German & Allied radar

[edwest]

Referring to the late 1930s:

"German radar was concentrated for the moment in two companies, GEMA and Telefunken, each with a basic design. GEMA had two bands, 80 cm for Seetakt and 2.4 m for Freya. Telefunken used 50 cm for the Wurzburg and the decimeter communication relays.

When the Luftwaffe became an independent arm of the Wehrmacht it obtained from the Army the AA artillery. Initially, it did not have an organization to evaluate new weapons other than aircraft, so it relied on an army agency, the Heereswaffenamt (Ordnance Department) for judgement about its AA guns and, when the matter arose, for radar. This office arbitrarily classified the early sets into three types. For various reasons they referred to GEMA's Freya as A-1, to Lorenz's Kufurst as A-2 and Telefunken's Wurzburg as A-3. Initially this coincided with A-1 for early warning, A-2 for searchlight direction and gun laying and A-3 for local observation and tracking respectively.

As the importance of radar became more obvious. Goring wanted it added to his beureacratic empire and had it moved from the Heereswaffenamt to the Reichsluftfahrtsministerium...

It is scarcely necessary to point out to the reader the parallels in American and German work. The earliest work started in service radio laboratories with heavy emphasis on microwaves. Both dropped these wavelengths in their prototypes for want of transmitter power, although retaining some research. This resulted in excellent meter-wave equipment: XAF/CXAM for the US Navy, SCR-270 for the US Army, Freya for the Luftwaffe and Seetakt for the Kriegsmarine. The approach to decimeter waves by Bell Telephone Labs is remarkably similar to the path followed by Telefunken and probably came about because both had tube laboratories. The Bell FD/mark 4 was the equal of the Wurzburg, indeed its design cousin; it was with modification the US Navy's AA gun-laying radar throughout the war. The Wurzburg was a better gun-laying set than the SCR-268, and the American equivalent, FD/mark 4, was used only by the Navy. On the other hand the SCR-268 functioned also for distant target acquisition, which the Wurzburg did not. The Germans were generally about a year ahead of the Americans.

In 1939 the German and American prototypes were superior to the British except for CD/CHL, which was a typical dipole array on 1.5 m. Neither Germany or the United States had a significant number of operational sets in 1939..."


Please pardon the lack of umlauts. Excerpted from A Radar History of World War II by Louis Brown, published by the Institute of Physics Publishing, Bristol and Philadelphia.



Ed

Originally Posted by Nick Beale

(...) in what areas did Germany have a significant lead on 1 September 1939? (...) In infantry weapons the MG 42 and the Sturmgewehr 44 were probably ahead of the pack.

- I think you're aware that these weapons didn't exist 1939, not even 1940 and that the number (42 or 44) refers to the year in which they were first introduced (I think). Mind you, I am certainly not an expert!

The MG 42 was, and still is, a remarkable light infantry machine-gun with the standard German calibre of 7,92 mm (which certainly was changed in other countries after WW II). All other usual light machine-guns (French, British, etc.) had a rate of fire of 1,200 rounds per minute (20 per second) which probably was determined by some physical or technical factor, for otherwise various countries would have had various rates of fire. The Soviet ShKAS (7,62 mm), though, designed for aircraft, had a rof of 1,800. The MG 42's rof was 1,500 (25 per second), which was a sensation for infantry weapons at the time and made it very effective. It had been specially designed for simple production, replacing all machining of parts (cutting, drilling...), if possible, with stamped steel-sheet parts. Their production is much more simple and cheap. Of course not the barrel and the mechanical parts (breech etc.). After WW II the MG 42 was copied virtually all over the world. Even today we can often see the typical muzzle and barrel radiator of the MG 42 on TV pictures from Iraq, Afghanistan etc. Ex-Wehrmacht MG 42s were still being used for a very long time after WW II in all countries where Wehrmacht units were stationed.

I understand the Sturmgewehr 44 was the result of complaints by German soldiers having to perform the actual, very hard fighting against the Red Army, that the "Rotarmisten", the red soldiers, were equipped with assault rifles whereas they had to contend with their old carbines etc. I think it was a good weapon but came somewhat too late. The Soviet Kalashnikov was almost ready for WW II but not quite.

