In Dagestan one may find such a wonder – a shaft-sinking and tunnelling complex Robbins (USA) that overcame 5 km in the mountains?!
It used to be a diversion tunnel 5,2 km long from the dam to the station. Water went through the generator producing electricity. It was done for elevation changes for bigger station power. The first machine of such type in Russia was exactly here, at Irganaiskaya hydrostation.
James Robbins made its first drilling machine in 1950. He designed the equipment with rotary heads and saws, the technologies that exist today too. Tunneling machines are faster and safer for making tunnels than those that had been used before.
The original Main Beam TBM, manufactured by Robbins in 1968
Here’s how it looks when it’s moving.
Location: Untsukulsky district, Dagestan