At the midpoint of the engine vault rose the Primary Flywheel of the World-Keel. A huge disk of solid cast bell-bronze, thirty-six arm-lengths in width and four arm-lengths thick at the rim, weighing over twelve thousand tons.
This monstrous wheel was the inertial heart of the Primordial Ark. Cast in the foundries of the First Epoch by three thousand master-metallurgists who had laboured through eighty years of constant pouring, its function was to store the spinning striking force generated by the thermobaric pistons and smooth out the water-flow shocks of the deep-sea currents. The Ark pitched down the face of a hundred-fathom oceanic trough. Then, or struck the underwater shoals of a drowned mountain range, the angular driving force stored within this rotating mountain of bronze carried the vessel through the crisis without breaking the rhythm of its pumps.
Mounted along the outer edge of the wheel-well were the huge reduction gears. Helical gear-trains of forged star-fallen iron whose teeth were three feet broad, transmitting forty thousand horsepower from the flywheel to the backup bilge drain tubes.
The flywheel was spinning, but it looked like a dying giant beast caught in a fisherman’s net.
Wrapped around its massive bronze rim, choking the eight huge spokes that supported the hub, was a dense, pulsating mat of hardened void-kelp. The kelp was black as charred leather, its rubbery fronds as thick as ship’s hawsers, crusted with sharp, calcareous plates of stone-hard void-barnacles that clicked with a menacing, clockwork drone as the wheel…
