A new material calls for new forms: iron should be used in slender members that show its strength in tension and bending, not cast in imitation of stone columns and vaults.
One system of transit for the centre
Treat the city’s railways, elevated lines and streetcars as a single system serving the business centre, and plan their stations and routes together, relieving the elevated loop with subways and through routes.
The Union Loop, completed in 1897, tied the elevated lines from the south, west and north into a single rectangle over Lake Street, Wabash Avenue, Van Buren Street and Wells Street, so that every train could circle the business district and return. It concentrated the city’s commerce inside the ring, and gave the district its name, but also its congestion. The Plan of 1909 proposed to reorganise passenger terminals and add subways so that the centre would be served by a coordinated network.
Related rules
In a framed building the columns and beams carry every load; the outer wall can be reduced to a light cladding hung on the frame, floor by floor, and need grow no thicker as the building rises.
load-bearing wall: thickness grows with height · frame: cladding thickness constant
Lay the whole island out in a single rectangular grid regardless of the ground: avenues 100 ft wide running its length, cross streets 60 ft wide across it, and blocks 200 ft deep between them, the houses to be straight-sided and right-angled because such houses are cheapest to build and most convenient to live in.
avenue 100 ft (30 m) · street 60 ft (18 m) · block 200 ft (61 m) deep, 600–900 ft long
Cap the height of new buildings (at 130 feet from 1893) so that the business district does not become a canyon of towers; the cap was raised to 260 feet in 1902 and lowered to 200 in 1911.
1893: 130 ft (≈ 40 m) · 1902: 260 ft · 1911: 200 ft
Keep the whole shore of the lake as public park, with lagoons, beaches and harbours, and set the city’s museums and libraries along it as its cultural forecourt.
Widen one street into the city’s main axis, running from a monument on the lakefront to a domed civic centre on high ground inland, and let the rest of the plan hang on it.
Cite this page Chris Paton, “One system of transit for the centre”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/burnham-loop-transit. Text, drawings and models licensed under CC BY-NC 4.0.