19
Roads, bridges, flyovers and tall buildings
Earth parallel: 1885–1950. Goal: a land that can be crossed quickly in any weather, and towns that grow upward on frames of steel and concrete.
| ID | Achievement | About year |
|---|---|---|
| 19.01 | Theodolite and builder's levelangles and heights measured to a hair: a straight road, a level floor, a true tower | 55 |
| 19.02 | Materials testing and structural calculationevery steel and concrete is pulled, crushed and bent until it breaks, and every beam is sized by sums before it is made | 55 |
| 19.03 | Stone crusher and gravel plantrock broken and sorted by size for roads and concrete | 56 |
| 19.04 | Rotary cement kilna long sloping tube that turns day and night: cement by the hundred tons | 56 |
| 19.05 | Concrete mixera turning drum mixes every batch alike | 56 |
| 19.06 | Road roller and graderthe road bed shaped and pressed hard before it is surfaced | 57 |
| 19.07 | Piled foundations and pile driver ⚠long piles hammered down to firm ground, under a bridge pier or a tall building | 57 |
| 19.08 | Cofferdam and caisson ⚠a dry place to work under water, for the piers of bridges and the walls of harbours | 58 |
| 19.09 | Steel building framea skeleton of girders carries the floors, and the walls only keep the weather out | 58 |
| 19.10 | Electric lift with safety brake ⚠a car hung on wire ropes in a shaft, with a catch that grips the rails if a rope breaks | 59 |
| 19.11 | Machine-drawn sheet glassglass drawn up from the melt in a wide endless sheet: windows for every wall | 59 |
| 19.12 | Fire sprinklers and hydrantswater under pressure at every street corner and over every floor | 60 |
| 19.13 | Town plan and building codestreets, water, drains and open ground laid out before anyone builds, and rules for how high and how safe | 60 |
| 19.14 | Roadsa net of many roads with junctions, wide and hard enough for lorries and buses | 60 |
| 19.15 | Road signs, markings and traffic lightspainted lines, signs that need no words, and coloured lamps at the crossings | 62 |
| 19.16 | Rules of the road and the driving testone side of the road, a speed for each place, and nobody drives until they have shown that they can | 62 |
| 19.17 | Bridgesof steel and of concrete, across the river and the gulf | 62 |
| 19.18 | Prestressed concretesteel wires pulled tight inside the concrete, so that a slender beam carries a great load | 64 |
| 19.19 | Harbour with quay, breakwater and lighthouseships lie in still water beside a crane, and a light marks the entrance at night | 66 |
| 19.20 | Dual carriagewaytwo separate roadways, one for each direction, for fast traffic between the settlements | 68 |
| 19.21 | Tunnel ⚠a road or a railway driven through a hill | 70 |
| 19.22 | Flyoversone road carried over another on concrete piers, so that neither stream of traffic stops | 72 |
| 19.23 | Concrete dam and reservoir ⚠a valley closed by a wall of concrete: water for the towns and power for the grid | 75 |