Could proximity fuses have halted the bomber offensive against Germany in 1944?

[pattle]

Germany was only still developing the proximity fuse at wars end after its development had been interrupted by a Hitler order around 1941. The proximity fuse was used with great effect by the Allies, most notably against the V1 flying bombs against which it was highly successful. The Americans were very mindful of the Germans reverse engineering proximity fuses and would at first not allow their use over enemy held territory through fear of a dud being captured. Proximity fuses were later used against ground targets with devastating effect and are generally considered to be one of the major inventions to come out of World War Two.
German anti aircraft batteries concentrated their fire into a box and relied on timed fuses which were timed to exploded at a pre-determined altitude with the hope and expectation that shell splinters would destroy the oncoming enemy aircraft. If the Germans had of had proximity fuses fitted to their anti-aircraft shells then presumably this would have made them far more effective as the fuse itself would have exploded the shell upon detecting the presence of a bomber.
Obviously the Allies had seen for themselves just how effective proximity fused shells were against the fast moving flying bombs and they would have been more than a bit concerned about the safety of their slow moving four engine bombers should the Germans had developed their own.

 

[Civettone]

I predict some people will come up with the result of American studies on the efficiency of VT fuses in the Pacific or in use against the V1s. These conclude that effectiveness was 3-4 times greater with the Proxy Fuse. But those studies are questionnable.

Anyway, the Germans were developing a whole range of proxy fuses. By 1945, they were ready to produce them, but they came too late. Also, we have no idea how reliable these would have been. Most (if not all) were designed for use on missiles/rockets, which is quite different from cannon shells.

The Americans had developed counter measures against proxy fuses. Worked quite well against their own radio fuses, but the German shells worked differently. Some say there was a German flak electrostatic sensor.

Also, German flak effectiveness increased greatly when they stopped using barrage tactics, i.e. bombing at an imaginary box over the target.

My take is that the best use for these proxy fuses would be on the Enzian air defence missile, which due to its much larger warhead was more effective than the other Fla-Raketen in development.

Kris

 

[pattle]

I don't think we will see a stampede of posts on this topic, fuses are after all not the most glamorous or interesting of subjects although it is often the less glamorous of inventions that have the biggest impact. I personally have no idea how much difference German possession of VT or any other type of Proximity fuse in 1943 or 44 would have made but I feel they would certainly have made life more difficult for the bomber crews and infantry alike.

 

[GregP]

I worked on proximity fuzes for Motorola in the 1980's and they could not have been used in artillery shells in WWII. The circuit components would not survive the positive 5,000-g push and the negative 8,500-g stop when the copper lands hit the rifling groves. Tubes just aren't going to take it. It took transistors to survive the g-load of gunfire.

Two of the prox fuzes I worked on were 6-inch and 8-inch projectiles. We shot them down a 150-foot air cannon into a solid kiln-dried plywood block about a 30 inches square with 100+ pounds of lead plate behind it for recoil absorption. Virtually none were damaged tubes would have turned into glass powder with metal bits in it.

Solid state didn't get around to existence until Bardeen, Brattain, and Shockley invented the transistor in 1947. It didn't result in anything much useful until the early 1950's and artillery proximity fuzes were still a decade or more away.

Would NOT have been possible for a German 88 or any other gun to have a proximity fuxe in WWII. Rockets and missiles? Yes. MUCH less acceleration, all in one direction, and not fueled by a gunpowder explosion. Tubes would survive.

Prox fuzes are essentially a small radar set inside the nose of a projectile with the ability to detect range to target. When the range gets into the proper interval, a fire pulse is initiated and the detonator exercises the warhead or explosive cargo.

 

[Milosh]

Proximity fuse were used in the Battle of the Bulge.

wiki
The Pentagon had decided it was too dangerous to have a fuze fall into German hands because they might reverse engineer it and create a weapon that would destroy the Allied bombers, or at least find a way to jam the radio signals. Therefore they refused to allow the Allied artillery use of the fuzes in 1944. But General Dwight D. Eisenhower protested vehemently and demanded he be allowed to use the fuzes. He prevailed and the VT fuzes were first used in the Battle of the Bulge in December 1944, when they made the Allied artillery far more devastating, as all the shells now exploded just before hitting the ground. It decimated German divisions caught in the open. The Germans felt safe from timed fire because they thought that the bad weather would prevent accurate observation. The effectiveness of the new VT fused shells exploding in mid-air, on exposed personnel, caused a minor mutiny when German soldiers started refusing orders to move out of their bunkers during an artillery attack. U.S. General George S. Patton said that the introduction of the proximity fuze required a full revision of the tactics of land warfare.

