A bridge didn’t conquer empty space by brute strength. It conquered it through internal balance.
He stood on the northern edge of the fiery fissure. Giles Croft adjusted the brass tangent screw of his sight sighting scope.
A thousand feet below the cliff edge, the river of liquid red magma churned and bubbled, streaming heat that washed against his face in steady, choking waves. The updraft carried flakes of glowing dark rock ash into the cave vault. There, they drifted like fireflies before cooling into gray dust.
Six hundred and twelve feet across the fiery deep pit rose the southern cliff wall. It was dark, upright, and silent.
Behind Giles, Master Mason Orson Briggs and Master Duncan Stone-Splitter supervised the unloading of the first hollow box-girder segments from the narrow-gauge rail flatcars.
Each girder segment was a twelve-foot hollow box of steam-cured water-setting concrete, twelve feet wide and eight feet tall, cast with internal ducts running through its thick bottom and top slabs.
“We’re using the balanced cantilever method,” Giles explained. He pointed across the deep gap with his wooden ruler. “No timber work frames.
No temporary center towers in that lake of lava. We build the bridge outward from both cliff walls at the same time, segment by segment, reaching toward each other in mid-air.”
