Critical Challenge: A History of the Proximity Fuze presented by Stephen Phillips

The Johns Hopkins University Applied Physics Laboratory developed the proximity fuze during the Second World War. It was one of the war’s closest guarded secrets, and is recognized as one of three technological innovations with profound impact on Allied victory. In this JHU/APL Colloquium, Stephen Phillips will describe the history of proximity fuze to include testing, development, production, and deployment. Join us to learn about the lab’s first critical challenge.

[@setsemit777]

Excellent! My Father was on Saratoga. If it wasn't for this fuze I may have never been born. Thanks goes to all who created and used this wonderful device.

[@briangodden5569]

As a boy of 10 in late August or early September !944 I was on the Lees at Folkestone looking at the long line of large American anti-aircraft guns all pointing out over the channel. We were very used to watching V1s flying over and seeing the earlier AA guns firing at them and the explosions being all over the sky and only very rarely having any affect. On this particular day however I was very surprised when all hell broke loose and this battery of guns opened up at a Vi approaching. This time I was amazed to see that as it approached it was surrounded by a column of explosions approaching with it until shortly it blew up. It was many years later that I found out that these were 120mm. guns using the proximity shells and MOST IMPORTANTLY radar controlled. Without direct radar control the explosions would have been far fewer as the shells would not have got close enough to be activated as they passed the aircraft.

[@enginkazanci4727]

The VT fuze is nothing short of a miracle and saved countless lifes. God bless those who worked on it to realize it when it was most needed...thanks

[@falconeaterf15]

Did God help the US drop the atomic bomb too? That’s one nasty God !

[@TomKappeln]

@@falconeaterf15 : No ! Some GODLESS, HOMELESS Jews did ! Greet's from Germany (No, not a Nazi)

[@TomKappeln]

59.000 views in 5 years tells me how small is our "community". Greet's from a former mine diver (German Navy). "When I run ... RUN"

[@12gauge1oz]

Mr Phillips, Excellent presentation. Also, thank you to all of those dedicated Americans working at the lab, Thank you for what you do.

[@crhans5]

After WWII my father built one of the first countermeasures to the proximity fuse. He simply used a wide-band "distributed amplifier" to rebroadcast any signal received by the plane. They put the prototype on a drone towed by an aircraft. The army shot shells at it all day. All detonated prematurely. The conventional proximity fuse was withdrawn from service.

[@vancouverguy2533]

Thanks, great lecture. This is the project J A Hynek (Close Encounters, and UFO fame, Project Blue Book), worked on during the war under Tuve, as technical administration and "reports manager". Before working under Van Allen on spectrographic gear for the V2 panel.

[@johnlshilling1446]

Thank God for these people who are immensely more intelligent, creative, and productive than I could ever hope to be. If either of the AXIS powers had developed this first, I doubt we would have won WWII.

[@mo07r1]

If only they had the “make it work no matter the price” attitude for the Mark 14 torpedo

[@TomKappeln]

lol

[@AdurianJ]

When Bofors and Philips (i think it's Swedish Philips) developed a Proximity fuze for it's 57mm guns in the 1960's they still used a vacuum tube. But in the 70's a 40mm proximity fuze was developed but this was made with transistor technology. But because of miniaturization this proximity fuze was used as the basis for a family of proximity fuzes in a number of calibers. (Bofors 350år - Stig A Fransson : page 212-213 (The book is in Swedish)) To my knowledge 40mm is still the smallest gun to use a proximity fuze.

[@michaelroberts1420]

A point that has been glossed over is that dumb rounds were thought to have a 1 in 1000 chance on the high end and a 1 in 20,000 chance of hitting on the low end.

[@ypaulbrown]

Outstanding Sir.....my father was in AAA during WWII in New Guinea and The Philippines. Where both radar and proximity fuzes were used. Thank You for a great lecture... PB

[@FallNorth]

It's amazing to think that NOW, my rear bike light can identify the proximity of cars approaching and communicate their distances and speed to my watch and phone. It's sensitive enough to detect other cyclists approaching me. Technology moves ever onwards!

