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Set the oven to "Apocalypse": a review of the device for pre-control of nuclear weapons
Material posted: Publication date: 27-09-2017
With this article I want to achieve three important goals. First, bear in the ether of the Internet accessible pictures of equipment used with nuclear weapons (security controllers), which are quite hard to find. Second, briefly describe what it does and how it is used, based on the major sources and reasonable assumptions. And finally, realize your emotional response to the pre-flight controllers as the material embodiment of preparations for nuclear war.

A very brief history of control over the use of nuclear weapons

Best of all, I am familiar with attempts to control the use of nuclear weapons (NW) in the United States that began in the late 1950s and early 1960s. the Proliferation of American weapons across the globe, including the supply of NATO members, is strongly influenced by the concerns of the civilian population by his obedience to the laws of the U.S. and prevent unauthorized use of weapons by the allies. In the popular anecdote of Harold Agnew [American physicist, known as a scientific observer of the atomic bombing of Hiroshima and Nagasaki, and later the third Director of the National laboratory in Los Alamos – approx. transl.], arrives at the airfield and sees as an American nuclear bomb is loaded onto German planes with German pilots, and next is the lone sentry of the United States. Agnew asked the sentry what he will do if the pilot tries to take off without authorization. The sentry replied that he would shoot the pilot, but Agnew says that instead it is better to shoot the bomb.

The excitement and information from the field made by John Kennedy in 1962 to the release of national security Memorandum No. 160, according to which all the weapons are on European territory, must be set to "deny" locks (Permissive Action Link PAL), which at that time was both mechanical and Electromechanical. By the early 1980s approximately half of all nuclear weapons in the United States, located in Europe, protected only by means of mechanical code locks. Today, all 180 weapons in Europe, PAL is equipped with a code switch, code length from 6 to 12 digits.

Meeting with a bomb

Pre-flight controllers were (and are) to change the flow of weapons and to open locks PAL on earth. PAL is a coded switch that after entering the correct key includes a basic outline of the weapon. Some aircraft, for example, in B2, it is possible to access the PAL and also hold all the settings right from the cockpit in flight. Using nuclear weapons pre-flight controller can be configured to burst at a certain altitude at a certain time and with a specific output.

To paraphrase some comments from Twitter, and replicas of people I took at the National nuclear Museum of nuclear science & history (NMNSH), pre-flight controllers Yao would be better suited to your washing machine or oven than nuclear weapons.

Scientific American 200, No. 4 (1959)

For the anthropologist, these moments of anxiety and strangeness associated with nuclear weapons – a very interesting topic for a productive analysis. Occult and obscure information on nuclear weapons and nuclear wars reveals the personal and cultural imagination a vast field for building their own concepts about how these things can look. From mundane reality, there is little chance to support our ideas about the nuclear bombs caused us to complacency. From my point of view as from the point of view of some of my friends, the apocalyptic nature of nuclear weapons demands that procedures and equipment designed for its use, was appropriately solemn, complex and impressive. But in reality they are not. At least in the US, nuclear weapons were developed for the unconditional and immediate use in case of authorization. And no wonder preflight remind controllers of a control system of ovens and washing machines. They were created with the same care, the simplicity and high speed.

Stromberg-Carlson. “Talent management systems” Scientific American 202, no. 1 (1960)

I would say that the fear of nuclear weapons is a feeling of discomfort and anxiety experienced by some people at the meeting with the banality controls nuclear weapons, similar to those that I have met (and himself experienced) in the discussion of the procedures for launching nuclear weapons in the United States. Secrecy and opacity have done much to spread people's beliefs about the restrictions on the use of weapons for the US President. It seems that the President has virtually unchecked ability to give orders to use nuclear weapons. The system of management and control over nuclear weapons of the United States, materialized metonimia which are pre-flight controllers are specially created so that they can react quickly to authorized the order to launch. By definition, almost all the orders of the President at the launch of AO authorized.

