Operation Hardtack I

Operation Hardtack I
Hardtack Oak
Information
Country	United States
Test site	Pacific Proving Grounds
Period	April - October 1958
Number of tests	35
Max. yield	9.3 Mt
Test chronology

Operation Hardtack I was a series of 35 nuclear tests conducted by the United States in 1958 in the Pacific Ocean.

Test Blasts

Hardtack I Test Blasts

Test Name	Date	Location	Yield	Note	Image
Yucca	28 April, 1958	Enewetak	1.7 kilotons	85nm NE of Enewetak, high-altitude balloon test at 86,000 feet for ABM development
Cactus	5 May, 1958	Enewetak	18 kilotons	Test of Mark-43 Primary 11°33′09″N 162°20′50″E, crater has been filled with contaminated soil and debris and covered with concrete cap called "Cactus Dome".
Fir	11 May, 1958	Bikini Atoll	1.36 megatons	93.4 % fusion yield
Butternut	11 May, 1958	Enewetak	81 kilotons	TX-46 test, primary only
Koa	12 May, 1958	Enewetak	1.37 megatons	XW-35 ICBM warhead test
Wahoo	16 May, 1958	Enewetak	9 kilotons	Deep underwater test (3200 ft.)
Holly	20 May, 1958	Enewetak	5.9 kilotons
Nutmeg	21 May, 1958	Bikini Atoll	25.1 kilotons
Yellowwood	26 May, 1958	Enewetak	330 kilotons	Fizzled, TX-46 test, 2.5 megaton yield predicted
Magnolia	26 May, 1958	Enewetak	57 kilotons
Tobacco	30 May, 1958	Enewetak	11.6 kilotons	2nd stage failed to ignite
Sycamore	31 May, 1958	Bikini Atoll	92 kilotons	Fizzle, 5 megaton yield predicted
Rose	2 June, 1958	Enewetak	15 kilotons	Fizzle, 125 kiloton yield predicted
Umbrella	8 June, 1958	Enewetak	8 kilotons	Shallow depth underwater shot (150 ft.)
Maple	10 June, 1958	Bikini Atoll	213 kilotons	89 % fission yield predicted
Aspen	14 June, 1958	Bikini Atoll	319 kilotons	Fired in Castle Bravo crater
Walnut	14 June, 1958	Enewetak	1.45 megatons
Linden	18 June, 1958	Enewetak	11 kilotons
Redwood	27 June, 1958	Bikini Atoll	412 kilotons
Elder	27 June, 1958	Enewetak	880 kilotons
Oak	28 June, 1958	Enewetak	8.9 megatons	TX-46 redesigned full-yield test, successful.
Hickory	30 June, 1958	Bikini Atoll	14 kilotons
Sequoia	1 July, 1958	Enewetak	5.2 kilotons
Cedar	2 July, 1958	Bikini Atoll	220 kilotons
Dogwood	5 July, 1958	Enewetak	397 kilotons
Poplar	12 July, 1958	Bikini Atoll	9.3 megatons	Highest test of the Dominic Series, 5th largest U.S. test overall
Scaevola	14 July, 1958	Enewetak	zero	Zero yield safety test
Pisonia	17 July, 1958	Enewetak	255 kilotons
Juniper	22 July, 1958	Bikini Atoll	65 kilotons	Final test at Bikini Atoll
Olive	22 July, 1958	Enewetak	202 kilotons
Pine	26 July, 1958	Enewetak	2 megatons	"Clean" version of the three stage Mark-41 design, yield well below the 4-6 megaton prediction
Teak	1 Aug., 1958	Johnston Island	3.8 megatons	ABM effects test, launched by the Redstone ballistic missile, with a 252,000 foot burst height. Miscalculation resulted in detonation directly above launch site.
Quince	6 Aug., 1958	Enewetak	zero	Fizzle
Orange	12 Aug., 1958	Johnston Island	3.8 megatons	ABM effects test, launched on the Redstone ballistic missile, 141,000 foot burst height
Fig	18 Aug., 1958	Enewetak	0.02 kilotons	Final test at Enewetak

See also

• Operation Hardtack II

References

• Chuck Hansen, U. S. Nuclear Weapons: The Secret History (Arlington: AeroFax, 1988) ISBN 0517567407
• The Nuclear Weapons Archive
• "United States Nuclear Tests, July 1945 through September 1992 (DOE/NV-209)" (pdf). U.S. Department of Energy Nevada Operations Office. 2000.

External links

• Operation HARDTACK Military Effects Studies Part I: Basic Effects Structures and Materiel (1958), Department of Defense documentary film, Lookout Mountain Laboratory USAF.
• Operation HARDTACK Military Effects Studies Part II: Underwater Tests (1958), Department of Defense documentary film, Lookout Mountain Laboratory USAF.
• Operation HARDTACK Military Effects Studies Part III: High Altitude Tests (1958), Department of Defense documentary film, Lookout Mountain Laboratory USAF.