Boiler Operation / Locomotive Operation

May I rise my voice again after reading all these posts? After lots of thinking I would like to say that to run a locomotive is like doing two different things: The first thing is boiler operation. This is not an outdated "art". Boilers (whether for steam or something else) are still in use in various factories and plants (like chemical plants). This keeps the knowledge up to date and rules and regulations are not gathering dust. E.g. over here you are not entitled to operate a boiler if you do not have a certificate issued by a state boiler inspector. This is to ensure that you know what you are doing.
The second thing with locomotives is keeping the engine running. Frames, rods, bearings, cylinders. As terrible a failure can be this part is not as critical as the boiler. Please note that I am excluding again the basics like axles and wheels which have to be tested with ultrasonic and x-ray. This, too, is modern means and ensures the basic safety. Those arts of the old days which have to be relearned are imho not relevant for safety. If your engine breaks down because of a hot box it is inconvenient but nobody will get harmed.
May I conclude with the words of a railroad authority who was to approve one of our firemen. He said to our manager: "I am not interested whether this guy knows how to raise steam. This is your problem, Mr. X. I am only making sure that he knows what the signals mean."
With this I wish you all to always have a handspan water above the crownsheet, another yard of track in front of the engine and a good fire on the grates.