Mixed Elev. 3-car/3-station cityblock. 300 boilers + 600 steam engines = 540 MW. Three double-ended 1-1-1 mixed-fuel requesters retain the source-book train-interrupt workflow. Fuel priority: wood, coal, solid fuel, rocket fuel, nuclear fuel. Wood is opportunistic; continuous sizing is coal-or-better. All 300 boiler inserters are isolated on 108 solar panels + 100 accumulators (0.926 ratio). Roboports cover the full block, join adjacent blocks, and remain on the steam/main grid. Belt-only fuel logistics; no logistic robots/chests; steam engines only.