Here's the Johnny Cooper recording, with attribution to Hank Williams. Apparently, it's about a train named the Humming Bird, which ran from Cincinnati to somewhere. No listing for the song in Norm Cohen's Long Steel Rail, the most significant study of train songs I've ever seen.
https://www.youtube.com/watch?v=zV69OM7Zoi4Here's a 1955 recording of "Humming Bird" by the Chordettes. I think it's a different song. Songwriter is D Robertson
https://www.youtube.com/watch?v=au_gIPZkH20Songfile.com has a song called "The Humming Bird" attributed to Hank Williams Jr. (born 1949), but I don't think young Hank was writing songs in 1955.