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History Forum / General / What If / May 2005The German proximity fuse.
The German proximity fuse. The development of the US proximity fuse by the US in WW Two is regarded as a unique allied triumph. Little known however is that the Germans independently developed and successfully test fired almost 1000 rounds of a similar proximity fuse near the wars end that if introduced into service would have had a dramatic effect. The allies estimated that the availability of the proximity fuse would force them to abandon use of the B-24 Liberator due to its lower flying altitude compared to the B-17. The Allied Proximity fuse was used on both Anti-Aircraft Artillery and anti-personnel howitzers where they were set to explode approximately 50 feet above the ground. At that height they would produce a lethal zone over a terrifyingly wide area. When used against aircraft it seemed to increase effectiveness of a round by 3-7 or more. The proximity fuse was fielded as an AA weapon from ships in the Pacific from June 1943 where it was reasoned that secrecy could not be compromised as dud rounds would fall into the sea. (I have no knowledge of its use against the Japanese Troops on islands). It on one occasion apparently helped shoot down 90 of 120 attacking Japanese planes. It was first supplied to Britain to help overcome the V1 cruise missile fired at London where it in combination with radar and computer directed guns reduced the mean number of rounds expended to destroy a V1 from 4000 to 180. Finally there are records of it used against German troops during the Ardennes Offensive (Battle of Bulge). It was reasoned that the Germans would not be able to reconstruct the fuses in time to make use of them. In fact the 'folklore' on the Internet is that they captured some 20,000 but did not recognize them and also that they recovered duds and reasoned that they were triggered by the Earth's magnetic Field. (Note the magnet field theory probably came from the troops themselves before being analysed by more technical branches of the German forces) The allied fuse workings. Technically the Allied fuse was not radar: it did not send out a pulse and listen for an echo. It had 4 tubes. One tube was part of the oscillator. When a 'target' that was about a ½ wavelength in size came within a few wavelengths it would load the amplifier and the anode current would increase. Two additional amplifiers would detect this change and then triggered the 4th valve (a gas filled thyraton) to set of the detonator. Contrary to other reports it apparently did not trigger on Doppler shift either or on frequency change. There were many shock hardening techniques including planar electrodes and packing the components in wax and oil to equalize the stresses. The German fuse workings. The fuse was based on electrostatic principles. The circuitry of the German fuse is not precisely known to me as I do not have the schematics however the details are in allied files refred to I do not have a circuit layout drawing. It is known that the nose of the shell was electrically insulated and isolated from the rest of the shell. It was built by the company Rheinmetall. The program was halted in 1940 then restarted in early 1944 and then terminated again due to being over run by the allies at the point that it was ready for production. Initial fuse testing demonstrated a sensitivity of 1-2 meters and a reliability of 80% when fired against a metal cable target. A circuit adjustment yielded an increase to 3-4 meters and a reliability of close to 95%. Further work showed a 10-15 meter sensitivity. This was with 88mm canon shells. The shell to all intents and purposes ready for production. References are "Truth About the Wunderwaffen" by Igor Witowski who cites "Proximity Fuse Development - Rheinmettal Borsig A.G. Mullhausen. CIOS report ITEM nos 3 file nos XXVI -1 (1945) Capacitance based fuses became highly developed after the second world war due to their high resistance against jamming techniques. It is unlikely that the shell could have been easily degraded by jamming or chaff. (unlike the Allied shell). I can speculate as to several ways that this might work. It is referred to as a "influenz zunder" based in electrostatic principles. Method 1: Bridge Cicuit. The shells external capacitance is made part of a bridge circuite with an internal reference capacitor in the other arm. Any disturbance caused by an large object such as an aircraft would cause a current to flow across the bridge that would be amplified. Method 2: QT or charge transfer methods. A high speed vibrating contact charges the shell and then discharges it into a known capacitance which is then measured. Method 3: making the shell body part of a resonant circuit and detecting frequency changes. I can not find the precise reason for the abandonment of the work in 1940 however it probably relates to the 'fuhrer befehle' or fuhrer directive that with few exceptions all work that could not be put into production within 6 months were to be terminated to increase resources for those that could (in order to support operation Barborosa). It was at this time that the Germans also abandoned their magnetron and microwave development teams and programs. Many programs suffered severely due to this; something that was to have far reaching consequences for the German war effort. What would have happened if the proximity fuse was not abandoned in 1940 but development continued such that it entered service in 1943? > consequences for the German war effort. > > What would have happened if the proximity fuse was not abandoned in > 1940 but development continued such that it entered service in 1943? The Allies would have need bombers to fly at higher altitudes than the B-17 mormally did and would have required some kind of "smart bomb" technology. Maybe bombs guided by narrow beam radio signals. Lasers would not have been ready on time. Bob Kolker As far as I can see the only aircraft the allies would have that could survive above German airspace and much of Europe would be the Mosquito. The B29 would eventually come along but it wouldn't be available in quantity till late 1944. Becuase of the high casualities the American would have to cut their B17 based bombing rates in half and opperate at higher altitudes. The lack of B24s means no Ploesti raid. Presumably Wellingtons could be fitted with two stage supercharged merlins and a presurised fueselage. Basically I think you are right. Bombing altitude would increase from the usuall 20,000-25,000 to 35,000-40,000 to avoid casualites. Medium altitdue aircraft such as the B26 Marauder and B25 become outmoded. German industry would reamin more productive and strong. Bomb gudience becomes essential. > As far as I can see the only aircraft the allies would have that could > survive above German airspace and much of Europe would be the Mosquito. > The B29 would eventually come along but it wouldn't be available in > quantity till late 1944. Becuase of the high casualities the American > would have to cut their B17 based bombing rates in half and opperate at > higher altitudes. The lack of B24s means no Ploesti raid. Only if you assume the proximity fuse is a 100% effective super weapon > Presumably Wellingtons could be fitted with two stage supercharged > merlins and a presurised fueselage. Presumably NOT, a pressurised fuselage is a non trivial modn. > Basically I think you are right. Bombing altitude would increase from > the usuall 20,000-25,000 to 35,000-40,000 to avoid casualites. Medium > altitdue aircraft such as the B26 Marauder and B25 become outmoded. > German industry would reamin more productive and strong. Bomb gudience > becomes essential. Reality intrudes here, you still need to aim the gun someplace close to where the bomber is for the fuse to work, losses would undoubtedly rise but the presence of proximity fuses post war didnt halt bombing and the simple reality is Germany would have to produce em by the million and lacked the industrial capacity to do so. Keith >"Eunometic" <eunometic@yahoo.com.au> wrote in message >Only if you assume the proximity fuse is a 100% effective super weapon [quoted text clipped - 3 lines] > >Presumably NOT, a pressurised fuselage is a non trivial modn. Actually, the flying breadbasket /was/ built in a high-altitude, pressurised version (in fact much of the UK development of pressurisation was done using the Wellington). Obviously the fuselage itself wasn't pressurised (fabric not being much good for that) but a pressurised crew area was developed and flown. The two types were the Mk.V and VI, both fitted with pressurised cockpit and high-altitude versions of the Bristol Hercules. http://www.fortunecity.com/tattooine/farmer/120/welly.html Vickers were leaders (in .uk) in working on stratospheric aircraft - the Barnes Wallis proposals for the Victory Bomber was one strand, the original design for the Windsor another (hence the guns in remote-control barbettes in the tails of the engine nacelles) and the 75- and 100- ton giants of the 1944 programme a third. None ever reached squadron service, but all (except the Victory) were far more than just paper aeroplanes.  