The smell of hot crushed dark rock was unlike any quarry dust Giles Croft had ever met.
It wasn’t the damp, earthy scent of surface gravel. It smelled of high-friction quartz dust. It scorched iron, and ancient fiery glass being crushed to powder beneath four thousand tons of relentless high-pressure force.
Inside the steel worker’s cab of the Iron Mole, the noise was a nonstop, rhythmic roar.
Every three seconds, forty-eight heavy dark metal-hardened carbon-iron disc cutters rolled across the upright dark rock face at two turns a minute. At thirty-five hundred pounds of pressure of crushing pressure, each disc exerted forty tons of packed wedge-force on a point no wider than a pencil lead.
The rock face didn’t surrender by wearing away. It failed in tension.
Pulling stress cracks shot through the dark stone like frozen lightning bolts. Fist-sized chunks of shattered stone popped off the face with sharp, metal cracks, cascading down the curved muck-scoops into the central auger.
Giles kept his eyes on the twin bubble-levels mounted on the steering console.
With his left hand, he adjusted the flow-control valve to the lower left thrust metal tube, bleeding five gallons a minute into the return line. The needle on the yaw indicator drifted smoothly back toward true zero.