[@the1andonlydjt]

I enjoyed your presentation. I had just finished viewing the History Channel show that you mentioned at the startof your talk. I thought it interesrtig that youtube suggested your talk next. I am a history buff, specifically WWII, and a fan of technology. You combined them all in one talk, which was quite a bit of fun. Hurray for our side!

[@saraboglecrayne86]

Well my father worked on this project in the war years. I hope this vid makes it clear to someone as non-techie as myself how the Fuze worked. He had a model of it on his desk forever and I have a pair pf Proximity Fuze earrings (Mom's) in my jewelry case yet.

[@danphariss133]

Great lecture. I believe by my time in VN that the 40mm were using Proximity Fuze. At least from the air bursts I saw when a duster was putting fire on "Rocket Ridge" inside the DMZ.

[@joeblow8593]

Great presentation

[@gpslightlock1422]

Outstanding!

[@paulschonfeld1777]

The photo at 29:40 is of the post-WW2 heavy cruiser Helena (CA-75) rather than the light cruiser Helena (CA-50), which on Jan. 5 1943 was the first to shoot down an aircraft using VT-fuzed shells. CA-50 was sunk by the Japanese on July 6 1943. There were several reasons to fire a mix of conventional and VT shells: 1. Secrecy, to prevent the enemy pilots from noticing that shells were only exploding extremely near aircraft. 2. To help AA crews identify major fire control errors, if conventional shells were exploding very far from targets. 3. Availability and cost of VT fuzes. Until security restrictions were lifted in Dec. 1944, other fuze types were needed when ships fired near or over land.

[@paulschonfeld1777]

Sorry, that should be CL-50 rater than CA-50.

[@StephenPhillipseodauthor]

@@paulschonfeld1777 Thank you for this correction.

[@paulschonfeld1777]

@@StephenPhillipseodauthor You are welcome.

[@zs6jce]

Great Presentation.

[@davidb6576]

Great presentation, but I wish the sound capture was a little better for the questions at the end. There was a comment on "tungsten" and use of the material - anyone know the fuller question regarding its use? Was it for material properties or for increased shrapnel lethality? Minor nits - I believe inflation would have been closer to 14x rather than the 100x mentioned re: $800K/$80M from 1942 to 2016, and the state of Hawaii code is HI, not HA.

[@sailoryan]

My father served on LCS 91 until the end of the war he died 1 year ago.

[@dryan8377]

This was great!

[@emmgeevideo]

I enjoyed your talk very much. I googled Tuve's Standing Orders and didn't find them. If you could point to a place to find them I would appreciate it. We are fascinated by the technology; I'm fascinated by technology leadership - how does someone like Tuve get the best out of others.

[@utah133]

They made so many of the vacuum tubes for this fuse that they are still available on the surplus market for low cost. I've built simple radio receivers with them.

[@StephenPhillipseodauthor]

Amazing. If able, please share a link. I would love to obtain one.

[@worddunlap]

@@StephenPhillipseodauthor Microwave oscillator fuses. www.radiolaguy.com/Showca…/PortableRadios/submini.htm

[@MostlyPennyCat]

@@StephenPhillipseodauthor That link is broken, but if you go to it's home page you can contact him it seems. I'm the mean time, here's what I've found: www.tubecollector.org/equipment/proximity-fuse.htm

[@MostlyPennyCat]

www.valvecollector.uk/2e27.htm

[@MostlyPennyCat]

www.vintage-radio.net/forum/showthread.php?t=96822

[@mushmorant9253]

What about the critical (high gee tolerant) vacuum tube, battery and other advancements/innovations made by the team at the University of Toronto under the leadership of Dr. Arnold Pitt? Your presentation implies that the RP fuze was almost entirely a product of expertise at Johns Hopkins labs, which it wasn't. I suggest relevant portions of the following references as a supplement to this presentation: "The Science of War: Canadian Scientists and Allied Military Technology during the Second World War." By Donald Avery "The University of Toronto: A History, Second Edition." By Martin Friedland "George J. Klein: The Great Inventor." By Richard I. Bourgeois-Doyle

[@StephenPhillipseodauthor]

The Avery work is available on Google Books. It is clear from the section on the proximity fuze that Tuve saw the team at Toronto as valuable partners.

