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

all right well welcome everybody to today's colloquium today is the last colloquium of the academic year so um there's no more fitting topic than the vt fuse or proximity fuse and steve kindly volunteered to give the talk on the vt fuse so it's just an amazing thing that it all came together for for today particularly on our 75th anniversary so our speaker today is stephen phillips he's a member of the senior professional staff here at apl since 2005 he's an analyst supporting u.s navy program offices the u.s army special operations command and other parts of dod he has his bs in political science from the united states naval academy and he served as a surface warfare officer a special operations officer a diving officer and an explosive ordnance disposal technician and he's a very successful one as you can tell [Music] steve is also an award-winning novelist his first work proximity garnered the military writers society america gold medal in 2008 and his second novel the recipient's son has been used for a tool as for honor remediation at the united states naval academy steve is currently pursuing his ph.d in war studies at through his king colle through king's college in london and his dissertation is a historical case study of operation earnest well which was the u.s military operation to protect tankers in the persian gulf back in the late 1980s and with that let's welcome steve and let him get on with this thank you thank you everyone for coming today it's a friday of a holiday weekend and yet you're here so i've had discussions with uh fellow co-workers of how many people are going to be here and i said on the one hand some folks are probably already leaving for the holiday but on the other hand that might mean that those around like nothing's going on let's go see this colloquium on the proximity so thank you for coming i'm going to take you back in time to august of 1942. the united states has been involved in the war world war ii for a little bit over uh eight months in the pacific the united states is about to conduct an amphibious operation in canal in the atlantic theater the united states doesn't have a robust presence yet erwin rommel general rummel of the german army is still engulfed in a battle in el alamein against the british but much closer to home here in the chesapeake bay near tannager island a radio-controlled drone is launched towards uss cleveland a brand new cruiser was only commissioned in june of 1942. on board is dr merle tube pictured here on the left the founding director of johns hopkins university applied physics lab and commander deak parsons pictured on the right as an admiral whom this auditorium is named for and you might recognize that's the photo of him over there on the wall there's also a number of other scientists and engineers from johns hopkins university applied physics lab the first radio-controlled drone crashes into the water a second drone is launched it is shot down in less than 10 rounds a third drone is launched it shot down in less than 20 rounds the navy drone detachment was apoplectic no one had ever shot down a navy drone before dr tuve commander parsons the scientist and engineer from apl the commanding officer of the cleveland they were ecstatic because no one had ever shot down a navy drone before this was the first operational test of the proximity fuse for aerial gunnery i think it's important in our 75th year to talk about this our founding critical challenge both the story of how the fuse was developed how it was sent to war how we evaluated it in its production are something that needs to be discussed and analyzed today i want to talk a little bit about some of my sources there was a moment when i felt like i was doing a book report on the deadly fuse written by ralph baldwin i suspect that some of you have at least heard of this book maybe some of you have read it dr baldwin was one of the founding members of apl i also looked at things like apl's 40th anniversary book the 50th anniversary book i read a couple of tech digest articles like the one that's pictured here in the middle written by james van allen who also was one of the founding members of apl similarly i asked i accessed some historical documents like this assessment of anti-aircraft summary written in 1945. i also want to talk about video sources so believe it or not i know there's a lot of silly stuff on youtube my sons and i we always like watching the silly stuff and we send silly videos to each other but there's also a lot of serious content on there and as a historian i have found that folks are putting a lot of original source material and there's a lot of valuable documentaries that are on youtube so i recommend for those doing research to go and check out the stuff that's there the video pictured on the left is from johns hopkins university applied physics i'll have our own story the vt fuse the one pictured on the right is from the history channel and that's ralph baldwin the gentleman who wrote the deadly fuse i'm going to make it easy for folks who want to learn about the proximity fuse more i've set it up on my own youtube channel you can see a picture on the right of my clean-shaven self so if you're interested the link is uh available on the bottom you can send me an email if you just go on and look for stephen phillips i think all seven of my subscribers might be here is that right there's seven of you but i've made an entire list of the proximity fused videos that i reviewed and so if you want you can go there and watch each of these at your leisure there are three critical inventions that are recognized as having a positive impact on the war effort the first one of course is radar the second one is nuke weapons the atomic bomb and the third one that i submit is not as well known is the proximity fuse the proximity fuse had a positive impact in many ways but there's three sort of main stories that folks like to tell when when telling about the fuse and the first one it was important to countering japanese air power the second is that it countered the german v1 buzz bomb and so this was an allied technological advancement