The Remarkable Mechanism That Secures Nuclear Weapons

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In the early days of nuclear weapons, security measures were surprisingly basic. This video explores the fascinating history and development of Permissive Action Links (PALs), the sophisticated systems that now safeguard nuclear arsenals.
Timeline:
1940s-1950s: Primitive security measures
Weapons kept partially disassembled
No formal policy on custody, control, and proliferation
Simple 3-digit combination locks introduced
1953: Missiles and Rockets agreements
Defined roles of Atomic Energy Commission (AEC) and Department of Defense (DoD)
1961: Committees formed to study use control
Special Warhead Arming Control (SWAC) Committee
Safety Steering Group
Joint Command and Control Study Group Project 106
August 1961: Secretary of Defense requests AEC to create permissive links for NATO weapons
June 1962: President Kennedy issues NSAM 160
Mandates PALs on all U.S. nuclear weapons in NATO countries
How PALs Work:
1. Isolation: Critical components enclosed in "exclusion region"
2. Incompatibility: Designed to prevent accidental activation
3. Inoperability: "Weak links" render weapon inoperable in extreme conditions
Key Components:
Stronglinks: Rugged electromechanical devices controlling weapon arming
Energy control elements: Create pathways into exclusion region
PAL Categories:
Category A (1960s):
MC1541 coded switch (5-digit code)
Complex operation, took 30 seconds to 2.5 minutes
Required multiple support equipment pieces
Category B (mid-1960s):
MC1707 coded switch (4-digit code)
Faster operation, cockpit control possible
Fewer wires, parallel unlocking for multiple weapons
Category C (mid-1970s):
Extended Cat B capabilities
6-digit code
Introduced limited code attempt lockouts
Category D (1975):
First microprocessor-based PAL (MC2764)
Multiple Code Coded-Switch (MCCS) concept
6-digit codes for various functions (arm, train, disable)
Interfaced with MC2969 Intent stronglink
Anti-intrusion sensors, some self-powered
Category F (mid-1980s):
12-digit code system
Advanced features: code-driven disable modes, emergency stops
Variable yield adjustment via code
Encryption in the arming process
Key Developments:
1980s: Modernization efforts
Second-generation stronglinks: detonator and dual magnetic
Improved reliability and reduced manufacturing costs
1997: PALs installed on all U.S. nuclear devices
U.S. Navy last to receive them
2001: PAL Code Management System (CMS) deployed
End-to-end encrypted method for re-coding weapons
MC4519 MCCS Encryption Translator Assembly
2004: CMS fully implemented across all PAL systems
Future Developments:
Ongoing miniaturization and ruggedization
Micromachining technologies for mm-sized components
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/ newmind
#NuclearSecurity #PermissiveActionLinks #MilitaryHistory #DefenseTechnology #NuclearWeapons #ColdWar

[@NewMind]

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[@StaticM223]

No

[@GJones462-2W1]

I was a weapons systems specialist in the USAF in the 80's and 90's. On the B-61 bombs we loaded, we connected a device called the PAL/USG. Permissive Action Link / Unique Signal Generator that transfered the codes to the Pilot, and the Weapons Systems Operator on the F-111F's I worked on. Exercises were run using the actual live weapons, and we went through the routine, as if it were for real. The jets ran down the runway, but killed the throttles, and hit the brakes, and returned to the victor alert area. You can't fly with nuclear weapons anymore, unless you were actually going to use them, as intended. Those exercises were a real sobering, eye-opening experience. Seeing this vid brings back a LOT of memories....

[@oculosprudentium8486]

So in the end, all those exercises burned out a lot of aircraft tires are brakes Not to mention the frayed human nerves!!

[@rekire___]

Wait till lockpicking lawyer said "inexcusable design flaws"

[@HansLasser]

LPL: I will detonate this thermonuclear device a 2nd time to show it is not a flucke.

[@Oldtanktapper]

I’ve got a click on three….

[@RILEYLEIFSON_UTAH]

​@@Oldtanktapper ....False gate on 4.......

[@JorgetePanete]

'til* says*

[@ChocoLater1]

Hahah what a legend

[@woodwaker1]

I found this very interesting. I was in the USAF 1969-1973 as a crypto maintenance tech. After school for 1 year I was assigned to Offutt AFB which was SAC HQ and I maintained the Crypto gear in the underground command center as well as the many communication centers. I was able to see the machine that encoded the missile coordinates that were fed into the ground based systems. Lots of changes since then.

[@patrickvolk7031]

Nuclear weapons are designed to be two-point safe. Two points of failure will not allow a nuclear detonation. There also is another concept, which sounds scary; instead of fail-safe, it is fail-deadly. A failure will render the weapon unusable, and not necessarily in a manner where it can be reused. A fizzle is a possible fail-deadly outcome, which is essentially a dirty bomb without the nuclear payload going critical. There is some environmental checks, where the warhead doesn't arm unless it is launched, reaches space, and achieves a ballistic trajectory (e.g. you can't take a warhead and detonate it on your own). They also have training and tactical settings.

[@larrybremer4930]

Yes, fail deadly is used in situations where the weapon could be captured unused so that attempts to gain access to its materials will result in unplanned rapid disassembly by design to prevent the nuclear materials from being salvaged without PALs and proper equipment. This is easily done by the intentional detonation of just one chemical explosive lense which will distort the shockwave as the remaining lenses would be detonated by the propagating shockwave but also out of sequence enough to prevent criticality of the core while ensuring the material will be scattered significantly enough to be totally useless, basically a weak dirty bomb.

[@SB-mr2nk]

My brain isn’t braining. By saying two points of failure won’t allow it to work, does that mean a single point of failure will? Or does that mean you need three points of failure to cause it to detonate?

[@larrybremer4930]

@@SB-mr2nk see the comment I just posted and keep in mind "detonation" can refer to only the chemical explosive payload without any criticality being attained. Also even with criticality there can be a low order detonation (also called a fizzle) or high order. A nuclear reaction happens in cycles where each fission is doubling the yield. This is why sometimes in a test they will be off by an order of magnitude from the prediction because maybe 75 doublings is 1 MT but 76 doublings is 2 MT, then 4 MT, 8 MT, etc as you keep adding one more doubling. Each doubling is approx 10ns (called a shake). The same applies to a fizzle where removal of just a few doublings means the bomb will have very low yield since each lost doubling cuts the yield in half. The crazy part to keep in mind is that the entire primary and and secondary stages will be completely detonated before any affects have left the bomb casing, that is how fast the fission and fusion happens.

