How the USSR tried to build a subterrene

In the 1930s, Soviet engineer Alexander Treblev developed a tunnel boring machine for "underground navigation" to search for oil deposits and lay pipelines to them.

The "mechanical mole" dug into the soil using a drill and moved at a speed of 10 km/h. It was controlled either by a driver or remotely and was powered by an electric cable from the surface.

Treblev envisioned a promising future for his invention beyond industry: "Sciences, such as paleontology, will open up new opportunities for searching for fossilized animals; archaeologists will be able to easily penetrate deep into alluvial rocks and uncover many secrets of ancient peoples."

During tests in the Urals in 1946, the "mechanical mole" managed to bore 40 meters underground. However, officials were still dissatisfied: the mechanisms were constantly breaking down and repairs were too time-consuming and labor-intensive. In their opinion, the costs didn't justify the end result.

The military also showed no interest in the subterrene, so the project was canceled.