being used against a german technological advancement and the third one is it was used in the battle of the bulge to turn the tide of that conflict that led to the end of the war in europe i also have to talk about the spelling for a moment fused with an s of course is something that interrupts an electrical circuit for safety but fuse with a z is something that's used to initiate an ordinance device to make something go boom microsoft doesn't like it i have these red lines on my thing underneath fuse with a z throughout but there it is so before i talk about the fuse and development itself i want to talk about the organization that brought the fuse to bear in 1940 june of 1940 dr vanevar bush who was the head of the carnegie institute in washington d.c realized that war is coming on the horizon and so what he did was he had friends in the roosevelt administration and he approached the administration and said listen we need to stand up some technical body that's going to look at these challenges for the nation and we're going to help us in the war effort that's what we can bring to bear so an organization was made called the national defense research committee ndrc and then a year later with congressional authority this body changed and became the office of scientific research and uh and development osrd the founding members most of them were from the carnegie institute to include dr tuve who was the director of terrestrial magnetism at the at the carnegie institute now dr tube first took on board this development of the proximity fuse for anti-air govern and he formed a section that was called section t t for two for his last name the basic concept of a proximity fuse was a fuse that would enable a round to get just close enough to the aircraft and then detonate at an optimum time to create maximum lethality in other words you didn't have to actually hit the aircraft when you're talking about our founding story of course we have to show the wolf building on georgia avenue i think they had a better parking situation back then what do you think looks like plenty parking so there was a stipulation that the fuse had to reach 50 percent success rate and testing before it would go to production that occurred in january of 1942. i'll get into that more in a moment but then thereafter dr tube said okay i need to move this entity section t outside of ndrc or osrd at the time and i need to find some place for this to live and the reason was carnegie was a past pacifist and when he wrote the charter for the institute he said it can only support a war effort in time of war other than that we have to resort to our other science and engineering projects and to have had an idea that at the end of the war if this thing grows into something larger i don't want to have to lay folks off because there was this imagination that the osrd ndrc etc would stand down and section t would be part of the carnegie institute so he had to move it someplace else and being part of johns hopkins university applied or johns hopkins university as a graduate he decided to move it underneath that there were some negotiations with johns hopkins i also find it ironic that the president of the board of trustees at the time mr hopkins uh he didn't have a security clearance so he was not allowed to know what it was that this section t entity would do until finally uh fdr called him up and assured him that these guys were on the up and up and he should take him on board and so through negotiations on the 6th of march the contract was signed and of course on the 10th of march 1942 75 years ago we received our first 800 thousand dollars that would take us through to september and that equates to eighty million dollars in two thousand sixteen dollars amazing so two thought that section t sounded too military he decided to rename it the applied physics laboratory or apl and common usage the lab had a newspaper at the time i love these little anecdotal stories that come out when you study history they had a newspaper that was called the jhu apl news which folks called the apple juice it was on 20 april that the contract was signed with mr wolf to build this uh to build apl at this location it was a used car garage that he had the building was actually built to two stories above property was acquired next door another building was built there and then a connecting building was put in between a passageway that was covered so throughout the war apl at this location continued to grow and i think that first latticework of buildings probably looked not unlike the buildings here you know that feeling of walking through a habit trail you know to get to the other side there were less than 100 people in 1942 by 44 there were 700 and of course the lab has continued to grow ever since so in summaries from the june of 1940 this entity was ndrc came from the carnegie institute in 41 it became osrd and after january 42 when we reached a production uh line situation testing and development still continued that's when it became johns hopkins university applied physics lab so now i'll talk about uh the fuse testing and developing itself so again the notion was that you wanted to have a round that would get close enough to an aircraft and detonate at the optimum time before this all of the five inch rounds were in effect impact rounds and i'm sorry we're mech time rounds and what would happen is you would set the time on the round the ordinance officer or the gunnery guy would set the time on the fuse and then launch it and send it down range okay and what would happen is they would create a mix of fuses and the timings were like a 50th of a second so it was a guesstimation at what range are we going to shoot down these aircraft the idea was that if we're going to develop this proximity fuse that'll be able to figure out what the optimum time is it will increase lethality and they needed a name for it the word proximity was decided to be classified or if you said radio wave proximity fuse so the name that they came up to reflect against the mechanical time fuse was vt or variable time fuse so you'll often see vt in replace of proximity fuse so if you see vt proximity it's the same saying