Petra's remarkable thermal bore cuts through undrillable rock
San Francisco startup Petra says its new contactless thermal drilling robot can make steady progress through the hardest rock on Earth – stuff that would normally destroy drilling equipment – so quickly and cheaply that it could make a lot of underground infrastructure projects economically feasible.
The semi-autonomous "Swifty" robotic system can create 18-60 inch (46-152 cm) diameter tunnels through any geology, blasting the rock with an extremely hot, high-pressure spallation head such that it glows, chars and flings away.
Petra, founded by serial entrepreneur Kim Abrams, says it's demonstrated the robot's capabilities by boring a 24-inch tunnel through 20 feet of Sioux Quartzite – which Abrams describes in a CNBC interview as "the hardest rock on earth ... harder than bluestone granite ... the type of rock that would normally have to be dynamited." Swifty progressed at a rate of an inch a minute.
The company says this new robot uses a combination of remote control and machine vision to get its job done, and it's the first microtunneling robot that can reverse out of its own tunnel.
Costing "30-90 percent less than conventional trenchless methods," and opening up access to previously undrillable areas, Petra says its new tech will make it much more economically viable for governments and utilities to run vital power and communications cables underground, where they're safe from vandalism, wildfires, high winds and other threats.