German Air Defenses: Fliegerabwehrkanone (Flak)

Figure 1.--This is a Hitler Youth in front of the 88-mm Flak gun he manned. The German 88 was one of the most effective artiller piece of the War. Developed as an antiaircraft gun, the Whrmact soon found it ws an extremely effective tank killer. Unfortunately for the Wehrmacht, most of the Reich's production of 88s was installed pointing u to the skies in an effort to ward off Allied bombing, rather than on the Eastern Front to stop Red Army T-34 tanks. Click on the image to see the damahe inflicted on a British bomber. A CIH reader tells us that it is a Short Stirling heavy bomber not a Vickers Wellington as we at first thought. He tells us that this is evidenced by the distinctive retractable twin tail wheels clearly visible in the image. He refers us to a Wellington single tailwheel. This is the Stirling's tailwheels, gear doors removed to prevent retraction malfunction and jamming.

The Luftwaffe installed massive batteries of anti-aircraft batteries called Fliegerabwehrkanone. The Allies began calling the resulting shells and shell fragments tearing through their planes flak. The Germans produced a range of these artillery pieces, including light, medium, and heavy artillery pieces. The artillery ranged in size from 12.7-128 mm flak guns. The light and medium guns were used to protect German field armies as well as facilities like important bridges, ports, and dams from low-level attack. The heavy batteries were used to target the high-altitude strategic bombers. The Germans by 1942 had installed . over 15,000 88 mm flak guns in cannons Flak belts stretching across the route into the Reich's industrial heartland. They stretched from the Netherlands through Belgium and western Germany. At some points they were 20 km thick. The Flak batteries were an important part of the Kammhuber Line. The Germans had radar directed batteries and searchlights to direct the fire. There were also Flak batteries installed around major German cities and high priority targets like Ploesti and U-Boat facilities. Some Luftwaffe analysts were dubious about the huge effort involved. It was very difficult to shoot down a bomber. One Luftwaffe study estimated it took over 3,300 88 mm shells to successfully shoot down a bomber. The principal German anti-aircraft weapon was the 88 mm artillery piece. These weapons were in great demand as early in the war it was discovered to be a very effective against tanks. Thus these weapons were needed on the Eastern Front to stop the steadily increasing Red Army armor driving the Wehrmacht east. The Germans also began deploying 128 mm guns which were even more effective. The Luftwaffe deployed rectangular formations of 40 AA pieces in Grossbatterien able to deal out box barrages. These defenses were manned by the diverse personnel, but included many Hitler Youth boys.



Fliegerabwehrkanone

The Luftwaffe installed massive batteries of anti-aircraft batteries called Fliegerabwehrkanone. The Allies began calling the resulting shells and shell fragments tearing through their planes Flak.



Artillery Types

The Germans produced a range of these artillery pieces, including light, medium, and heavy artillery pieces. The artillery ranged in size from 12.7-128 mm flak guns. Some sources place the caliber range at 20-128 mm. The principal calibers were: light (20-mm and 37-mm), medium (88-mm), and heavy (105-mm and 128-mm) guns. The light and medium guns were used to protect German field armies as well as facilities like important bridges, ports, and dams from low-level attack. Here mobility was a factor. The heavy batteries were used to target the high-altitude strategic bombers. The principal German anti-aircraft weapon was the 88 mm artillery piece. This was a multi-purpose gun. The Germans also deployed heavier guns. There were 105mm guns that fired 15 rounds per minute as high as 31,00 feet. The heaviest German gun was the 128mm. Crews were able to fire 10 shells per minute to 35,000 feet. The 128 was a distinctive piece with two firing tubes on a common traverse and elevating mounting. It was the 128 that was used on virtually impregnable giant Flak towers built in Berlin and other German cities.



Installation

Hitler never imagines that the War he launched would last 6 years or that a major part of it would be fought in the skies over the Reich. As a result, German cities were not heavily protected by anti-aircraft batteries. It was assumed that the Luftwaffe would prevent Allied bombing raids. As the War continued and the RAF expanded its Bomber Command and the U.S. Army Air Forces began to mount raids on the Reich, the Luftwaffe significantly increased the deployment of Flak units. A little recognized aspect of the air war is the extent to which the Allied strategic air campaign forced the Germans to divert artillery from the Heer to Flak units defending German cities. The German 88 mm gun was a very effective tank killer. And the building up of Flak batteries in the Reich limited deliveries of these guns to the all important Eastern Front. The Germans by 1942 had installed . over 15,000 88 mm flak guns in Flak belts stretching across the route into the Reich's industrial heartland. They stretched from the Netherlands through Belgium and western Germany. At some points they were 20 km thick. The Flak batteries were an important part of the Kammhuber Line. The Germans had radar directed batteries and searchlights to direct the fire. There were also Flak batteries installed around major German cities and high priority targets like Ploesti, synthetic oil plants, and U-Boat facilities. At first these batteries were to supplement Luftwaffe fighter defenses (1943-43). After the defeat of the Luftwaffe they became the Reich's primary air defense (1944-45).