SignatureAndy Breen ~ Interplanetary Scintillation Research Group http://users.aber.ac.uk/azb/ "Who dies with the most toys wins" (Gary Barnes) The rare Windsor bomber: http://www.jaapteeuwen.com/ww2aircraft/pictures/gallery/vickers%20windsor.jpg Rob > The rare Windsor bomber: > http://www.jaapteeuwen.com/ww2aircraft/pictures/gallery/vickers%20windsor.jpg > > Rob Was not a Wellington Keith Keith, Andrew Breen brought up the Windsor and I provided a photo of it. Yes, it is not a Wellington... but they are both of geodetic construction and I was posting for those that might not have ever seen a Windsor or knew it existed. Maybe you should read the posts before saying something since Barnes Wallis is connected here. Rob > Keith, > > Andrew Breen brought up the Windsor and I provided a photo of it. Yes, > it is not a Wellington... but they are both of geodetic construction > and I was posting for those that might not have ever seen a Windsor or > knew it existed. Then you should have made that clear > Maybe you should read the posts before saying something since Barnes > Wallis is connected here. Maybe you should do more than posting links to pictures Keith Germany had a wide range of proximity fuses under development and/or testing in the last year of the war: Code Names & Descriptions: BAD, Acoustic, under Graf Zeppelin Institute ELKU (Elektro-Akoustic), and applied to PAPLITZ FUCHS, Radio by AEG Berlin, intended for Hs-117, Hs-298, and other missiles ISEGRIMM, Electromagnetic by Orlich Institute of Danzig. KAKADU, Radio by Donaulandische GmbH of Vienna. 3,000 were produced for the Hs-293- used Doppler effect. KRANICH, Acoustic by Ruhrstahl AG of Brackwerde. Highly rated German proximity fuse. KUGELBLITZ, Radio by Patent Verwertungs Gesellschaft of Salzvurg. Developed for the Rhinetocktor missile. Used Doppler-shift effect. KUHGLOCKE, Electrostatic by Rhinemetall-Borsig. Intended for missiles. Prototypes only. KUHGLOCKEN, Smaller version designed for AA shells. LOTTE, Infrared for an unspecified missile- abandoned. MARABU, Radio by Siemens-Halske under sub-contract of Rheinmetall AG. Designed for the Hs-117, Hs-298, Rheintocktor and Wasserfall missiles. Firing trials. MARDER, Radio by Orlich Institute of Danzig. MEISE, Acoustic by Neumann & Borm of Berlin. PAPLITZ, Infrared by Elektro Akoustic Institute at Namslau then at Kiel. A.K.A. "ELKU". Developed for Hs-117 and Wasserfall. Test firings. PINSCHER, Radio by Orlich Institute of Danzig. Five prototypes. PISTOLE, Photo-Electric, this project was incorporated into WASSERMAUS. ROULETTE, Infrared by Brickmann of Gera. STIMMGABEL, Acoustic by the Graf Zeppelin Institute. Developed for parachute-retarded bomb dropped over Allied bomber streams. Tested. TRICHTER, Radio by Blaupunkt. Field tested. WASSERMAUS, Photo-Electric, developed for the Wasserfall missile. WIESEL, Radio by Orlich Institute of Danzig. ZUNDER-19, Developed for 250kg bomb by Rheinmetall-Borsig. Started 1937. Cancelled 1943. Work continued into 1944. Rob Arndt the Clueless wrote: > Germany had a wide range of proximity fuses under development and/or > testing in the last year of the war: SNIP Just gazing at this list makes you realize the TOTAL madness of the German R&D effort during WWII While the US and Britain combined efforts in Project V of Section T of the NDRC (hence "VT" fuze) > Germany had a wide range of proximity fuses under development and/or > testing in the last year of the war: [quoted text clipped - 57 lines] > > Rob The very length of that list goes a long way to explaining why Germany never got a working fuze into production. The Western allies thought 2 development projects (one British , the other American) would have been extravagantly wasteful. Keith You'll find that there were at least two other allied photoelectric based fuses. The first one entered service on rockets (it couldn't handle the shock of a gun launch) but its photocells found application in the punched paper tape reader of the colossus machine used in decrypting Enigma. The second system could withstand a cannon lauch and entered service. It used a torrodial perspex lens around the circumference or rim of the shell that focused on a photocell. To be fair most of these German fuses were for different purposes than cannon shell launch. Missiles need more sophisticated and jam resistent radio proximity fuses. In addition the Germans were clearly hedging their bets by developing a spread of systems to reduce their exposure to Allied Jamming attempts. The German were big investors in both passive and active infrared technology and this was begining to pay of in 1945. In part the plethora of projects represents the secrecy compartmentalisation, as well as intersevice rivalries but also a policy of phased development was in place so that the Germans could catch up and stay ahead in areas such as radar. In reality relying on one proximity fuze type is a recipe for disaster. The allies relied on secrecy and then the hope that the Germans couldn't react in time. The Wasserfall and Enzian Surface to Air missiles for instance had a spread of guidence and proximity fuze systems under development. Wasserfall had a 3 axis gyroscopic version of the two axis gyroscopic guidence system in the V2 including apparently the PIGA accelerometer. Even without external guidence it would have placed itself within a few hundred meters of its target. There an infrared terminal homing system was to be used (Madrid), or alternatively command guidence using a radar called "Mannheim" (80 of these track-lock entered service) or visual command guidence. There was also a semi active guidence system under development called "Moritz". The command link was based on a specially developed version of the "Khel/Strassbourg" system used on Fritiz-X and Hs 293 but also on a purpose built system called "Kogge/Brigge" The smaller Ruhrstahl X-4 wire guided Air to Air missile opperated with basic wire guidence and a contact fuse backed up accoustic proximity fuse called "Kranich". A accoustic terminal homing system "Dogge" was also under development as was an infrared terminal homing system and proxitmity fuse. The same systems were planed for the Enzian missile including an accoustic homing head called "Archimedes" The accoustic homing systems worked quite well. A Me 262 Jet equiped with accoustic homing systems could detect a bomber and its directions to about 4-5 miles range. There were 5 quite effective surface to air missiles bodies were developed: Wasserfall, Enzian, Hs-117, Rheintochter R1.and R3 but non received the focus they needed to enter service. To one degree or another they suffered manpower shortages or sabotage. > You'll find that there were at least two other allied photoelectric > based fuses. The first one entered service on rockets (it couldn't [quoted text clipped - 34 lines] > Fritiz-X and Hs 293 but also on a purpose built system called > "Kogge/Brigge" SNIP See the US guided and glider bomb programs for a similar list of proposed and experimented with guidance systems (VB/BG series) Fletcher BG-1 After the USAAF had cancelled the order for the Fletcher PQ-11A radio-controlled target drone, ten of the PQ-11As under construction were completed as XBG-1 bomb gliders. In the XBG-1, the PQ-11A's engine was replaced by a 900 kg (2000 lb) bomb. The XBG-1 was to be towed to the target area by a larger aircraft and upon release was to be guided to target impact by radio-commands using imagery transmitted from a TV camera in the glider's nose. No information on the XBG-1 test program is available, but the model was never used operationally. Fletcher BG-2 When the Frankfort CG-1 troop-carrying glider was cancelled in 1941, the three XCG-1s under construction were completed by Fletcher as XBG-2 bomb gliders. No information about the bomb load or the results of tests (if any!) is available, but the BG-2 program was cancelled in 1942. Cornelius BG-3 The BG-3 was a design with nose-mounted horizontal stabilizers and forward-swept wings. As such it was possibly similar to Cornelius' XFG-1 fuel glider. Although the USAAF had planned to procure one XBG-3 prototype, this order was cancelled in 1942 The VB designation was introduced by the U.S. Army Air Force in 1943, and covered unpowered guided bombs with effectively no standoff gliding range (i.e. "vertical" bombs). ATSC VB-1/VB-2 Azon In April 1942, the USAAF's Materiel Command (became part of ATSC (Air Technical Service Command) in 1944) began the development of the Azon family of guided bombs. The initial variant, designated VB-1, was based on a 450 kg (1000 lb) bomb (initially the M44, but later models apparently switched to the standard AN-M65), which was modified with a new tail unit. The latter consisted of a gyroscopic unit to provent the bomb from rolling, a flare for optical tracking, an octagonal shroud with control surfaces, and a radio-command receiver. When a VB-1 was dropped, the bombardier could track it through his bombsight and use a joystick-type control to send corrective commands to the bomb. The Azon guidance system allowed only lateral course corrections, but errors in range could not be corrected (hence the name Azon = "Azimuth Only"). The Azon development phase ended in late 1943, and the VB-1 was subsequently ordered into mass production. The second Azon variant was the heavier VB-2, which was based on a 900 kg (2000 lb) bomb, but that version was apparently not produced in very large numbers. The first VB-1/2 bombs were sent to Europe in February 1944, and a total of 15000 Azons were produced until November 1944. Because of their azimuth-only guidance, the VB-1 was particularly suited to long and narrow targets (like bridges or railways) where range errors would be irrelevant. For "normal" targets, however, the VB-1 was actually not as good as unguided free-fall bombs, because a bomber could not