[@jimparsons6803]

Interesting. I had heard of this because it was one of the first commercial uses of printed circuit boards.

[@lasagnajohn]

this stuff soooo cool, KZbin algorythm you know me so well :) i think i got here because i watched some civil war stuff from the us army war college + some astronomy about exo planets. WOOO!!!

[@russellweatherly9625]

One quibble. The USS Helena shown is CL-75 was named after an earlier USS Helena CL-50 that was the one with the first kill.

[@brunonikodemski2420]

VT fuzes did not use "radar" as per the presenters commentary. They used a simplistic Q-detuning, in a superheterodyne receiver, which acted as sensor of local metal. Similar to what is used now in induction-heaters, ans similar such devices. I worked on these in the 70's, and then later on "actual radar" fusing & range-finding.

[@ronmccabe7164]

I had never heard of the proximity fuse development during WW2. I was scratching my head during this talk of how they could use one tube, generate a radar signal, receive it ?superhetrodyne? the received signal and then use Doppler shift to determine distance. That was surely impossible. The Q detuning makes obvious sense! Thanks.

[@worddunlap]

FYI in the 1980s we had advanced missiles also with tubes. I had asked and it had something to do with reliability. Solid state was available but not as good....

[@FallNorth]

Surprised the Dry Cell batteries had such a short life, so I'm assuming they drew current when doing nothing unless dry cells were totally rubbish back then? So .. could they not have done something that when the high G came, completed the circuit, similar to the "broken ampule" but no doubt simpler?

[@88njtrigg88]

19:34 That would only cut down the time of data accusation by the logistics back to lab. The transmission back to lab from field, was most likely done for counter espionage activities.

[@nofeerz]

explain the mercury switch and method to self destruct if no interaction with target, and how centrifugal force made this possible thank you

[@MARKWHITE007]

It's too bad they don't teach these little details in school. I was always fascinated with the pacific war. Our little history books left this out along with the shooting down of Yamamoto. Thanks!!

[@norwoodbaybridge761]

Where can a person find a copy of Tuve's Standing Orders/Rules? Thank you.

[@StephenPhillipseodauthor]

Can you send me your email address via message to my facebook page? facebook.com/AuthorStephenPhillips/ If so, I will email the orders to you that I handed out after this lecture.

[@jasoncabral3831]

What information do you have about the VT fuse in conjunction with the SCR-584 radar?

[@StephenPhillipseodauthor]

Jason, I did not pursue the use of the SCR-584 radar in conjunction with the proximity fuze. I understand these two were an important combination to counter the V-1.

[@jasoncabral3831]

Stephen Phillips as well as the V2. My grandfather was part of the team from MIT who developed and field tested the scr584 in north africa and italy.

[@jasoncabral3831]

he was also at Johns Hopkins APL where he led the Tracking and Guidance Group from 1948 on to 1953

[@nezircaglar2381]

vt fuzes were gamechangers

[@gusparaguss]

Any idea what the procedure was for using these in combat? Were they use more sparingly because of the expense or would they be fired off at the same rate as a normal shell?

[@StephenPhillipseodauthor]

Gusparagus...the rounds were included in the mix at the discretion of the gunnery officer. So, mech time rounds and impact rounds were also still employed. I have seen one quote that proximity fuzes were one in five.

[@adamtennant4936]

@@StephenPhillipseodauthor That ratio was what I immediately thought of because it's the tracer mix ratio.

[@stasysba1]

Thanks for presentation. What price had this fuse in 1942 when it entered service? and compare to simple mechanical time fuse?

[@StephenPhillipseodauthor]

The proximity fuze started at $732.00, but was $18.00 per unit by the war's end. See this comment at around 25:50. I do not know what the cost of the mech time fuze was during this time.

[@stasysba1]

Thanks missed. Average weekly earning in 1943 was $43.14 ,fuse$18 in today money? $500?