[@jastrapper190]

DOES IT MATTER IF THE SYSTEM IS FOOLPROOF IF THE CH0WDER HEADED COMMANDER IN CHIEF IS TOO SEA NILE TO REMEMBER HIS GOLD CODES? ROBERT HURR SAID “EL PRESIDENTE” COMMITTED HIGH CRIMES… AND WAS SEA NILE… SO… Y EXACTLY R WE CONCERNED ABOUT THE “SECURITY” OF OUR RETALIATORY CAPABILITY? SHOULDN’T WE BE MORE CONCERNED W/LOOKING UP THE PURPOSE OF THE 25TH AMENDMENT?

[@tomnguyen9931]

You mean if I hit the nose with a hammer it won't go BOOM?

[@Zardox-The-Heretic-Slayer]

next gen nuclear weapons will require you to input an impossible to read captcha to arm it and a subscription to change the yield.

[@Obsidian-Nebula]

It will be face id

[@rule1dontgosplat]

"They put a paywall on a bomb???" -Nick Locarno (Star Trek Lower Decks)

[@curiousentertainment3008]

We already have Dial-a-yield (love that name)

[@christopherleubner6633]

@@Zardox-The-Heretic-Slayer We have incoming, we need to launch! NOW! We are sorry but your subscription to MAD has expired, to renew please fill out our form on the website and your access will be restored in 24 to 48 hours.. 😳💀💩

[@ownage11445]

No it would be an endless of selection of “pick the photos with the cross walk” oops try again “select all photos with buses” oops try again

[@daveb4446]

Im surprised he didn’t talk about the time a quarter of the entire nuclear arsenal had to be rebuilt because neutron absorbers used as safeties ended up crumbling and getting stuck in the cores.

[@christopherleubner6633]

Yup it turned out cadmium boron wire was a bit brittle and corrosion prone.😂

[@kellymoses8566]

link?

[@orbitingeyes2540]

D'oh!

[@monad_tcp]

but that's a good thing, isn't ? that means the arsenal can't be detonated

[@JurekOK]

@@monad_tcp no. It means that it's ineffective at protecting you from getting killed.

[@uriituw]

These videos are among the most well researched and comprehensive on KZbin.

[@Lyoishi]

They do seem accurate, I would prefer a citation document in the description though.

[@uiopuiop3472]

people get on watchlist for those vidios (in my openion)

[@chiichan3774]

@@uiopuiop3472 it's sad that we're in an era where merely having knowledge gets you onto watch lists.

[@uiopuiop3472]

@@chiichan3774 yes true

[@VariantAEC]

​@@chiichan3774 Just be glad you don't know anything about remote intercept systems made to deal with weapons like these. These are tightly controlled. Can't even provide the codenames for these systems. Some day, the public will be made aware of them. Perhaps only a few decades after we make much more deadly armaments?

[@ARKSYN]

Although not the purpose, this video is the best explanation I've seen for how nuclear weapon detonations work on a mechanical level. I never knew how the explosion was actually triggered until now.

[@VariantAEC]

Learned about that from encyclopedias in middle school.

[@VariantAEC]

@@tafdiz I know, I read about it in school over 2 decades ago. I just look young.

[@darrennew8211]

That's one of several ways of doing it. Likely the "safest" in the sense of "least likely to happen automatically."

[@chonchjohnch]

It cracks me up that he didn’t name the detonator type. It’s an extremely controlled tech for this reason Rhymes with “fridge tire detonator”

[@mountainjeff]

I've know most of this stuff since the 70s. (not the part numbers, but how the device actually works) What I didn't know, was that they could vary the magnitude of the explosion, or how. How do they do that?

[@michaelimbesi2314]

<a href="#" class="seekto" data-time="445">7:25</a> This section is easily the most beautiful and peaceful video segment ever produced on the functioning of atomic weapons.

[@dbblues.9168]

Once you mentioned being able to unlock weapons from a cockpit, I immediately thought of the scene in Dr Strangelove when Slim Pickens is arming the bombs in his B52

[@johnclawed]

Electronic Barometric Impact Timed Shoot, a feller could have a pretty good weekend in Vegas with all that stuff.

[@dkoz8321]

@@johnclawed THose were fuses, not PALs. Also the Vegas is for survival kit. Kit contained pantyhose, dollars, rubles, gold, condoms. Exactly what is needed in Vegas.

[@johnclawed]

@@dkoz8321 I know that. They probably didn't even have PALs on those bombs yet since they weren't deployed in Europe.

[@shawnmcgrath299]

Be careful, the coke company will come after you.

[@dkoz8321]

@@shawnmcgrath299 It did tale me 30 years to figure out names in Dr. Strangelove. THey are all word plays Soviet Premier Kiss-Off. As in eff OFF. Gen Trugedson. Son of a turd. But in Scandanavian culture means a ...hithead with capital S. Dr. Strangelove means sexual deviant in Germanic. A molester. Col. Batguano. bat-exceremtn crazy Grp.Cpt. Mandrake. Either a poson personality and a sus sissy. Gen. Ripper. Someone with chronic flatulence.

[@fredericklockard3854]

I worked on the Nike Hercules missiles in the 80s. Our PAL device was different of course, but putting the codes in under the duress of inspectors watching while in MOPP level 4 was extremely stressful and intense. We practiced weekly.

[@Awesomes007]

I recommend watching any and all of the Sandia videos - there are some stellar ones with dozens of the most influential people of the Cold War and after.

