Thanks for the video(s), i have a fascination with steam locomotives, and this entire series is absolutely fantastic.

hmm this don't look that old, like 70's or 80s maybe, the introspection and display of tools is a bit different then how we did things in the states, the flue welder I believe was different here and completely automatic but used induction heating I believe in the latter years of steam in the usa, and stays here are also welded but they also cut off the ends and hammer over the ends to lock them in place caulk them tight and then welded to thermally bond it to the sheets and the stay itself. and we also safe end our tubes and reuse them if possible up to 6 times after each need of occasional regulated inspection for us its 15 years or 1472 operating days, if I had to guess though this was in east Germany the footage being shown or maybe Poland, but they are very detailed about the parts and processes in the documentary superb even talks about sanding the flues to clean them, you will often hear about sanding the flues but they don't tell you why. and they even talk about the advanced concepts of exhausting like the kylchap and giesel, which a man named Livio Dante Porta improved on and continued in steam engine improvement to his dying day in 2003, as well as the gas producer firebox and reheating the steam and compounding its fascinating stuff if you like to read about engineering, balancing of locos and thermal dynamics, he also experimented with a cyclonic gas producer firebox that would further mix the gases of combustion and the heavier entrained particles would get trapped better and not get sucked though the flues and pipes which causes erosion from the unburned coal and further causes black smoke which is inefficient even if it looks cool, the smoke should be light gray coming out of the stack. sorry for getting wordy and bad spelling but growing up in a railroad town its kind of in your blood.

how much steam boiler capacity required for steam locomotive