Go here and listen to Ewan MacColl describing shanties briefly to an audience in October, 1953:

http://www.tobarandualchais.co.uk/en/fullrecord/61808/3

He claims that editors removed not only all the obscenity (which he implies was the usual subject of shanties) and (rather oddly, even for a Marxist) all references to hard work.

The same excellent site has him singing a few shanties, evidently at the same recording session. (His intro to "Paddy Doyle" combines Doyle with Paddy West.)

MacColl already has traces of the "Hugill style," or so it seems to
me. If so, the question is where he got it from.