[@fridaycaliforniaa236]

Totally agreed ! =)

[@christopherleubner6633]

The actual lock is a still electromechanical.its a BCD electromechanical relay on the AF&F control board. The device is a little gold box similar to the size of one of the CP claire DIP reed relays. It has a small mechanism similar to the type you would expect in a combination lock that is driven by a tiny solenoid motor. If the correct code is entered the motor pulses allign the wheels to activate a switch. If all is good then the switch pops a nonrecindable thermal delay fuse relay that enables the system to arm. Once armed the only way to cancel is to use the destructive command disable. The switch must also be pulsed to the correct position fast enough that the disable relay doesnt fire. If this happens the nuke must have the PAL control module and the EF&F board must be replaced. Both the single shot relays look like glass top TO3 transistors. All of this stuff is potted in a nondescript epoxy block buried deep inside the forward section of the canned subassembly. This would make it extremely difficult for someone take apart the device, hotwire it, then reassemble as a usable weapon.

[@kellymoses8566]

How do you know this?

[@SunriseLAW]

​@@kellymoses8566 Look at the last sentence, he just had to brag. Obviously, an extremely smart "someone" purchased some surplus warheads at a government auction, and he needs to re-code the devices.

[@hurricanemeridian8712]

Bruh wants to get arrested

[@charlesjustice8771]

He did time at KUMMSC with me. The fact that people cannot disassemble and reassemble a 61 disturbs me.

[@TadashiAbashi]

​@@charlesjustice8771KUMMSC huh? The ol' Korean University of Missiles, Mayhem, Spying, & Cartoons. The central source of North Korean special agent training where they study western culture and weaponry?! Commie spy!

[@martinoamello3017]

My brother was in AF missile security in the 70s @ Malmstrom AFB. Every day he had to enter a long numerical code that changed every day. He kept the old readouts that looked like a long grocery receipt from hell. I don't think he still has them. Being disposable they were useless once changed daily.

[@petersmythe6462]

Douglas MacArthur: "can I have use a nucle- Everyone: *absolutely not*

[@danstermeister]

thankfully, too. That guy was nuts.

[@grlt23]

Wing Attack Plan R. R for Romeo.

[@garyjones6142]

Dugout Doug was an irreverent nickname used by his soldiers in the Philippines. yeah, it’s easy to consider the nuclear option as a winnable strategy as long as you don’t believe you’re getting nuked.

[@josephastier7421]

Curtis LeMay (having just won a nuclear war with Japan) wanted to obliterate the Soviet Union in the short window of time before they developed their own bombs. He would have succeeded. Fortunately he was not given permission. I think part of the Russian paranoia that the USA wants to destroy them came from this incident.

[@artysanmobile]

It was the precision of capacitive discharge that made nuclear weapons possible. No other mechanism could deliver the needed energy with temporal accuracy.

[@Stoney3K]

That's also the reason why high-speed electrical switches such as thyratrons are still considered to be a nuclear proliferation hazard, because they are the only devices that can deliver the charge to the detonators within the right timing margins.

[@kurtnowak8895]

My company uses a strobe light made by Gen -Rad. They also made Thyratron tubes. One model of GenRad strobe lamp (bulb) looks just like a Thyratron. You can see the technology similarities. Strobe lamps work on the same principle of a Thyratron- a gate voltage is used to trigger a fast short pulse of energy.

[@gilesleggett]

Okay so there's a lot they are not explicitly telling you. They have had a non-nuclear primary since 1962. The Housatonic test was 99.9% clean because it used a special technology as the primary. They don't need a nuclear primary anymore. Also, the laser fuses used to trigger little boy and fat man were not developed by the US. Sub U-234 was allowed passage to the states near the end of WW2. It was part of a deal made with the Nazis. They had a bunch of these laser fuses on board, along with the Nazi scientist who invented them. They also had a load of weapons grade U-235 on board which they had refined using laser isotope enrichment technology, which they had also developed during the war. This was the actual origin of the fissile material used in the bombs dropped on Japan, as in the timeframe we simply would not have been capable of refining enough weapons grade uranium using the technology of the time. They were further along then than they will tell you now, and they have good reason to never tell, plus plenty of form for it! Incidentally, the Canadians nearly fucked the whole thing up as they intercepted Sub U-234 as it was crossing the Atlantic, but they were ordered to stand down.

[@Stoney3K]

@@gilesleggett ChatGPT comment? It's total nonsense, lasers didn't exist in 1944.

[@rael5469]

<a href="#" class="seekto" data-time="1040">17:20</a> Those are the type of coded switch we had on the bombers in the 1980s. We were always told that we didn't want our finger prints to be found on that.....for obvious reasons.

[@flomojo2u]

Fascinating stuff! Not a whole lot of information about this topic for obvious reasons, so it's great to get a high-level view of some of the design decisions.

[@Venom2U]

There is a ton of stuff I would like to say here. However, I don't want to spend the rest of my life in jail. But there is one correction I can make. "weak links" (as you term it) do not render a weapon inop. Weapons are stored "inop". "Weak links" simply prevent a P1 detonation. (P1 - Primary explosive, layer 1)

[@gooman989898]

Who is your CO??

[@rollvideo]

You know too much. We are watching you.

[@colinstewart1432]

On Sandia's KZbin channel, there's an awesome 2 part documentary called Always/Never about the safety and security of the U.S. Nuclear Stockpile and the progress of the concept of deterrence.

[@MR-MR-ud5oo]

What a misfortune to never hear what you would say. :(

[@bradbrandon2506]

​@@MR-MR-ud5oo believe me. You don't want to know.

[@Little_h]

"...against unauthorized, or accidental, detonation." Having 'accidental' and 'detonation' in the same sentence brings on the good ol' existential crisis feels.

[@brunonikodemski2420]

It is believed by many who were involved in Project Azorian, that the K129 Russian submarine which was partially recovered by the US, was attempting to make a nuclear strike toward US territory, via one of its R21 missiles. The only relevant target would have been the Hawaii naval bases, or possibly Alaska. Because the warhead exploded on one of the missiles, causing a large hole in the submarine, it is conjectured that one of the launch officers decided to enter an incorrect enabling code to the warhead, which caused it to asymmetrically, as a result of their PAL link deciding that not properly enabled, and decided to safe itself. Unfortunately, Azorian was not able to bring up the other two missiles, but did bring up some torpedos and mechanical engine structures. As such, no one will ever know the true cause of this explosive event. The Russians did go back to that location, after it became known that there were nuclear assets still remaining there, but to my knowledge, they have never released information about what they dredged up. Theoretically, there may still be two nuclear missile warheads and one nuclear torpedo remaining at that site. Some of our company employees were part of that project.

