Similar comment here: The British industrial revolution was built from iron, not steel. Mass production of steel didn't appear until the 1880s, with the Bessem

Similar comment here: The British industrial revolution was built from iron, not steel. Mass production of steel didn't appear until the 1880s, with the Bessemer converter. This was half a century after the deployment of successful railroads. Iron and steel was known to the Roman empire. The steel wasn't very good, even by the standards of antiquity, but it was good enough for short swords and some tools. They got as far as the "bloom" process, but no further. Despite this, there was a modest iron and steel industry. A Bessemer converter is a simple thing. It's a big iron vessel lined with brick attached to a furnace and blower. Roman ironworkers could have built one. It's the metallurgy that's hard. Bessemer built the thing, but steel quality was random at first. Robert Mushet, a metallurgist, after about 10,000 experiments, figured out how to get consistent quality from the process. The basic idea, from Wikipedia, is to apply enough heat and air to burn off almost all the carbon in iron ore, leaving pure iron. Then add 'spiegel glanz' or spiegel eisen, a "double carbonate of iron and manganese found in the Rhenish mountains" which was iron, 86…25; manganese, 8…50; and carbon, 5…25. Controlled amounts of manganese and carbon are thus put back into the molten iron, and steel comes out. https://news.ycombinator.com/item?id=32611002 https://news.ycombinator.com/item?id=32611002