ganger vs navvy

ganger

noun
  • One who is employed in conveying the coal through the gangways. 

  • One who oversees a gang of workmen. 

  • One who or that which walks or goes; a goer; a walker. 

  • A horse that goes quickly. 

  • A length of chain, one end of which is fastened to an anchor when let go, when the other end is fastened to a hawser. 

navvy

noun
  • A laborer on a civil engineering project such as a canal or railroad. 

verb
  • To carry out physical labor on a civil engineering project. 

How often have the words ganger and navvy occurred in a corpus of books? (source: Google Ngram Viewer )