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World War II Technology Electronics Applications: Navigation--The Battle of the Beams

World War II Battle of the Beams
Figure 1.--.

As strategic bombing targetting distant sites became an important feature of World War II, the beligerant countries began developing navigational sugnals. The resulting technological effort became what is now called the Battle of the Beams or as Chufrchill phrased it--the Wizzard War. Here the Germans were even more ahead of the British than on radar. And in this case were the first to develop a usable system. This is rather curious because the Germans had developed a largely tactical airfirce. It was the Britush that had ficused in bimbers, almost entering World War II with biplane figters, (Actually the Navy wsas still using biplanes well into the War.) The Luftwaffe began working on navaigational beams for bombers (1939). There first system was Knickebein (Crocked Leg), using a system of interesting beams. This was not at first of major importance to the Germans because the Luftwaffe was developed as a tactical air force. Its inintial assignments were daylight operations in support of ground forces. The German pilots and crews could over relatively short distances navigate by land marks or revive directions from ground spotters. This changed with the Battle of Britain, specifically the Blitz. When the Germans were forced to bomb at night because of day light losses, the began to use Knickebein which could direct the Luftwaffe bombers to the cities which were targetted. The system was not precise, but good enough to get the bombers to the targetted city at night. The British did not believe that such a system was possible because of the curviture of the earth. Thankfully British intelligence picked up some warmings and R.V. Jonese in Air Ministry (Intelligence) managed to detect the signals and develop counter measures. What followed was a cat and mouse operation with the Germans developing new systens and the British counter measures. This declined in importance as the Luftwaffe withdrew most of their fighter and bomber squadrons to support the Barbarossa invasion of the Soviet Uniin (March 1941). It is at this point that the Battle of the Beams shifted primarily to British navigational beams. Incredably, RAF Bomber Command had no such systemns. RAF bombers were susposed to find targers using celestial navigation. There was no effort to test the effectiveness of such findings before the War which borders in sheer lunacy. Not surprisingly, early raids were not only inaccurate, but often could not even find whole cities. The British as a result, well after the War began, commenced working on navigational signals of their own. The British early in the War had found that their bombers could not attack during the day because of Luftwaffe fighter defenses and even when penetrating fighter defenbses, cloud cover often obscured ground land marks. Bomber Command thus has to shift to night bombing. T hey thus faced the same problem the Luftwaffe faced--navigation. The Briish developed navigation beam systems of their own: Gee and Oboe were developed. Gee-H eventually proved so precise that RAF Bomber Command could bomb more accurately at night than the Americans during the day with their Nordon Bombsights.

Country Electronics


The German Luftwaffe (1939-41)

