McAlpine's Fusiliers

Not a "hydro[electric] dam" but a reservoir, the Alwen Dam in North Wales only a few miles from where Paddy had landed, was built by Sir Robert McAlpine's company.

The song mentions the Isle of Grain. This is the power station there.

McAlpine's Fusiliers is an Irish ballad set to a traditional air, popularised in the early 1960s by Dominic Behan.

The song relates to the migration of Irish labourers from Ireland to Britain, including around the period of the Second World War. The ballad's title refers to the eponymous construction company of Sir Robert McAlpine (1847–1934), a major employer of Irish workmen at the time. John Laing and Wimpey (also referred to in the opening monologue; an integral part of the ballad although not included in some cover versions of the song) were other major construction companies employing Irish 'navvies' (a British term referring to building labourers and originally coined for the labourers who built the British canals or 'navigations').

There are several colloquial and local references in the monologue and the song's lyrics. A 'spike' was a hostel or 'reception centre' (originally a casual ward in a workhouse) for men with no fixed abode or homeless, sometimes used by Irish navvies who could not find or afford lodgings. Shuttering (sometimes incorrectly reproduced as 'shuddering') is a rapidly constructed wooden casing made to hold concrete while it sets. Holyhead (referred to in the monologue) is a port on Anglesey (Ynys Môn) in Wales where the main ferry service across the Irish Sea from Dún Laoghaire used to dock. Cricklewood is a district of North West London (near to Kilburn and Brent) which had a relatively large Irish population. The Isle of Grain is an area in Kent where the River Medway joins the Thames Estuary east of London which was a large construction site for several years while a large power station was built there.

The song offers a satirical view of the life and work of the Irish labourers of the times and as such proved popular, resonating with the Irish populations in London and other British cities.

According to remaining members of Behan's family, the song was written with The Dubliners in mind. At this time Behan was engaged by Phil Solomon, the owner of Major Minor Records, to provide mentoring services for some of the label's acts, including the Dubliners, David McWilliams and Christy Moore. Over a three-month period, Behan provided the Dubliners with a new two-hour set structure and new songs - among which was McAlpine's Fusiliers and The Black Velvet Band. The song went on to become a staple of the Dubliners live set and has been covered by others since.

In its original form, the song was performed in two parts, a spoken monologue (originally spoken by Ronnie Drew of the Dubliners self-accompanied by his flamenco guitar) followed by the sung verses supported by the full band.