Found once only in tradition, so far as can be told; all variant forms are recent and seem to derive from commercial recordings. See

THE BLACKLEG MINERS  Text and tune from A. L. Lloyd, Folksong in England.

Lyr Req: Black Leg Miner  Transcription from a Ewan MacColl record by a Polish person with very good English but an understandable weakness when it came to placenames. With some background information.

Help: 'duds' in Blackleg Miner  Worth a look for the bizarre and unlikely suggestions it contains.

Lyr Req: Blackleg miner  In spite of its title, this thread is about a completely different song with a completely different name.