Series Number Id: UNKNOWN. Sheet number: part of Sheet 51. Canal du Nord, Hindenburg Line and Marquion Line, 1918; trench, counter-battery and Intelligence target map. "Trenches corrected to 22-9-18." "[1st] Field Survey Battn 6941 (numbers crossed out and replaced with red overprint) 6961." Detail and grid grey; contours ochre; pale blue water. Approximate British Front Line in dark blue. Shows all trenches in blue, including the German positions of the Hindenburg Line, Canal du Nord Line and Marquion Line., Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC27; envelope_number: 786.