Go Back  PPRuNe Forums > Aircrew Forums > Military Aviation
Reload this Page >

Bucket of Sunshine Question - Yellow Sun

Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

Bucket of Sunshine Question - Yellow Sun

Old 21st Mar 2017, 18:30
  #1 (permalink)  
Thread Starter
 
Join Date: Jan 2011
Location: In a van down by the river
Posts: 706
Received 1 Like on 1 Post
Bucket of Sunshine Question - Yellow Sun

Not OpSec (in my opinion) just in case you were concerned.

Some time around 1956, the UK being somewhat backed into a corner in terms of weapon development due to the McMahon act and the resultant lack of US cooperation (until it was repealed in 1958) and needing a Megaton range weapon, came up with what is arguably the worst nuclear weapon design in history, the Green Grass device. Installed in either a Yellow Sun or Violet Club casing this bomb had so much fissile material fashioned into a thin outer shell combined with a large central void, that any simple collapse of the shell could potentially result in a prompt critical reaction and a partial detonation, even without a neutron initiator. In other words simply dropping it off the cradle could potentially remove an RAF base from the map. The RAF were given 5 of them, and they regarded that as 5 too many.

As a safety feature the central void of the bomb was filled with ball bearings which were held in place by a simple plastic plug, when removed the ball bearings trickled out into a large bucket and the bomb was technically armed or at least "dangerous". This process apparently took around 30 minutes unless it was freezing, in which case they would often lock together and refuse to budge, and technicians were understandably loathe to hit the casing with a hammer.

It's a long time ago, and with only 5 of the nightmarish things ever made this is something of a stretch, but did anyone on V Force ever come across one of these cold war terrors, any tales to share ?
Fonsini is offline  
Old 21st Mar 2017, 18:49
  #2 (permalink)  
I don't own this space under my name. I should have leased it while I still could
 
Join Date: Dec 2002
Location: Lincolnshire
Age: 80
Posts: 16,777
Received 5 Likes on 5 Posts
Not personally but my boss at Wittering, Billie Wells did.

He says at one time the ball bearings were emptied and rather than landing in a bucket ran all over the dispersal.

Of course to get them out the hole was at the bottom and of course you could not stuff them back. I believe the bomb had to be rotated to get them back in. Said quickly that sounds OK.

But that means offloading the live bomb.

Then it was not a simple issue of dropping them back in as the impact could . . .

Then of course it was necessary to ensure they were properly packed. To that end a secret tool, a 76z item, a Tools, Puddling was used to gently tamp them down.

Woe betide anyone that lost one of these tools though you could get one from Barrack Stores provided you didn't say what it was for.

In Barrack Stores it was a C class item aka Handles, Broom.

I think a friend of mine might know some more.
Pontius Navigator is offline  
Old 21st Mar 2017, 19:11
  #3 (permalink)  
 
Join Date: Apr 2005
Location: UK
Posts: 2,164
Received 46 Likes on 22 Posts
There was a lot more than 5 Green Grass warheads, over 30 of them were deployed. The weapons were stored upside down after the first inadvertent ball bearing cascade.
Just This Once... is offline  
Old 21st Mar 2017, 20:05
  #4 (permalink)  
 
Join Date: Apr 2005
Location: UK
Posts: 2,164
Received 46 Likes on 22 Posts
I should add that the ball bearings were fed into a rubber bag which lowered itself into place under its increasing weight. There was no risk of anything beyond expensive damage if the balls were dropped in.

The bomb was not really live with the balls removed so lowering the weapon onto its cradle without them fitted didn't really add any risk from manhandling or (heaven forbid) being dropped. The true risk was from fire which could puddle the enriched uranium and the balls added some much needed protection. They would also mitigate the risk of an unplanned HE explosion triggering a more sunny event, but clearly any explosion with radioactive shrapnel would not be fun.
Just This Once... is offline  
Old 21st Mar 2017, 20:09
  #5 (permalink)  
Thread Starter
 
Join Date: Jan 2011
Location: In a van down by the river
Posts: 706
Received 1 Like on 1 Post
Originally Posted by Just This Once...
There was a lot more than 5 Green Grass warheads, over 30 of them were deployed. The weapons were stored upside down after the first inadvertent ball bearing cascade.
Quite right, I stand corrected. There were 5 Green Grass physics packages installed in 5 early Violet Club bomb casings, and these were later transferred to Yellow Sun Mk1 casings in addition to 32 new builds for a total of 37 before the switch to an American design (US W28/ UK Red Snow) in the Mk2 version.