it significantly improved anti-air gunnery throughout the war there had been five approaches that were developed for the fuse and the radio wave concept was determined to be the one that had the greatest potential in general it's like putting a radar in the re in the nose of a five inch round the fuse would transmit a radio wave signal when that signal would get reflected back from the aircraft it would detonate the concept had been around for a while you can find references to the concept as far back as 1925. there was a physicist named milliken who had been developing this in 1938 there was a polish naval officer who was in the united kingdom in exile in 1940 and he came up with the idea and proposed it to the british government they were developing one already and so they sort of held them off at arm's length because they already had one now the concept that the british were developing was slightly different they were for example transmitting their radio wave from the the transmitter was on the ground the receiver was in the round they sent us their concept with a process called the tizzard commission a group of folks sent over from the united kingdom at the direction of winston churchill brought technology to the u.s because they knew that we were going to be joining them in the in the war so this included things like the radio magnetron and proximity fuse technology and it was buenament who designed the circuit for the radio proximity fuse tuve and section t then took this data and used that to build the fuse for the five inch anti-air round so what was the challenge first the bureau of ordnance said before we're going to allow you to go to production you need to demonstrate to us that in a test environment that 50 of your rounds are successful that was the standard set by a gentleman by the name of captain shoemaker the challenge within the round itself was they had a component inside of it a vacuum tube that was in effect the weak link this vacuum tube had to be able to endure 20 000 g's on firing and 475 revolutions per second so they had to figure out how to do that what they ended up doing was going through a series of several firings and test and development of this sending the rounds back to a limited production line i'll call it a test production line and then keeping a constant cycle of test product produce test produce etc there were a couple of other issues that had to get looked at so during the war production continues testing continues there are two other challenges that were developed and one was batteries and the other was safety devices and i'll get into that in a again in a little bit later but before i go on i wanted to talk about two's directives his standing orders that he had for the members of section t for apl and in fact i have a copy of these there's 30 of them over there on the table you can take a copy if you want additionally if you send me an email i will send you this slide i'm not going to read all of these but i'm going to read a couple of them i like the first one i don't want any fool in this laboratory to save money i only want him to save time i also like number 10 our moral responsibility goes all the way to the final battle use of this unit its failure therefore is our failure regardless of who is technically responsible for the cause of failure it is our job to achieve the end result i also like the last one shoot at an 80 job how many folks have heard the 80 solution that's where it comes from shoot at an 80 job we can't afford perfection don't try for an a an award d is necessary enough but an f is fatal don't forget that the best job in the world is a total failure if it's too late this is a photo from new mexico proving grounds from the guns there that were used for testing so again there was this issue of let's figure out which are the best vacuum tubes that we can use and how do we test them and protect them so that they're able to survive all the forces when firing it turned out that hearing aid tubes from raytheon and hytron were thought to be the most robust radio tubes vacuum tubes were being used for radio controlled aircraft at the time and there was somebody that worked at the facility that said hey i have these uh these vacuum tubes from sylvania i think they're pretty effective and that's why they ended up choosing those as the the test rounds the tubes were tested first and centrifuges at 30 000 g's and then there was a series of firings that were conducted first at a place called newtown neck and then later stump neck down here on the potomac river near indian head aberdeen proving grounds north of baltimore dahlgren and then finally at new mexico proving grounds and what would happen is these rounds would be obtained from the test production lines apl personnel literally would take a number of rounds to one of these locations for firings they carried a sidearm with them because there was a concern that saboteurs or spies would try to get uh these uh the rounds from them can you imagine going around to a test event with a sidearm today so they would take these fuses and they would fire from the the guns and in fact at the height of the war there was one day they fired 780 rounds in one day to test the fuses so the units then were recover with post hole diggers they'd pull them out they would do an initial assessment sometimes they would call back to georgia avenue with code using a code that was numbers and cents that would express how they performed and then naturally it would bring them back to the lab analyze them make suggestions for the changes give that feedback to the folks who are doing the test production lines make those changes so it was built a little test a little so the designs were incorporated rapidly this is what it looks like inside and there's some fuses that are over here in fact the one that's on the blue panel here is the same one that's over here this is a later design in fact the mark 53 version of it and then this is the electrical portion of it with the the tubes or the vacuum tubes inside and so you can see on this device here how this angled cup here and the pins on the bottom that equates to this up here that's the angled and