[@murdo_mck]

We can speculate but the public evidence only shows that a warhead exploded while the sub was on the surface (the firing position for that model of sub), and the USSR were searching for it in the wrong place. It is equally possible the warhead exploded due to an unauthorised launch attempt and there was a deadly precaution against unauthorised launch not known to whichever officers were involved. A mistake or a fault is possible but USA and USSR behaviour is not consistent with that. Personally I like Craven's informed speculation that the vastly expensive Project Azorian was designed to become known to the USSR and the object was to put pressure on the USSR in nuclear arms control negotiations. An unathorised launch attempt, if the USSR believed that might have happened, would be extremely embarrasing and damaging if made public with enough supporting evidence.

[@brunonikodemski2420]

@@murdo_mck A couple of other operarative theories are that 1) they were trying to do a "practice launch", and for some reason the rocket motor was accidentally ignited while still in the tube. The heat from the rocket fuel may have caused that warhead to explode (somewhat unlikely, would have just burned), and 2) based on some skeletal evidence, it appears that the tube door was actually partially open, and then they actually tried to fire it off, but it got hung up on the door. Number 2) is word of mouth from one of our guys, when they apparently got pictures of the actual upper surface, near the tower. The other doors were observed to be closed, so this was a one-tube event of some sort. Somewhere, in the bowels of the CIA, there are photos of this. Our company hired about a half-dozen of the Azorian crew afterwards, and resulted in other odd jobs for us.

[@H33t3Speaks]

@@brunonikodemski2420Thank you for your service!

[@kurtnowak8895]

@@murdo_mck…now Dimitri, you know how we’ve always talked about the possibility of something going wrong with The Bomb… well of one of our Commanders ordered his planes to attack your country …of course I’m upset about it, how do you think I feel?!?

[@Melanie16040]

We recovered 2 nuclear armed torpedoes in the forward section.

[@bluegizmo1983]

All that insane clockwork like design for a highly sophisticated locking mechanism, and it'll never be seen by anyone and will be vaporized if it's ever used for its intended purpose.

[@NuclearSunrise-b1c]

You've done your research well this is spot on. The amount of "nuclear weapons" videos is drastically growing .

[@Jimtheneals]

And for the first 20 years of the pal system the arming codes for ICBM silos were all zero's.

[@daveeyes]

Actually, that was for SAC bombs. No one wanted to fight their way into the USSR and drop a dud bomb. This was rescinded around 1975, and true codes started being used.

[@Stoney3K]

@@daveeyes Because the newer systems could be coded remotely so they didn't rely on people turning dials inside a bunker or in the belly of a plane. One mistake in entering a code, and it's a dud.

[@rael5469]

"This was in the 80’s, and used 6 digits. " One time when I was in the AF someone actually messed with the coded switch on one of our bombers. The thing was always just sitting there......no special protection. Anyone could touch it or ....whatever. But we all understood that doing so would be a quick trip to Leavenworth. Well.....one day I get a tap on the shoulder and told to immediately report to such and such office WITHOUT DELAY. It was the office of the O.S.I. Office of special investigation. The Air Force equivalent of the FBI. They grilled me for several minutes. They said they knew I did it.....or that I knew who did it. DID WHAT ???? After maybe 45 minutes I think they became convinced that I didn't know anything......that my answers matched my actual whereabouts on the day of the incident. The incident was that someone had dialed in SACSUC ....(or something to that effect) on the dang coded switch. It started a X storm, I can tell you. We never heard the end of that.

[@josephastier7421]

When I was a civilian A&P contractor during the Cold War my buddies and I would always set them to JANCFU.

[@rael5469]

@@josephastier7421 OK, are you going to tell us the meaning of your acronym? Just Another New .....what?

[@Tuck-Shop]

@@rael5469 Just above the stencil was the acronym “JANCFU,” short for “Joint Army-Navy-Combined/Civilian ‘Fouled’ Up” (this being a polite translation).

[@Cutest-Bunny998]

I assumed it was literal: Jank F You

[@GJones462-2W1]

I was a 462 in the USAF in the 80's on the F-111D and F models. We used the PAL/USG all the time, but our six digit code was numerical. No letters. Yes, the DCM, QA and the OSI would be all over that. Being that it was a nuclear component in question, they likely filled out a Dull Sword Report, with vandalism as the possible cause. You know how over-reactionary they are.....

[@shawnmcgrath299]

This must have been a hell of a document request.

[@rael5469]

In 1985 on my very last day on the flight line in the Air Force I was part of two man Crew Chief team preparing a B-52 for a flight. What they were doing is taking one of the nukes out to test it's triggering mechanism. Of course it's core had been removed......but I think they wanted to test the PAL and the triggering mechanism. I'm assuming it was some kind of audit of the nukes to make sure the triggering mechanisms work. Maybe testing the bomber's connection to the nuke also.

[@JK360noscope]

Wish you hadn't explained all that, blacked out SUVs are now outside with long hair individuals walking around everywhere... Pray for me 😅

[@Stoney3K]

Awesome. The most comprehensive video regarding PALs so far. Kind of interesting to see that the system more or less evolved from glorified bicycle code locks to a complete encryption network. It surprises me that this information is now public, I thought a lot of it was under NDA or top secret for very long.

[@maninthemiddleground2316]

Oooooh … thanks sooo much for making this video about PAL. 👍👍👍 been looking for one for years.

[@JK360noscope]

Why you lookin, bud??

[@maninthemiddleground2316]

@@JK360noscope always wondered how these things work especially how engineers in the 60's were able to come up with something that applies to "Always ... never" principle.

[@RaceBanner_]

What they didn’t take into account with the T1501 and T1502 was that TK421 was not at his post. Probably due to a bad transmitter.

[@blacklistnr1]

Cool video, but by about the half-way point the word bag of { permissive, action, strong, link, system, category A/B/C/D/E/F, control } became just funny noises

[@RT-qd8yl]

I feel like we're all on a list for watching this. Great video 😁

[@petergerdes1094]

Yah, those dangerous people worried about keeping our nuclear weapons safe and only useable by the president.

