Anti-Aircraft Defence (Flak)
It is impossible to give a comprehensive description of anti-aircraft guns, their function and mode of action as well as their technical command and control here; it would go beyond the scope of this website. I recommend that you obtain detailed information in the extensive specialist literature or on the Internet.
Therefore, here is only a basic summary of the anti-aircraft emplacements in and around Cologne.
The anti-aircraft belt around Cologne
Anti-aircraft positions were set up to ward off air attacks on Cologne and the industry based here, but also to protect the surrounding industrial sites such as the coal-fired power station in Knapsack and the fuel-producing "Hermann-Göring-Werk" in Wesseling.
At the outbreak of the war, the first anti-aircraft gun emplacement was set up near Porz-Eil, at the present-day junction of Theodor-Heuss-Str./Humboldtstr. Other emplacements for heavy guns of 8.8 and 10.5 cm calibre were at the Gremberg waterworks, in Porz-Langel and Porz-Libur.
At the motorway bridge in Köln-Eil, at the Bieselwald in Porz-Wahnheide and at the Weiler Höfe in Porz-Libur were light anti-aircraft emplacements, mostly with quadruple guns of 2.0 cm calibre.
Flak searchlights were located in Porz-Leidenhausen, Elsdorf, Porz-Libur and Porz-Langel, among other places.
In the course of the war years, new anti-aircraft emplacements were repeatedly erected and old emplacements abandoned or relocated.
(It is difficult to determine the exact time and location of the individual anti-aircraft units, who was where and when, and for how long, after more than 80 years. For more detailed information, I recommend the article by Gebhard Aders in issues 19-21 of the series "Rechtsrheinisches Köln").
The anti-aircraft defence in and around Cologne was under the command of the 7th Flak Division, a large unit of the German Air Force.
It was subordinate to the Flak Group Cologne, led by the staff of Flak Rgt. 14 with the sub-groups:
Fortuna for the brown coal area,
Klettenberg for Cologne South-West,
Ossendorf for Cologne-Northeast,
Bayenthal for Cologne city centre and the left bank of the Rhine,
Deutz for Mülheim, Deutz, Kalk, Vingst and Poll,
Mielenforst for Dellbrück, Höhenberg, Holweide, Ostheim, Westhoven, Gremberg and Eil.
Subgroup Flittard was led by Flakgruppe Leverkusen and had positions in Stammheim, Manfort, Flittard and Kunstfeld.
Subgroup Wesseling-Ost was under the command of Flakgruppe Brühl and had positions in
Porz-Zündorf, Porz-Wahn, Porz-Langel, Porz-Libur, Niederkassel-Lülsdorf, Niederkassel-Ranzel.
Flak construction and mode of action of the flak ammunition in principle
An anti-aircraft battery usually consisted of six heavy anti-aircraft guns of 8.8 cm or 10.5 cm calibre permanently installed in firing positions.
For the close defence of bridges, industrial plants, anti-aircraft positions and other military or economic targets, the light anti-aircraft guns with a calibre of 2.0 cm were used.
Each battery was equipped with its own command structure. This included optical and electronic command and target finding equipment. Additional powerful radar units were also used to guide the fighter aircraft.
Flak searchlights were used at night as optical support for target acquisition.
In order to take an enemy aircraft under fire, the flight altitude had to be calculated via a distance measuring device. In addition to the distance, the speed of the aircraft in relation to the gun battery had to be determined.
Once these values were determined, the flak ammunition was prepared accordingly. The mechanical clockwork fuze on the head of the explosive shell was set exactly to the flight altitude of the aircraft to be engaged with the help of the fuze setting machine or with a fuze setting key.
When the 9kg projectile reached the set height, the explosive charge exploded. This detonation broke the pressed steel casing into countless sharp-edged fragments.
Not all of these dangerous fragments hit a target in the air, but fell to the ground, pelting the houses and streets and hitting countless people who were out in the open when flak hit. Countless people were seriously injured or died directly as a result.
After such a shower of flak, it was a macabre pleasure for children to collect these flak fragments.
Later in the war, anti-aircraft shells were given an additional impact fuse which detonated the shell on direct contact with the target.
Forum der Wehrmacht.de
HAStCologne Order 83
Air War Archive Weichert
Gebhard Aders : The Cologne Air Defence and its Student Soldiers in the Second World War, Parts 1-3, in: Rechtsrheinisches Köln, Vol. 19-21, Cologne 1993-96.