The film covers events from the last phase of the Battle of the Somme. It shows in detail the preperations for artillery attack which serves as a prelude for the first tank-attack in history.
R. Smither (ed.). The Battles of the Somme and Ancre. London: Imperial War Musem. 1993.
remarks:
The first tank attack near the French village of Flers took place on September 15th 1916 and included 49 tanks. The attack was a success but not quite as triumphant as the film suggests. Merely 32 of the new war-maschines reached the battle-field, the others broke down because of engine- or chain-damages. The Germans were helpless against this new kind of weapon. Handgranates thrown into the tanks or artillery fire were the only countermeasures that proved to be successful - nine times on this day. The other tanks suffered engine-damages or were stuck in craters. Only nine tanks returned to their base. As a consequence of the events of this day, the German High Command decided to start the production of tanks for German army as well immediatly.