine they were more of a project planning and management nature than pure engineering problems. It is quite impressive nontheless.
abduhl 11y ago
Two miles of mountain does not "weigh down on you". As I said earlier, the alps are known to have very good rock. What this means is that it is, essentially, self supporting. You are not designing for two miles of overburden pressure, you are designing for maybe a couple diameter's worth of overburden. If you read my comment history you'll realize that I work in the tunneling industry. I have designed, inspected, or helped construct large diameter hard rock tunnels, small diameter soil tunnels, and everything in between.
hueving 11y ago
Those are bad comparisons (at least the dam and the bridge) because projects of that scale would be nowhere near that fast in the US because of environmental impact studies, NIMBYism, and just improved safety conditions of the labor itself (tons of people died in the construction of the dam).
eps 11y ago
> The project has been in construction for 20 years. And, as impressive, it's still on schedule and on budget.

by SeoxyS 11y ago

jo909 11y ago

There are deeper mines than that. The long time the project is taking is also an indicator that it is mostly about repeating a certain set of tasks over and over and over again. Certainly there were big challenges, but I imagine they were more of a project planning and management nature than pure engineering problems. It is quite impressive nontheless.

abduhl 11y ago

Two miles of mountain does not "weigh down on you". As I said earlier, the alps are known to have very good rock. What this means is that it is, essentially, self supporting. You are not designing for two miles of overburden pressure, you are designing for maybe a couple diameter's worth of overburden. If you read my comment history you'll realize that I work in the tunneling industry. I have designed, inspected, or helped construct large diameter hard rock tunnels, small diameter soil tunnels, and everything in between.

hueving 11y ago

Those are bad comparisons (at least the dam and the bridge) because projects of that scale would be nowhere near that fast in the US because of environmental impact studies, NIMBYism, and just improved safety conditions of the labor itself (tons of people died in the construction of the dam).

eps 11y ago

> The project has been in construction for 20 years. And, as impressive, it's still on schedule and on budget.