[@ralfbaechle]

Beware of two guys wearing black suits and sunglasses and one of them a strange looking pen-like device knocking your door.

[@SpydersByte]

Why? That would be incredibly stupid. This information has been in the public domain for ages, you can find it anywhere, and it is not dangerous in the slightest. It doesnt actually provide you with the information on how to BUILD one, just how they work in general. There seem to be a lot of children in the comments here that just automatically think "ermagerd its information about nuclear bombs so now we're gonna be put on a watchlist!" when that couldnt be further from the truth.

[@philipsweet480]

Well, if the algorithm sent it your way - you already were 🤐

[@vernonworsham2363]

I remember some of this stuff when I was stationed at RAF lakenheath 1980-81. I'm glad none of it was actually used.

[@mikedang3613]

This is an incredible and comprehensive analysis. Thank you for taking the time and effort to share information of these mechanisms and securities.

[@dakrontu]

Enormously detailed video. Very impressive.

[@YISP7]

One of the very few channels that have earned the medal of: "Turning on the bell"

[@CedroCron]

Great video... I really enjoyed this. Thank you.

[@irradix213]

My roommates worked at a medical plastics company that just made cock fighting spurs and timer caps, there were always little grey discs in the laundry

[@frontier164]

The Million Dollar Question is: Could the Lockpick Lawyer crack this?

[@DogmaticAtheist]

No. I think that's the whole point.

[@christopherleubner6633]

I'm sue he could but with the limited time/ attempt it is extremely unlikely.

[@DisgrunteledDachshund]

This minuteman nuclear missile arming lock can be opened with..... a minutemen nuclear missile

[@patrickvolk7031]

There are missiles he could try in Kings Bay, GA, although the locks aren't the problem there. It's the Marines who guard them in the EHW's (explosive handling wharves). You also could try at Offutt AFB in Omaha, NE, but there you have AF people with guns. Same for the Peacekeeper sites in North Dakota and elsewhere. Assuming he's a ninja, and can carry a W87 or W88 away, and tries to pick it, how does he 'open' it? Success..... BOOOOOOOOOOOOOOOOOMMMMMMMMMM. As you can see, the explosion was 150 kilotons, which indicates a successful pick! Please like and subscribe... sorry, gotta go, there's some black vans outside....

[@VariantAEC]

​@@DisgrunteledDachshund Underrated comment.

[@psychosis7325]

Wow, took them a long time to implement brute force protection.

[@EddSjo]

I've wanted to suggest you make a video about the evolution of truck brakes. 🤔

[@snakezdewiggle6084]

So How to Activate a nuk, is now in the public domain.! Whats the number to call for an Uber share-ride in an SR-71.?

[@spvillano]

None, those all got retired. Too much maintenance and better solutions are available.

[@MrNerdHair]

It was always in the US's best interest to disclose enough details about the PAL systems that its adversaries could have confidence in their correct functionality. We even offered them for free to other countries who developed weapons.

[@Karagoth444]

Curious naming quirk of a "permissive" control system, when today it sounds like it allows more than denies, when it actually denies in all but a single approved state. (And yes I know, "permissive" as in: it needs permission to give action)

[@kellymoses8566]

It is analogous to Authentication and Authorization in IT.

[@cybercastor6873]

Military didn't like the conotation of being "denied" of using the weapon. It's psychology to deal with jarheads

[@danstermeister]

@@cybercastor6873 They like to do the denying, not the other way around.

[@blasater]

I used to work on the strong links. It was an interesting time.

[@JK360noscope]

I would love to learn more about what I don't at all need to know based on geopolitical events I have nothing to do with! Great!

[@davidwest8905]

This is superb. Well done.

[@ophthojooeileyecirclehisha4917]

THANK YOU SO MUCH FOR YOUR SCIENCE, AND KINDNESS

[@jesse00pno]

There’s a whoooole lot of information in this video than I was prepared for. I wanted to know about the mechanism that secures the weapons. It felt like trying to drink from a firehose vs a garden hose.

[@duckmyass]

An excessive amount of fluff designed to burn time and generate more money for the creator. It could have been distilled down to less than 5 minutes and still give all the info anyone would want to know.

[@vasiovasio]

Amazing video! Thank you!

[@jefism]

This just put so many people on a watchlist.

[@DanielDogeanu]

I hope they've put me on a scientist's list, and not just simply on a bad guys list! 😂

[@ravener96]

Nobodys on a watchlist for this. None if this is anywhere near sensitive

[@failuretocommunicate]

What a wonderful video. The progressing developments seemed to me as if they were based on cryptanalysis in reverse.

[@Frankthetank-zr5mc]

From a Time magazine article: “Now, in 1959, Agnew was at Los Alamos overseeing thermonuclear bomb tests; he later became the lab’s director. During the trip to the NATO base, Agnew noticed something that made him wary. “I observed four F84F aircraft . . . sitting on the end of a runway, each was carrying two MK 7 [nuclear] gravity bombs,” he wrote in a document declassified in 2023. What this meant was that “custody of the MK 7s was under the watchful eye of one very young U.S. Army private armed with a M1 rifle with 8 rounds of ammunition.” Agnew told his colleagues: “The only safeguard against unauthorized use of an atomic bomb was this single G.I. surrounded by a large number of foreign troops on foreign territory with thousands of Soviet troops just miles away.”

[@vladimirkuharik34]

I really tried my best to imagine how this thing (safety mechanism) look like few days ago... either youtube is reading my mind or world is full with look - alikers :D THANKS FOR THIS!

[@channelsixtyeight068_]

First time I've seen this channel appear in KZbin. I subscribed after watching this video, very good.

[@VariantAEC]

There is also a very specific system created to disable or detonate such weapons without any permission bypassing every single safety measure employed by these locks remotely from a great distance. It's for security, of course.

[@gilbertinho2309]

Another excellent video as always. Is there any chance you could allow community made subtitles ?