It has to be noted that most Soviet weapons, if not (almost) all of them, were better than their German counterparts, probably with the exception of the universal 88. The Soviet infantry sub-machine-gun was far better and much more reliable than the German one, which didn't take kindly to mud etc., and German soldiers always tried to lay their hands on one. The standard Soviet Army gun, the 76,2 mm field gun, was far better than anything the German army had got. Its shell had supersonic velocity, so that the German "Landser" (soldiers) at the receiving end heard its explosion first, then the firing noise and called this gun "Ratschbumm" (pronounce "Ratshboom"), a nickname emulating both noises which followed one another. The German 37 mm antitank-gun was useless against French and Soviet tanks (not against infantry, trucks, buildings etc.), so that the angry German gunners called it "Heeresanklopfgerät", "Army Device for Knocking at Doors" - so harmless it was against armour. The "Heer" (Army) was compelled to have a better antitank-gun designed and produced (47 or 50 mm I think) for the very heavy and very expensive 88 couldn't be everywhere. When the Red Army engaged T-34 tanks already 1941 - and they were almost perfect - German soldiers were horrified, sometimes in despair. Nothing seemed to be able to stop these monsters except the 88 and gallant individual attacks by isolated infantrymen with explosives, mines etc. Only very poor Soviet strategy and tactics saved the Germans already 1941 (not unlike what happened in France 1940, the French having superior weapons, in particular tanks, and the Germans (generals) being much more clever).

Hitler and Göring made a mistake when considering the Russians "illiterates".

All right, I am leaving the field of airpower - sorry! But as you know "even" the USSR had got quite a few good combat AC types. Too bad they served mainly Stalin and the other blood-thirsty lunatics.

[John Beaman]

Grozibou, you are dead-on correct, especially about the MG 42. It is probably still the best in the world. Our M60 and successors are not even close in terms of usability and effectiveness.

I have asked people why the US did not adopt a clone of the 42 and the answer always is that they, espcially, the Springfield Armory, did not like the stamped metal and thought it was cheap. the result was to continue to use machined (albiet beautiful) parts in weapons that were not that effective or useable and in the case of our M16 had all sorts of problems, even today. I guess us taxpayers have to suffer the egos of Army types and government bureacrats who don't want to admit that something "foreign" is better. too bad.

[Nick Beale]

Originally Posted by Grozibou

- I think you're aware that these weapons didn't exist 1939, not even 1940 and that the number (42 or 44) refers to the year in which they were first introduced (I think) ... After WW II the MG 42 was copied virtually all over the world.

Yes, I was trying to say that with these weapons the Germans were setting trends for the post-war era as you have written.

[Juha]

John
this is off topic but IIRC USA copied and tested MG 42 for possible adaption for the Army but there happened or "happened" a small error when they converted from mm to inch metering in the chamber and as a result the test weapon suffered badly on stoppages. So the idea was dumpped. Again IIRC the designers of M60 borrowed some features from MG 42 and some others from FG 42.

Juha

[Kurfürst]

Originally Posted by edwest

In 1939 the German and American prototypes were superior to the British except for CD/CHL, which was a typical dipole array on 1.5 m. Neither Germany or the United States had a significant number of operational sets in 1939..."

Please pardon the lack of umlauts. Excerpted from A Radar History of World War II by Louis Brown, published by the Institute of Physics Publishing, Bristol and Philadelphia.

Ed

This part is not particularly true. I am not sure about the US radar deployement (obviously there wasn't much a threat either), but German radar was deployed and working at the start of the war. Freya's development and deployement went exactly parellel to the CH system, only that Freya was a much superior system, both in resolution and because it covered a much greater area, as it could be rotated 360 degrees. At the start of the war, there were 20 or so Freya sets available, the first wartime interception being made sometime in 1939 against RAF bombers attacking Kriegsmarine targets. At the same time CH consisted of a similiar number of sets, but they had some major limitations, most notable their large 'blind zone' at low altitudes, and the fact that they could only search the area they were facing, ie. the sea, and the whole 'radar coverage' went totally nil and blind asa enemy aircraft passed the radar towers, as they couldn't rotate. Effectively, the whole CH system offered little more than early warning, other than that the British interceptions relied on human observers and telephone wires over England, just like any other country. AFAIK Würzburg was just begun to be deployed in 1939, and some 200 were produced by 1940, if my memory serves me right and if Ian Hogg`s information is correct. Of course, Britain's unique geographical position was a great advantage for building out an early warning radar system, even with primitive radar sets, because of the ease of radar detection over sea.