then the pins on the bottom again for reference when i talk about batteries later this is an electrical ampule for the wet cell battery and then the safe and arm device in the bottom so again those vacuum tubes they were about the size of a pencil eraser the first thing that was brought to bear in order to make them be able to endure the forces was a little spring that was called the mouse trap it was designed by james van allen the gentleman whose article was written in the front end that i talked to you about he received a patent for it it was classified until 1965 when his patent was declassified apl sent a check for one dollar yeah so the tubes were placed uh in a rubber sock uh they were then encased in syris wax and then that was found to be successful to protect them so that they would uh survive the forces of firing the first successful test was down in dahlgren on the 29th of january 1942. uh what was happening was they were using the surface of the water to act as the skin of the aircraft so these were being shot over the river and as the rounds would descend the reflection of the radio wave signal from the surface of the water would reflect back to the proximity fuse and that's what would cause it to detonate so they had 52 success rate and then they were able to claim we've exceeded 50 percent and then they were told you can now go to production another issue that they had to figure out is what is the optimum distance what is the fuse sensitivity that we need in order to ensure that the detonation of the round creates the maximum effect and so out at new mexico proving grounds two large towers were set up that looked like antenna towers it's pictured here and we obtained a japanese nakama ki-27 aircraft also known as a type 97 fighter and it was strung up between those two towers and a 5-inch 38 gun from two miles away was fired at it and it was spun around and set at various angles to try to figure out the maximum effect of the fragmentation of the aircraft by setting the fuse to create a certain amount of the reflective signal coming back in order for it to detonate and what was determined is 50 to 70 feet was the was the best as you can imagine if the round was too close sort of the relative motion of the aircraft flying away in the detonation it wouldn't create enough fragmentation for it to cause the effect similarly clearly if it was too far away when it detonated it wouldn't create the impact so it was 50 to 70 feet was determined to be the best throughout the war they continued to test this with other aircraft in fact american aircraft were obtained and set up on the two towers and spun around and evaluated and throughout it all 50 70 feet seem to be the best uh so i talked about the two other challenges that were looked at as we continued with production test and evaluation and one of them was the first fuses that were sent down range had battery issues the dry batteries would only last for about 90 days so in fact there was a point in which logisticians and apl folks were flying into theater with batteries to help the folks replace the batteries in the proximity fuses so national carbon decided we're going to figure out a way to set up a dry or a wet cell battery and what's ironic it's sort of the opposite of the vacuum tube they wanted to do something that would ensure that it would break when it launched and so they put inside of it a little ampule filled with electrolyte that when fired the glass ampule would break the electrolyte would connect across two battery plates that would create the electrical signal so that the system could transmit and receive and that would only last for about a minute but of course for an air engagement that was enough similarly there had been some problems with pre-debts detonations inside the muzzle of the gun or detonation immediately after something emerged from the round and so they needed to develop a safe and armed device and there were a number of different types there was a clockwork device that was developed there was a mercury switch that was developed later these would ensure that when the rounds were fired it wouldn't detonate until it had gone so far downrange so a little bit about production again apl folks looked at and evaluated production as well as the results of the rounds that went into theater of course during the second world war women were an indispensable part of the workforce the batteries were built by national carbon and eastman kodak tubes were built by raytheon and sylvania fuses were built by three different companies er would crossland sylvania the sylvania engineers when it was brought to them the first sample they were like we needed you to build it exactly like this and the engineer said if there's a fly in there i will send sylvania engineers out to capture flies and we will put one in every proximity fuse i went too fast so yeah another there's another production line this was a huge effort during the war by the end of 44 there were 87 companies 110 separate plants 23 slovenia plants built 95 percent of the tubes 10 000 people built one million every two and a half days 140 million during the war five plants were producing 70 000 fuses per day 22 million fuses were built during the war 330 000 were fired as part of test rounds and 1.5 million were fired at the enemy the procurement contract in 42 was 60 million the contract in 45 was 450 million and the cost of the fuse went from 732 dollars down to about 18 right the more that you produce the cost per unit goes down so again production was constantly evaluated for example the crossley plant in cincinnati had some issues they were like why is it that the production seems to be declining on these days and so apl scientists and engineers went out to figure out what was going on and i can already see if the thank goodness they didn't have powerpoint then right what was figured out was they had days in which there was hot and humid weather those were the days in which the production was going down so they mapped this all out and they were like it's hot humidity and so they gave them air conditioning problem went away another thing that happened and this is one of my favorite stories