[@JoseLopez-hp5oo]

We know the WarGames WOPR computer has the amazing ability to crack the code by trialing the code 1 digit at a time as if they are evaluated individually even though a code is actually attested as a whole including all digits.

[@thetimebinder]

It was playing Wordle

[@sarthakdeore1815]

​@@thetimebinder haha 😅

[@B20C0]

We can be happy it used 80s computers that were somehow even slower by multiple orders of magnitude than other chips of that time. 😀

[@petergerdes1094]

TBF they did say the system included a mode for checking the code was correct. That sounds like it might genuinely allow a brute force attack. I mean, ultimately, these systems do all suppose that no one with sufficient technical ability and equipment has uncontrolled access to the system for a prolonged period -- at that point they just strip out the PAL and replace the stronglinks. So they may not even be trying to guard against brute forcing the code.

[@petergerdes1094]

@@B20C0Not that implausible for military hardware :-)

[@bentos117]

thanks, this will be useful

[@grlt23]

I hope everybody watched Dr. Strangelove [Not to be confused with Doctor Strange] - that movie presents perfectlyu why PAL was needed and invented [but distributed only after that movie went to cinema]....

[@socal33]

The guy who designed the Nestle Purina plant near our town is a semi-retired, old-school, engineer. This plant makes 3 kinds of cat food and takes up probably 100+ acres. It looks like a car manufacturing plant ,it's that big. He's stayed in our rental a few times because he gets called down to re-design parts of the plant to new methods of production. He says today's young engineers aren't able to adapt and think outside the box so he's taken out of "mothballs" to keep the plant going. Do you think today's engineers could even replicate what these guys did back in the 50s-80s? I'm doubtful now.

[@MR-MR-ud5oo]

Yea, the 40's-60's Engineers were on a whole other level.

[@chetmcdonald]

Nuclear weapons and nuclear war is hardly discussed anymore and yet its still very possible.

[@rael5469]

<a href="#" class="seekto" data-time="1029">17:09</a> That's odd. Those are Airbus type screws, not Phillips head. How long have those been around?

[@kryts27]

That's good that permissive action links for nuclear weapins have strongly improved since the extremely hazardous times of the late 1940s/1950s, for example the Vancouver Island nuclear amed B-36 accidentally dropped nuclear weapon crash. Appraently when recovered, there was one more arming circuit in the trigger mechanism that didn't deploy from the dropping that would have made the bomb go critical. But how have other nuclear armed countries, other than the US, have handled their nuclear weapons security?

[@PeterHamiltonz]

The original machine had a base plate of pre-famulated amulite surmounted by a malleable logarithmic casing in such a way that the two spurving bearings were in a direct line with the panametric fan. The latter consisted simply of six hydrocoptic marzlevanes, so fitted to the ambifacient lunar waneshaft that side fumbling was effectively prevented.

[@watchm4ker]

It's not cheap, but I'm sure the Government will buy it.

[@FrancisKinsleyJr]

Are you trolling? That sounds like you made it up.

[@watchm4ker]

@@FrancisKinsleyJr It's a very old joke: en.wikipedia.org/wiki/Turbo_encabulator

[@PeterHamiltonz]

@@FrancisKinsleyJr Google "turbo encabulator".

[@johnopalko5223]

Yes, but can you forge a seven-sided Ferris piece? (See _Winter's Tale_ by Mark Helprin. The book. Don't bother with the film.)

[@hagerty1952]

Great video! But I was waiting to see the CRM-114 Discriminator...

[@JiveDadson]

Ain't nobody ever got the go-code yet.

[@ragtowne]

Thank you Jack D. Ripper😅

[@grlt23]

Wing attack plan R. R for Romeo.

[@ragtowne]

@@grlt23 Well I've been to one world fair a picnic and a rodeo and that's the stupidest thing I ever heard come over a set of earphones. You sure you got today's code?

[@LordOfNihil]

so what keeps you from extracting the core and building your own initiation hardware? the enrichment process is the weapon in most cases.

[@captaincat1743]

That's what I thought. And according to the nuclear weapons expert Professor Matthew Bunn, there are methods that do not require symmetrical explosive compression, that can be used to build a plutonium based weapon. The details of this, as he advises in his lectures, are highly classified, but it does mean that terrorist organizations have the ability to build such a weapon if they manage to secure enough plutonium.

[@Angel9932]

I would imagine that's where the anti-tamper devices come into play. It is possible that one of the devices would cause the explosives to detonate in a manner which does not cause criticality.

[@Stoney3K]

Probably the risk of more-than-certain death by irradiation once you get your hands within 3 feet of the fissile material.

[@captaincat1743]

@@Stoney3K Plutonium is actually not that radioactive in terms of neutron or gamma radiation, it is more of an alpha emitter than anything whilst subcritical . Louis Slotin and other scientists who worked on the Demon Core and other warhead assemblies at Los Alamos used to do experiments on the unshielded core with no protective clothing or face mask and he was often within a foot of it. Only when it approaches criticality does it start to emit gamma photons and neutrons in significant quantities.

[@johnopalko5223]

@@captaincat1743 I always thought the design essentials of the gun-type nuke were common knowledge. It still takes a fair bit of machining skill but it's a lot less fiddly than the implosion type.

[@samueldamewood5273]

One and only one ,man was "responsible" for the use of the PAL. Thomas Sarsfield Power

[@robbarnes9047]

Great. Now even "Whopper" knows what to do. Thanks, Brilliant.

[@doughudgens9275]

We sold a number of Lance surface-to-surface missiles to NATO partners (Turkey, Belgium, UK, etc.)where they owned the missile and conventional warheads but the US controlling the nukes. US Army personnel maintained possession and PAL was used so no big boom without National Command Authority permission. I had friends in these “warhead detachments”. This was in the 80’s, and used 6 digits. However, for two man control, you only decoded 3 numbers and covered them with a lid. Your partner did his 3 and it was armed.