break away immediately after dropping the bomb, and the accuracy was effectively not increased because of the lack of range control. Another peculiarity of the Azon guidance set was the fact that only five different radio channels were available for the command link, meaning that not more than five bombs could be controlled independently. Although in theory a whole group of bombs using the same command channel could be controlled simultaneously, this was not practical. The accuracy of all but the "primary" bomb (i.e. the one which was tracked by the bombardier) in such a group was rather bad, because the non-spinning Azon bombs showed a significant dispersion. The drawbacks of the Azon meant that its use remained very limited. However, it was employed rather successfully in Burma, where it was used to destroy very vital and therefore heavily defended bridges along the Japanese supply lines. Less the 500 Azons were needed to destroy 27 bridges. When the war ended, the USAAF quickly removed the VB-1 and VB-2 from its inventory. Because of the much reduced post-war funding, the USAAF limited its guided vertical bomb research to the more advanced VB-3/VB-4 Razon family. ATSC VB-3/VB-4 Razon In parallel with the Azon tests, the ATSC also developed a more advanced variant called Razon, which was to be controllable in both range and azimuth. The designations VB-3 and VB-4 were assigned to the 450 kg (1000 lb) and 900 kg (2000 lb) Razon versions, respectively. The Razon guidance kit had two octagonal shrouds in a tandem arrangement. The most problematic part in Razon development was to build a suitably modified bombsight, which would allow the bombardier to correctly judge the bomb's deviation in range so that the range control could be used effectively. The Razon also had an improved radio-command link with 47 separate channels, effectively eliminating the Azon's problems with concurrent drops by a multitude of bombers. The VB-3/VB-4 was combat-ready in summer 1945, and about 3000 Razons were subsequently produced, but none of them were used before World War II was over. However, the VB-3 was operationally tested five years later during the first months of the Korean War. B-29 aircraft, which could carry eight VB-3s, dropped several hundred Razons on North Korean bridges, and although the overall reliability of the bombs was rather low, some targets were actually destroyed. However, in general multiple hits by the small the 450 kg (1000 lb) bombs were needed to destroy a large bridge span, and the USAF's use of guided bombs for these special missions switched to the much larger VB-13/ASM-A-1 Tarzon. ATSC VB-5 The VB-5 was a 450 kg (1000 lb) bomb, which used the same tandem octagonal control shroud arrangement as the VB-3/VB-4 Razon. However, the VB-5 was not command guided but used an autonomous light contrast seeker. This bomb did not go into production, presumably because the guidance mechanism didn't work as planned. ATSC VB-6 Felix The VB-6 Felix was a 450 kg (1000 lb) bomb with an octagonal control shroud and a heat seeking device in the nose. Intended for use against strong infrared emitters (like e.g. blast furnaces), the VB-6 was tested with some success during 1945, but the program was cancelled at the end of World War II. The U.S. Navy developed a very similar IR-guided bomb as the ASM-N-4 Dove. ATSC VB-7, VB-8 The VB-7 and VB-8 both used a TV/radio-command guidance, where a TV camera in the bomb's nose transmitted the image to a display set for the bombardier, who could then correct the bomb's course by radio-commands. The weights of the VB-7/VB-8 are unclear, but it can be assumed that these two guided bombs were cancelled early in the development phase. Douglas VB-9/VB-10/VB-11/VB-12 Roc The Roc series of guided bombs was developed by Douglas, the MIT and the NDRC (National Defense Research Committee). The VB-9 model was a 450 kg (1000 lb) bomb with cruciform wings and fins and a radar seeker in the nose. The radar image was transmitted to the bombardier who could use it to direct the bomb's path by radio commands. However, the radar was often useless because of ground clutter, and the VB-9 program was terminated in early 1945. VB-9 The later Roc models all used a 450 kg (1000 lb) bomb body of 61 cm (24 in) diameter and 3 m (10 ft) length. They were fitted with two circular shrouds, a larger one which could move around two axes for directional steering, and a smaller one in the tail designed to slow down the bomb to facilitate the tracking and guidance task of the bombardier. The VB-10 had a TV camera and transmitter, so that the bombardier could track the bomb via the image on his TV display set. The VB-11 had an infrared seeker for autonomous heat-seeking guidance, and the VB-12 was tracked visually (making it similar in operation to the VB-3/VB-4 Razon). VB-10/11/12 The VB-10 (and presumably also the VB-11/VB-12 models) was tested between September 1944 and May 1945, when the Roc program was terminated without any model going into production. Bell VB-13 Tarzon The VB-13 is discussed on a separate page about the VB-13/ASM-A-1 Tarzon. Specifications The few available data on the dimensions and weights of the VB-series bombs are mentioned in the main text http://www.designation-systems.net/dusrm/app1/index.html http://www.wpafb.af.mil/museum/arm/vb.htm > The smaller Ruhrstahl X-4 wire guided Air to Air missile opperated with > basic wire guidence and a contact fuse backed up accoustic proximity [quoted text clipped - 6 lines] > with accoustic homing systems could detect a bomber and its directions > to about 4-5 miles range. SNIP I'm sorry, but I find an acoustic system that sensitive, yet able to filter out the wind noise of going 500 mph, along with the howl of two turbojets a bit hard to believe. Could you provide more details or a citation? renabor...@aol.com wrote: > > You'll find that there were at least two other allied photoelectric > > based fuses. The first one entered service on rockets (it couldn't [quoted text clipped - 154 lines] > seeker. This bomb did not go into production, presumably because the > guidance mechanism didn't work as planned. I am quite aware of AZON and RAZON and TARZON. AZON was given development impetus by US awareness of Fritz-X. Both Fritz-X and the Hs 293 were extremely accurate and quite reliable. The TV guidence systems the Germans latter developed didn't match them. Hit rate (10m dia circle) under combat conditions was 45%. Unlike AZON they were designed from the outset for point targets and shiping and thus had controll on all axis as well as larger fin areas for extra range controll. The defficiency of Fritz-X (also known as the SC1400) was that the aircraft was limited in its range of evasive manouver. After release the bomber would conduct a sharp pullup as this aligned the bomb flare for tracking as well as throwing of predicted FLAK. The Hs 293 allowed more evasive manouvers and essentially replace Fritz-X. Although allied success at jamming seems exaggerated (sigint failed to come up with jamming that worked; only capture of the bombs in Italy lead to jammers that MAY have worked) the last set of Hs 293 missiles used wire guidence. About 400 were used mainly in the retreat in the east. > ATSC VB-6 Felix > The VB-6 Felix was a 450 kg (1000 lb) bomb with an octagonal control [quoted text clipped - 3 lines] > the end of World War II. The U.S. Navy developed a very similar > IR-guided bomb as the ASM-N-4 Dove. The Germans had several infrared seekers under development for use against ships, aircraft and ground targets (blast furnaces) etc. The company Kepke produced for testing "netzhaut" (means retina in German) for attacking blast furnaces with BV 246 glide bombs (200km range). Part of a series known as "Widder", "Netzhout" and "Krebs" Hamburg I by the company Elac. 30mm detector with 30cm mirror for Wasserfall warhead. 60 degree sweep, 10 degree accuracy. Intended for Wassefall missile. It worked but needed a more sophisticated scan to extend acquistion range to 2-5km. This more sophisticate rossete scan was never completed. The device was known as "Kiel III". Hamburg II replaced the Lead Sulphide Cell with a Caesium Oxide Cell and a 14cm mirror. It was smaller but not much of an improvement but considered good for attacking shipping. Simulated attacks using a He 111 showed that it was necessary to gyro-stabalise the head. I believe lack of gyro-stabilisation is what reduced early TV guidence accruacy as well. "Embden" was an AEG competitor of Hamburg. Kepke produced "Madrid" for use on Glide bombs and Enzian missiles. Most "state of the art" was "armin-2" by Dr Kutscher of Elac. Armin-2 used 'thermovision'and had a range of 1.5km when tracking a He 111 bomber. Probably used electronic spiral scaning of an image. Kepke series of homers for ships and aircraft. Some of the tests showed that the homers clealy worked. Usaully the problem was inadaquet range:the powers wanted more than the 1.5km due to inadaquet scan pattern or lack of gyrostabalisation. The fancy scan patterns existed for scanners used on infrared imaging systems. Gluhwurmchen (glowworm) by Rheinmetall for missiles. Much hope was placed in these homing devices and they showed every signe of being practical. For some reason ranges of 1.5km were never considered adaquete. > ATSC VB-7, VB-8 > The VB-7 and VB-8 both used a TV/radio-command guidance, where a TV [quoted text clipped - 3 lines] > assumed that these two guided bombs were cancelled early in the > development phase. The problem with TV guidence was the poor resolution,poor light sensitivity (esp in europe) and poor scan update and lack of gyrostabilisation. Nevertheless the Germans seem to have gotten confident that it would work both for SAM missiles and Ground attack. > Douglas VB-9/VB-10/VB-11/VB-12 Roc > The Roc series of guided bombs was developed by Douglas, the MIT and [quoted text clipped - 16 lines] > tracked visually (making it similar in operation to the VB-3/VB-4 > Razon). The Germans were only just begining to introduce to troop testing ground mapping microwave radars. There was work on correlating photograhed images with a image of the terrain below for cruise missile guidence. > VB-10/11/12 > The VB-10 (and presumably also the VB-11/VB-12 models) was tested [quoted text clipped - 34 lines] > turbojets a bit hard to believe. Could you provide more details or a > citation? Several accoustic homers for aircraft and missiles were under development. 