Roughneck is a term for a person whose occupation is hard manual labor. The term applies across a number of industries, but is most commonly associated with the workers on a drilling rig. The ideal of the hard-working, tough roughneck has been adopted by several sports teams who use the phrase as part of their name or logo. Originally the term was used in the traveling carnivals of 19th-century United States, almost interchangeably with roustabout. By the 1930s the terms had transferred to the oil drilling industry. In the United Kingdom's oil industry starting in the 1970s, roughneck specifically meant those who worked on the drill floor of a drilling rig handling specialised drilling equipment for drilling and pressure controls. In practice, these workers ranged from unskilled to highly skilled, depending subjectively on the individual worker's aptitude and experience. By contrast, a roustabout would perform general labor, such as loading and unloading cargo from crane baskets and assisting welders, mechanics, electricians and other skilled workers. The word roughneck was in use in the U.S. oil drilling industry even earlier and had a similar meaning. In oil fields, a roughneck's duties can include anything involved with connecting pipe down the well bore, as well as general work around a rig. The crew of a land-based oil rig can be further divided into several positions: Toolpusher: The highest position at the drilling location, responsible for every crew. A toolpusher may stay on location for a few days or weeks at a time during operations, whereas individual drilling crews work only eight- or 12-hour shifts or "tours" (pronounced as "towers"). Driller: The head of an individual crew, responsible for controlling a rig's machinery during drilling, as well as most other rig operations. Derrickhand (derrick-man): Responsible for the drilling mud, the mud pits where drilling fluids are circulated around the system, and the mud pumps, as well as being the hand up in the derrick manipulating stands into and out of the fingers during tripping operations.