 

[GregP]

Would be interesting to see what could withstand the g-force in 1945 .... I have built stuff with that vintage parts and it isn't very durable when you talk about thousands of g's. I'd disbeileve it unless it was mechanical with something a broomstick sticking out of the shell nose ... we did that in Vietnam to get through the jungle canopy.

Without a shematic and the projected parts list, I say BS. Must be somethinhg simple and mechanical or a fabrication. No way tubes can do it. If nothing else, the filaments won't take 5,000 g-s much less more.

 

[Greyman]

I'm not sure what you're saying. Are you calling 'BS' on proximity fuze development and use in WWII?

 

[nincomp]

A film about WWII VT fuses

View: https://www.youtube.com/watch?v=6-D592VR4RU

 

[GregP]

Doesn't tell us anything at all about the fuze. Maybe they cobbled together some back to back Flemming valves (an early diode) to make something, but I'm still wondering what the amplifier was. Wiki says it was a Thyrotron trigger, which is a tube.

Perhaps they made 5.000+-g rugged tubes in WWII, but all the tubes we tested in the early 1980's didn't survive gunshot shock. None.

I surmise they had to have made rugged tubes since either solid state was invented earlier than history says or they made gun-rugged tubes. Of the two choices, military gun-rugged tubes seem more realistic.

I've never seen one myself (34+ years in electronic engineering) but, considering the evidence, there must be a way to do it since they could NOT have a prox fuze without an amplifier for the transmit function. I have 10+ prox fuzes in my collection, but ALL are solid state and I have not sectioned them. The only "early" prox fuze I ever saw was whole, not cutaway, and the circuit wasn't described ... just the effect of the function on the artillery shell.

Must be so, but have never seen a gun-rugged tube ... go figure.

Makes me wonder how far the bow and arrow could be developed, actually using a bowstring.

 

[cherry blossom]

The problem of making a useful proximity fuse in WW2 was that you needed a thermionic valve (vacuum tube in US English) which would survive firing. The USA was the only country able to produce these and the reason was because they had previously designed miniature valves for use in hearing aids. There is a history of the development at http://www.history.navy.mil/faqs/faq96-1.htm#anchor1191745.

The British and the Germans both started the development of proximity fuses but neither could produce valves which could reliably survive firing. Some of the British ideas may have helped the American effort although it started and continued mostly independently. The Germans may have been testing proximity fuses by 1945 and they certainly could have fitted fuses to rockets which did not need to survive such high acceleration.

I suspect that the US reluctance to use proximity fuse where they might fall into enemy hands was not solely due to fear of them being copied. It is possible that ECM could have made American fuses ineffective. I have read that in the Okinawa Campaign, the US Navy had some problems after the US Army installed interfering radars on Okinawa. Thus it has been suggested that post-war development moved towards the German electrostatic fuses.

 

[Tante Ju]

I do not think VT fuses would have made any difference against high flying bombers, those are very different targets than V1/PTO kamikazes. Better Flak guns with better ballistics would help a whole lot more...

 

[pattle]

A film about WWII VT fuses

View: https://www.youtube.com/watch?v=6-D592VR4RU

Thanks for the link, that was a really interesting video and a bit of an eye opener for me.

 

[delcyros]

CIOS report ITEM nos 3 file nos XXVI -1 (1945) contains information about german proximity fuses in ww2.
Also files from Rheinmetall-Borsig contain informations.

The proxy fuse project for AAA was designated either Kuhglöckchen (88mm) or Kuhglocke (128mm) and suppsoedly was based upon electrostatic principles. Trial firing carried out in Kummersdorf was effective. Series production scheduled march 45 but never executed.

 

[Civettone]

Delcyros, some say that CIOS report is bogus. I read somewhere that all these CIOS reports are listed, except that one ...


GregP, does a fuse with electrostatic sensor also require a transistor?


Kris

 

[OldSkeptic]

Then short answer is "yes". If you look at the improved performance of proximity fuses when they were introduced against the V1s then you could easily extrapolate to an significant improvement in the effectiveness of German flak. In fact you would expect it to be far greater, in that PFs used against V1s had only a short engagement time (due to low altitude and speed), against slow and high 'heavies' (both night and day) you would expect considerably better performance. Possibly to the point where operations against targets that had them would have had to have been curtailed.

Bomber Command would have been put out of the area bombing business for example.

 

[GregP]

I've worked on radar fuzes but not electrostatic fuzes. I don't see how an electrostatic circuit of 1940's vintage would detect an uncharged aircraft or even the ground, but it could be. I won't say no to it, but remain skeptical unless I could see the circuit and know the sensitivity of the detector.

How would it work against a Mosquito, were the metal was mostly the engines, propellers, engine mounts and landing gear, none of which should be overly charged for any reason.

