Could any of you help me with research on my great grandfather who served in WW1. There are no relatives to assist me in this task unfortunately. No army number or regiment unfortunately, only things i've got are his name and DOB and the fact that he served on a railway mounted gun carriage. My father swears that he remembers him being told that his granfather told him it was called Big Bertha (the gun carriage) I was always under the impression that Big Bertha was German. Any help would be much appreciated.