And now to illustrate the anecdote. Within the class of "nuclear new Mexico" at the University of new Mexico in the fall of 2016, I was in the expert group, the audience after a public screening of the documentary "Management and control" [Command and Control] (book better). The discussion turned to the procedures for launching nuclear weapons in the United States. One person called me "simplistic" and claimed that I forgot to take into account "checks and balances" the use of nuclear weapons by the President, but he refused to talk in detail about them. I personally quite hard, participating in disputes of this kind, not to remember the psychological mechanism, which Robert Lifton called "psychic numbing": the emergence of ideas and emotional "calluses" that enable us to ignore the ever-present possibility of nuclear destruction of the world.

Anyway, the next part of this article will be entertainment: there will be pictures and comments! All images preflight controllers and bombs are mine, except for having a special registry. Enjoy.

What is the pre-flight controllers and what they do?

Pre-flight controllers are devices used by the ground team to set up the method feeder and output power of nuclear weapons, and to unlock the weapons before the flight. Some bombers all the settings can be done with system hardware monitoring and control aircraft (Aircraft Monitoring And Control, AMAC) located in the plane. For other aircraft, these settings need to do on the ground before the flight. Based on my experience with declassified documents and third-party sources, then I bring my quite plausible assumptions about the purpose of all those knobs and buttons.

Disassembled B61

Nuclear bomb the B61 is available today in the Arsenal of the United States in modifications (mods) 3, 4, 10 (the so-called tactical version), 7 (strategic) and 11 (penetrating). The programme to extend the service life of the B61 is engaged in the conversion of the B61-4, B61-12, which will have four options of the explosion, from 0.3 kt to 50 kt. The B61-12 will get rid of the parachute in favor of sending the tail of the device. It is likely that all the other mods of the B61 and В83 then retire. Here I discuss the preflight controller for two legacy B61: mods 0 and 5. Start with B61-5, because it is most similar to still used controllers.


B61 preflight controller-5 at the Museum NMNSH

Honestly, B61-5 like an embarrassing relative that nobody remembers after his death. I was looking for basic information about the B61-5, except that it has output setting bombs, and that there were plans to transform it into the B61 mods 6 and 8. Based on what I read in the declassified documents say that the new mods of the B61 wanted to do to add more bombs (1), additional output settings, special mission (7, 11), because of the reluctance of the army to dismantle the warheads of other systems (10) and for security and updates. Let's start the description of the controller from the upper left corner and go counter-clockwise.

TA, TB: 10-69

Not surprisingly, the aircraft in flight is quite sensitive to the effects of nuclear explosions, so the B61 was designed to deliver these weapons could exercise and a low-flying plane. Switches TA/TB set up "time for leaving the epicenter for two independent planes" that must pass before the bomb goes off – this gives the plane time to leave the scene of the explosion. The range of intervals – from 10 to 69 seconds, and the team selects TA and TB with the help of equipment on the plane.


Is there a hole for allowing the start key. I think the key closes the circuit of internal power supply systems.


The choice between shipping a free fall and a parachute. The team makes a choice with AMAC equipment.

OPTION: A, B, C, D, E, F

Most of the B61 mods was a choice of output power of a bomb with "out" (Dial-A-Yield, DAY). Choices six, all open source were mentioned only four possible output for any mod. As I understand it, penetrating weapon-the B61-11 was only one way, 400 CT. B61-5 could switch from 10 to 150 kt, which is very similar to the W80 warhead.


In the case of parachute delivery there was exhibited a delay between the bombs and release the parachute. G = 0.3, H = 0.6 and J = 1,6 sec. To blast, after falling to the ground (with a parachute) there is a delay between hitting the ground and detonation. G and H – 30 seconds, J = 80 seconds. If you, it is unlikely to suddenly find yourself in the vicinity of the place where the parachute descends a nuclear bomb, I suggest you very quickly come to terms with the fact that you are mortal.

COMMAND DISABLE SYSTEM: adjustment A, B, & C (0-9); T-handle; adjustment with the notation N, CC, DI, & R

The US has a habit to throw nuclear weapons around the globe, then the leaders are worried about the fact that their enemies, terrorists or allies get access to a gun and use it. If, for example, of the US nuclear weapons stored at the Incirlik base in Turkey will be threatened with capture in the event of a coup, the ban system will bring the weapon down. After you enter the three-digit code turn the handle on the DI (disable) and pull the T-shaped handle. Thermopile starts and will probably fry any important part of the scheme. Then have to return the gun to the factory for the production of nuclear weapons "Pentax" to fix. Or, you can just get the plutonium and get it for yourself – but it's a terrible headache and probably there may be an active security system, punishes penetration through the protective membrane (e.g. by explosion). Declassified documents are silent about all this, but it's not such a crazy possibility. Like PAL, the ban system will give you some time, but it's probably not 100% protection from penetration. It is better not to produce nuclear weapons out of sight.


