Researched
Bessemer Steel
Air blown through liquid pig iron makes steel in minutes instead of days - cheap and in bulk.
Open in the interactive tree →Henry Bessemer patented the converter in 1856; the Siemens-Martin furnace (1860s) and the Thomas process (1878) complemented it. Steel became so cheap that rails, bridges, ships and skyscrapers were made from it. Today roughly 7-9% of global CO2 emissions come from steelmaking.
Prerequisites
- Blast Furnace & Cast Iron~1400
- Wood, Charcoal & Coal~1709
- Steam Engine1712
- Crucible Steel~1740Bessemer's process aimed to make in bulk the steel crucibles made in small batches
Unlocks
More in Manufacturing & Construction · Industrial Age
- Crucible Steel~1740
- Mechanized Textile Mills1764-1785
- Machine Tools1775
- Iron Bridge1779
- Puddling & Rolling Mills1783-84
- Centrifugal Governor1788
- Interchangeable Parts~1800–1850
- Jacquard Loom (Punched Cards)1804