Fort IV in Bocklemünd on the Freimersdorfer Weg is one of the major forts in Cologne.
It was built in the period March 1874-1876.
The big forts were built on strategically important railway lines.
Fort V at the Aachener Bahn and Fort VII at the Eifeltor.
The Fort IV was an exception, because there was at the time in Bocklemünd still no strategic railway line (possibly the route Venlo was already pre-engineered).
The Fort IV was conceived and built like all other Cologne forts as an artillery fort with infantry support.
The neighboring forts were located at a distance of 2550m (Fort III) / 3150m (Fort V).
Also this strategically very important fortress was rebuilt in the framework of the modernization into an infantry defense structure. Within the fortress only small-caliber guns remained to protect the dry trenches.
The heavy artillery was stationed in the connecting batteries and in the intermediate field.
From spring 1909 to July 28, 1914 were soldiers of Luftschifferbtl. 3 stationed in Fort IV. On July 28, the soldiers moved to the newly built airship barracks. On the Entfestungskarte you can also see the airship hall. The proximity to the airship port was also the reason for the stationing in Fort IV.
After World War I Cologne was occupied by British troops.
According to Versailer contract, the grinding took place in 1921/22
For the time being, the forts no longer played any military role and orphaned.