It doesn't make sense of the use of the word "rattling" in the song though.A bog is soft and squelchy, it doesn't rattle.If you walk across a bog it will slow you down, not speed you up.In Ireland we say about an enjoyable occasion that people had "a rattling good time" so it could be to do with that - by all accounts , everybody enjoyed a good day or a "rattling good time" in the bog at turf -cutting time. But that would be a stretch .