These are the main things I would like to know: 1. What are the rank-and-file worker's duties? Are they specialized to particular parts of the work of dredging oil or does everybody generally do everything? 2. Does s/he have supervisors? Is there a chain of command? What authority do the superiors have over this rank-and-file worker? 3. Do people tend to be seasonally employed by an oil drilling company or is it on a permanent basis? Thanks in advance! Edit: If the oil derrick machinery is automated now, would anyone be able to remark about how it used to be? My setting is a world with technology roughly analogous to the 1940s/1950s anyway.