[@StephenPhillipseodauthor]

Indeed. I found an online inflation calculator that says in 2017 - $498.62/

[@stasysba1]

Thanks, I was thinking how much mercury was in this type triggers? and how many ammo was used in Guadalcanal with this triggers? or other biggest battles in Pacific? Just interesting how much mercury still there.

[@booger1118]

@7:18 Should the Ultra progamme ( breaking of the Enigma code ) be in the presented list ?

[@MostlyPennyCat]

Probably not all of ULTRA, but certainly the digital computer (Colossus)

[@johnhill4901]

This is a great talk. Can you post a copy of Tuve's Standing Orders?

[@StephenPhillipseodauthor]

John Hill, I've posted on my fb page here: facebook.com/photo/?fbid=661462152652170&set=a.437058151759239 Please follow, and let me know if this link works.

[@PacoOtis]

CORRECTION! It was the British who were responsible for the fuse! It appears we are not very good and putting credit where it is due!

[@thisoldboat7393]

Surely predetonation had to be catastrophic for the operator...

[@djosearth3618]

c.9:00 What a title; "Director of Terrestrial Magnetism"!

[@johnantliff]

Were proximity fuses used on torpedoes during WW2?

[@StephenPhillipseodauthor]

Torpedoes during this era were either initiated by contact or magnetic exploders, meaning the either hit the target or sensed the magnetism of the hull. The principle is similar, but I've never heard of this approach referred to as "proximity" fuzing.

[@michael3263]

John Antliff No, although actress Hedy Lamar came up with a design for variable frequency radio transmitter that would have allowed for the creation of radio controlled torpedoes. The Navy didn't use her design though. They thought that a sex symbol like Lamar couldn't possibly know anything about weapons design so they didn't even bother to investigate her invention. That hubris cost the lives of hundreds, possibly thousands of sailors. Ironically her invention is used today in every secure piece of wireless tech.

[@geraldsahd3413]

Navy used a TDC (analog computer) that used trigonometry to come up with a firing solution which is essensce could "track" a ship. Probaly another great advancement of WW2

[@herosstratos]

Ratsch-Bumm, as the naming of the sowjet 7,62 cm FG by the German soldiers.

[@annaoaulinovna]

so difficult challenge.

[@stephenwalters4798]

Shame you can't hear the questions

[@djosearth3618]

I ear you there.. Positive take from it is in reminding presenters that do Q&A to please repeat the question as having no context is easily beat by any simple sparsest form. ;]

[@michealdean3750]

I don't know if the speaker was ever a Marine, but after listening to this incredible presentation I want to do a 'HooRah'! Many of the idiots-er-people that I've seen on TED-Talks should take a page from Mr. Philips method.

[@StephenPhillipseodauthor]

Michael, I'm a retired Navy EOD Technician. I served in the Navy and Navy Reserves retiring as an O5 in 2012.

[@clitisswood7330]

Engineers win wars !

[@LuvThatDirtyWater]

My screen name refers to the Red Sox for whom I am the colloquium but do not be deceived. The VT Fuze was one of the best kept secrets of WWII. It was so well guarded most people still haven't heard of it nor do they realize its significance but contained therein is a thriller with the magic in the mix. Without VT, the War would've gone on at precisely the wrong time. With German technological advances time was our worst enemy and the clock was ticking on the bomb they never knew. Had Germany developed a nuclear device there's no doubt they would've dropped it on Stalin. Russia would've been enslaved, oil from the caucuses would've been in German hands and War outcome would've been in doubt Had fascism prevailed the world would be a very different place and that's being charitable. In the best case scenario we'd all speak German while eating our weinerschnitzel but I like Fenway hot dogs and I love the Red Sox. No shame in that but this documentary is the best kept secret on KZbin. That's a shame and the book should be a movie. Spielberg should direct it and Rylance should be the British connection in the greatest historical war thriller of all time. The shame is that we haven't yet seen it but that doesn't mean we won't. Keep up the good work Mr Phillips. You're onto something. 98% 'likes' proves it and I'm not sure if you're aware but that kind of approval on KZbin is unheard of. It proves everyone who saw what you did likes it and not enough people have seen it. That means you're a technical genius with a common problem and self promotion is such a foreign concept to detail oriented wizards it's not a priority but that's OK. There is a solution and when 5% of a $200M blockbuster is part of the mix the only contempt we know is prior to investigation. It's called marketing and at the risk of presumption I'm a marketing genius but you'll have to wait until after the World Series. The Red Sox are in the hunt again. There is no doubt

