 Kerr's parents and maternal grandparents were Australian-born, while his paternal grandparents came from Sunderland, England, arriving in Sydney in 1886.He came from a line of waterside workers—his father was a boilermaker, his grandfather was a stevedore, and his great-grandfather was a shipwright.At the time of his son's birth, Kerr's father was employed at the Eveleigh Railway Workshops.