Why should an electroctatic detector function as it approaches the ground?

You know, they'd roll over and beg for one of our fuzes but, in the absence of smart electronic countermeasures, a continuous wave (CW) device would work just fine. Perhaps pulsed CW. The problem, to me, is still the amplifier for the transmit function. Receiver? No issue. Antenna? No issue. Transmitting after a +5,000 and - 9,000 - g shock? I wonder very hard if tubes are involved. But they had to have made working, gun-rugged amplifiers SOMEHOW or it's all a lie.

 

[Jabberwocky]

The VT radio proximity fuse was produced in a wide variety of Mks through the war, starting with the MK 32 for the US 5 inch gun. Here's an image of the Mk 53 fuse of 1944 vintage:

http://upload.wikimedia.org/wikipedia/commons/b/b7/MK53_fuze.jpg

The British and the US had been working on ruggedising vacuum tubes for a radio proximity fuse from 1939 and 1940, respectively. The US devoted far more resources into it and had a workable fuse in the form of the Mk 32 by early 1942. Work on a photo-electric fuse was abandoned when the solution to the VT fuse was found.

The US developed the VT fuse through the National Defense Research Committee, specifically Section T of Division A. The US spent more than 1 billion on the research and development and purchase of VT fuses during WW2 and bought more than 22 million fuses.

The technical challenges were immense. Not only did they need to shock harden the tubes, they had to design new types of circuitry, a new type of battery, new filament types ect.

There's a pretty thorough history here http://www.history.navy.mil/faqs/faq96-1.htm

 

[bbear]

just on the internet:

http://drdo.gov.in/drdo/pub/monographs/Introduction/Proximity_Fuzes.pdf

Radio Proximity Fuzes

I hope those links work - if not the title of the first is Proximity Fuses Theory and Techniques by V K Arora

It's from the indian government, just a snippet of longer work but seems to give more technical detail than anything I've seen so far here and backs up Jabberwocky's chain of events. and is referenced. It makes sense to my rusty electronic mind but.....

the second is a survey of proximity fuses by ed sharpe that I don't think has been mentioned yet and gives the context and significance

It's only one and a half sources really, but some estimate of the quality might be made? Amongst other items, (I think they may they use the same reference to source 'A. Price 1963 The History of US Electronic Warfare ') during the Battle of the Bulge a munitions store including VT fuses was captured by the Germans - Wright Field in two weeks came up with a lab working ECM solution in case the enemy started using 'copy cat' fuses in their flak.

So the answer to the first question would be 'yes but no but yes but no...'. In any case thanks to previous bombing German valve production had been hit? Mosquito pin point raid low level if I remember took out one centre

Unfortunately neither source details the valve design which was GregPs question. The 1963 Price reference might clinch it for those with the right access?

 

[OldSkeptic]

The VT radio proximity fuse was produced in a wide variety of Mks through the war, starting with the MK 32 for the US 5 inch gun. Here's an image of the Mk 53 fuse of 1944 vintage:

http://upload.wikimedia.org/wikipedia/commons/b/b7/MK53_fuze.jpg

The British and the US had been working on ruggedising vacuum tubes for a radio proximity fuse from 1939 and 1940, respectively. The US devoted far more resources into it and had a workable fuse in the form of the Mk 32 by early 1942. Work on a photo-electric fuse was abandoned when the solution to the VT fuse was found.

The US developed the VT fuse through the National Defense Research Committee, specifically Section T of Division A. The US spent more than 1 billion on the research and development and purchase of VT fuses during WW2 and bought more than 22 million fuses.

The technical challenges were immense. Not only did they need to shock harden the tubes, they had to design new types of circuitry, a new type of battery, new filament types ect.

There's a pretty thorough history here http://www.history.navy.mil/faqs/faq96-1.htm

Thanks, beat me too it. We tend to have a bit of modern arrogance about what people did in the past, even without the 'magic' of silicon.
A cynic would say "once upon a time people used their brains".

Jabberwocky, you will appreciate this, how good was the Concorde's original analog control system? Superb basically, not changed to digital until long into it's life.

 

[OldSkeptic]

How would it work against a Mosquito, were the metal was mostly the engines, propellers, engine mounts and landing gear, none of which should be overly charged for any reason.

Not as well basically as against other planes. Short range signal and needs a return signal. If it got close too the engines then fine. Plus it was fast.
Then again the V1 was as fast or faster, and it worked real well against them. Though it was all metal of course.

But against a Lanc, or a B-17 or a B-24 .. ugly.

We were lucky they didn't crack it until too late.

But against a Lanc, or B-17 or B-24 ... would work real well...