1 "Baldrin" by Messerscmitt and Telefunken. Used 16 valves and 4 microphones. Range was 350m when flown on piston engined aircraft and several kilometers when flown on an Me 262. It had a wide 180 degree view. 2 Parrallel development at ELAC with an estimated range of 2km but never named or tested. 3 "Pudel" single microphone homer for the axially spining X-4 missile. 4 A Dr Trage of "Reichs Post" had a 4 microphone system under development. Baldrin was the only one tested. I estimate that a 3 or 4 bladed propeller at 1500 rpm will produce 75 to 100 hertz and that a 12 to 18 cylinder exhaust will produced 150 to 225 hertz. A 9000 rpm 60 bladed jet starts at about 4000 hertz. The germans on their sub sonars used electro-accoustic crystals to phase shift to use constructive interferience to determin direction and I expect the same technique in sonic aircraft trackers. Don't forget that sound was used to aim and range FLAK and that even in WW1 in britain huge granit parabolic sound dishes would detect and triangulate gotha bombers and zepplins out to 20-25 knautical miles. Sound can locate artillery fire and can even track bullets and shells. Its a little slow but it is apparently a concern for stealth aircraft. > The Germans were only just begining to introduce to troop testing > ground mapping microwave radars. Whereas the RAF and USAF were using them in service by the thousand <snip> > Several accoustic homers for aircraft and missiles were under > development. [quoted text clipped - 8 lines] > > 3 "Pudel" single microphone homer for the axially spining X-4 missile. Which was of course never deployed > 4 A Dr Trage of "Reichs Post" had a 4 microphone system under > development. [quoted text clipped - 4 lines] > to 100 hertz and that a 12 to 18 cylinder exhaust will produced 150 to > 225 hertz. Take a sound meter to an airshow, you'll get a broader band of frequencies than that > A 9000 rpm 60 bladed jet starts at about 4000 hertz. > > The germans on their sub sonars used electro-accoustic crystals to > phase shift to use constructive interferience to determin direction and > I expect the same technique in sonic aircraft trackers. Submarines suffer from somewhat less flow noise than an aircraft > Don't forget that sound was used to aim and range FLAK and that even in > WW1 in britain huge granit parabolic sound dishes would detect and > triangulate gotha bombers and zepplins out to 20-25 knautical miles. No the sound dishes were built in the late 1920's and early 1930's > Sound can locate artillery fire and can even track bullets and shells. Lots of luck trying to track a supersonic projectile with a medium that travels less than half as fast. It can tell you where it WAS and perhaps even where it was fired from but not where its now. > Its a little slow but it is apparently a concern for stealth aircraft. Indeed but the inbuilt limitations make it almost useless for targetting. Keith <much snippaggio> > The German were big investors in > both passive and active infrared technology and this was begining to > pay of in 1945. Just in time, eh? Yeah, right. Says it all, really. Signature"The past resembles the future as water resembles water" Ibn Khaldun My .mac.com address is a spam sink. If you wish to email me, try atlothian at blueyonder dot co dot uk > Basically I think you are right. Bombing altitude would increase from > the usuall 20,000-25,000 to 35,000-40,000 to avoid casualites. Medium > altitdue aircraft such as the B26 Marauder and B25 become outmoded. > German industry would reamin more productive and strong. Bomb gudience > becomes essential. If the strategic (hi-altitude) bombing campaigns become more difficult, could those resources have been redirected to provide a massive increase in low-altitude tactical aircraft? Would Thunderbolts and the like have been less vulnerable to proximity fuses? (Or would B-17 / B-29 production have surged and the war continued business as usual?) -- Zamboni > > Basically I think you are right. Bombing altitude would increase > from [quoted text clipped - 8 lines] > could those resources have been redirected to provide a massive > increase in low-altitude tactical aircraft? SNIP British low-level fighter sweeps ("Rodeo" operations) developed a nasty reputation for lots of casualties for few results Would Thunderbolts and the > like have been less vulnerable to proximity fuses? SNIP Probbaly yes, but vulnerable to things like 20-mm Vierling (Quad) mounts, barrage balloons, power cables, etc, etc... (Or would B-17 / > B-29 production have surged and the war continued business as usual?) > -- > Zamboni >> If the strategic (hi-altitude) bombing campaigns become more > difficult, [quoted text clipped - 5 lines] > British low-level fighter sweeps ("Rodeo" operations) developed a nasty > reputation for lots of casualties for few results Thanks, I'll look into that. I've been curious if prioritizing tactical air would have had an effect, but couldn't find much information if it was actually tried anywhere. -- Zamboni > What would have happened if the proximity fuse was not abandoned in > 1940 but development continued such that it entered service in 1943? one of the problems is the before the War, Germany didn't have much consumer industry for primary cell batteries, unlike the US. Many German items that would have used batteries in the US, used magnetos in Germany, like flashlights and such[1]. So they would also need to invent mini batteries that could survive being shot out of a cannon, yet last thru hot times in the Summer in Italy and cold on the Eastern Front for months in Depots. And then make millions of them. Not a problem for the US, which had many battery companies waiting to switch over to War work. Not the case in Nazi Germany, even with Hungary and France, which had more for Battery companies. Given the cutthroat contracting that was in Nazi Germany, what other secret weapon would get defunded to provide workers and materials? [1] Primary Cells were widely used in US telephones and Radios. While helpful for Walkie-Talkies,and hearing aids, was a problem with Bazookas in very cold weather, which didn't switch over to a magneto system till Korea ** mike ** > References are "Truth About the Wunderwaffen" by Igor Witowski who > cites "Proximity Fuse Development - Rheinmettal Borsig A.G. [quoted text clipped - 8 lines] > What would have happened if the proximity fuse was not abandoned in > 1940 but development continued such that it entered service in 1943? SNIP The Allies would have developed specific ways of jamming the fuse - nothing is unvulnerable renabor...@aol.com wrote: > > References are "Truth About the Wunderwaffen" by Igor Witowski who > > cites "Proximity Fuse Development - Rheinmettal Borsig A.G. [quoted text clipped - 14 lines] > The Allies would have developed specific ways of jamming the fuse - > nothing is unvulnerable. Some things are so difficult they are not realistically viable. Laser, Photoelectric and Capacitative proximity fuses are simply very difficult to jam or deceive. The Allied VT was based on RF (radio frequency) methods) and it was shown to be vulnerable to predetonation becuase it was easy to get RF energy into the detection circuity using a mechnically swept oscilator. Capacitence based fuses use much lower frequencies that are effectively DC. They more or less rely on detecting changes in 'fields'. It is very hard to radiate interfering energy into the circuity while it is easier to introduce changes to avoid deception. Getting sufficient range is more of a struggle with these fuses. Fuze jamming doesn't seem to be regarded as a very viable method today excepting the most primitive of munitions. British Scientific Developments - A British scientific mission carries to the United States details of many important developments. Amongst these is the recently invented cavity magnetron, vital for short wavelength radar and the eventual defeat of conventional U-boats. Also for the close-proximity fuse which becomes so important in the 1945 battles with Japanese Kamikaze aircraft The German proximity fuse. The development of the US proximity fuse by the US in WW Two is regarded as a unique allied triumph. Little known however is that the Germans independently developed and successfully test fired almost 1000 rounds of a similar proximity fuse near the wars end that if introduced into service would have had a dramatic effect. The allies estimated that the availability of the proximity fuse would force them to abandon use of the B-24 Liberator due to its lower flying altitude compared to the B-17. The Allied Proximity