[DecoPerson]

I'm not sure about this particular project, but while riding on their high speed trains between various cities, I witnessed a great quantity of tunnels of a variety of lengths. Some of them were very, very long.

China is doing a lot of drilling, based on what I've seen first-hand.

[fifilura]

I'd imagine the amount drilling is dependent of the quality of the mountain you are drilling. If it is pure granite it is easy, but if it is a mix of other softer materials it is a lot of work.