The discovery of the three-mile-wide underground magma cave altered the entire strategic equation of Haven-Hold.
Standing on the edge of the breakthrough fissure, Giles Croft had not seen a deep pit of demons. He had seen an underground transit hall with an unlimited supply of high-grade earth-heat process heat.
“We’re not going to pick and shovel our way through three miles of dark rock fault zones,” Giles declared, unrolling an eight-foot linen blueprint across the central planning table in the Upper Citadel.
Captain Kenneth Drake, Master Borin Bronze-Lung, Corbin Cross, and Master Mason Orson Briggs leaned over the parchment.
Borin let out a low whistle, his thick eyebrows knitting together as his stubby fingers traced the circular profile. “A twenty-five-foot circle? Solid steel? With rotating teeth on the front?”
“It’s an open-face rotary shield Tunnel Boring Machine,” Giles explained. He tapped the drawing with his wooden ruler. “The Iron Mole.
The circular outer shield protects the crew from overburden cave-ins while we excavate. At the front, a rotating cutterhead carries forty-eight hardened heavy dark metal-hardened carbon-iron disc cutters.”
“How does it cut stone without black powder?” Corbin asked, leaning closer. “Even our hardest bronze picks dull after six blows against that dark stone.”
