Guide To German Night Fighters In World War II The Night Defenders Of The Reich

Night-fighters  zd2

The “Fernnachtjagd” was a success because many enemy bombers were shot down, mainly during January to early October 1941, but on October 12, 1941 a Hitler´s order was received: stop immediately all the “Fernnachtjagd” missions. The main reason was that enemy bombers continued their attacks despite the “Fernnachtjagd” missions.
We have to remark that Germany took the first steps for the modern night fighting with the Spanner-Gerät infrared detection system. It consisted in an IF searchlight and a monitor display that could enable the pilot to illuminate with the infrared light the enemy bomber in the dark of the night then locate it in the monitor; but it never worked well because it received too many signals that confused the pilot.


1942-1943
Although after 1941, the Helle Nachtjagd was abandoned slowly in favor of the “combined” fighting zone, both Dunkel Nachtjagd and Helle Nachtjagd continued, but several important improvements were achieved in the night fighting.
For example, the HENAJA was aided with the arriving of the new Würzburg radar, which had the precision to direct a searchlight beam onto a bomber. The DUNAJA was improved thanks to the “‘Giant” Würzburg (Würzburg-Riese) that complemented the Freya radar.
Thanks to the higher experience in both tactics, about the spring of 1942 it´s considered that the German night fighting system began to work effectively.
But when everything was more controlled, the Hitler’s orders to gradually withdrawn the searchlight belt from March to July 1942 to reinforce the main cities defense. So, the HENAJA had to change to a “combined” fighting zone (named KONAJA) that tried to combine Flak, the searchlights and fighters over several target cities.
It was very important for the KONAJA that the Flak fired only below 4000 meters and the night fighters always had to fly over this height to avoid any surprise from their own artillery. The risk when flying into the Flak zone always was present when the night fighter pursued the enemy aircraft.

 

Night-fighters  zd3

The withdrawing of the searchlights motived that emerged a new night fighting method, the Himmelbett (Four Post Bed). It consisted in a line of radar stations about 30 km apart one from another completed with Flak (AAA) and searchlights. Every radar station was equipped with a Freya (160 km range) and 2 Würzburg radars (65 km range).  So, the Freya had to locate the enemy aircraft as early warning and the two Würzburg (“Red Giant” Würzburg-Riese and “Green Giant” Würzburg-Riese) tracked a night fighter and guided it towards the enemy aircraft (measuring altitude, numbers and direction). When the position of the bomber and the night fighter were known these ones were transmitted to a Seeburg plotting table (on wich positions of friend or foe aircraft were displayed) from which a controller would guide the pilot in order to intercept the bomber. The night fighters had to be assigned to defined zones where they had to fly while waiting orders from ground control. It was necessary that always the aircraft were flying circling over a radio beacon in the waiting area, because the time to intercept the enemy aircraft was very little. One important limitation of the Himmelbett system was that each ground control station only has capability to manage to guide one night fighter against one enemy aircraft at any one time in each zone (while one night fighter was flying, a second aircraft was on ground ready to take off and the third one was held in reserve).
The creator of the Himmelbett, Josef Kammhuber (the head of the German night fighters) achieved to build a line of ground-controlled night-fighting zones from France to Denmark in the so called Himmelbett system and nicknamed the Kammhuber Line.
The importance of the night fighting was showed when during 1942 were activated two new units: NJG 4 and NJG 5.
Another important point was the deployment of FuG 202 Lichtenstein B/C AI radar (with 32 di-pole antennas) aboard aircraft in mid-1942. Thanks to the radar fitted in the night fighters, the pilots could get terminal guidance to the bombers because its limited range. With the arriving of the airborne radars, the German night fighters gained air superiority in many cases. But many pilots preferred to maintain the performance of the night fighter better than increase the drag of the aircraft because the antenna arrangement, and continue being guided to the bombers stream from the ground.