Formations

The Luftwaffe deployed rectangular formations of as many as 40 88-mm guns in Grossbatterien able to deal out box Flak barrages. The German Flax units at first faced relatively small-scale RAF night raids. A standard Flak battery early in the War consisted of two or three groups of 6 guns. As the air war increased in intensity, the Germans began deploying8 guns in each group. The American 8th Air Force joined the air war in force and began day light bombing (1943). With the entry of the Americans into the daylight bombing raids and intensified Bomber Command night raids, the Luftwaffe began grouping two or three Flak batteries together under a single command post to direct the firing. The 88 mm heavy Flak guns were normally deployed in semi-permanent batteries intended to provide long-term protection in the western Flak belts and important targets like industrial cities and petroleum refineries and synthetic fuel plants. The 88s were mobile guns and could easily be dismounted to be redeployed.



Support

Searchlights were deployed to help locate the RAF bombers at night. The initial approach was three (later four) batteries with 9 (later 12-16) lights. The search lights were set up in the preparation zone. The Luftwaffe also deployed sound locators during the first years of the War, but radar proved much more effective in acquiring targets.



Flak Towers

One innovation introduced by the Germans as the air war escalated was the Flak Tower. They were built in large cities like Berlin, Hamburg and Vienna. They were large virtually indestructible structures rising high in the cities and built with reinforced concrete. They were topped with four heavy guns, either 105mm or 128 mm guns. They were built in pairs to support each other. They also served as effective bomb shelters.



Early flak batteries used optical range finders. As the war progressed, the Germans introduced radar direction and ranging. The batteries commonly worked in conjunction with searchlights. The Germans developed both time- and altitude-fused high-explosive shells. The Germans worked on a proximity fused shell like the one developed by the Americans. They had trouble, however, developing an effective devise. German engineers did introduce an effective controlled-fragmentation shell which was used for both the 88s and 105s (1943). These shells had grooves cut on the inside face of the casings. This meant that upon detonation that the casing would disintegrate into a smaller number of larger shrapnel fragments. Only a small number of high-explosive shells scored direct hits. Most of the damage done by German Flak was the shrapnel hitting the bombers. The larger fragments appears to have been more effective. The most effective shell developed by the Germans was incendiary shrapnel. This thin-walled shell was packed with containing numerous small pellets. Fortunately for allied air crews, this shell was not introduced until the final months of the war. The 88s could hit Allied bombers at high altitudes. I have noted estimates up up to up to an altitude of 35,000-49,000 feet. The Flak 88 at first had 10-man crews, but this was eventually reduced to 8-man crews. I have seen varying estimates as to the firing rate. One report indicates that a well trained crew could fire 3 shells/min. We have seen estimates as high as 15-20 shells/minute.



These defenses were manned by the diverse personnel. The total effort was massive. Early in the War, the Luftwaffe Flak units had about 1 million men. This was nearly two-thirds of the total Luftwaffe strength. Eventually the Flak personnel in 1944 approached 1.3 people, including men women, and youth. Actual Luftwaffe personnel were gradually replaced, often deployed in mobile units. They were replaced by older men in the Home Guard, Reich Labor Service (RAD) boys, and HJ boys and girls. There were a variety of other personnel involved, including Italian, Hungarian, and Russian POWs. (Italy and Hungary were NAZI allies, but Germany occupied Italy (1943) and Hungary (1944) when those countries attempted to leave the War. Women auxiliaries were also involved. I'm not sure at this time as to the relative importance of these various groups. Some like the Hitler Youth boys would have only been employed within the Reich close to their homes. We are not entirely sure who was manning the guns in many available images. Some show youths in both civilian clothes and Wehrmacht uniforms.



Effectiveness

Some Luftwaffe analysts were dubious about the huge effort involved. It was very difficult to shoot down a bomber. One Luftwaffe study estimated it took over 3,300 88-mm shells to successfully shoot down a bomber. As a result, huge numbers of shells were expended in the effort--shells that were not directed at Allied armies closing in on the Reich. Whatever the effectiveness of the expenditure of resources, the German Flak proved to be nightmare for Allied bomber crews. One reason for this was its unpredictability. Unlike the fighters, you couldn't see it coming. Bomber raids were tightly packed and pilots could not maneuver independently least they crash into other bombers in the formation. Worse still formations once committed to a bomb run could not deviate their flight pattern at all. The appearance varied during night and day. American flyers reported puffs of black smoke with bright red interiors. This is clearly visible in the war film footage. British flyers reported yellow or red flashed. A direct hit would usually bring down a bomber. Some bombers simply disappeared in a massive fireball and huge cloud of smoke. This was relatively rare, but countless bombers were damaged and air crews killed or wounded by the resulting shrapnel.



Impact on the Battlefield

These weapons were in great demand as early in the war it was discovered to be a very useful artillery piece and especially effective against tanks. Thus these weapons were needed on the Eastern Front to stop the steadily increasing Red Army armor driving the Wehrmacht east. This particularly concerned Albert Speer who took over as Armaments Minister (1943). He saw how desperately 88s were needed on the Eastern Front.







