Ironically the first navvies, technically speaking, were the 'Excavators' who worked on the Newry Canal (completed 1745), and so were in fact Irish.'Navvy' was the abbreviated form of navigator, the term applied to the excavators of the commercial canal network known as the Inland Navigation System, the Newry Canal being the first example.

I say ironically because, although the modern British public assume that all navvies were Irish, exhaustive research carried out in the early '80s by Dr. David Brooke of Bath proved that approximately 90% of the 19th century railway navvies employed in the United Kingdom were in fact British - predominantly from the North of England (in the US it was a different matter and Brooke does state that the only 'the ubiquitous Irish' were a truly international force in railway construction). His very scholarly book, based on a doctoral thesis, is The Railway Navvy: That Despicable Race of Men (London, 1983).

Other non-fiction works on the navvy:
Terry Coleman's The Railway Navvies (London, 1965). A very good read with a wealth of anecdote.

James Handley (Brother Clare) wrote The Navvy in Scotland (Cork University Press, 1947) also based on Ph.D. research, and it remains the definitive work on that specific aspect of the subject.

Navvyman (London, 1983), another history of the railway navvies, is in similar vein to Coleman's but its author, the surname notwithstanding, is not only English but the son of a navvy father and a mother born on site to a railway navvy. This excellent book is marred only by the author's marked prejudice against the Irish in the industry, echoing that of a great many railway navvies of Scottish origin.

To the best of my knowledge the subject of the Irish in British construction overall was not seriously addressed in print until the publication of my own book, The Men who built Britain: A History of the Irish Navvy, in 2001. My objective was to put the Irish navvy in the twin contexts of Irish emigration and British civil engineering history, while at the same time giving an authentic voice to the men concerned (and their women) as individuals. This was a difficult circle to square and the extent to which I was successful is a matter of opinion!

Donal MacAuligh, John B. Keane, Timothy O'Grady,the author of 'Kings of the Kilburn High Road (?), and Peter Woods have all written fictional treatments of the subject - in every case, I believe, based on some degree of fist-hand experience. Interest in the subject, it seems to me, is now largely confined to a small proportion of the Irish abroad and a shrinking number of returned emigrants and their families in Ireland.