How do builders dig tunnels through mountains and under water?
Mountain Doorways
How do builders dig tunnels through mountains and under water?
A mountain is a very large, very stubborn thing. It does not move out of the way when you want to build a road. So when people need to get to the other side without climbing all day, they do something marvelously cheeky: they go straight through the middle. This is the story of how a tunnel gets made.
Long ago, the only tools were hammers, chisels, and aching arms. Crews chipped at the rock one swing at a time, inch by stubborn inch. A single tunnel could take years, with workers starting from both ends and hoping desperately to meet in the middle. Astonishingly, sometimes they did.