[@steepruncaver2]

Dear Stephen Phillips, I have one video that my father took of proximity fuze tests. Also, some aircraft carriers someplace. He was one of the guys who took fuzes to Dahlgren and Aberdeen for testing. He said he had a gun and a fifth of whiskey in case he had to bribe someone. I could put it on KZbin if you want. KZbin videos seem to have poor resolution even in HD. Let me know if you would like to purse this discussion. Toby

[@amascia8327]

17:06 "...a copy of these..." please??

[@StephenPhillipseodauthor]

Is there an email address that I can send them to?

[@amascia8327]

@@StephenPhillipseodauthor Hi & Thanks! I'm at [e-mail]

[@MrKen-wy5dk]

360p in 2017??? Are you still on CompUserve?

[@patrickeh696]

Idiot aka Mr. Ken, the original wasn't available

[@Waferdicing]

😱

[@marksilva309]

Oh, you want to go to war? Wait, let me hire a bunch of people and equip a big factory with all kinds of specialized and precision machinery, and train the people. Ok, now you can go to war.

[@stephenarling1667]

Wonderful presentation. One question unasked by your audience: Is it true that the proximity fuze design was stolen by Soviet spy Julius Rosenberg, as the wikipedia article on the proximity fuze claims?

[@StephenPhillipseodauthor]

Stephen, I did not find any reference to this in my research. I do not recall seeing the wikipedia page before. It does seem to have much of the information presented here. Perhaps I'll add a link to this video there.

[@PAULLONDEN]

War has its uses.....

[@michael3263]

That speaker is ridiculously handsome. Woof!!!

[@MostlyPennyCat]

3 critical inventions? Shouldn't that include one more, the digital computer?

[@rogerknights857]

Or the Ultra Secret?

[@MostlyPennyCat]

@@rogerknights857 depends how you define invention. Ultra was all umbrella term for all of the station Ys and station x, the mathematics they produced, several different decryption machines.

[@qwadratix]

Fuse is spelled as 'Fuse' in the UK. Always was, always will be. The term 'electrical fuse' came much later than the simple gunpowder fuse. Having got it wrong in the first place the USA is now trying to insist that it's everyone else making a mistake. :D

[@clayz1]

Verruca English came to the US for badly needed improvement.

[@howardsimpson489]

Not the only mistakes the yanks make with history. Like the Australians, anything they associate with is then theirs.

[@rustyrebar9647]

Just a lot of anecdotal info.... I expected a discussion of the electronic circuit inside the VT fuze... What a letdown....

[@augustreigns9716]

while inside of this realm, ............we keep imagining (..............new and exciting ...) . .................................. ways to imprison ever more deeply, ......................................our fellow prisoners.

[@matthewchin6454]

Russia's ineffectiveness on the battlefield today is partly due to lack of proximity-fuzed artillery. And let's not downplay the substantial logistical effort it took for all those women working in those factories to put their hair in curlers every single day

[@jimwilson946]

So according to you timeline the British passed the information about the Proximiter fuse to the American military for them to develop further, whilst the UK was under extreme pressure. Amazing that you now call it your own invention. So sad.

[@geraldsahd3413]

When is something a concept and when is it invented? The British could not overcome the G force issue. The Americans miniturized the vaccum tube and other parts. Interestingly, and this was a question in the video, the soder was developed in England.

[@howardsimpson489]

The English were already firing them but terrified that the Axis would get some, further developed in the states in well kept secrecy.

[@howardsimpson489]

The first work was done by Philips Eindhoven.

[@arsenalroo]

A bit rah rah.