Allied search radars

[Dave Saxton]

The French Navy began to be concerned about rumors of radio detection systems by 1939, and the French firm of SFR in Paris began experiments. SFR employed noted researcher H Gutton.

Using a 12 segment magnetron, the first devices produced power outputs of 6 watts at 10 cm wave length, and 10 watts at 16 cm wave length. Using a pulsing technique, the power was up to 50 watts operating on a wave length of 16cm, just before the the fall of France in 1940. This set demonstrated an ability to detect a battleship to a max range of 10,000 meters. Gutton tried using an oxide cathode in place of a thoriated tungsten, and that increased the power ten fold to 0.5 kw. As France fell, these test results were transfered to Megaw in England, resulting in Megaw insisting on modifying the British cavity magnetron to include a large oxide cathode.

The Vichy Navy attempted continued clandestine development of the SFR 16cm equipment. Little is known, but some claim that the equipment was eventually able to detect a battleship to a max range of 25,000 meters by 1944. All prototypes were destroyed, along with the documentation, when the Vichy fleet was scuttled.

[RF]

Was the KM aware of the work by the French?

[Dave Saxton]

I don't know. I doubt it though. At any rate the French were many years behind the Germans in radar development and capability.

[RF]

That does surprise me that the Germans didn't pursue the work started by the French, given the degree of collaboration between the French and Germans during the period between the fall of France and the start of Barbarossa, including the usage of French naval facilities in the German occupied zones of France.

[RF]

Although this is going off at an angle, I am aware that the French did collaborate with the Poles during the period of the ''Phoney War'' on radio cryptology work in connection with Enigma, but when France fell all the people involved in this work escaped to Britain and the Germans were left with no means of being aware of this work; the ''escape'' in this respect was masterminded by the British Secret Service.
Maybe a similar thing happened with the French radar, but I have heard nothing concrete in that respect.

[Dave Saxton]

Hi RF,

I kind of suspect that the Germans were not aware. Anything involving radar during this time frame was super secret, regardless of nation. In most cases there was no thought of sharing things with others. The German Navy had even tried to keep it secret from the Luftwaffe. The Tizard Mission was the exception, and many in Britian were dead set against sharing secrets with the Americans, anyway. Adm Somerville even argued that the Americans would spill the beans to the Germans. Almost everone thought they had something the other guys didn't have. The secrecy was to the point of being counter productive in many cases. If the Germans were aware of the French efforts, it would not have provided anything that they didn't already know about, or have, so there would be little point in pursuing it.

The Germans had produced lab models working at 13cm, with the performance of the French 16cm equipment some six years previously. By 1940 German radar had advanced far beyond this rather embryonic state.

The French experimental radar still lacked some key ingrediants needed to make operational radar at the microwave frequencies viable, so it could not provide an avenue to providing the Germans solutions to their own ongoing efforts in that regard.

Gutton sent scientific data to his British counterparts as France fell by secret currier. Many of the Dutch and Danish scientists got over to Britian as well.

[RF]

I was thinking in my post of French collaborators working for the Germans, especially as in the period prior to Barbarossa there were a huge number of French collaborators, far more than there were in the resistance. But as you say in your post petty organisational segmentation and jealousies make the degree of potential collaboration far greater than it was, and on the German side there were a great number of competing projects, many of them unproductive.

[Dave Saxton]

Some additional information on the British search radars (the British used the term warning radars were the term search is used by the Americans)

The use of Types 277 and 293 together as a team came from the intention of having a new "warning" radar that would be useful vs surface targets and air targets all in one compact unit. A new generation 10cm warning radar to replace Types 273 and 271 came as Type 276 in late 1944 on a few destroyers. The problem with the 276 was that it didn't pickup and track high flying aircraft well, although it's surface performance was very good.

It was then decided by committe to replace (or rather convert) the 276 to Type 293 with a new tilted antenna design. The 293 eventually became very good at tracking high flying aircraft, but it wasn't good at tracking low flying aircraft.

The 277 was good vs both low flying aircraft and surface targets, but recieved much critism, because of the need to stop continous rotation inorder to find the height. With the antenna stopped, and focusing on one target, the panoramic view on the PPI was temporarily lost. Moreover, pressed into the role of fighter direction late in the war on carriers, it couldn't do that additional job as well as radar designed just for that role.

[Dave Saxton]

Don't forget the incomparable RCN CSC and SW1C series of naval Radars.

The head of the Royal Navy's radar effort was a Canadian. This was Sir Charles Wright.

The Canadians contributed a very important British naval radar postwar. It was found that the new Type 274 10cm gunnery radar could not spot the fall shot for azimuth. The first attempted remedy came as a British Army S band radar piggybacked onto the firecontrol system on the new battleship Vanguard in 1946, but this didn't work either. The Canadian designed and built Type 931 provided an operational solution from 1947.

[lwd]

I seam to recall something about some Canadian troops and thier radars being sent down to help protect the Panama canal very soon after the US entered the war as well.

[RF]

lwd, can you recall the source of this info, as I was under the impression that the Canal Zone was occuppied by substantial US forces and I would be surprised at Canadian involvement in what at that time was regarded as being part of the US - and remained so until the Carter Administration agreed to its handing back to Panama.

[lwd]

Here's a source but I'm pretty sure it wasn't the one I saw before:
http://www.commelec.forces.gc.ca/org/hi ... -c-eng.asp

By 1942 the superior Canadian radar equipment soon found itself protecting the strategically vital Panama Canal with Canadians providing "know how" to the American forces. At the same time, less effective American manufactured equipment was being rushed into service to protect parts of the Canadian West Coast.

[RF]

Interesting - the US interest as Isuspected predominated here. The Canadian Pacfic coast however didn't face any direct enemy threat so perehaps could afford the lesser quality equipment.

[lwd]

I'm not sure it's a case of "US" interest predominating. The Canal was more important than almost anything else on the West Coast US or Canada. Meanwhile the Canadians may not have had enough stuff to get good coverage of their west coast. So inferior but more plentiful equipment to the less important and less threatened target. Note that at one point the US and Canada had a pretty strong defencive postion around the Great Lakes as well. By mid war most of it got shipped elsewhere and a number of projects were canceled before completion. I think it may actually be another indicator on just how well the Western Allies worked as a team.

[RF]

Don't forget also that of course by the time Japan entered the war Canada was fully mobilised, certainly in terms of its naval forces even though up to that point it was an Atlantic based strategy.
Although a Jap sub did lob a few shells at an oil plant at Santa Barbara, California and they also occupied Attu and Kiska in the Aleution Islands, the Japanese did not direct any attention to the Canadian mainland that I am aware of.