That's really all I can remember of the song ; I was always impressed by those two lines myself . I heard them from my father who was a leading miner ;he worked building the underground tunnels ,sewers etc all around England . A ganger or gangerman is a man in charge of a small gang of navvies .
My old fella is into his ninetees now. When I see him again I'll ask him if he knows any more of the words ,but his memory is slipping as you can guess