Series Number Id: GSGS 3389. Sheet number: part of sheet 51. Battle of Arras preparations; trench, target and hostile battery map 19-3-17. "3rd Field Survey Co. R.E (1456)". "Ordnance Survey, February 1917." Grey base map; German trenches and names red; British trenches to depth of 300 yards blue. Overprint in dark blue: "Target Map" [and hostile battery] with artillery details. Overprint in green: [enemy organisation] reference; shows railways, roads and tracks chiefly used, and more., Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC21; envelope_number: 669.