As strategic bombing targetting distant sites became an important feature of World War II, the beligerant countries began developing navigational sugnals. The resulting technological effort became what is now called the Battle of the Beams or as Churchill phrased it--the Wizzard War. Here the Germans were even more ahead of the British than on radar. And in this case were the first to develop a usable system. This is rather curious because the Germans had developed a largely tactical airforce. It was the British that had focused in bombers, almost entering World War II with biplane figters, (Actually the Navy wsas still using biplanes well into the War.) The Luftwaffe began working on navaigational beams for bombers (1939). There first system was Knickebein (Crocked Leg), using a system of interesting beams. This was not at first of major importance to the Germans because the Luftwaffe was developed as a tactical air force. Its inintial assignments were daylight operations in support of ground forces. The German pilots and crews could over relatively short distances navigate by land marks or receive directions from ground spotters. This changed with the Battle of Britain, specificalkly the Blitz. When the Germans were forced to bomb at night because of day light losses, the began to use Knickebein which could direct the Luftwaffe bombers to the cities which were targetted. The British eventually called ut Headache. The system was not precise, but good enough to get the bombers to the targetted city at night. The Oslo Report provide bt Germnan scientiust H.F. Mayer povided invaluable clues on German weapons in serviuce and under development. The British led by Professor Lindemann, Churchill's scientific adviser, did not believe that such a beamed navigational system was possible because of the curiuture of the earth. Thankfully British intelligence picked up some warmings. R.V. Jones in Air Ministry (Intelligence) became suspious when he found that the instrumentation in shot doiwn German bombers were highly sensitive. He managed to detect German signals intersectiing above Derby (when Rolls Royce aircraft engines were being built. That settled the matter and the British began developing counter measures referred to fittingly as Asperin. 【Jones, pp. 127-29.】 What followed was a cat and mouse operation with the Germans developing new systems and the British counter measures. The first efforts were interference and then more sopohisticated fake beams. The Germans responded with an alternative system -- (X-Gerät -- X Apatatus). This was a single beam sustem used by pathfinfer aircraft dropping flares to mark targets. The single beam was intersected by other waves over target cities. The Germans referred to it as Moonlight Sonata (Beethoven's Piano Sonata No. 1). The accuracy was greater than achieved during daylight raids. Jones and his team began sending interesecting beams of their own to get the German bombers to release their bombs over farm land or other lightly populated areas. A downed German bomber gave the British access to the instrumentation. -The Germans were anything if not persistent. They tried a new system that did not involve interesecting beams. This one was Y-Gerät, a single beam system which the Germans cunningly referred to as Wotan--a one-eyed Germanic god. 【Jones, p. 120.】 The Germans used a transponder system to send a moduated signal back to a base station. Using this system, the Germans could calculate distance and thus alert the nomber when they should dropo their bombs. a freak cioincuidence resulted in the Germans selected the samne frequancy being used by the BBC television transmitter at Alexandraia Palace. Using the Palace transmitter, the British were able to scaramble the Luftwaffe system. The Luftwaffe air crews and base staff were left to blaming each other for the systems failure. At this stage, the Luftwaffe seemed to have given up on radio navigation. And in any case, this all declined in importance as the Luftwaffe began withdrawing most of their fighter and bomber squadrons east to support the Barbarossa invasion of the Soviet Union (March 1941).

British Royal Air Force (1941-45)

As the Luftwaffe move East, the Battle of the Beams shifted primarily to British navigational beams. Incredably, RAF Bomber Command had no such systemns. RAF bombers were susposed to find targers using celestial navigation. Bomber Command invested heavily in navigation training. RAF bombers were equipping with various devices, including an astrodome to facilitate taking a star fix. 【Price, p. 109.】 There was, however, no effort to test the effectiveness of such efforts -- which borders on sheer lunacy. Not surprisingly, early Bomber Command raids were not only inaccurate, but often could not even find whole cities. The Butt Report fonud that aerial reconnaissance proved that RAF bombing raids rarely struck anywhere near their assigned targets. 【Walsh】 The British as a result, well after the War began and learning of German electronic navigational signals, commenced working on navigational signals of their own. The British early in the War had found that their bombers could not attack during the day because of Luftwaffe fighter defenses and even when penetrating fighter defenbses, cloud cover often obscured ground land marks. Bomber Command thus has to shift to night bombing. They thus faced the same problem the Luftwaffe faced--navigation. Thus the Briish developed navigation beam systems of their own: Gee and Oboe were developed. Gee-H eventually proved so precise that RAF Bomber Command could bomb more accurately at night than the Americans during the day with their Nordon Bombsights.

