Featherbedding claims notwithstanding, I'm surprised no one here has mentioned the obvious need for the valuable "co-pilot" duties of the left-hand man. And, a good hogger with enough integrity will teach that man how to run trains over the territory. Not that that happend a whole lot, but what the hell. It's a good idea to try and learn the territory before one acutally marks up as an Engineer.

Spending time learning the trade as an apprentice, giving a second opinion as unusual events unfold at track speed, reminding of temporary speed restricitons, lining switches, calling out signals in blinding conditions (bright horizon sun, blinding fog, blizzard, etc.) What else did I leave out?