[@rael5469]

"This was in the 80’s, and used 6 digits. " One time when I was in the AF someone actually messed with the coded switch on one of our bombers. The thing was always just sitting there......no special protection. Anyone could touch it or ....whatever. But we all understood that doing so would be a quick trip to Leavenworth. Well.....one day I get a tap on the shoulder and told to immediately report to such and such office WITHOUT DELAY. It was the office of the O.S.I. Office of special investigation. The Air Force equivalent of the FBI. They grilled me for several minutes. They said they knew I did it.....or that I knew who did it. DID WHAT ???? After maybe 45 minutes I think they became convinced that I didn't know anything......that my answers matched my actual whereabouts on the day of the incident. The incident was that someone had dialed in SACSUC ....(or something to that effect) on the dang coded switch. It started a X storm, I can tell you. We never heard the end of that.

[@virtualinfinity6280]

In principle, this has not changed until today. US-Nukes here in Germany consists of free-fall bombs, that can be delivered by Tornado aircraft. Aircrew and aircraft are German, but the nukes ( B61 type) are controlled by US personnal. Soon the aircraft will be replaced by F-35s which will also be purchased and operated by Germans. IIRC, the same concept is followed with Italy.

[@bobsmith6079]

Of course it turns out all the encryption technology and anti bypass measures were meaningless because to assure the operational ability of the devices all the codes were 00000000.

[@skunkjobb]

That's just a legend, not true.

[@bobsmith6079]

@@skunkjobb One of my high school and college classmates got her PhD in chemistry and was hired at the Sandia Labs and spent her career working on the initiating explosive stage. She said the explosive shell could not be hotwired because the exploding wire detonators had varying delay mechanisms so that uniform explosive lens compression of the pit wouldn't occur and you'd spread the plutonium around but not get a fission reaction. She also said commercial chemical detonators had too much timing variation and that's why flux capacitors and exploding wire detonators were used because they wouldn't cause a fission reaction either.

[@RT-qd8yl]

@@bobsmith6079 Why is she telling people all this stuff?

[@kellymoses8566]

@@skunkjobb It was true for a while.

[@KennyTheB]

​@@bobsmith6079 Well, up until you realize you can't capacitate flux. 😂😂😂

[@charlesmanning3454]

So can Slim Pickens arm the weapon from the cockpit?

[@tomnguyen9931]

From the look of thing. He have to pull the pin out of the fuse to arm it!

[@Timothyshannon-fz4jx]

On a British nuclear sub two keys are turned at the same time by the captain and the first officer, the missile can then be fired.

[@eamonnfanton2165]

Wait, they are using capacitors as a safety mechanism to disable the chance of any nuclear detonation? Surely the first thing to be rendered inoperable in an EMP attack would be a capacitor? I don't claim to be knowledgeable in electronics or nuclear weapons but surely this must mean that missile silo's are not only hardened with steel and concrete to survive a nearby nuclear strike but must also be electromagnetically shielded as well? I would love to know how that is achieved. I'm not doubting it if it is done but just very curious as to how. Maybe I am misunderstanding the situation, but if a nearby nuclear strike would render any silo'd missiles useless, then it follows that the US or Russia would have no choice but to immediately launch every missile in the areas of a predicted strike or give up any hope of a retaliation. That's as scary as it gets, as it makes a limited nuclear exchange almost impossible. I hope I am misunderstanding this, ands someone can correct me.

[@saumyacow4435]

That's an excellent video. A couple of questions though. If you had physical possession of a US nuke, how hard is it to bypass these safeties and cause it to explode and on missile systems, how hard is it to set the target. That leads up to the next question. What is the Russian equivalent of this security system and in the even that the Russian federation were to break up, are these nukes a threat to anyone? I would assume the first line of defense is that the Russian custodians would have a means to disable the weapons in storage before hightailing it. But how disabled would this be? Removal of vital components in the control system? Removal of components in the core (meaning a fizzle)?

[@Stoney3K]

There's even a tale of a Russian system called "Perimetr" (or Dead Hand) that would arm all nuclear weapons in case the Soviet military leadership stopped communicating. But in reality, Perimetr would be more like the American PALs. Nobody is stupid enough to hurl their entire arsenal at the planet and create a Doomsday as a failsafe because it would also blow up your own people.

[@StarGateSG7]

To detonate a rogue/stolen nuclear devices, you just need to rip out the wires and security devices that are connected to the explosive lenses and replace them with mining explosive detonation blasting caps and then solder in some new high-current cables which are truly the exact same length connected from the new blasting cap detonators to a super-high-current IGBT (Insulated Gate Bipolar Transistor) which is connected to a set of high amperage 12V batteries which are enough to set off the blasting caps which set off the explosive lenses. Then hook up a smartphone to a primary mechanically-driven switch that comes after the IGBT's and and before the 12V high amperage batteries. We use the mechanical switch so that we don't accidentally detonate the explosive lenses which will eventually have that current be switched and go at lightning speed from the IGBT so as to trigger all the blasting cap detonators all at the exact same time. IGBT chips can switch as fast as 7 nanoseconds. That ensures the explosive lenses will fire at the same time compressing the nuke core evenly to start the fission/fusion process correctly. You have now bypassed all nuclear weapons security!

[@marklatimer7333]

Where in the video is the Thumbnail that got me to come here?

[@hendriklubbe]

Fascinating! But what happens if a nuke is stolen, surely the core and explosive shell can be reprocessed/remanufactured? Or is there protection against this hopefully unlikely event?

[@dannydetonator]

That's why there was at least two point "dirty" failure system, which set off the bomb assymetrically, apparently from a clear by-pass attempt. It turns a nuclear bomb into a dirty bomb, but criticality is not achieved. That's called "fail-deadly" and in itself it's an old info. Who knows how it works now, but i bet the western NW have self-destruct modes just for such an occasion.

[@CharleyMur]

Seems weird to not credit the other KZbin videos that several of these clips were taken directly from.

[@y2ksw1]

It reminds me about the German lock codes of 10 times 0 😅

[@jeromegaces6184]

Will you make a video about the automotive transmissions?

[@sno_crash]

The danger is not with USA arsenal, it is with the other nuclear states without the technological development of Permissive Access Links, that being India, Pakistan, Israel and China. It would be an interesting discussion as to the history of how those countries have been forced to incorporate robust PAL by Russia and the USA.