fuse was used on both Anti-Aircraft Artillery and anti-personnel howitzers where they were set to explode approximately 50 feet above the ground. At that height they would produce a lethal zone over a terrifyingly wide area. When used against aircraft it seemed to increase effectiveness of a round by 3-7 or more. The proximity fuse was fielded as an AA weapon from ships in the Pacific from June 1943 where it was reasoned that secrecy could not be compromised as dud rounds would fall into the sea. (I have no knowledge of its use against the Japanese Troops on islands). It on one occasion apparently helped shoot down 90 of 120 attacking Japanese planes. It was first supplied to Britain to help overcome the V1 cruise missile fired at London where it in combination with radar and computer directed guns reduced the mean number of rounds expended to destroy a V1 from 4000 to 180. Finally there are records of it used against German troops during the Ardennes Offensive (Battle of Bulge). It was reasoned that the Germans would not be able to reconstruct the fuses in time to make use of them. In fact the 'folklore' on the Internet is that they captured some 20,000 but did not recognize them and also that they recovered duds and reasoned that they were triggered by the Earth's magnetic Field. (Note the magnet field theory probably came from the troops themselves before being analysed by more technical branches of the German forces) The allied fuse workings. Technically the Allied fuse was not radar: it did not send out a pulse and listen for an echo. It had 4 tubes. One tube was part of the oscillator. When a 'target' that was about a ½ wavelength in size came within a few wavelengths it would load the amplifier and the anode current would increase. Two additional amplifiers would detect this change and then triggered the 4th valve (a gas filled thyraton) to set of the detonator. Contrary to other reports it apparently did not trigger on Doppler shift either or on frequency change. There were many shock hardening techniques including planar electrodes and packing the components in wax and oil to equalize the stresses. The German fuse workings. The fuse was based on electrostatic principles. The circuitry of the German fuse is not precisely known to me as I do not have the schematics however the details are in allied files refred to I do not have a circuit layout drawing. It is known that the nose of the shell was electrically insulated and isolated from the rest of the shell. It was built by the company Rheinmetall. The program was halted in 1940 then restarted in early 1944 and then terminated again due to being over run by the allies at the point that it was ready for production. Initial fuse testing demonstrated a sensitivity of 1-2 meters and a reliability of 80% when fired against a metal cable target. A circuit adjustment yielded an increase to 3-4 meters and a reliability of close to 95%. Further work showed a 10-15 meter sensitivity. This was with 88mm canon shells. The shell to all intents and purposes ready for production. References are "Truth About the Wunderwaffen" by Igor Witowski who cites "Proximity Fuse Development - Rheinmettal Borsig A.G. Mullhausen. CIOS report ITEM nos 3 file nos XXVI -1 (1945) Capacitance based fuses became highly developed after the second world war due to their high resistance against jamming techniques. It is unlikely that the shell could have been easily degraded by jamming or chaff. (unlike the Allied shell). I can speculate as to several ways that this might work. It is referred to as a "influenz zunder" based in electrostatic principles. Method 1: Bridge Cicuit. The shells external capacitance is made part of a bridge circuite with an internal reference capacitor in the other arm. Any disturbance caused by an large object such as an aircraft would cause a current to flow across the bridge that would be amplified. Method 2: QT or charge transfer methods. A high speed vibrating contact charges the shell and then discharges it into a known capacitance which is then measured. Method 3: making the shell body part of a resonant circuit and detecting frequency changes. I can not find the precise reason for the abandonment of the work in 1940 however it probably relates to the 'fuhrer befehle' or fuhrer directive that with few exceptions all work that could not be put into production within 6 months were to be terminated to increase resources for those that could (in order to support operation Barborosa). It was at this time that the Germans also abandoned their magnetron and microwave development teams and programs. Many programs suffered severely due to this; something that was to have far reaching consequences for the German war effort. What would have happened if the proximity fuse was not abandoned in 1940 but development continued such that it entered service in 1943? > British Scientific Developments - A British scientific mission carries to > the United States details of many important developments. Amongst these is > the recently invented cavity magnetron, vital for short wavelength radar and > the eventual defeat of conventional U-boats. Also for the close-proximity > fuse which becomes so important in the 1945 battles with Japanese Kamikaze > aircraft I seem to recall hearing that an RAF officer developed a laboratory prototype jet engine in the 1937-38 timeframe. I wonder why that information was not mentioned in the British scientific mission to the United States. The U.S. had more engineering and manfacturing resources free at that time than did Britain. I know that the U.S. developed its own jet engine that reached the flight test stage towards the end of WW2, but it seems like if this prototype jet engine had been made available to U.S. engineers and manufacturers, it could have allowed the U.S. to develop a working jet engine much faster and maybe even introduce it into operational service before the end of WW2. J >> British Scientific Developments - A British scientific mission carries to >> the United States details of many important developments. Amongst these [quoted text clipped - 11 lines] > United States. The U.S. had more engineering and manfacturing resources > free at that time than did Britain. It was > I know that the U.S. developed its own > jet engine that reached the flight test stage towards the end of WW2, but [quoted text clipped - 4 lines] > operational > service before the end of WW2. Like the GE I-A engine , based on Whittle's designs that first ran on April 18, 1942 perhaps. Keith >The German proximity fuse. > [quoted text clipped - 7 lines] >proximity fuse would force them to abandon use of the B-24 Liberator >due to its lower flying altitude compared to the B-17. The B-24 made up around 1/3 of the 8th Air Force and 2/3 of the 15th Air force, all up just under half the USAAF bombers. The main deployment of B-24s to Europe was in 1944. It was a USAAF estimate, flak losses would triple, bombing heights would have to increase and the B-24 not used against well defended targets. When the German flak concentration around the main synthetic oil plants became so great the USAAF started to use cloudy days, relying on radar aids, assuming the loss of accuracy for the gunners was greater than that of the bombers. Not flak losses were never above the critical loss rates, but would have approached it if they were tripled. It took fighters to really cut up a bomber formation. >The Allied Proximity fuse was used on both Anti-Aircraft Artillery and >anti-personnel howitzers where they were set to explode approximately >50 feet above the ground. At that height they would produce a lethal >zone over a terrifyingly wide area. When used against aircraft it >seemed to increase effectiveness of a round by 3-7 or more. So the 16,000 88mm shells per shoot down fired would be reduced to 2,300 to 5,300. The Germans did better early in the war in terms of shells per aircraft but this was the sort of price paid for using effectively reserve manpower in the flak units alongside less accurate fire control systems. The proximity fuse effects can be replicated by wires on the bomb noses and by having trees in the combat area. If the shell or bomb hits the tree the results are an airburst. You can also have time fuses for shells. Of course none as accurate as a proximity fuse for bursts at the optimum height. >The proximity fuse was fielded as an AA weapon from ships in the >Pacific from June 1943 where it was reasoned that secrecy could not be >compromised as dud rounds would fall into the sea. (I have no >knowledge of its use against the Japanese Troops on islands). It on >one occasion apparently helped shoot down 90 of 120 attacking Japanese >planes. As has been stated the last time this information was posted, The claim ignores the USS Helena firing proximity fused shells off Guadalcanal in January 1943. Fuse production was 500 per day in October 1942. Note by the end of 1944 the delivery rate was 40,000 per day, or in other words just over half an hour to equal the entire claimed German production. The other point was to design a shell to take the fuse, the allies started with the USN 5 inch gun. It should be noted the claimed major shoot down was the USN ships reporting what they thought they had shot down. In the fights with Kamikazes the USN ships reported they needed to fire 100% VT (proximity) fuses, since there was normally no time to set and use time fuses. >It was first supplied to Britain to help overcome the V1 cruise missile >fired at London where it in