The Radio Proximity Fuse

The proximity fuse was a radio transmitter/receiver that detected an object in its path. When the object was close enough, about 30 feet, the fuse would go off. Before the proximity fuse, the range to the target had to be estimated and that range dialed into the shell. This was difficult against a maneuvering attack aircraft. The trick was to get the tiny radios rugged enough to withstand firing from an anti-aircraft gun. The success of the proximity fuse was confirmed with tests aboard Cleveland (CL-55), 12 Aug 42, which downed three drones with four shots from 5" dual purpose guns. The fuse was ordered into mass production. The first combat use of the proximity fuse was by the Helena (CL-50) off Guadalcanal, 5Jan43. The proximity fuse was such a valuable secret that it was forbidden to be used over enemy territory until late in the war in case the enemy found a dud and become aware and possibly reproduce the technology or develop a countermeasure.

Heralded as an "organizational achievement transcending anything of the time ... one of the most effective alliances among the military, academia, and industry," the development of the Proximity Fuze during World War II was credited for reducing the duration of the war by at least a year. WWII is singularly distinguished as the only war in history in which the outcome of the war was significantly influenced by scientific breakthroughs that created weapons unknown at the war's commencement.

Development of a radio-transmitter proximity fuse to detonate near a plane would require not just technological breakthroughs involving a variety of fields of expertise, but miniaturization of electronic systems that had never been accomplished, plus near perfect cooperation and coordination of the military forces (specifically the Navy and Army), universities (principally five), diversity of scientists from a variety of fields, industry (engineering laboratories, quality control, and production facilities), amateur radio operators, ordinance experts, testing facilities, along with an unprecedented level of teamwork.1 Further, the project had to remain top secret during the war, despite ultimately employing about 1 million people in the production effort.
The magnitude of the manufacturing ramp-up is noteworthy. 22 million fuze units, composed of over 300 components, were produced between 1942 and 1945. During this time the cost per unit dropped from $742 to $18. Overall, 110 plants were involved in production of the fuzes and their components without a single breach of security, resulting in neither German nor Japanese intelligence having knowledge of the technology nor its deployment.

Key Issues:
Development of the Proximity Fuze, used to detonate bombs & Anti-Aircraft shells required:
1. massive breakthrough in technology,
2. rapid innovation and continuous improvements,
3. unification of diverse inputs of thinking,
4. superb organizational coordination within the alliance
5. flawless speed of execution from research to development to commercialization to field proliferation.
Critical Measures of Impact:
a. Prior to the war's outbreak, anti-aircraft fire was incredibly inaccurate:
Typical Rates of accuracy:
1940: Without Fuze: Thousands of Rounds per airplane destroyed by ground-fire during day, tens of thousands of Rounds per airplane destroyed at night
1944: With Fuze: 90% kill rates of V-1 Buzz Bombs with 10 rounds of fire,
similar impact on Japanese Kamakaze attacks on US Pacific Fleet
Nearly total elimination of Japanese Aircraft and ships in Pacific Theatre
b. Citations from Eisenhower, Patton, & Churchill for the fuze's impact on war
c. Production of Proximity Fuzes:
1940: None
1945: 22,000,000 fuses produced, incorporating miniaturized electronics:
140,000,000 miniaturized rugged vacuum tubes and numerous impact resistant components totaling over 1 billion components
Nearly 100% reliability and safety in sub-zero weather and tropical heat
Employed over 1 million people in production in 110 plants, with such total secrecy as to be unknown to either Japanese or German intelligence
d: Ability to withstand shocks of:
20,000 G-forces at impact of firing
5,000 G-forces shell spin during trajectory

Category:

Entertainment

Tags:

• Radio
• Proximity
• Fuse
• ww2
• aviation
• history

[Bomberguy]

It's a good thing the Germans didn't develop this technology first, they would have devastated our bomber formations and possibly changed the course of the war

[tgot]

"Over a million people working in 110 in total secrecy without a single security breech." Wow, in this day, it would be absolutely impossible. All it would take is one disgruntled anti-war type to feed this to the New York Times and they would gladly report on any secret in the US that would harm us and benefit our enemies.

[Wally1967]

World War two

[rivrat210]

Thank you Ham Radio operators of that time for with out them this fuse would have been impossible at that time!

[datzfast]

@bio2020 that would be an interesting read,

[beachcomber2008]

@bio2020 I've already lived through what you so accurately describe. Even so, the whole business keeps evolving. (I wonder how WAR will evolve the next time round?) and like other living creatures we'll adapt

Maybe we'll return to the sea like other mammals, dispensing with brains as too prone before disastrous memes and only useful for eating, dancing, and sex

I don't know what came over me for a moment there. What a temporary blessing it is that Man is mortal...

[bio2020]

@beachcomber2008 I would like to add that our economic policies and social constructs are the bigger problem. The best minds are recruited by wealthy corporations that focus their talents into developing a better tasting corn that is cheaper to grow, or a new scientifically formulated Gatorade drink, etc....

Human invention and progress is currently at the mercy of philanthropists and uninterested governments. Sad times.

[bio2020]

@tgot Times sure have changed, haven't they?

[Binky40SW]

2:08 - "say-ah-NOR-ah, JAPS!" -Archie Bunker

[clintonearlwalker]

While I don't mean to belittle the atomic bomb or proximity fuses, another invention equally as important was "radar". It was said at the time, "Without the atomic bomb we might have won the war, without radar we might have lost".

[MrBEB123]

@tgot Sounds like you are describing a follower of Islam. Coming soon to a neighborhood near you.

[beachcomber2008]

@jonewer "I'd put centimetric radar up their with proxy fuses and enigma. Damn we used to be good. WTF went wrong?"

R&D was so critical in wartime that govt funded it freely, & it's bonds were good

In peacetime isn't R&D less critical?

The govt doesn't fund it much, and private investment is relatively meager, subject to financial "weather", & with smaller goals & expectations?

Also people's general reaction after hostilities ceased was AWAY from public duties to hedonism

The path was set...