I do not understand the ego that a "master" would have that they can stay awake for 72 hours and make reasonable decisions without mistakes.
Quite literally, he's "the guy." The traditions dictate his participation. I've worked with him and he's quite modest about his position. He is a well educated metallurgist who readily admits that traditional smelting is making the point the hard way. His day job is working for Hitachi Metals. I've operated a couple short stack smelters with him watching over a couple weeks when he came to the US for demos at the Univ of MN. For the big smelt in January, all the sword smiths in Japan depend on him for their base materials. A lot rides on his shoulders.
Hmm, I really don't know how to tell the story, but more than anything his spirit infuses the place. The art students were almost paralyzed with him overseeing the process. But they were in awe of the special person and unsure of their own abilities. They kind of stalled and he had to jump in to show them what to do a lot. I just got to work. He never really moved into my space, but clearly had everything I was doing under observation. He asked me a lot of questions but never told me to do anything differently. The Japanese (of his kind) are all about the spirit of the human being as able to influence a physical non living object. I had a great feeling about him, he felt good about me, it was all going to work out.
If he wasn't prepared or willing or was in a bad mood, it would affect the outcome of the steel. His spirit affects the people on the team. You don't see stuff like that in modern industrial processes. They would never let someone like me (gaijin) near the big smelt as I would "stink up the steel." He knows well that I'd find a peephole to watch through and that nothing about me would really mess things up. It's more for the other superstitious types who really worry about such things. Any other days of the year, I could do whatever I chose to in his shop.
He's as worried as most teachers are in Japan. The traditional crafts simply cannot attract new apprentices. It's a big chunk of time to work on subsistence wages doing all the drudge work for a master-crafter. Heck, they can't afford to pay an apprentice much less house you and all you bring with you. When he dies, the knowledge goes with him. I'm a cup he poured some things into so they wouldn't get lost.
One element still impresses me. The professor hosting everyone had this big blackboard and they wrote down the time of every charge, the weight of iron and charcoal, when they added a little chicken grit to juice up the slags, etc. I kept a little notebook for about an hour and then went native. He'd come over to check on my burn and asked why I wasn't taking notes any more. How did I keep time? Well, I breath about six times a minute so 60 breaths or so, it's time to add material, but if I'm watching I had this level just inside the stack that was low enough to add materials. How did I know how much iron to put in and how much charcoal? I had to interrupt him to unplug the taphole and got a nice flow of liquid slag and plugged it up again. How did I know that was the time, he asked?
I said that I was listening to the fire. It was burbling a little and needed to clear its throat. So, how do you balance the air flow? I listen and adjust the air until it sounds smooth like a flute, get rid of the off-harmonics and correct the tone to be on-key. That earned a big smile from him. As to the charges of iron and charcoal, after an hour I have a pretty good idea of how much is right by seeing the stuff in the shovel we were using rather than measuring every little gram. Later he grabbed me and had me follow him over to another of the student stacks. That one sounded like it was gargling. He made a big show of coming over to my stack and holding a hand behind his ear for all to see him listening and to compare the two fires. A couple of gestures by the man, and I got to explain all the rest in English. I had the students tap the slag hole and adjust the air and they starting running a lot better.
It's a science versus art thing. The old timers used to sing songs as a way to keep the pace. The retired prostitutes who operated the smelter's bellows would sing to regulate the air flow. There's a classic tamahagane song somewhere on the net and I can't find it.