This is what the Short Sharp Shanties notes said on this song:

Sharp, Terry and, of course, Hugill are the only collectors to have published Tommy's Gone Away, and all regard it as a version of Tom's Gone to Ilo/Hilo/Ylo.  Definitely not a short-haul shanty. Sharp and Terry both had it from Short: Hugill says "My version from S.Wales seaman who had served in the copper trade." This becomes interesting, because another very close version of Tommy's Gone Away is in the Carpenter collection having been collected at Barry Docks, S.Wales.  So is this particularly shanty a Bristol Channel and/or copper trade version? (Short did sail in the copper trade, on the Conference to Callao in 1867/68 – and he had been familiar with the Bristol Channel since a boy).  Whatever its 'location' in the period when Carpenter and subsequently Hugill were amassing material, Sharp's notes from Short (who was learning it up to half a century earlier) say the shanty was "Used not only for pulling, but, at New Orleans, for screwing the cotton for loading to set the bales in – screwing it up into a very small compass."  Short evidently used similar verses for both Tom's Gone to Ilo and Tommy's Gone Away – we have sought to use different locations in the two recordings.  Jackie's arrangement offers a really melancholic feel to the song – perhaps as many a seaman would have wished the girl they left behind to feel!