Perched at the very summit of Grand Vane, Stratum 1—known as the High Spires—is the city's crown, existing far above the soot-line and the grime of the lower working decks. Bathed in the rare, unfiltered light of the Solar Towers, this elite tier replaces heavy iron with architecture of reinforced crystalline glass and white marble, serving as the ancestral home to the Exalted Houses, Archduke Valerius, and the city's aristocracy. The wealthy inhabitants reside in grand mansions, sealed crypt-villas, and even luxury, heavy-armored airships that hover perpetually above the mountain miasma. Surrounded by gravity-defying Hanging Orchards that provide oxygen and luxury crops, the citizens of Stratum 1 live completely insulated from the industrial struggle far below, viewing the muck of the bottom tiers as little more than a faint, orange glow beneath the clouds. 

Situated just beneath the High Spires, Stratum 2—known as the Mid-Gears—serves as the bustling, amber-lit heart of Grand Vane's commerce and upward mobility. It is a plateau constructed of polished brass and mahogany, serving as the residential and administrative domain for the city’s Merchant Princes, guild elites, and Master Scriveners who oversee businesses operating throughout the lower tiers. The architecture balances industrial necessity with aggressive luxury, featuring cobblestone plazas lined with private academies, Refraction Lounges, and the cavernous Sovereign Exchange where clockwork ticker-tapes track the fluctuating prices of coal and aether-cores. While it lacks the unfiltered sunlight and pristine marble of the highest tier, life here is comfortable and fiercely competitive, heavily perfumed with artificial scents designed to mask the rising metallic tang of the foundries burning just below. 

Operating as the industrial powerhouse and iron gut of Grand Vane, Stratum 3 is a sprawling labyrinth of soot-stained foundries and massive reciprocating pistons where the city's vast workforce of engineers, technicians, and laborers reside. The architecture is brutal and purely functional, constructed from riveted steel and heavy masonry designed to withstand the unending vibrations of the Great Gears that power the city's life-support systems. Beneath a claustrophobic sky choked by groaning catwalks, massive cast-iron support beams, and sprawling brass conduits, the atmosphere burns with a flickering, industrial orange glow as the air hangs thick with the scent of hot oil, ozone, and Aether-Coal smoke. Life in this labor district is measured in exhausting fourteen-hour shifts to keep the perimeter heaters running, yet a fierce sense of "Squad-Kinship" unites the residents as they gather in Steam-Wash taverns and unpaved alleyways to survive the constant, deafening roar of the machines. 

Located at the claustrophobic, canyon-like base of the city, Stratum 4—commonly known as "The Muck" or "The Roots"—is a raw, dangerous frontier of deep shadows and damp iron. Buildings here do not stand but cling directly to the mountain rock faces, hanging precariously over a network of churning silt canals and sludge outlets where massive, steam-driven Hoist-Stacks pull cargo into the belly of the machine. Serving as Grand Vane's primary intake, the docks groan with the weight of iron-hulled barges unloaded by a diverse, transient workforce of weathered captains, dock-laborers, the undocumented "Unregistered," and indentured penal workers. Dimly illuminated by flickering bioluminescent "Muck-Lamps," life is a daily struggle for ration-packets in an atmosphere choked with sea-mist, industrial runoff, and the creeping rot of the Sallow Heath waiting just beyond the perimeter floodgates.