The German third line defences took advantage of the long raised bank of the Triangular Bluff. On the northern angle, the Damm gun was surrounded by trenches and concrete emplacements. The long southern tail ran parallel and some 50 metres from Granatwaldchen. Should Allied troops break into the woods, as they did in June 1917, this position allowed the edge of the woods to be raked by machine guns from the elevated bank.
Until this position was captured by the 47th London Division in June 1917 it was indicated on maps by the usual trench squiggle, but following examination by British cartographers this former reserve line was redrawn as a straight trench with three loops. Presumably machine gun pits, two of these loops survive, the third and southernmost one disappearing under the tracks of a logging contractor in November 2015.
Behind the larger of the two remaining pits, the wreckage of the concrete shelter for the gun crew is still in situ. It is likely that this was blown up prior to the British retreat of April 1918 when this position fell back into German hands.
Underneath this position ran a German Stollen ‘Von Der Lippe‘, an underground refuge for the defenders during any pre-attack artillery bombardment. The entrance point of this can still be seen but I need to keep a few secrets if there is ever to be another book.