A Subterrene (Latin: Subterrina) (Russian: Подземная лодка) is a vehicle that travels underground (through solid rock/soil) much as a submarine travels underwater, either by mechanical drilling, or by melting its way forward. Subterrenes existed first in fiction as mechanical drillers, with real-world thermal designs and examples following in the second half of the 20th century.
Fictional subterrenes are often depicted as cylindrical in shape with conical drill heads at one or both ends, sometimes with some kind of tank-tread for propulsion, and described either as leaving an empty tunnel behind it, or as filling the space behind it with mining debris. The plausibility of such machines has declined with the advent of the real-world tunnel boring machines, which demonstrate the reality of the boring task. Tunnel boring machine themselves are not usually considered to be subterrenes, possibly because they lack the secondary attributes - mobility and independence - that are normally applied to vehicles.
A real-world, mobile subterrene must work thermally, using massive amounts of heat (and immense pressure) to melt and push through rock. The front of the machine is equipped with a stationary drill tip which is kept at 1,300–1,700 °F (700–930 °C). The molten rock is pushed around the edges as the vehicle is forced forward, and cools to a glass-like lining of the tunnel. Massive amounts of energy are required to heat the drill head, supplied via nuclear power or electricity. Patents issued in the 1970s indicate that US scientists had planned on utilizing nuclear power to liquefy lithium metal and circulate it to the front of the machine (drill). An onboard nuclear reactor can permit a truly independent subterrene, but cooling the reactor is a difficult problem. The Soviet Union did build such a "battle mole", which operated until its onboard reactor failed.
- In theory, tunnels can be built much more cheaply and quickly because of their reduced complexity, equipment costs and operational overhead.
- A smooth glass-lined tunnel wall is created as a result of the process. This can further reduce costs and provides an insulating barrier and basic support structure.
- These machines inherently use a very large amount of energy.
- Unknown safety and performance records.
- "APPARATUS AND METHOD FOR LARGE TUNNEL EXCAVATION IN HARD ROCK". US Patent Office. 1974. Retrieved 2013-09-30.
- статья |автор=Федоров В., Кокоев М. |заглавие=Ядерный крот |тип=журнал |издание=Техника — молодёжи |номер=12 |год=1997