I am a huge fan of Graeme Mile's songs. My own particular favourites are the Young Engineer (about the building of the Forth Road Bridge) and Snows of Winters Fall.

The former (describing how workers came from all over Britain to work on the bridge, building from each side of the river) has the most perfect line I have ever read.

"When the men from the south and the men from the north,
Will meet and complete the bridge over the the Forth".