6207; A Study in Steel is a 1935 British documentary film about the construction of a steam locomotive, the London Midland and Scottish Railway Princess Royal Class No.
The 17-minute B&W film shows various stages of locomotive production at Crewe works, from casting through to assembly.
[2][3] Prior to the locomotive being assembled in the Crewe plant, there are scenes from its earliest stage.
These are of various parts of the locomotive being cut, cast and forged from raw metal.
[2] The film shows the materials, tools, process, and what is involved to make a complete working steam locomotive.