a "dog" or dogging iron is a piece of steel pipe which fits over the handle of the "dog" giving tremendous leverage to insure that the hatch or the door is water tight. I question the truth of this tale, one reason, he refers to some others as..laughing drunken rats.. grounds for slander and libel. To the best of my knowledge, Stan was not a sailor, so, he came close enough to be forgiven. It's a great song in any case.