and i believe this is at one of the plants in texas which would fit because of the music i'm gonna try to do this right you guys know the song deep in the heart of texas you didn't know i was gonna sing so there was a planet that started having problems with production they didn't know why so the apl scientists and engineers went on site to see what was going on and they're walking around the floor hundreds of workers they've got jewelry tools in their hands they're putting the fuses together and music is getting piped into the space and that song was the popular song of the day it's getting played four times an hour and each time it would come to the refrain everyone would stop and go deep in the heart of texas and then go back to working on the fuse the refrain what like four times during the song popular song being played four times an hour that was the cause of the production decline it was decided that it was important for morale so they said we're just not gonna we're not gonna stop it we're not gonna tell him we're gonna let him do it eventually the song stopped having so much air time and the production returned and everybody was happy there was also evaluation again of the performance of the rounds that went downrange so for example there was a moment in which uh fuses that were being used in the european theater by the u.s army were experiencing pre-detonations so again engineers went forward tried to figure out what was happening observing what's going on and what they found was some of the soldiers were pulling the fuses out of storage and mating them to the rounds without pulling off a thin paper protective coating that was on top of it and so they said hey guys you got to pull the paper off and once they figured that out they they stopped having those pre-detonations so it was an end-to-end problem just like item number 10 in tube's standing orders so now i want to talk about the impact of the proximity fuse i always think that's like a pun when i say impact the proximity fuse so when we deployed the proximity fuse in fact a couple of scientists and engineers from here were commissioned in the united states navy to take it forward neil dailey robert patterson and the aforementioned james van allen he's pictured here the top picture of him in his naval uniform in the bottom is is later on in his life james van allen some of you may have heard before he was a big guy in the space program quite an accomplished scientist in the atlantic and mediterranean theaters it was er cham and r morrison additionally apl people went to england to the united kingdom to train them in employment of the proximity fuse and at one point the u.s army actually sent 200 soldiers to come to apl to learn how to use the fuse and it became a train the trainer thing we trained them in use and employment of the fuse they then took those skill sets uh out to the theater with them this is uss helena parsons took the first set of fuses out to uss helena off iguada canal and it had the first successful downing of a japanese aircraft with a proximity fuse on january 4 or january 5th 1943. so think about that timing the first successful test was january 29th of 1942 52 over out at dahlgren the test uh operationally in august of 42 in the chesapeake bay and the first japanese aircraft that was shot down was january of 43. i think that's amazing so i want to talk for a minute about layered defense a lot of folks who know air warfare probably know about this so the laird defense approach in the pacific theater was fighters were on the outer rim and shipboard gunnery obviously was for the latter part of the engagement anti-air engagement we have to recognize that combat air patrol throughout the war was credited with 60 percent of enemy shoot down so the fighter pilots clearly had a huge part in shooting down japanese air when the proximity fuse was brought to bear however it improved the lethality of five-inch gunnery against the japanese air power by two to six times this and that's a measurement of rounds per bird so in other words less rounds were needed for the same effect there are several quotes out there about the japanese recognizing this change in uh lethality of their own self and in fact one of them this is actually someone reflecting on the japanese notion of that and his japanese official frankly stated that it was this increased efficiency that our anti-aircraft power which forced them to resort to suicide tactics so this is important to me because this is why i became interested in this topic in the first place i've been at apl since 2005 and from time to time i've heard folks say apl built the proximity fuse to thwart the japanese kamikazes or in response to the japanese kamikazes and i was i don't do well i don't do math in public very well but i would always but i'm a historian and i would say that that was a tactic late in the war apo was built in 42 and that's why i wanted to get to the bottom of this so i have come to this notion that in fact the kamikazes were because naval gunnery and combat air patrol were so effective against the japanese air that created the kamikaze tactic and the major battle that did this was the battle of the philippine sea june 19th and 20th in 1944. during this battle 600 japanese aircraft were shot down again the vast majority of them were from fighters but certainly there was contribution from the five inch proximity fuse japanese air power never recovered they were not able to build enough aircraft they were not able to build enough pilots in response so as a result starting in october 44 in the battle of leyte gulf they started using the kamikaze tactics now japanese pilots had committed suicide previous to this but it was always an individual that made that decision in the japanese culture at the time they had a notion of self-sacrifice and so there are known incidents where a pilot would get hit he believes he's going to die and he would choose to ditch his aircraft into a target but it's not until october 44 in which it's employed as an actual tactic a planned tactic to go forth and commit suicide when crashing the aircraft so when looking at uh shipboard anti-aircraft fire against the