Some say it originated from the early days of the film industry when a production crew consisted of a director, camera person, assistants and workers.
[3] It is most likely, however, that the term has origins in railway work, where "gaffers" and "grips" formed an integral part of the US rail transport system in the 19th century.
[1] To ensure that each series of shots can be created as envisioned, key grips direct where equipment is placed,[8] coordinate the rigging and work with the gaffer on lighting positions.
[8] The key grip is assisted primarily by the best boy, who acts as a second in charge, taking care of equipment, ordering supplies and supervising pre-rigging.
[4] To enact the directors vision, the key grip is expected to keep up with a wide array of tasks to achieve specific shots.
[9] To ensure that production runs smoothly key grips are required to have a personal tool kit with, at minimum, a 'claw hammer, screwdriver, wire cutters, pliers, crescent wrench, and a tape measure'.
[3][12] These basics are required by union contracts, as much of a film crew's safety and production depend on the ability of a key grip to efficiently and effectively complete their job.
[3] Typically, no degree is required of a key grip; however, those that have attended film school generally have some advantage as they are familiar with the processes of production.
[4] However, in places such as Chicago, key grips are expected to train in lighting, makeup, props and craft services as part of a three-year apprenticeship.
[14] Despite the benefit a formal education can provide, the most significant qualification of a potential key grip is extensive experience on set.