United States Air Forces

The U.S. Army Air Forces in Europe primarily bombed during the day and thus used celestial navigation and dead reckonung along with ground observations to navigate. Unlike RAF Bomber Commabnd, American air forces continued to use celestial navigation during the War. The Fairchild-Maxson Mark I Line of Position Computer was an effort to assist bomber navigators (1938). The A-12 sextant was developed just before World War II and manufactured by Ed Link. It was a new generation of 'averaging' sextants that compensated for 'Dutch roll' in airplanes by taking multiple sightings and computing an average without manual calculations. Navigators did not become standard crew members until the advent of war in Europe (1939). Curtis le May played a key role in this process. Navigators became essential members of the crew. Thousands of young nmen were trainedcin in celestial and dead reckoning. Mechanical calculators and chronometers were developed to assist them. The compact A-10sextant was commonly used in the Army Air Forces. Tens of thousands were made during the War II and many remained in service with the Air Force through the 1950s. The British-invented astrograph was used, but quickly fell out of favor because it was both heavy and unreliable. The Gatty drift meters was used on bombers and transports when ground landmarks or water could be clearly seen. A refinement was the B-3 Astrocompass. The Eighth Aurfore began using the GEE hyperbolic system developed by the British. Late in the war, GEE combined with a system of radar beacons (known as GEE-H) allowed American bomber crews to attack targets without visual sightings. RAF Bomber Command relied extensively on the GEE hyperbolic system in their bombing campaign over Europe, where it was essential in the overcast skies. Evenually American bombers began to be equipped wuth GEE and GEE-H which enablked the bomber crews to attack targets without vsual suighting. American bombers as the bombing casmpaign progressed were equipped with radar for short-range navigation (under 80 kilometers). This was not used to find cities, but for the bomb run as it could find thec target through clouds and at night, although less less accurately than visual bombsights. The limits of celestial navigation were an even greater problem in the vast streaches of the Pacific. Navy pilots at first had to rely on a plotting board. The first electronic systrem was the YE-ZB electronic navigation system. It enabled air men home in on their carrier without giving its position away to the enemy. Late in the War, the Air Position Indicator (API) was developed as a electromechanical system of dead reckoning. Data from airspeed sensors and gyro magnetic compasses were inputted which helpe to calculate latitude and longitude. This system was standard in the B-29 Superforts. The Western Electric AN/APS-2E Radar Plan Position Indicator became available for long-range Navy patrol aircraft late in the War. It used a radar scope and planes like the Consolidated PB4Y began to be equipped with them. The system was only effective in locating cities and shorelines.

The French Armée de l'Air


The Soviet Red Air Force


Electronics Systems

Radar was known to both the British and Germans before the War. The Brituish were primarily interested in defensive applications resulting in the Chain Home sustem. Thev Germans wereprimarily interested in offensive applications leading to the the Knickebein navigation system to find targets. As the War orogressed both sides continued their work on electronic systems and the Americans became a major factior. France's lack of radar was a major factor in its failure when the German's struck (May 1940). The Japanese did not have operational systems until fter the Battle of Midway (June 1942)--a major disadvantage in the Pacifuic War. The Italian Navy also did not have operational systems. We know little about theSoviets. .

----British


Cat/Mouse


Chain Home

The British Chain Home System consisted of Chain Home (CH) and Chain Home Low (CHL). It was the brain child of Fighter Commnnder Hugh Caswall Dowding (1882-1970). He fashioned the world's first integrated radar-based early warning system, It would play a major force is saving Britain in in the fatefull summer summer 1940. Both British and German scientists were working on radar. The British developed its defensive capabilities. The Germans its offensive capabilitities. The British suceeed in develioping countermeasures for the Gernan directiion beans targeting ssyem. The Germand did not understand the purpose and importance of the CH Systen and this made no serious effort to attack the all too visible CH towers.

Cigar

Cigar was the British jamming effort to disrupt VHF radio.

Circus

Circyus was esciorted shiort-range bombing raids to bring up and shoot down Luftwaffe fughters.

Corona

Cirina was the Btritish effort to issue false commands to German night air defebnse fighters.

DF

DF was the acroiynym for Directioinal Finding.

GEE

GEE was a radar system to oprovide long range navigation.

GH

GH was radar aud to bavigatiion abd bklind bombing.

H2S

H2S was an airborn system fior navigation and target identification.

OBOE

OBOE was a radar systen to aid navigatiion and blind bombing.

Radar


RCM

RCM was radio counter measures.

Window


-----German


Freya

Freya was German long range ground radar,

Knickebein

The Germans were first to realize that only very minor modifucations to Lorenz could created the world's first navigational beacon for long range beacon. Unlike the British, they were not committed to celestial navigation. And the Americans were comvinced that heavily armed bombers could fight their way through in daylight to enemy targets. The result was Knickebein (Crooked leg). The Knickebein system requited a larger antenna than basic Lorenz to achieve the needed asccuracy. The German sollutiin was aerials with a largev number of elements. Knickebein kept the Lorenz system of simple switching for the two reflector elements. This altered the beam directions slighly, but enough to get the desired result. The beam angles were reduced, but gave results that were only a few tens of meters over even distant targets. The shape of the aerials was the inspiration for the system's name, Knickebein -- the he name of a magical raven in Germanic mythology. The Germans attempted to disguise the system as a standard blind landing receiver system (EBL-1 and the EBL-2 receivers). The Germans first set up two beacons, one in Kleve (western Germany), and thev other at Stollberg Hill (North Frisia). The two radio beams were desihned to intersect over Derby. This was a prime target because the Rolls-Royce's Derby works was a major manufacturer of the all important Merlin engine. After seizing Norway. More stantions were set up there. Bombers followed a radio beam broadcast from a ground stations until that beam was intersected by another beam -- indicating they had reached the target. The system was not needed for the dalight phase of the Battle of Britain, but was needed for the Blitz--the night bombing. Not all the bombers neededc the receiving equiopment--only the lead bombers. The British picked up the radio emission, but at first wre not surewhat the Germans were doing. They eventually found the equioment in downed bombers that the Germans had tried to hide. This was the beginning of the Battle of the Beams.