[@Angel9932]

The US has supposedly offered the technology to other nuclear armed states so they can develop and employ PAL on their nuclear weapons. Russia/USSR already had something similar in place. I'm not sure about the other countries. I wish I remembered more but it has been several years since I watched that particular video on PALs. This video provides a lot more information about how they work and the other video was more about their use and implementation.

Perhaps we should give the bombs artificial intelligence like in "Dark Star".

[@spvillano]

I dunno, it did decide "Let there be light"...

[@vibrolax]

You are false input. Detonation will take place in 37 seconds.

[@unclejoeoakland]

I just love that one of our principle nuclear research facilities is named after watermelons.

[@THE-X-Force]

Fascinating.

[@MadgeChurch]

The golden retriever loved the fireworks each Fourth of July.

[@kid_missive]

People completely overuse this line on youtube videos, but I really do get "I am on some sort of list for watching this" vibes from this video. Super informative. I would have preferred a tiny bit more detail on the fireset, such as the technology of EBWs and slapper detonators.

[@PatrickAndFriendsPRO]

Exactly. KZbin comments are the same tired and unfunny joke on a broken record. It's all been officially declassified and made public info. Tons of academic research on the stuff and lots of things are readily available to read online regarding the subject.

[@VariantAEC]

​@@PatrickAndFriendsPRO You don't ever wonder why that is? Maybe we have stronger countermeasures, more destructive armaments or both. I know the answer... its both.

[@campbellmorrison8540]

Im missing something, you discussed Aircraft based systems but what about ground systems are they the same? I assume the codes are specific to a specific bomb or are they generalised so if a plane wants to drop multiple bombs does each one have to be armed separately? Assuming each code is matched to each bombs serial number or similar where are the codes stored what is the restrictions on access. If the US is going for an all out response to a ICBM attack how would they get all these codes to each missile so they could respond quickly? If an EMP attack happened killing comms to say aircraft or non US based systems how are the codes sent? all sounds a bit questionable in real situations to me

[@patrickvolk7031]

Land-based ICBMs rely on multiple launch votes from missile launch crews (e.g. 6 of 8 turn their keys), which launch all missiles in the wing. Similarly on SLBMs, you have one code to enable, they targeting is separate (they use mnemonics, so you don't know the targets), the captain has a permission to fire key, and the weapons officer has access to the safe where the trigger is. ELF was used previously, which literally goes through the earth, and is slow. The trick is detection of launches, both sides have satellites looking for that. Satellite communications is also used I think. I know the ELF system was used to send 60-word family grams to the sailors (they couldn't respond).

[@spvillano]

@@patrickvolk7031 detonation detection had sound based, pressure based, seismic based and satellite based. Our intermediate nuclear missiles were of course, theater based, so theater command gets codes for launch, forwards local missile codes to plug into the PDP-11/70, it sent its voodoo to the missile's computer. They got retired as they were being deployed to replace the earlier generation. Thankfully. Yeah, I was Pershing at the beginning of my career.

[@watchm4ker]

The sequences I've seen from demonstrations and training footage is that the actual launch orders aren't transmitted. Each unit has with it a set of coded orders containing a number of hypothetical launch scenarios, along with many invalid or decoy orders. When a launch order is issued, they're given a coded sequence that reveals which set of orders has been given, allowing the operators to pick out the correct set of activation codes, destinations, and launch timings, and execute them. Each command has only one code for all the missiles under its authority, but that does not necessarily mean the orders will be to launch all of them

[@patrickvolk7031]

@watchm4ker it was defined in the SIOP, Strategic Integrated Operations Package. You has scenarios with MAO (major attack option), LAO (limited attack option), and TAO (theater attack option). Those are provided resources (sea, land, air). It's a code, but it's still a command with the orders predefined. There are multiple WPs (weapons procedures) depending on launch scenario. They're like a play script, where every person has the script, and their part.

[@spvillano]

@@patrickvolk7031 the SIOP was replaced in 2012 by OPLAN 8010-12, that was updated in 2023 by OPLAN 8044. Same basic beast, streamlined and updated and someone justified their job by renaming it.

[@mattilindstrom]

There's a story that the US armed forces, a bit unhappy with the introduction of coded PALs tended for a short time to set the codes to all zeros, just in case. Don't know if this really happened, but doesn't seem impossible.

[@Indrid__Cold]

We should go to a matchlit gunpowder fuse😊

[@morticialatex]

PALs are still not used on certain types of weapon. Class D PALs are still not rolled out.

[@cussuol]

Russian failsafe system: A piece of tape written "do not press" over the red button.

[@jmchez]

Now, how did the Soviets, with their lag in electronics tech, guard their systems? Because, if there's one thing that I've learned is that the Soviets used double locks everywhere but they could all be bypassed easily. This might be one instance where the US might not have minded if the Soviets stole the tech. It could have even wanted to share it.

[@KB4QAA]

The US shared the principles of PAL's with the Soviets in the late 1960's in the interest of world safety.

[@glennquagmire3258]

I miss Radio Shack. 😁😁😁

[@jamesronson]

Checkout Always/Never: The Quest for Safety, Control, and Survivability Parts 1 - 3 by Sandia Laboratories.

[@flyer617]

Well, partially reassuring..

[@Ozzy3333333]

After 6 months in 7-10 papy server i got a SS 10 ranking, another guy told me that aint sht, come out to the rest of the tracks. Best thing i ever did, i got the the 2nd overall highest ranking in papy at year 3, played for 6 more years, then there just wasnt enough comp to have fun any more. OD/UD was my favorite trick i came up with, huge advantage, with that fuel, tape and clutch tricks got better (albe to extract more from them), and then the WR. Iaveraged 28 races a week for the 1st 4 years, i miss that game.

[@foxtrot151000]

I cannot express to you how big of a nerdgasm i just had, i've been obsessed with the concept of weak and strong links for at least a year or two. The algorithm hath bless me, you have earned my subscription, now to see what else you hold

[@dfloper]

Their safety systems sound primitive and easy to reverse engineer if you have access to one copy.

[@apocolypse11]

Make a video on how the battery's kept the lunar module operating on the moon surface while being charge by solar n other means. Don't forget charging watts n watts usage of the lunar module. Have fun 😊