From March 20th 1940, four 120 mm DE BANGE guns equip the Schoenenbourg's crew ; though such equipments, made in 1878, were old and had a slow rate of fire, they were very precise and suited harassing fire very well.
The guns are operational on April 5th 1940 already, and divided into two batteries served by the crew of Block 5.
S4 Battery, with two guns is set up near Block 6 and communicates with it by the means of a trench.
S5 Battery, with the two guns left, is set up between the two entrance blocks, namely Block 7 and 8.
During the 1940 campaign, these four DE BANGE guns fired 723 shells.
On June 4th 1940 by 3.00 p.m., the S4 battery of the Schoenenbourg's forward areas carries out a harassing fire upon the cross-roads near the Schleithal church. Suddenly, the first gun disappears in a black cloud, a shell having burst too early in its barrel, where the trunnion is.
The wheels are broken, the carriage had slanted, but, whereas the personnel of this very gun suffers no loss, the servants of the second gun are hit by the splinters.
The gunners DERRENDINGER, WEISREINER and MATT are severely wounded.
Section Sergeant-Major ESCHENLAUER, Corporal VONAU, Lance-Sergeant STENGER and the gunners FRANCK and PAYEN are less severely wounded.
The wounded are evacuated to the Haguenau Hospital, the gunner MATT's leg is amputated
on June 5th, and the gunner DERRENDINGER dies on June 6th after a 300gr splinter had been
extracted from his chest.