Lorenz

The Versailles Treaty ending World War I prohibited Germany from having an air force. There was no limitation on commercial aviation. And of course there are huge crossovers between commercial and military aviation. Germany became a leader in commercial aviation in the inter-war era (1920s-30s). And blind landing became a real issue in Europe (especially northern Europe) where rain and cloudy skies were very common. Many earl aviation accident were the result of pilots trying to land at night in socked-in conditions. The first major advance was the Lorenz beam -- a blind-landing radio navigation system created by C. Lorenz AG in Berlin. The first Lorenz system system was set up at Berlin's Tempelhof Airport (1932). This was followed by Dübendorf in Switzerland (1934), and Essendon Airport in Australia (1936), and then many other airports all over the world. 【Meyer, Job, Young, and Vabre】 The German Lorenz system was comparable to Diamond-Dunmore equi-signal radio guidance system, developed by the U.S. Bureau of Standards at thec same time as Lorenz (early-1930s). 【Diamond and Dunmore】 The Lorenz Company called it the Ultrakurzwellen-Landefunkfeuer (LLF--ultra-short-wave landing radio beacon). It was adopted in Britain where it became known as Standard Beam Approach (SBA). 【Blanchard】 We are not sure just when the German military picked up on this, but Reuich Marshal Herman Göring announced the existence of the Luftwaffe (1935). The Luftwaffe before World War II deployed Lorenz at major Luftwaffe airfields and equipped most of their new bombers with the needed equipment. They also in secret behan adapting Lorenz creating the Knickebein/X-Gerät systems using narrower and longer-range beams. This created the world's first navigational guide for bombers that could be used on long missions and importantly night missions. It was first used by the Germans in the Battle of Britain (1940). RAF Bomber Command in contras=st began the Wa still relying on celestial navigation which probed to be totally unreliable. Neither Bomber Command or the U.S. Army Air Force forsaw the need for electrionic navugar=tionjal systems and night bombing, in pat because until the mid-1930s, bombers were actually fastrer than fighters. Here the German Me-109 was ground breaking (1937) and it would take some time for the British and Americans to adjust to this.

Würzburg

Würzburg was German shirt-range ground radar for anified auir defebse, controling fufgters, anti-airraft guns, ans searchlights,

X-Gerät

Germans responded as the Brutish began taking counter measures to Knickebein with an alternative system -- (X-Gerät -- X Apatatus). This was a single beam sustem used by pathfinfer aircraft dropping flares to mark targets. It used a single beam which intersected by other waves over target cities. The Germans referred to it as Moonlight Sonata (Beethoven's Piano Sonata No. 1). The accuracy was greater than achieved during daylight raids.

Sources

Blanchard, Walter. "Hyperbolic Airborne Radio Navigation Aids", The Journal of Navigation<. Vol, 44 No. 3 (September 1991).

Diamond, H. and F. Dunmore. "A Radio System for Blind Landing of Aircraft in Fog", Proceedings of the National Academy of Sciences Vol. 16 ( September 19, 1930), pp. 678-685.

Jones, R. V. (1978). Most Secret War (London: Book Club Associates, 1978).

Meyer, Roger, Macarthur Job, Bob Young, and Phil Vabre. "The 33Mc 'Lorenz' Radio Range System".

Price, Alfred. Instruments of Darkness: The History of Electronic Warfare (Granada: 1977).

Walsh, Ben. "World War II: Western Europe: Graph to show the accuracy of night bombing of German cities," The National Archives. Cataloge ref: AIR 16/487.






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Created: 9:13 PM 9/23/2020
Last updated: 5:35 PM 11/15/2023