The main reason I accepted this as a chantey/shanty when I first heard it is the repeated single burden, "Roll, Alabama, Roll," which seems to match the pattern of other chanteys and similar work songs, whether the burden is "Go down, ye blood-red roses, go down," or "Roll the woodpile down" or whatever.

And yes, I know you get repeated single burdens in non-worksongs as well, since they work well with any call-and-response song. And of course you get burdens of two alternating lines in chanteys as well, as with "Away, you rolling river/.../Across the wide Missouri."

But it's my impression that I've heard a far higher proportion of single-line burdens in chanteys and other work songs than in other ballads, lyrics, and other traditional songs.

--Nonie