1989 T. Pratchett Pyramids (1990) 120: You drew the plans, and then got in ten thousand lads on time-and-a-half and double bubble at weekends.at double bubble (n.) under double, adj.
1989 T. Pratchett Pyramids (1990) 120: After you’d knocked your pipes out seeing to it that the nobility had their tickets to eternity, were you allowed to turn your expertise homeward [...] ?at knock one’s pipes out (v.) under pipes, n.1