combination with radar and computer >directed guns reduced the mean number of rounds expended to destroy a >V1 from 4000 to 180. The note being it was a combination of better fire control and fuses. >Finally there are records of it used against German troops during the >Ardennes Offensive (Battle of Bulge). It was reasoned that the [quoted text clipped - 5 lines] >troops themselves before being analysed by more technical branches of >the German forces) Ah so the folk lore is they captured a US ammunition dump with the fused shells and then inventoried the catch, as opposed to destroying it? By the way the troops would not be checking the fusing of any dud rounds, but removing the shells to a safer place. The experts would be looking at things like fuses. >The allied fuse workings. > [quoted text clipped - 8 lines] >many shock hardening techniques including planar electrodes and packing >the components in wax and oil to equalize the stresses. Given we are talking about wavelengths in the order of centimetres the axis mist have been flying very small aircraft if they were around a half wavelength in size. Try this for an explanation, "One method that was experimented with used radio waves transmitted from the ground. These radio waves would be reflected by the target and received by the fuze. Once the radio waves were at a sufficient level, the fuze would activate causing the shell to explode. Another method that was more logical and became the accepted means, was to develop a fuze which was capable of obtaining its own intelligence and of using it to ignite the shell. When assembled this fuze consisted of four major parts: A miniature radio transceiver, complete with amplifier and capacitor; a battery; an explosive train; and the necessary safety devices. The theory was that the fuze transmitter, alone, would not produce sufficient signal intensity, to trigger a thyratron tube switch. However, as the projectile approached a target the radio waves reflected by the target would gradually increase and come more and more into phase with the fuze-generated signal. Once the signal level was high enough, the fuze would know that the shell could do a maximum amount of damage, and the thyratron tube switch would be triggered releasing the energy in a charged capacitor and thus igniting the shell." >The German fuse workings. > >The fuse was based on electrostatic principles. At least this hopefully stops the previous claims the Germans handed the design to the British who then used it. >The circuitry of the German fuse is not precisely known to me as I do >not have the schematics however the details are in allied files refred [quoted text clipped - 4 lines] >due to being over run by the allies at the point that it was ready for >production. The above assumes the program was producing fused shells in 1940 as opposed to heading towards the idea. After all if the restart was in early 1944 and the production facilities were over run something like 15 months later just as production was about to start it shows how long things actually took. How long the Germans really were from production. The US started work on the fuse in July 1940 and later developed optical and magnetic proximity fuses for mines and 4.5 inch rockets. >Initial fuse testing demonstrated a sensitivity of 1-2 meters and a >reliability of 80% when fired against a metal cable target. A circuit [quoted text clipped - 4 lines] >canon shells. The shell to all intents and purposes ready for >production. Again no dates are given, presumably we are to believe it was ready for production in 1940, but then shut down because it was not ready for production within 6 months, see below, and the time it actually took in 1944/45 above. There were considerable strides made during the war when it came to reliability and miniaturisation of radio parts, the later war experiments would have benefited from this. Note the lethal burst radius for a standard 88mm shell was around 30 feet, or 9 metres. Given the standard fire control radar some 59,000 88 mm shells were needed to cover the volume the aircraft could be in when flying at 24,000 feet. >References are "Truth About the Wunderwaffen" by Igor Witowski who >cites "Proximity Fuse Development - Rheinmettal Borsig A.G. >Mullhausen. CIOS report ITEM nos 3 file nos XXVI -1 (1945) > >Capacitance based fuses became highly developed after the second world >war due to their high resistance against jamming techniques. Ah, so the plan is to stop claiming the Germans gave the fuse to the allies but to claim they thought of it first and did it better. >It is unlikely that the shell could have been easily degraded by >jamming or chaff. (unlike the Allied shell). Yes, claim it does things better. Just ignore the idea the whole idea of window was to mimic a bomber, and all that has to be done now is to explain how the shell would discriminate against aluminium in falling foils and in aircraft flying along. >I can speculate as to several ways that this might work. It is >referred to as a "influenz zunder" based in electrostatic [quoted text clipped - 5 lines] >aircraft would cause a current to flow across the bridge that would be >amplified. main problem, surviving the firing accelerations. >Method 2: QT or charge transfer methods. A high speed vibrating >contact charges the shell and then discharges it into a known >capacitance which is then measured. Should be fun to create the mechanism to allow a high speed vibrating contact, have it survive the acceleration of the firing and then spin up to arm the shell >Method 3: making the shell body part of a resonant circuit and >detecting frequency changes. Should be fun lugging the fused shells around metal guns. >I can not find the precise reason for the abandonment of the work in >1940 however it probably relates to the 'fuhrer befehle' or fuhrer >directive that with few exceptions all work that could not be put into >production within 6 months were to be terminated to increase resources >for those that could (in order to support operation Barborosa). So in other words in 1940 the fuse was not ready for production. > It >was at this time that the Germans also abandoned their magnetron and >microwave development teams and programs. Many programs suffered >severely due to this; something that was to have far reaching >consequences for the German war effort. It would be better to say scaled back as opposed to abandoned. >What would have happened if the proximity fuse was not abandoned in >1940 but development continued such that it entered service in 1943? The USAAF would have flown more night missions and deployed B-29s to Europe. The allies would have devoted more to flak suppression. The allies would have flown more missions on cloudy days using the better navigation aids in 1944. Note the half way point for Bomber Command for bombs on Germany was in late September 1944, the 8th was mid November 1944. It was a very end loaded campaign. The number of flak batteries out ran the German ability to provide them with proper fire control systems. Hence there were still sound locators in use in 1944 to use an extreme example. The idea of massed batteries was also driven by the amount of fire control systems needed. Before the RAF introduced window Bomber Command was recording that around 6 to 9% of returning aircraft on night missions had flak damage, March to July 1943. This dropped to 2.85% in August and averaged 2.3% for all of 1944 and 1.4% for 1945. Window remained effective against the fire control radars for the remainder of the war. The average for aircraft returning damaged by flak on night raids February to December 1942 was 6.5%, for all of 1943 5.8%. In effect a proximity fuse at around 3 to 7 times the lethality would restore to exceed the pre window hit rates. The USAAF carried window and active jammers but, of course, by day the gunners could correct their aim by eye. Some batteries even had the ability to track the H2X radars of USAAF pathfinders and use this for ranging, electronic warfare was a 2 way street. Geoffrey Sinclair Remove the nb for email. > >The German proximity fuse. > > [quoted text clipped - 22 lines] > have approached it if they were tripled. It took fighters to really cut > up a bomber formation. What were the critical levels? 10% losses would mean a 65% loss after only 10 missions. 