England 1940 - Battle of the Beams. We continue our look at the equipment involved from a German perspective.
During World War II, Germany developed a radio navigation system called Knickebein (German for "crooked leg") to guide bombers to their targets. The system used two intersecting radio beams that the bomber pilot would fly along to accurately locate the target. The beams were transmitted from ground-based radio stations in occupied Europe and could be picked up by a receiver on the bomber.
The system was first used in the bombing of England in 1940 and successfully allowed German bombers to navigate to their targets day or night regardless of cloud cover. However, the British quickly developed countermeasures. Despite these efforts, the German bombing campaign was still effective for some time.
A later system called Wotan I or the X-Beam system improved on the Knickebein two-beam method and used one primary (or marching) beam and three transverse beams. The X-Beam used a network of ground-based radio stations to transmit a series of X-shaped beams. The bomber pilot would fly along the primary beam to locate the target. The X-Beam system was more accurate than Knickebein and was harder for the British to neutralise. Later Wotan II would use a single beam and the 'Y' electronic distance measurement method controlled from the Y ground station to place the bomber over the target. The pilot was not required to 'fly the beam' as with the older systems but was able to follow direct instructions relayed to him from the Y ground controller. However, despite the Y system's sophistication, the British were still able to develop countermeasures, helped by secret intelligence received in the 'Oslo Report' of 1939, and create false signals to spoil the system's accuracy and render it unusable. Ultimately, the German bombing campaign was much less effective than it could have been due to the British's efforts to disrupt these radio navigation systems.
This video was recorded at one of Europe's finest private collections of German avionics equipment, covering the early days of military radio communication and radar to the end of the vacuum tube era.
Presented by Dieter Beikirch with additional narration by Robert J Dalby.
Video produced by Astronomy and Nature TV
