Hello Sorry for coming in late to the discussion My Scots Dialect Dictionary gives various definitions of "Gig". Non directly related to Mining but two definitions come close 1) A fan and 2) Anything that spins. Did they use fans to ventilate the Mines? My G.G. grandfather was described on his death certificate as a "colliery banksman" Henmuir Pit Gladsmuir. I got the definition from a member of staff at the Coal Mining Museum in Thornhill near Dewsbury Yorkshire. The job entailed checking that the miners were not taking contraband down the pit on their shift and keeping the tallies. I think there is a dedicated GenUk Mining List that may help you with your job title. Regards and Seasons Greetings George Wallace ( Yorkshire )