EarthGrid’s plasma‑torched tunnel boring machine operated in a California quarry in January, melting three metres of granite with a plasma stream reaching 27,000 °C. The company said the machine created a vortex to remove debris as it bored through the rock, though the cut veered slightly to the top left of the intended path.

Underground placement of power lines, data centres and other critical infrastructure can protect assets from physical damage and cyber threats, but it is costly and technically challenging. Industry representatives have linked rising demand to observations from the Russia‑Ukraine conflict that above‑ground facilities are vulnerable to drone attacks.

The machine uses three plasma torches at the front that ignite to produce a 27,000 °C plasma stream. During the test the rotating boring head excavated a tunnel segment, and the team plans to adjust the vortex direction every five minutes to improve alignment. Commercial deployment is targeted for as early as next year, pending further refinements.

Interest has been expressed by companies seeking routes for power cables, fibre optic lines, water, natural gas and ammonia pipelines, as well as freight‑distribution tunnels around airports and warehouses to reduce truck traffic.

Other underground installations include Trentino DataMine’s data centre located 100 m beneath the surface, which uses natural dolomite rock for protection against physical intrusion, electromagnetic interference, seismic events and hydrogeological risks, according to the company.

Analyst Lane Burdette of TeleGeography noted that buried submarine cables experience fewer faults per kilometre, with some installations buried to depths of three metres or more in seismically active regions.

Senior lecturer Alexander RE Taylor of the University of Exeter identified a growing “data bunker” trend, in which data centres are placed underground to benefit from stable temperatures and natural shielding.

Robbie McGoran of Joseph Gallagher said geopolitical events, particularly the war in Ukraine, have increased requests for underground solutions in countries bordering Russia, and that recent advances in laser guidance and gyroscopic positioning have improved tunnelling precision.

Challenges remain, including the release of trapped gases and occasional flooding, and tunnelling progress is typically measured in millimetres per minute, McGoran added.

In the United Kingdom, the £1 billion London Power Tunnels project constructed 18 miles of underground conduits to accommodate high‑voltage cables, a cost that exceeds above‑ground alternatives, according to Arup energy leader Mark Neller, who said the UK has not seen a broad shift toward underground critical infrastructure.

Policy consultant Richard Little noted that while full‑scale underground placement is limited, identifying facilities that are difficult to replace — such as semiconductor manufacturing plants — could justify targeted underground solutions.

Switzerland requires all citizens to have access to nuclear bunkers, a legacy of Cold War thinking, and some modern buildings incorporate basement bunkers, Little said.

Industry observers suggest that as technology improves and geopolitical concerns persist, underground infrastructure may see increased adoption, though cost and technical hurdles will continue to shape its expansion.