Operation Plumbob

Workers at Area 51 have had to endure difficult conditions since the earliest days of the facility. In the 1950s, when the focus of the57-048 base was testing the U-2 spy plane, the CIA had to cease operations and evacuate the facility due to nearby nuclear testing on the neighboring Nevada test site. Sometimes the AEC would announce tests ahead of schedule to allow nearby residents time to evacuate if they felt it was necessary, but other times the tests would remain unannounced. The results from these tests could be seen from towns 100 miles away. People in Las Vegas would often organize trips to nearby peaks and picnic in view of mushroom clouds.

In 1957, one such test called HOOD was part of an overall program called Operation Plumbob, which was designed to see if damaged nuclear bombs emitted harmful levels of radioactivity. The AEC detonated a 74-kiloton nuclear device 1,500 feet over Area 9 of the NTS. This was the most powerful airburst ever detonated over the continental United States. The AEC did not announce the test ahead of time, though they did tell Area 51 to evacuate beforehand. The resulting blast caused some minor damage at Area 51 - mostly some broken windows and doors. Radiation was a much bigger concern, and, in fact, the soil in Area 51 has absorbed a lot of radiation over years of nuclear tests. 

1957 - Nevada Test Site

57-037Operation Plumbbob was conducted at the Nevada Test Site (NTS) from May through October of 1957. It was the sixth test series at NTS and consisted of 29 tests. Six of these were safety tests, and two did not produce any nuclear yield. This series addressed several objectives, including tactical weapon proof tests, safety tests, and component and mockup testing for thermonuclear systems to be detonated in Hardtack I, among other things.   During Plumbbob 16,000 DOD personnel participated in the Desert Rock VII and VIII exercises.   The LASL shots were named for deceased scientists, the UCRL shots were named for North American mountains. 


 Operation Plumbbob Summary

Test NameTime and Date (GMT)LocationTest TypeHeight (Ft)Yield - Actual (Predicted)SponsorPurposeComments
Boltzmann11:55 28-May-57NTS, Area 7cTower50012 kt (11 kt)LASLWDXW-40 boosted fission warhead test
Franklin 11:55 2-Jun-57NTS, Area 3Tower300140 Tons (2 kt)LASLWDFizzle, XW-30? boosted all-oralloy fission warhead test
Lassen11:45 5-Jun-57NTS, Area 9aBalloon5000.5 Tons (600 Tons)UCRLWDFizzle, unboosted all-oralloy small weapon design
Wilson11:45 18-Jun-57NTS, Area 9aBalloon50010 kt (8 kt, 2-12 kt)UCRLWDXW-45X1 Swan test, gas-boosted composite pit
Priscilla13:30 24-Jun-57NTS, Area 5Balloon70037 kt (40 kt)LASL/DODWEMk-15/39 primary, stockpiled device of known yield
Coulomb-A17:30 1-Jul-57NTS, Area 3hSurface0Zero (1-2 Lb)LASLSTXW-31 1-point safety test
Hood11:40.00.4 5-Jul-57NTS, Area 9aBalloon150074 kt (60-80 kt)UCRLWDLargest atmospheric test at NTS, 2-stage thermonuclear device
Diablo11:30.00.1 15-Jul-57NTS, Area 2bTower50017 kt (11-15 kt)UCRLWD2-stage device, some thermonuclear yield
John14:00 19-Jul-57NTS, Area 10Rocket18,5001.7 kt (1.7 kt)DODWEW-25 warhead for Genie air-to-air missile
Kepler11:50 24-Jul-57NTS, Area 4Tower50010 kt (11 kt)LASLWDXW-35 ICBM warhead development, primary in thermonuclear mockup
Owens13:30 25-Jul-57NTS, Area 9bBalloon5009.7 kt (2-10 kt)UCRLWDVery small boosted plutonium device, XW-51 progenitor
Pascal-A8:00 26-Jul-57NTS, Area 3jShaft-485Listed as "slight", about 55 tons (predicted 1-2 Lb)LASLST1-point safety test
Stokes12:25 7-Aug-57NTS, Area 7bBalloon150019 kt (10-20 kt)LASLWDXW-30 test, all oralloy gas-boosted system
Saturn1:00 10-Aug-57NTS, Area 12cTunnel-100Zero (100 Lb)UCRLST1-point safety test of XW-45X1, oralloy-Pu composite core filled with helium; first shot fired in Ranier Mesa tunnel
Shasta12:00 18-Aug-57NTS, Area 2aTower50017 kt (11-15 kt)UCRLWDNearly identical to Diablo, DT gas boosted Swan primary
Doppler12:30 23-Aug-57NTS, Area 7Balloon150011 kt (-)LASLWDGas boosted implosion device, possible XW-34 test
Pascal-B22:35 27-Aug-57NTS, Area 3cShaft-5000.3 kt (1-2 Lb)LASLST1-point test for upper limits of safety, similar to Pascal-A
Franklin Prime12:40 30-Aug-57NTS, Area 7bBalloon7504.7 kt (2 kt)LASLWDRetest of Franklin with more U-235 added to core
Smoky12:30.00.1 31-Aug-57NTS, Area 8Tower70044 kt (45-50 kt)UCRLWDTX-41 2-stage device, some thermonuclear yield
Galileo12:40 2-Sep-57NTS, Area 1Tower50011 kt (-)LASLWDBoosted fission device, exploratory test
Wheeler12:45 6-Sep-57NTS, Area 9aBalloon500197 Tons (200 Tons)UCRLWDRetest of redesigned Lassen device, possible XW-51 air-to-air warhead progenitor
Coulomb-B20:50 6-Sep-57NTS, Area 3gSurface00.3 kt (1-2 Lb, 20 Tons max)LASLST1-point test for upper limits of safety, similar to Coulomb-A, all-oralloy gas boosted
Laplace13:00 8-Sep-57NTS, Area 7bBalloon7501 kt (1.5-2 kt)LASLWDFleegle device: all-oralloy gun-type weapon
Fizeau16:45 14-Sep-57NTS, Area 3bTower50011 kt (8-10 kt)LASLWDXW-34 test, boosted fission device
Newton12:50 16-Sep-57NTS, Area 7bBalloon150012 kt (50-70 kt)LASLWDTest of XW-31 variant, boosted primary in thermonuclear system mockup
Rainier16:59.59.5 19-Sep-57NTS, Area 12Tunnel-8991.7 kt (-)UCRLWEDeep underground test shot, modified W-25 warhead
Whitney12:30 23-Sep-57NTS, Area 2Tower50019 kt (15 kt)UCRLWDTest of boosted Swan primary in W-27 thermonuclear system mockup
Charleston13:00 28-Sep-57NTS, Area 9Balloon150012 kt (less than 50-100 kt)UCRLWDClean tactical 2-stage thermonuclear device, 2nd stage failed to fire
Morgan13:00 7-Oct-57NTS, Area 9Balloon5008 kt (2-10 kt)UCRLWDXW-45X1 test, boosted Swan primary and Flamingo secondary

 

N.A.T.O. Observers, Troops in the field near a blast, and Military Officials watching a blast                                             

57-076


300px-November_1951_nuclear_test_at_Nevada_Test_Site


57-028

Here is a photo of a blast with Groom Lake in the foreground

igroomabomb2

 
     
  Absence of evidence is not evidence of absence. -Carl Sagan  
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