3% sounds sustainable. > >The Allied Proximity fuse was used on both Anti-Aircraft Artillery and > >anti-personnel howitzers where they were set to explode approximately [quoted text clipped - 7 lines] > reserve manpower in the flak units alongside less accurate fire control > systems. I suspect that the use of the proximity fuse would place pressure on increasing accuracy. I suspect that barrels were not renewed as often as was optimal. The 128mm FLAK gun had a fuse setter installed on the barrel to allow the fuse time to be set while the round was in the barrel. It is my understanding that most 88 guns had an external fuse setting device that was a box next to the barrel. So the FLAK crew (9 men or children) would neet to maintain a rhythm of following the dials and pointing the gun, inseting the round in the fuse setter removing it inserting the round in the barrel etc. Putting servo drives on the gun and in barrel fuse setters would I suspect also have increased accuracy. The problem is that there isn't enough skilled labour to build, calibrate,maintain this equipement. > The proximity fuse effects can be replicated by wires on the bomb > noses and by having trees in the combat area. If the shell or bomb [quoted text clipped - 33 lines] > > The note being it was a combination of better fire control and fuses. It would appear that the 20:1 reduction came 3:1 from VT fuses and 7:1 from servo driven and computer aimed radar slaved guns. Or perhaps the other way around. I suspect optically directed servo driven computer aimed guns could have been as effective on a clear day. > >Finally there are records of it used against German troops during the > >Ardennes Offensive (Battle of Bulge). It was reasoned that the [quoted text clipped - 9 lines] > the fused shells and then inventoried the catch, as opposed to > destroying it? I don't know what the custom would have been. It is said they didn't recongise the nature of the shells. However they did recover dud shells (they must have known there was something unique about them) and surmised that they had a electronic fuse. > By the way the troops would not be checking the fusing of any > dud rounds, but removing the shells to a safer place. The [quoted text clipped - 16 lines] > the axis mist have been flying very small aircraft if they were around > a half wavelength in size. VT fuse opperated at about 220-280Mhz or so. A wavelenght would have been about 1.5 meters. Targets would need to be 1/4 to 1/2 a wavelenght to produce a stronger return. > Try this for an explanation, > [quoted text clipped - 23 lines] > At least this hopefully stops the previous claims the Germans > handed the design to the British who then used it. I never suggested that the Allies or British coppied the German fuse,I suggested that it accelerated the allied work. Early German investigations seem to go back to 1935. There is British work going to 1937 and I suspect 1934 for optical fuses. > >The circuitry of the German fuse is not precisely known to me as I do > >not have the schematics however the details are in allied files refred [quoted text clipped - 10 lines] > 15 months later just as production was about to start it shows how long > things actually took. How long the Germans really were from production. In actualy fact the 1000 test firings were conducted in 1944. There may have been firings in 1940 before cancellation but they were almost certainly not succesfull. > The US started work on the fuse in July 1940 and later developed > optical and magnetic proximity fuses for mines and 4.5 inch rockets. [quoted text clipped - 12 lines] > for production within 6 months, see below, and the time it actually > took in 1944/45 above. No, I believe there were NO test firings in 1940 that were succesfull. > There were considerable strides made > during the war when it came to reliability and miniaturisation of radio > parts, the later war experiments would have benefited from this. There are some notes kicking around somewhere on german techniques for valve seals in ceramic amplifier tubes. I believe they produced quite small ceramic valves, > Note the lethal burst radius for a standard 88mm shell was around > 30 feet, or 9 metres. Given the standard fire control radar some [quoted text clipped - 10 lines] > Ah, so the plan is to stop claiming the Germans gave the fuse to the > allies but to claim they thought of it first and did it better. Electrostatic fuses are apparently intrinisically hightly resistent to jamming. The allies looked at using electrostatic principles but preceded with radio methods instead. I belive the Germans struggled to get the range up from 3-4 meters to 10-14 meters. It looks like they had to add a small antenna cable or tailing wire to achieve this. > >It is unlikely that the shell could have been easily degraded by > >jamming or chaff. (unlike the Allied shell). [quoted text clipped - 3 lines] > is to explain how the shell would discriminate against aluminium > in falling foils and in aircraft flying along. Window and Chaff could be used to form a layer below the bomber to predetonate some of the fuses. > >I can speculate as to several ways that this might work. It is > >referred to as a "influenz zunder" based in electrostatic [quoted text clipped - 7 lines] > > main problem, surviving the firing accelerations. True, but they seem to have succeded. > >Method 2: QT or charge transfer methods. A high speed vibrating > >contact charges the shell and then discharges it into a known [quoted text clipped - 3 lines] > vibrating contact, have it survive the acceleration of the firing > and then spin up to arm the shell The contact could be aligned along the axis to avoid centrifugal forces or a rotating button could be used. > >Method 3: making the shell body part of a resonant circuit and > >detecting frequency changes. [quoted text clipped - 8 lines] > > So in other words in 1940 the fuse was not ready for production. No it wasn't. Production of 1000 rounds occured for testing in 1944. > > It > >was at this time that the Germans also abandoned their magnetron and [quoted text clipped - 3 lines] > > It would be better to say scaled back as opposed to abandoned. Abandoned is accurate. They had to get the personel back out of the Army. They didn't even recognise the value of the magnetron since the microwave experts werent there to look at it. It was taken by some initally as proof that microwaves are not good for detecting aircraft. > >What would have happened if the proximity fuse was not abandoned in > >1940 but development continued such that it entered service in 1943? > > The USAAF would have flown more night missions and deployed > B-29s to Europe. The B29 wasn't reliable till late 44. The engines overheated, caught fire (they were magnesium) and then burned through the spar. Nasty. > The allies would have devoted more to flak > suppression. The allies would have flown more missions on [quoted text clipped - 9 lines] > massed batteries was also driven by the amount of fire control > systems needed. All guns fired at once apparently. > Before the RAF introduced window Bomber Command was recording > that around 6 to 9% of returning aircraft on night missions had flak > damage, March to July 1943. This dropped to 2.85% in August and > averaged 2.3% for all of 1944 and 1.4% for 1945. Window remained > effective against the fire control radars for the remainder of the war. An moving target indicator called k-laus that used a 2 microsecond delay line to detect moving targets was expected to resolve window and chaff much better than wurzlaus and nurenberg. It didn't quite enter service. > The average for aircraft returning damaged by flak on night raids > February to December 1942 was 6.5%, for all of 1943 5.8%. In effect [quoted text clipped - 8 lines] > Geoffrey Sinclair > Remove the nb for email. >> >The German proximity fuse. >> > [quoted text clipped - 25 lines] >What were the critical levels? 10% losses would mean a 65% loss after >only 10 missions. 3% sounds sustainable. Overall according to the USAAF statistical digest the 8th Air force flew 1,034,052 heavy bomber sorties, 898,758 considered effective, losing 2,439 to flak. So between a 0.23 and 0.27% loss rate. The RAF considered 5% loss rates unsustainable long term and the USAAF seems to have agreed. >> >The Allied Proximity fuse was used on both Anti-Aircraft Artillery and >> >anti-personnel howitzers where they were set to explode approximately [quoted text clipped - 11 lines] >increasing accuracy. I suspect that barrels were not renewed as often >as was optimal. Alternatively the proximity fuse could reduce the pressure for new guns, so the savings could be used elsewhere. The flak service needed to replace an average of 380 88mm guns a month in 1944, thanks to wear or destruction. Even in 1942 it was 148 guns a month. Increasing accuracy is firstly a function of the fire control systems, something the Germans struggled to provide. Then go for barrel wear and ammunition quality. >The 128mm FLAK gun had a fuse setter installed on the barrel to allow >the fuse time to be set while the round was in the barrel. This was so the time fuses could be set at the last possible moment, eliminating the differences in time taken between setting the fuse then manually loading and firing the shell. The time tended to go up as the crew tired. >It is my understanding that most 88 guns had an external fuse setting >device that was a box next to the barrel. So the FLAK crew (9 men or [quoted text clipped - 7 lines] >The problem is that there isn't enough skilled labour to build, >calibrate,maintain this equipement. Then add the shortage of radars to provide accurate range information, in particular height. (snip) >> As has been stated the last time this information was posted, >> [quoted text clipped - 27 lines] >I suspect optically directed servo driven computer aimed guns could >have been as effective on a clear day. This ignores radar's great advantage over optics, much more accurate range information. Where optics works better is bearings, the smaller wavelengths give greater accuracy. >> >Finally there are records of it used against German troops during the >> >Ardennes Offensive (Battle of Bulge). It was reasoned that the [quoted text clipped - 14 lines] >shells (they must have known there was something unique about them) and >surmised that they had a electronic fuse. Recovering dud shells is not something the infantry usually has time to do, it usually requires some specialists. The recovery of some shells is possible, but it would be alongside other dud shells. Given the known number of dud bombs in WWII there would be plenty of dud shells to look for. >> By the way the troops would not be checking the fusing of