Tim Wescott wrote:
OTOH, those 15 percent are more likely to be good at what they do. I bet
a lot of those mill operators in the '50s just knew how to work at the
level of "turn the big handle over there until the number 55 is on top" ...

I'd say that it's just the opposite. In the '50s machining was
predominately manual. In the steel mill the roller was king, because it
took so much skill. The surveyor's transit was the same technology as
George Washington's. The bulldozer controls were so rough that a lot of
experience was required. Even paper tape NC didn't come in until the
'60s (I think).

Today, a "lathe operator" loads stock and programs into a CNC machine.
Rolling mills don't take much more skill. Surveying is all lasers and
computers. The new hydraulic controls allow most anyone to operate
earthmoving equipment. A lot of this was driven by productivity, but it
was also driven by a desire to get away from the need for the highly
skilled labor that dominated '50s manufacturing.

Bob