Connector for PAL. Here the cable is connected from ground equipment which can be used to lock, unlock, transcode and check the status of the bomb. PAL is probably coded switches that are connected to critical circuits. Without entering a valid key, the weapon does not detonate. On some aircraft installed AMAC equipment performing the functions of a PAL; the other weapons have to hit the ground before the flight.



In the case of the B61-0, the first B61 bomb, it works almost as well, except, as you can see, no ban management. Not sure when it became a standard part B61.



B83 is the only megaton bomb (1,2 MT) in the United States. He, like arms full melt (Full Fuzing Options, FUFO) as the B61, the settings more than the drinks in the casino. Consider the top panel down and move from left to right.


After the release of the bomb, through which will open the parachute, or free fall time after a fall, after which the bomb goes off.

FUNC: A, B, C, D, blank, blank

This is probably the selector output, Dial-A-Yield. В83 the maximum yield of 1.2 megatons, but other possibilities I have not seen. Interestingly, the controllers of the B61-0, -5, there are six such settings, and В83 four, as two positions are empty.


Options of explosion at В83 more than variations of pizza from "Papa Johns". FF – free fall, R is the release of a parachute. Not sure about the difference between R1 and R2. Perhaps it is the choice of explosion in the air or Bang on the ground, but this is under question because of the existence of the settings CONT/HOB.


I believe this version of the explosion in the air, in contact or delivery by parachute. Don't know what these abbreviations. H – maybe high and L is low? Also I'm not sure at what altitude the explosion happens, if you choose this option – maybe it selects the pilot, using AMAC. Choose the precise height makes sense because it allows you to maximize the area of coverage in specific circumstances.


Sets the minimum separation time from the time we dropped the bomb to the moment of the explosion. Safe time set by the switches up and down. They go from 00 to 99 (switches for tens and units), but the actual waiting time could not be reached to 99 seconds. For example, not producing already B61-6 and 8, the maximum time can be set to 99, but real time doesn't exceed 69 seconds.


A connector for a PAL to lock/unlock, check status, etc. On some planes this can all be done from the cockpit through AMAC. AMAC connects at the top of the arms. The Museum В83 is placed with the controller T1563 PAL and nutrition T1571B. The photo shows the cable going from the controller.

COMMAND DISABLE SYSTEM: A, B, C (0-9); T-handle; handle with “N,” “CC,” “DI,” and “R”

Setting the desired code using A, B, C, turn the handle to DI and pulling the T-handle starts the thermopile in the controller, which makes the weapon unusable. According to declassified documents, everything happens within the "protected volume", and, probably, in the nuclear subsystem. Speculation on this score come from the melting of the detonators before the explosion of small charges, killing the necessary wiring diagrams.

Ground controller WE177

WE177 – the British bomb, produced in three basic versions from 1966 about 1998. Apparently, the functional equivalent of a U.S. pre-flight controller. In Britain it was called "ground control module" [Ground Control Unit, GCU]


GCU's funny to compare controllers from the USA. There are no such things as a ban system or connector for PAL. Access control is physically implemented by means of a lock resembling a Bicycle. Starting from top left and clockwise:


“L” “H”

WE177A was the only version of the bomb with a choice of output. L (probably Low) up to 0.6 CT, H – 10 CT. Selecting an output of 0.5 kt bomb was used as a deep.


Like B61, WE177 could be delivered by parachute and free fall. This arm is allowed to choose the possibility of an explosion after the fall, in case the explosion in the air didn't work.

ARMING TIME SEC., PRIMARY & ALTERNATIVE: 8, 14, 20, 26, 32, 38, 44, 50

The time before the explosion. According to legend, these time intervals were chosen by the Queen herself! Just kidding, of course, but I have no more logical or plausible explanation for such timing. Brian Bernal describes this time as the setting of the delay between the discharge of the weapon from the aircraft and run the radar. This time you need the plane to leave the scene of the explosion. Also, this configuration reduces the likelihood of jamming the weapon by the enemy.


