Many thanks for your input, my gt gt grandfather John Martin (1823 -1918) who was a canal boatman resided in Grappenhall in the 1870s with his family prior, to settling down in Barton Upon Irwell. From what i was told many years ago, during his time there, himself and his family actually lived next to a Tannery. On the 1871 census entry, the family are listed as living on Canal Bank, but i don't know if this residence was a cottage or indeed their actual narrowboat.