Attached is a black and white diagram from a 1915 French news magazine depicting the depth of a German front-line dugout. Historian John Laffin makes it quite clear in his World War One book,The Western Front Companion, that the term "dugout" seems misleading when applied to the Germans:
"From 1915, the remarkably well developed German positions, notably on the Somme front, reflected their strategic advantage. They were on enemy soil, the Germans held the initiative and they could afford to settle down in their dugouts. Hence, most had electricity, drainage, sewage system, piped water, a telephone system and many were heated. The soldiers could lie down on mattresses resting on beds made of stacking stretched over wooden frames, and -and because of deep overhead cover - 30 to 40 feet of it, they were safe even during heavy shell fire."
Click here to read an article about life in a W.W. I German listening post...
More articles about W.W. I trench warfare can be read here.
From Amazon: The Western Front Companion
