McAlpine's Fusiliers

Etymology
After Sir Robert McAlpine, a major employer of Irish workmen, and (possibly) the military appearance of a group of men with shovels over their shoulders.

Noun

 * 1)  The Irish immigrant labour force in Britain in the early 20th century.

Usage notes

 * The term was popularized by the 1960s Dubliners song of the same name.