any >> dud rounds, but removing the shells to a safer place. The [quoted text clipped - 20 lines] >been about 1.5 meters. Targets would need to be 1/4 to 1/2 a >wavelenght to produce a stronger return. So the aircraft would have to be 0.75 to 0.4 metres in size? The system used compared the phase of the reflected wave, which is where wavelengths come into things, it does not apply to the size of the target. >> Try this for an explanation, >> [quoted text clipped - 28 lines] >investigations seem to go back to 1935. There is British work going to >1937 and I suspect 1934 for optical fuses. The claimed German system used an entirely different idea to find proximity but somehow this is supposed to accelerate the project initiated in the US that used another method? Simply it is clear, like radar, people were thinking about how they could have the shell explode near a target. This is not the same thing as the Germans, yet again, being claimed to help allied technology. >> >The circuitry of the German fuse is not precisely known to me as Ido >> >not have the schematics however the details are in allied files refred [quoted text clipped - 14 lines] >may have been firings in 1940 before cancellation but they were almost >certainly not succesfull. So the Germans had a design in 1940 that did not work but this is supposed to have been of help to the allies? >> The US started work on the fuse in July 1940 and later developed >> optical and magnetic proximity fuses for mines and 4.5 inch rockets. [quoted text clipped - 13 lines] > >No, I believe there were NO test firings in 1940 that were succesfull. Well that is cleared up at least. >> There were considerable strides made >> during the war when it came to reliability and miniaturisation of radio [quoted text clipped - 3 lines] >valve seals in ceramic amplifier tubes. I believe they produced quite >small ceramic valves, So, like radar, the proximity fuse were bleeding edge and were not something you could do off the shelf, additional technologies had to be developed. >> Note the lethal burst radius for a standard 88mm shell was around >> 30 feet, or 9 metres. Given the standard fire control radar some [quoted text clipped - 13 lines] >Electrostatic fuses are apparently intrinisically hightly resistent to >jamming. Anything passive is harder to jam, but the fuse had to measure something to explode and jamming could provide the something. >The allies looked at using electrostatic principles but preceded with >radio methods instead. I belive the Germans struggled to get the range >up from 3-4 meters to 10-14 meters. It looks like they had to add a >small antenna cable or tailing wire to achieve this. So the allies came to the conclusion an active fuse was possible with early 1940's technology and this avoided things like having to make special shells with trailing antennas, attached to the fuse. The Germans went down the route of requiring special shells, as opposed to the allies having the ability to use the same shell with different fuses. A range of 3 to 4 metres is around 1/3 to 1/2 the lethal range of the 88mm shell. >> >It is unlikely that the shell could have been easily degraded by >> >jamming or chaff. (unlike the Allied shell). [quoted text clipped - 6 lines] >Window and Chaff could be used to form a layer below the bomber to >predetonate some of the fuses. So why the assertion above? (snip) >> Should be fun to create the mechanism to allow a high speed >> vibrating contact, have it survive the acceleration of the firing >> and then spin up to arm the shell > >The contact could be aligned along the axis to avoid centrifugal forces >or a rotating button could be used. Try surviving the initial acceleration first given the parts have to then be able to move, after presumably bleeding some of the speed to start any vibrations. (snip) >> > It >> >was at this time that the Germans also abandoned their magnetron and [quoted text clipped - 8 lines] >microwave experts werent there to look at it. It was taken by some >initally as proof that microwaves are not good for detecting aircraft. Like so many of Germany's experimental aircraft trials that were officially shut down but continued the same applied to the electronics sector. >> >What would have happened if the proximity fuse was not abandoned in >> >1940 but development continued such that it entered service in 1943? [quoted text clipped - 4 lines] >The B29 wasn't reliable till late 44. The engines overheated, caught >fire (they were magnesium) and then burned through the spar. Nasty. One of the main problems causing engine fires were the high ambient air temperatures at the bases used in 1944 and the heavy loads being carried given the range to target. England is cooler and closer to the targets, plus having more engineering personnel available if needed. The B-29 was really a 1945 bomber. >> The allies would have devoted more to flak >> suppression. The allies would have flown more missions on [quoted text clipped - 11 lines] > >All guns fired at once apparently. Which shows the problems with fire controls. The massed firings did up the hit rate. >> Before the RAF introduced window Bomber Command was recording >> that around 6 to 9% of returning aircraft on night missions had flak [quoted text clipped - 6 lines] >chaff much better than wurzlaus and nurenberg. It didn't quite enter >service. Yet again the Germans were going to have it but never did. The average for aircraft returning damaged by flak on night raids February to December 1942 was 6.5%, for all of 1943 5.8%. In effect a proximity fuse at around 3 to 7 times the lethality would restore to exceed the pre window hit rates. The USAAF carried window and active jammers but, of course, by day the gunners could correct their aim by eye. Some batteries even had the ability to track the H2X radars of USAAF pathfinders and use this for ranging, electronic warfare was a 2 way street. Geoffrey Sinclair Remove the nb for email. Correction time, >Overall according to the USAAF statistical digest the 8th Air force >flew 1,034,052 heavy bomber sorties, 898,758 considered effective, >losing 2,439 to flak. So between a 0.23 and 0.27% loss rate. The >RAF considered 5% loss rates unsustainable long term and the >USAAF seems to have agreed. The heavy bomber loss figure is correct but the sortie totals are not, I managed to use the total sorties for all types, heavy bomber sorties totalled 332,904 airborne and 274,921 effective, giving loss rates for heavy bombers to flak guns between 0.73 and 0.89%, depending whether you use airborne or effective sorties. Sorry for the error. Geoffrey Sinclair Remove the nb for email. In message <428071df$0$3932$5a62ac22@per-qv1-newsreader-01.iinet.net.au>, Geoffrey Sinclair <gsinclairnb@froggy.com.au> writes snip >>Method 3: making the shell body part of a resonant circuit and >>detecting frequency changes. > >Should be fun lugging the fused shells around metal guns. IIRC the fuse was inactive until fired. The shock of firing broke a glass cell containing the battery acid, the battery then produced the required voltage. Mike SignatureM.J.Powell > In message > <428071df$0$3932$5a62ac22@per-qv1-newsreader-01.iinet.net.au>, Geoffrey [quoted text clipped - 9 lines] > IIRC the fuse was inactive until fired. The shock of firing broke a > glass cell containing the battery acid, the battery then produced the > required voltage. The initial fuses that entered service used a 'normal' battery. It worked quite well however the batteries would degrade in only a few months hence the above batteries were developed. Nose mounted wind turbine driven generators were also used in experimental shells but were rejected, probably for cost reasons. The German electrostatic influence fuse used a battery. I don't know what battery technology they used. > Mike In message <428071df$0$3932$5a62ac22@per-qv1-newsreader-01.iinet.net.au>, Geoffrey Sinclair <gsinclairnb@froggy.com.au> writes >It should be noted the claimed major shoot down was the USN >ships reporting what they thought they had shot down. And, like bomber gunners, both raid count and bandits splashed were prone to error... when Seaman Smith sees the aircraft he's hammering with 40mm shellfire burst into flames and ditch, naturally that's *his* kill. As it is also Seaman Jones who'd just riddled it with 20mm, and it's also a kill claimed by the 5" teams who had been shredding it with fragments on its way in... and every one of those claims is honestly made. >In the fights with Kamikazes the USN ships reported they needed >to fire 100% VT (proximity) fuses, since there was normally no time >to set and use time fuses. However, they were told by BuOrd to use 25% time fuzed shells: the bursts had deterrent effect, indicated the raid to other units, but primarily it pointed up any gross errors like the director aiming at the wrong group of aircraft. >Before the RAF introduced window Bomber Command was recording >that around 6 to 9% of returning aircraft on night missions had flak [quoted text clipped - 5 lines] >a proximity fuse at around 3 to 7 times the lethality would restore to >exceed the pre window hit rates. US experience was that VT fuzing was about three times more effective than time fuzing on a straight rounds-per-bird comparison: this rose to nearer four times by war's end as experience was gained and reliability improved. SignatureHe thinks too much: such men are dangerous. Julius Caesar I:2 Paul J. Adam MainBox<at>jrwlynch[dot]demon{dot}co(.)uk |
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