Vieille Chapelle : map 'F.1', secret, XIII Corps counter preparation, July 18th 1918
Series Number Id: UNKNOWN. Sheet number: 36a SE2. Edition number: 3. "Trenches corrected to 16-6-18." Portions of 36aSE and 36NW have been redrawn from recent surveys. The detail differs from the regular 1/20,000 sheets in these areas. Detail, grid and contours grey; British trenches blue; German trenches and names red; British trenches, rear defence lines and names blue; overprint black. Zones shown for Harrassing Area (pale blue), Forward Battery Area, and Trench Mortar Area (pale green), with A to U lettered barrage lanes. Corps boundaries in green; British Front Line in chain-dotted blue and light blue., At top of map, black overprint: Map 'F.1', secret, XIII Corps counter preparation, July 18th 1918. "Field Survey Co. R.E. 6372 [number crossed out and replaced with black overprint] 6562." WW1 Trench Map Collection: Box PC27, Envelope 779.