[Translate to EN:]
A sap is a protruding rampart for soldiers to find shelter. This is important to know in order to understand what a "sap tank" is. It lies there as if a gigantic insect had peeled its skin. A front soldier from Potsdam brought it back from World War I as a souvenir. After a short period of movement, the war had frozen to become static warfare. Both sides dug themselves deeper into the ground. Drumfire, storm, counter-attack became the rhythm of the war. Great dying. In 1916, the spiked helmets were replaced with steel helmets. For extremely hazardous positions, such as observer or MG gunman, there was the steel "sap tank" which was supposed to defend at least against infantry fire. Moving with it was as good as impossible. Perhaps it was more meant as psychological encouragement. The success went with different kinds of tanks. On 20 November 1917, the first tank offensive in history began in Cambrai.