I go with that completely, Gibb. A strong possibility to me is that Bullen was using the phrase 'grunting chantey' to describe a type in the same sense as 'short-haul chanty' or 'halyard chanty', in other words a chanty that contained grunts, rather than the whole thing being grunted, which would be somewhat difficult and unlikely anyway.

Another point worth repeating is the actual use of the word 'chantey' to describe the songs being used for screwing. I remember you also mention somewhere that the foreman of the stevedores was also called a 'chanteyman'. Are there more than these 2 contemporary references to the use of chanty in other contexts than shipboard?