Definition of "furnaceman"

We spent a lot of time up on the staging of the great furnaces, trying to pick up the tricks of the trade from the taciturn furnacemen who sat around placidly smoking, or chewing twist, and occasionally throwing in more pig iron to the molten white-hot metal.

1945 January and February, A Former Pupil, “Some Memories of Crewe Works—III”, in Railway Magazine, page 14