Ammunition Columns, Brigade or Divisional, were officered and manned by the Royal Artillery and national equivalents. Intended for direct affiliation to their Brigades, and Divisions, they were additionally called upon to furnish ammunition to any unit requiring it during an action. The Officers and Gunners of the R.A. employed with an Ammunition Column were, as a matter of course, immediately available to replace casualties in the batteries. Working mostly at night, moving forward, the Brigade Ammunition Columns ammunition wagons were interchangeable with a Firing Batteries own ammunition wagons (one per gun), so full wagons could be easily 'dropped-off', being unhooked and taken away for reloading.