kamikaze what you'll find and this comes from that 1945 report and others is in fact the 20 millimeter and the 40 millimeter guns are credited with more downings of them than the proximity fuse 80 to 20 percent so i've scratched my head and said why is this and i have a couple of ideas of why this is and the first one is opportunity a majority of kamikaze attacks were in fact against and it actually says these terms in the study small ships versus large ships and merchants that didn't have five inch guns so in fact they were flying against ships that had only 20 millimeter and 40 millimeter guns i'm gonna use one specific personal example my grandfather served on uss lcs 92. you guys didn't know they had lcs back then did you of course it wasn't a littoral combat ship it was a very small amphibious ship and what their mission was whenever they would go and do an amphibious assault on an island they'd drop off their marines and they would they would decide anti-aircraft picket duty and they would go and be on the outer layer of defense and normally there would be several of these lcs's and there would be one destroyer that was used to command sort of this flotilla and they would shoot down japanese aircraft that approached the battle group lcs 92 was credited with shooting down more than one kamikaze in fact another thing that was happening in this later part of the war is some ships were not using the five inch round because their friendly combat air patrol was flying in and around where the kamikazes were so the ships were choosing to not employ them the other thing that happened was tactics so by this time the japanese understand that the proximity fuse is there and the kamikaze's goal obviously is to try to hit the ship knowing that there's that five inch round realm where they're going to be challenged what they would do is fly very erratically when they were in that realm and as a result it was a more difficult problem for the gunnery even with the proximity fuse then as they went into their terminal dive in the last part of their flight that's when they were in the 20 millimeter and 40 millimeter realm it was also noted in the study that for some reason the gunnery officers and the gunners were not putting enough proximity fuses in the mix during this time period whenever they would have an aircraft salvo would not just be proximity fuses or mech time fuses they would have a mix a number of prox fuses a number of mech time for some reason they found this problem and you can imagine messages going out hey guys you need to increase the number of proximity fuses that you put into the mix the next piece i want to talk about is the v1 buzz bomb remember i said there were three major categories three major events that are recognized as proximity few successes so the v1 was a german technological advancement a pilotless bomb british intelligence found out that these were being developed and they had a campaign that first bombed the locations where the v1 was being developed and later bombed its magazines and launched sites in france and other parts of western europe and as a result they were able to prevent the germans from using the v1 until after d-day the first v-1 launch was on 12 june 1944 now one of the things that happened when we gave the brits the proximity fuse was we said we still were concerned that the enemy might obtain these fuses and so we want you to only shoot them over the channel so that any duds or misses end up in the channel and can't be recovered if you have your current layered defense of fighters on the outer edge and gunners on the inner edge those rounds might land up on the on the you know be on land and a german spy somebody could come and pick it up and get it back to them and they might figure out how it works it's interesting throughout the war there was a lot of security surrounding this fuse and that's why we again we had the term vt fuse they didn't use the word proximity and there was this concerted effort to make sure that it couldn't be recovered so much so that during the mediterranean theater when there was an invasion of sicily by accident some rounds were shot at a german aircraft and ended up hitting on land in sicily and they actually sent a party of marines to go ashore and recover the rounds that didn't hit and didn't detonate so again back to the v1 now with the guns and the outer defense the proximity fuse was very successful against the v1 as you can imagine it take a little time for them to develop their tactics but by the fourth week 79 of the v1 downings were being attributed to the proximity fuse and in fact in the largest salvo of the war there were 104 v on launched at the united kingdom 16 didn't make it to the coast so it never made it to the channel 14 were destroyed by fighters two were shot down by large balloons four did make it to london 68 were shot down by anti-air aircraft or anti-air guns with the proximity fuse that's amazing so think about what this does to the morale of the british people that they're able to defend themselves against this new terrible weapon conversely think what the impact would be on our war effort if london was getting hit by these the last is the battle of the bulge so by this time the allies believe that the war is going to end there's a little bit more confidence and there's a willingness to employ the proximity fuse over over ground and the proximity fuse had been issued to artillery batteries but they were told not to use them yet so they had them but they were told not to employ them well during the battle of bulge the 38th cavalry was dug in near monchau and it was a colonel axelson of the 406 artillery as they were calling in for fire he said these guys are in a bad way i'm going to violate orders i'm going to use this so on the 16th of december 44 that was the actual first employment of them during the battle of the bulge the germans were devastated by this they called the ordinance the rock boom or the electric grenade and they did obtain some duds and they tried to figure out how they worked and they were never able to replicate it so again this is our timeline i'm not going to read it line by line but it is amazing to note