The metal tubes for the barrels and gun cradles were purchased from firms in the United Kingdom, including Sheffield Forgemasters of South Yorkshire, and Walter Somers of Halesowen.
Most of the barrel sections for Big Babylon were delivered to, and assembled on, a site excavated from the side of a hill; instead of being suspended by cables from a steel framework as originally planned: calculations had shown that the original support framework would be insufficiently rigid.