The amazing thing is that steam engines were made out of iron for most of the 19th century. Steel wasn't available in bulk until about 1880.
The materials really matter. Early steam engines such as Newcomen's were insanely complicated and had terrible thermodynamic efficiency, because the parts couldn't stand any real pressure.
Consider a Diesel. A basic Diesel engine is a very simple machine. Here's a rural mechanic in China restoring one from junk status to running, using basic tools.[1] It's a brutally simple one-cylinder engine, widely used in Japan and India. No pollution controls. No water recycling; you have to add water as often as fuel. No electrical components. Started with a hand crank.
Costs about US$200-$300 for a new one.[2]
Seems like someone would have been able to build one of those by 1700 or so. But no.
You couldn't build that engine without reasonably good steel. Even if you had one to copy, you could not build that with the technology of 1870. You need a strong cylinder, a strong cylinder head, and good piston rings that precisely fit the cylinder, or you won't get the compression to ignite the fuel. The first Diesel engine that worked was built in 1897.
Steel is interesting, because it's thousands of years old, yet wasn't mass produced until the 1890s. A Bessemer converter is very simple. The Romans could have built one. But it took quite a bit of R&D to get the metallurgy right so that steel came out. Bessemer got his working, but others, with different ore sources, couldn't get theirs to work reliably. Robert Mushet did 10,000 trials over ten years of to get an understanding of exactly what ingredients do what. This debugged the Bessemer process, and the world changed.
The Romans had sword factories. They could make steel, but not in bulk. If that work had happened a centuries earlier...
[1] https://www.youtube.com/watch?v=s--QjXbdnME
[2] https://www.alibaba.com/product-detail/Changchai-Diesel-Engi...
The materials really matter. Early steam engines such as Newcomen's were insanely complicated and had terrible thermodynamic efficiency, because the parts couldn't stand any real pressure.
Consider a Diesel. A basic Diesel engine is a very simple machine. Here's a rural mechanic in China restoring one from junk status to running, using basic tools.[1] It's a brutally simple one-cylinder engine, widely used in Japan and India. No pollution controls. No water recycling; you have to add water as often as fuel. No electrical components. Started with a hand crank. Costs about US$200-$300 for a new one.[2]
Seems like someone would have been able to build one of those by 1700 or so. But no. You couldn't build that engine without reasonably good steel. Even if you had one to copy, you could not build that with the technology of 1870. You need a strong cylinder, a strong cylinder head, and good piston rings that precisely fit the cylinder, or you won't get the compression to ignite the fuel. The first Diesel engine that worked was built in 1897.
Steel is interesting, because it's thousands of years old, yet wasn't mass produced until the 1890s. A Bessemer converter is very simple. The Romans could have built one. But it took quite a bit of R&D to get the metallurgy right so that steel came out. Bessemer got his working, but others, with different ore sources, couldn't get theirs to work reliably. Robert Mushet did 10,000 trials over ten years of to get an understanding of exactly what ingredients do what. This debugged the Bessemer process, and the world changed.
The Romans had sword factories. They could make steel, but not in bulk. If that work had happened a centuries earlier...
[1] https://www.youtube.com/watch?v=s--QjXbdnME
[2] https://www.alibaba.com/product-detail/Changchai-Diesel-Engi...