september 40 the tizzard commission comes from the united kingdom and passes the proximity fuse information to [Music] uh to ndrc 16 months later in january is when the first test reaches 52 12 months later is the first operational use against the japanese on uss helena i just think that's it's fascinating how fast this thing was turned around it's amazing when when everybody is focused on this effort when they're following two standing orders what folks can do so i'm gonna this i am gonna read i'm gonna read some quotes james forrestal secretary of the navy without the project protection of this ingenious devices given the surface ships of our fleet our westward push could not have been so swift and the cost in men and ships would have been immeasurably greater sir winston churchill said these so-called proximity fuses made in the united states prove potent against the small unmanned v-1 with which we were assailed in 1944. general patton said the new shell with the funny fuse is devastating i think when all armies get the shell we will have to devise some new method of warfare i am glad that you all thought of this first and the last one that the book is new weapons for air warfare it's a historical count written by os uh rd james boyce was the editor the quote is according to observers the timely release of vt artillery fuses has vastly multiplied the lethal effect of interdictory and harassing fire by the unprecedented effectiveness of unseen fire at all hours of day and night the enemy has been severely upset as confirmed by prisoner of war reports in building 13 on the fourth floor sitting in a corner by a sort of like a coffee break table space with a telephone sitting on top of it is a display case of the proximity fuse with a technological poster sitting next to it how many folks have seen this and walked by it and how many knew what it was or took a moment smaller number of hands right i don't think there should be in building 13 sitting in the corner with a telephone on it i think it should be out here in the lobby how many people agree with me there's the poster i recommend that everybody go by and look at it and encased in glass or a number of fuses to include the one on the left that's the letter from george patton that has that quote that i just shared letter on the right is from president roosevelt to dr venevar bush who is the first director of ndrc there's a number of fuses in there so on this our 75th year again i thought it was just important that we come in and have a discussion about the proximity fuse i think it's an amazing accomplish for the scientists and engineers our founding fathers at apl that developed this thing and brought it to bear and got it out to the soldiers so that we could win that war it represents a significant critical challenge that helped us in both the pacific and in the atlantic theaters it's our foundation for initiating all ordinance afterwards you know i think you can draw a line from this to an air gunnery on ships today right and to missile defense and to modern initiation of all ordnance from this device thereafter and so we should be proud of this our first critical contribution thank you questions for steve sir so you said rf was one approach this approach you said there were four other approaches yes so for example one of them was a photoelectric fuse they had issues with that because it only worked during the day it would detonate when it encountered clouds and the like so that one was rejected another one was as i said one of the proximity fuse ideas was transmission from the ground there was a concern that the enemy might uh be able to jam those signals and everything so the idea was to contain it all in one yeah other questions sir um did the japanese or german war efforts ever try to produce something similar i have found some references that both have produced them uh i've heard that the japanese produced one and never brought it to bear only brought it to bear a couple of times like in saipan i have heard that the germans tried to develop something similar but i don't have any any details to share unfortunately anyone else sir i seem to recall that there was a kellogg corporation involved in the transition between the carnegie institution and and jhu if that's right and you clarify their role i don't remember any of that in specific sir but i could go back and look at my notes and see if i found something i do know that there were a lot of companies i think on one of my slides i said one there were 87 companies total that were involved in the effort at one point do you know how the enemy determined that the fuse existed and didn't just attribute the success to better timing of neck fuses yeah i think they could tell the difference in uh the effectiveness of the fuse and the fact that there was a shorter number of rounds that were rounds per bird to take down the aircraft and also the fact that the aircraft were getting hit at a precise distance i'm going to go back to that japanese slide of the japanese bomber or kamikaze rather what i think we see here that i think the bigger cloud is a is one of those proxy fuses and the rounds hit in the water of the 20 millimeter and 30 millimeter rounds they could tell that it was a different it was a different thing so they were getting shot at less rounds per bird less than getting hit and also the fact that they were dead they were so close to the aircraft when they were getting hit and that was very clearly different from a guesstimation so the aviators could tell that sir in that regard in that i um you this thing from there's a photograph in there at night where you can see v1s coming in and you see the uh rounds coming out from the guns and what happens is the only detonations are occurring near the airport right yeah sure enough if you look at nighttime photographs of actions you can tell this is what it's about yes japanese so it's the first one that i'm aware of remember we're doing this within our first year apl was founded in march of 42. they were doing that out at the proving grounds very shortly thereafter so certainly uh it was one of the that was that it must be the first employment of an actual you