The knocking came from a machine that had once crossed the city.
Iven expected a pump room. Vara led him instead into a long shed with rails beneath its doors. A wheeled furnace occupied the center track, its brick-lined belly dark, its tall exhaust pipe folded back along the roof. At one end a steam turbine drove a reduction gear through an open coupling. A temporary boiler supplied it from the yard.
The rotor turned slowly under a guarded test hood.
Knock.
A pause long enough for Iven to watch the chalk mark pass.
Knock.
Vara closed the steam admission. The rotor coasted down, the rhythm lengthening until the last knock sounded almost deliberate.
“Left bearing,” Iven said.