Pontius - I was hoping this would fall in your bailiwick.
Fonsini is offline  
Old 21st Mar 2017, 21:06
  #6 (permalink)  
I don't own this space under my name. I should have leased it while I still could
 
Join Date: Dec 2002
Location: Lincolnshire
Age: 80
Posts: 16,777
Received 5 Likes on 5 Posts
JTO, thanks, that detail was omitted by my boss.

Red Snow was also known as Unit 10,000. An one oddity, the same capsule was installed in Blue Steel but fitted in the opposite direction (180 degrees).
Pontius Navigator is offline  
Old 22nd Mar 2017, 07:17
  #7 (permalink)  
 
Join Date: Oct 2001
Location: Lost, but often Indonesia
Posts: 652
Received 0 Likes on 0 Posts
Would these have been devices tested at Woomera in Australia?
Octane is offline  
Old 22nd Mar 2017, 08:03
  #8 (permalink)  
 
Join Date: Jan 2009
Location: Brisbane Australia
Age: 81
Posts: 46
Likes: 0
Received 0 Likes on 0 Posts
I was posted to Cottesmore Armoury in 1961 just as YS1 was replacing Blue Danube. YS1 was definitely user unfriendly. The collapse of the chamber which the ball bearings occupied was a vital part of the chain reaction which is why the balls were there.From memory when the bombed up aircraft went to 30 minutes readiness the bomb was lowered and rolled over and the balls removed.When the readiness returned to 40 minutes the balls were replaced. It was not unknown for some damage or problem to occur in all this and so another serviceable aircraft would have to be bombed up.
On a Mickey Finn exercise we were at our Boscombe Down dispersal when the bomb carrier was damaged and so a pantechnicon was despatched from somewhere in Kent complete with police escort and the bomb was returned by road. YS1 also required heating blankets to keep the temperature stable so the poor armourer who checked it every hour did not get much sleep. YS2, when it came along, was a much more user friendly way to end it all.
ozleckie is offline  
Old 22nd Mar 2017, 09:05
  #9 (permalink)  
I don't own this space under my name. I should have leased it while I still could
 
Join Date: Dec 2002
Location: Lincolnshire
Age: 80
Posts: 16,777
Received 5 Likes on 5 Posts
Octane, no, Christmas Island. It was also Orange Herald that my uncle dropped. https://en.m.wikipedia.org/wiki/Operation_Grapple.

Green Grass, the YS1 warhead, was developed from OH.

Not Woomera which was rocket testing but Maralinga

https://en.m.wikipedia.org/wiki/Nucl...s_in_Australia
Pontius Navigator is offline  
Old 19th Feb 2018, 23:38
  #10 (permalink)  
 
Join Date: Sep 2006
Location: 59°09N 002°38W (IATA: SOY, ICAO: EGER)
Age: 80
Posts: 812
Likes: 0
Received 0 Likes on 0 Posts
Seen recently on FarceBook

ricardian is offline  
Old 20th Feb 2018, 08:04
  #11 (permalink)  
 
Join Date: Jan 2014
Location: Norfolk
Posts: 428
Likes: 0
Received 0 Likes on 0 Posts
Love it
Vendee is offline  
Old 20th Feb 2018, 08:57
  #12 (permalink)  
 
Join Date: Feb 2006
Location: Hanging off the end of a thread
Posts: 32,457
Received 2,591 Likes on 1,096 Posts
Haynes have missed "drop it" off the list for the Bruggen armourers.
NutLoose is offline  
Old 20th Feb 2018, 09:03
  #13 (permalink)  
 
Join Date: Feb 2006
Location: Hanging off the end of a thread
Posts: 32,457
Received 2,591 Likes on 1,096 Posts
Maralinga nuclear testing: Australia?s Hiroshima ? families speak out
NutLoose is offline  
Old 20th Feb 2018, 09:24
  #14 (permalink)  
 
Join Date: Aug 2007
Location: London, New York, Paris, Moscow.
Posts: 3,632
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by NutLoose
Haynes have missed "drop it" off the list for the Bruggen armourers.
Well hmmm ok but a Laarbruch it was 1/1 with the snowfalls...
glad rag is offline  
Old 20th Feb 2018, 10:08
  #15 (permalink)  
 
Join Date: Sep 2007
Location: Manchester
Posts: 92
Received 0 Likes on 0 Posts
I remember 27 Sqn dropped one in 1990.
Peter G-W is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.