It's a cotton-screwing shanty. Cotton was stowed in the ship's hold and packed down tight using jackscrews - a job which in Hugill's words required much shantying.

"Screw the cart and screw him down" is a mondegreen - it should be "screw the cotton".

To quote Hugill again: "Doerflinger seems to think that Fire Maringo is of Negro-origin, but I think that Ireland is as like as not its birthplace. The word 'maringo' is the clue. This quaint word is found in many Irish folk songs".

He says the tune has been lost. The current tune may have come from the influential British group The Young Tradition who recorded it in the 1960s.