[Bruce Dennis]

Originally Posted by edwest

Referring to the late 1930s:

The Germans were generally about a year ahead of the Americans.

....

In 1939 the German and American prototypes were superior to the British except for CD/CHL, which was a typical dipole array on 1.5 m. Neither Germany or the United States had a significant number of operational sets in 1939..."

Ed

Hello Ed, I read your extract from ‘A Radar History of World War II’ and have a problem with accepting the conclusion stated without some qualification. I find the parallels described in the quote from ‘A Radar History of World War II’ surprising. In 1939 America had nothing comparable to the various German sets. These were operational at the same time as the American sets which were, at best, undergoing operational testing. Much as Kurfürst has already said, one party was at war and the other wasn’t. If one looks ahead, there was no superiority (or parity for that matter) of US equipment until later with the introduction of the 10cm sets.

Choosing a date is important if the intention is to compare progress, and as far as American progress in radar development goes, the most significant point in time is more to do with funding and patronage than with a single technical breakthrough. In the spring of 1941, funding was agreed, from official as well as private sources, for MIT to continue the Radiation Laboratory work on 10cm equipment suitable for mass production. By autumn, military reticence was fading and orders for operational, not experimental, sets for ground, sea and air service were realistically expected. The source of future funding now shifted from ‘discrete sources’ (the White House under-the-counter budget) to Congress. The vast manufacturing facilities of the US could now be applied to radar, enabling equipment to be installed on aircraft production lines instead of by specialist technicians after acceptance at squadron level. (This is a slightly oversimplified version as there were other factors, but this was where the main savings in aircraft installations were to be found) Even though they hadn’t yet materialised, making it possible to accept Lend-Lease orders for radar equipment was part of FDR’s plan to prepare America for war and this meant appointing a supremo to oversee all of America’s war-related research and development. The man who took on this role was Vannevar Bush, chairman of the National Defence Research Committee (NDRC) since it was formed in June 1940. Virtually every American radar research project with military applications lived or died on his word of approval, and he was the right person for the job.

The unification and monitoring of the industry under the NDRC brought an efficiency and focus to the separate endeavours of the R & D labs around the USA. One of the first tasks of the NDRC was to conduct a survey of Army and Navy research activities and evaluate where the strengths and weaknesses lay. Most importantly, he ensured that the pure gold delivered by the British Technical and Scientific Mission (commonly known as the Tizard Mission) of August/September 1940 was put to best use, for example by preventing duplication of effort and also pairing up separate investigations that had common elements. Both the US and Britain had independently developed systems, CXAM and CHL, almost identical to each other and each completely unaware of the other. The US had better receivers, the British had airborne radar and IFF, but the star of the show was the cavity magnetron, which produced power approximately 1000 times greater than the best vacuum tube available at the time for use on US 10cm radar devices. Bell Labs, MIT and Stanford University had all been conducting advanced research on microwaves and they were able to immediately take on board the British data. The cavity magnetron was now out of the hands of the hard-pressed British labs and was eagerly adapted by a well directed organisation dedicated to finding as many uses as possible for this new wonder.

When war came to America, the many different universities, corporate labs and independent scientists were already gelled into a network of unparalleled potential. By 1942 mass produced Allied radar components were a fact of life and their superior characteristics were the result of the joining of forces of the British and American products.

Bruce

[PeterVerney]

Thanks Bruce for an excellent summary of the technical situation.
I think where the British had the beating of the Germans in the field, was in the command and control system, because we were definitely behind technically until the 10cm magnetron was developed. The command and control system used the CH and other reports intelligently and was able to put the fighters where they were needed, with some exceptions. The Germans of course were far too regimental and did not really get their act together until Kammhuber got organised.

[Nick Beale]

Originally Posted by Kurfürst

Freya was a much superior system, both in resolution and because it covered a much greater area, as it could be rotated 360 degrees. At the start of the war, there were 20 or so Freya sets... At the same time CH consisted of a similiar number of sets, but they had some major limitations ...

The difference being that CH was part of a fully integrated warning, command and control system. And it worked when it was needed.

[Juha]

Kurfürst
I you had read carefully Ed's message You had noticed that Ed wrote on CD/CHL not on CH, and CHL had rotaring antenna so it had 360 deg scanning ability.

Juha