The German Response to the Success of Tanks at Cambrai

Of particular importance [to planning for 1918] in light of the Cambrai experience was defense against tanks.

The appearance of tanks had often caused German soldiers to panic; OHL [Army High Command] reacted to stop this.  The artillery units were trained to engage tanks with direct fire. For the infantry, a 13-mm rifle was quickly manufactured, whose bullets could penetrate the armor of Allied tanks. Tank obstacles became part of defense preparation. The initial panic over tanks was overcome.

The 13.2mm Mauser Gewehr M1918 Anti-Tank Rifle: The only anti-tank rifle of the First World War was capable of penetrating 20 mm of armor at 100 yards.  Delivery began in May 1918.

This activity contrasted with the reluctance of OHL to begin a major effort in German use of tanks. German units had recommended the German use of tanks from the beginning of Allied employment of tanks, and, for example, a report of 2 October 1916 from the German First Army on the Somme recommended that Germany produce its own tanks. Ludendorff, however, was not enthusiastic. He thought that the limited resources of Germany were better directed to manufacture more motor transportation for greater strategic and operational mobility. Therefore, for the offensive of 1918, the Germans employed only a few German tanks and a limited number of captured ones. This small effort had a negligible effect on the campaign, and Ludendorff's failure to encourage German tank development has been severely criticized.

Disabled British Tanks Caught in a Trench, Possibly a German Tank-Trap

From: "The Dynamics of Doctrine: The Change in German Tactical Doctrine During the First World War" by Timothy T. Lupfer, U.S. Army Paper