The time delay between the reset of the weapon and deploying the parachute.

SEF: “Strike Enable Facility”

At the last stage of introduction of the WE177 the team on the ground put something strongly reminiscent of the key to the Bicycle lock into the slot and turned it. After that the weapon was ready for use. No coded switches or double keys.



I believe that through this port to check the status of weapons, food, etc.


Hope you liked this compilation. If you have additional sources of information or ideas about the unknown author of the parts, share them! Last remark: it is worth mentioning that USA enough outside the box approach to delivery and the preparation of nuclear weapons. China, India, Pakistan and (probably) Israel does not have weapons complete with delivery systems. Today only the United States and Russia practice team functional diagram of delivery systems, while Russia has traditionally readiness to deliver nuclear weapons is lower than in the United States. United States unusually, and perhaps uniquely suited to the autonomy of his arms and run dependent on one person. It is high time to reconsider the structure of nuclear weapons and the agreements associated with it so one person had the power of destruction of our world.

Sources of information

  1. Bellovin, Steven M. “Permissive Action Links.”, 2017. Accessed 06/12/2017.
  2. Bradbury, Norris K., and Schwartz, G. P. “NATO Weapons.” AW-765, Memo to General Starbird., January 5, 1961. Accessed 06/07/2017.
  3. Burnell, Brian. “We.177.” Nuclear Weapons: A Guide to British Nuclear Weapon Projects., 2016. Accessed 06/17/2017.
  4. Controls Company of America. “Who Are We.” Scientific American 200, no. 4 (1959): 31.
  5. Derrida, Jacques. “No Apocalypse, Not Now (Full Speed Ahead, Seven Missiles, Seven Missives).” Translated by Catherine Porter and Philip Lewis. Diacritics 14, no. 2 (1984): 20-31.
  6. “Glenn.” “Nuclear Bomb B61 Preflight Controller.” Glenn's Computer Museum., 2010. Accessed 06/12/2017.
  7. Huard, Paul Richard. “When to Shoot a Nuclear Bomb with Your Gun.” War is Boring., January 30, 2015. Accessed 06/16/2017.
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  9. Joseph Masco. The Nuclear Borderlands: The Manhattan Project in Post-Cold War New Mexico. Princeton: Princeton University Press, 2006.
  10. Kenner, Robert. “Command and Control.” Film. Robert Kenner Films, 2016.
  11. Kristensen, Hans M., and Robert S. Norris. “The B61 Family of Nuclear Bombs.” Bulletin of the Atomic Scientists 70, no. 3 (2014): 79-84.
  12. Lifton, Robert J., and Robert Falk. Indefensible Weapons: The Political and Psychological Case Against Nuclearism. New York: Basic Books, 1982.
  13. Plummer, David W., and William H. Greenwood. “The History of Nuclear Weapon Safety Devices.” SAND-98-1184C. Sandia National Laboratories: Albuquerque., 1998. Accessed 06/07/2017.
  14. Sandia National Laboratories. “Interim Development Report for the B61-6,8 Bombs.” SAND88-2986. Sandia National Laboratories, Albuquerque., 1989. Accessed 06/12/2017.
  15. Sandia National Laboratories. “PAL Control of Theatre Nuclear Weapons.” SAND82-2436. Sandia National Laboratories: Albuquerque., 1984. Accessed 06/07/2017.
  16. Stein, Peter and Feaver, Peter. Assuring Control of Nuclear Weapons: The Evolution of Permissive Action Links. Lanham: CSIA Occasional Paper Series, 1987.
  17. Stromberg-Carlson. “A Talent for Command Control Systems.” Scientific American 202, no. 1 (1960): 137.
  18. Wellerstein, Alex. “The President and the Bomb, Part III.” Restricted Data: The Nuclear Secrecy Blog., April 10, 2017. Accessed 06/07/2017.
  19. Wolfgang, Raymond B. “The Enhanced Nuclear Detonation Safety Theme – an Introduction.” SAND2012-0793C. Sandia National Laboratories, Albuquerque., 2012. Accessed 06/12/2017.


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