Well, I knew about the nails that the Bristol traders used to do their business upon, but why would the lamproom door be armoured? The powder store or the armoury I can understand, but the lamproom?I also saw Stan Hugill a while ago - he said that most of the explanations that one would hear of obscure seafarers' lyrics would be . . . er . . . rather unreliable (those weren't the exact words he used).
The explanation of the song's origins on "Mudcat"'s own version is the same as one that I heard when the shantymen were singing in Bristol, again several years ago.
But that phrase. Its so distinctive that I'm convinced that there's a definitive explanation.
And sorry Pheonix, but I'm not convinced that yours is the one - would you like to give us some links to follow?