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British strategic nuclear weapon designs used mechanical safeguards, including thousands of steel ball bearings poured in through a hole in the casing, which ma

British strategic nuclear weapon designs used mechanical safeguards, including thousands of steel ball bearings poured in through a hole in the casing, which made the bomb safe to carry but had to be drained out before use [1]. BLUE PEACOCK, however, used chickens [2]. [1] http://en.wikipedia.org/wiki/Violet_Club#Design_features http://en.wikipedia.org/wiki/Violet_Club#Design_features [2] http://en.wikipedia.org/wiki/Blue_Peacock#Chicken_power http://en.wikipedia.org/wiki/Blue_Peacock#Chicken_power

blueskin_ 12y ago
The chicken wasn't a safety feature; it was to keep the warhead's electronics warm for a few days when buried in the ground so it would still work when needed.
arethuza 12y ago
UK nukes used to use bicycle locks: http://news.bbc.co.uk/1/hi/7097101.stm http://news.bbc.co.uk/1/hi/7097101.stm "The Bomb is actually armed by inserting a bicycle lock key into the arming switch and turning it through 90 degrees. There is no code which needs to be entered or dual key system to prevent a rogue individual from arming the Bomb." NB To this day the crews of UK Trident submarines can launch their weapons on their own without requiring any codes to be transmitted to activate the weapons.
- andyjohnson0 12y ago
  "To this day the crews of UK Trident submarines can launch their weapons on their own without requiring any codes to be transmitted to activate the weapons." Isn't this also the case with US Trident submarines? That is, codes transmitted to the vessel are used to authenticate launch instructions, not to enable the missiles to be armed. Otherwise the submarine would be unable to launch in the event that land-based communications systems were destroyed.
  - arethuza 12y ago
    As far as I know, only the UK Tridents have this interesting arrangement. This link on Permissive Action Links suggests that US Trident submarines need to receive codes to unlock safes before they can launch: "Instead of another party confirming a missile launch as in the case of land-based ICBMs, the set of keys is distributed among the key personnel on the submarine and are kept in safes (each of these crew members has access only to his keys), some of which are locked by combination locks. Nobody on board has the combination to open these safes - the unlock key comes as a part of the launch order from the higher authority." http://en.wikipedia.org/wiki/Permissive_Action_Link http://en.wikipedia.org/wiki/Permissive_Action_Link
    - blueskin_ 12y ago
      So they could theoretically drill/destroy/crack the safe in the case of an emergency where codes could not be transmitted. That is why British submarines have letters of last resort, to be opened and followed if there are no communications. https://en.wikipedia.org/wiki/Letters_of_last_resort https://en.wikipedia.org/wiki/Letters_of_last_resort
- blueskin_ 12y ago
  The joke was that that made the missiles the world's safest - the key would inevitably be lost immediately, and it would take 3 weeks and 12 forms to requisition a pair of bolt cutters.
andyjohnson0 12y ago
The use of chickens to warm the electronics was a proposal. It seems clear that it was never actually implemented. Nice story though!
- blueskin_ 12y ago
  The entire weapon never reached active status IIRC, so it's moot anyway.

blueskin_ 12y ago

The chicken wasn't a safety feature; it was to keep the warhead's electronics warm for a few days when buried in the ground so it would still work when needed.

arethuza 12y ago

UK nukes used to use bicycle locks: http://news.bbc.co.uk/1/hi/7097101.stm http://news.bbc.co.uk/1/hi/7097101.stm "The Bomb is actually armed by inserting a bicycle lock key into the arming switch and turning it through 90 degrees. There is no code which needs to be entered or dual key system to prevent a rogue individual from arming the Bomb." NB To this day the crews of UK Trident submarines can launch their weapons on their own without requiring any codes to be transmitted to activate the weapons.

andyjohnson0 12y ago
"To this day the crews of UK Trident submarines can launch their weapons on their own without requiring any codes to be transmitted to activate the weapons." Isn't this also the case with US Trident submarines? That is, codes transmitted to the vessel are used to authenticate launch instructions, not to enable the missiles to be armed. Otherwise the submarine would be unable to launch in the event that land-based communications systems were destroyed.
- arethuza 12y ago
  As far as I know, only the UK Tridents have this interesting arrangement. This link on Permissive Action Links suggests that US Trident submarines need to receive codes to unlock safes before they can launch: "Instead of another party confirming a missile launch as in the case of land-based ICBMs, the set of keys is distributed among the key personnel on the submarine and are kept in safes (each of these crew members has access only to his keys), some of which are locked by combination locks. Nobody on board has the combination to open these safes - the unlock key comes as a part of the launch order from the higher authority." http://en.wikipedia.org/wiki/Permissive_Action_Link http://en.wikipedia.org/wiki/Permissive_Action_Link
  - blueskin_ 12y ago
    So they could theoretically drill/destroy/crack the safe in the case of an emergency where codes could not be transmitted. That is why British submarines have letters of last resort, to be opened and followed if there are no communications. https://en.wikipedia.org/wiki/Letters_of_last_resort https://en.wikipedia.org/wiki/Letters_of_last_resort
blueskin_ 12y ago
The joke was that that made the missiles the world's safest - the key would inevitably be lost immediately, and it would take 3 weeks and 12 forms to requisition a pair of bolt cutters.

andyjohnson0 12y ago

The use of chickens to warm the electronics was a proposal. It seems clear that it was never actually implemented. Nice story though!

blueskin_ 12y ago
The entire weapon never reached active status IIRC, so it's moot anyway.