Butterley Company correspondence file on opencast workings Including for Asherfields site at Swanwick,Golden Valley site, Codnor Park, Bridle Lane and Manor Farm sites, Heage, Kirkby Summit Sidings and Screening Plant, Robeyfields and Bulls Head sites, Denby, Bell House Farm near Ormonde Colliery, Heanor, The Fall and Hoggbarn , Heanor, Hartshay Lane and Green Hillock, Ripley, Newlands Farm near Alfreton and Portland Colliery (most of the above being with plans of sites). Also including loose plan of Kirkby Sidings lay-out, 1 Nov 1943 Jun 1944-Aug 1945