The erecting hall of the Grey Crag Roundhouse was colder than the mountain wind outside. But it smelled of hot sulfur and linseed oil.
Suspended from the heavy oak overhead frame, the twenty-eight-foot tube-shaped boiler shell of Hauler Zero-One hung six feet above the pit rails. Its curved skin was formed from three-quarter-inch rolled Bessemer steel plates, overlapping along the lengthwise seams in triple-riveted double-strap butt joints.
Giles Croft stood on the timber staging plank. He held a pair of hardened steel fine measuring tongs in his left hand.
“Rivet spacing on the lengthwise seam is three and one-quarter inches on center,” Giles said, his voice level despite the ear-splitting clatter of air-powered air tools below.
“Pitch line limit is plus or minus one-sixteenth of an inch. If a rivet head cools below cherry-red before it’s set, cut it out with a cold chisel and drive another.”
Down in the pit, Master Borin Bronze-Lung held the heavy steel bucking bar against the inside of the boiler shell. His bald scalp glistened with sweat and soot.
Opposite him on the staging, two young dwarven apprentices manned the air-powered riveting hammer. The tool was an eight-inch cast-iron metal tube connected by a wire-braided hose to the shop air pool at one hundred pounds of pressure.