know test device yeah sir in the back so 22 million of them were built about half a million were tested one and a half million were fired another 20 million sitting on a telephone somewhere yeah so i have a theory i'm i'm certain that the following happened some of them were probably used in the war and after some of them ended up in korea who knows maybe some of them ended up in vietnam i'm certain that and then others were probably destroyed as a former eod tech i had several times in my career where i would go to you know we'd go and do uh demolition of old ordnance so we'd go out and we'd just blow up old stuff when it was outside of its service life so some of that probably happened but you can find a lot of the fuses online you know some of the fuses that are here um you want to make sure you get them that are de-milled but uh you can you can find them on ebay and if you walk around the lab you'll find there's a number of folks that do have proximity fuses around sir at least until the 1970s navy 5-inch gun mount systems still included fuse headers for mechanical timing you know i'm sure that there probably were still used and maybe they're still used today i'll say this so i went through eod school in 1998 and i was taught mech time fuse uh you know render safe procedures and part of it is too is a lot of ordinance that we have i think some of it and especially components it ends up we sell it to other folks and they end up having it so oh well yeah sir interesting i mean i used to uh fire more grounds right and we had what you call mech time fuses but they were called vt fuses so they were all mechanical yeah and they were used for illumination right as well as other things but it was called a vt fuel interesting probably v2 in that you can vary the time you can vary the mechanical time yeah right fair enough other questions sir i understand there was a high temperature problem and that especially high temperature melting so the story that i know and i'm not going to get it exactly right tell me if this is what you're referring to sir i remember in my research that there was one of the proximity fuses for the army rounds had an issue where the solder was melting during the firing and the stories like this they were trying to figure out how to waterproof some of the fuses for some purposes and there was a gentleman who took a material of i think it was called visitex and he they were dipping them and trying to see what this would do for waterproofing and one of the trains that was delivering test rounds to apl got derailed and they didn't want to stop the process of test firings and so they said go get some of those rounds that we've been doing the waterproofing test with and use those and so they fired those and the fuses work in fact it was much greater was like a 70 success rate so they said aha when we dip them in the visitecs it protects this solder on this army fuse and as a result it's it's successful and so they said so that's the key so it was an accident that occurred that led to a design change and that's why they were dipped in the fuse is that what you're referring to does that sound familiar are you talking about the tungsten i think maybe yeah i do remember that story too as well sir and in fact they ended up using that single piece was used throughout the war they never they never ran out by the end of the war correct thank you sir in the back i heard that story about wrapping the rod yeah i wonder if visitex is a commercial name for it that somebody had or something of that nature yeah sir allies and they were also competent scientists did they pursue any of this technology well i have no idea i have no idea i'm sorry sir were there any differences between the views given to the army in the navy yeah there were slight differences difference in size a little bit difference in the design and again some of them are down here if you want to come and look at principally the same design but there were subtleties to them you know the first thing they had to start with the round sizes were different and so for and also the way that you would set the fuses so the army artillery rounds were typically set to go off at 30 feet that was sort of thought of the maximum where they'd get the best blast frag for you know for the enemy and that sort of thing anyone else sir how did the clearance process work for the uh production employees uh you know i don't know but i do know this they weren't told what they were building so most of the folks that were building components had no idea what they were building so think about folks building vacuum tubes they knew that they were vacuum tubes they didn't know what the what it was for so the only folks that probably figured out what it was that they were building were the at the five plants that were physically putting together and assembling the fuses themselves i'm sure there was some process you know to make sure that uh that they were cleared properly etc clearly all the scientists at apl you know were properly cleared but um yeah there was there were some talks there were a couple times where there was a problem with the process of folks getting cleared and uh tube would bring them in and they'd talk to them a little bit about the problem and there's some of them would figure it out they'd get they'd go here this is about ordinance isn't it you know so they they would figure it out other questions of course you want something that's going to be able to you know the signal will be able to pass through and the signal be able to receive through it and so it protects the all the components inside but yeah other than that it's some form of bakelite or plastic that they use you can see on the different ones here like that one's more of a plastic yeah so just like the radome on a radar you know in an aircraft or something so all right i think that's it folks if you want uh thank you [Applause] [Music]

Channel: Stephen Phillips

Views: 67,989

Keywords: Proximity, Proximity Fuze, Stephen Phillips, Johns Hopkins Univeristy Applied Physics Laboratory, JHU/APL, EOD, Navy EOD, The Recipient's Son

Id: LyDlq77GVPM

Length: 52min 58sec (3178 seconds)

Published: Mon Aug 21 2017