|Test site||Pacific Proving Grounds|
|Number of tests||17|
|Test type||Atmospheric tests|
|Max. yield||5 megatons of TNT (21 PJ)|
|Previous test series||Project 56|
|Next test series||Project 57|
Operation Redwing was a United States series of 17 nuclear test detonations from May to July 1956. They were conducted at Bikini and Enewetak atolls. The entire operation followed Project 56 and preceded Project 57. The primary intention was to test new, second-generation thermonuclear devices. Also tested were fission devices intended to be used as primaries for thermonuclear weapons, and small tactical weapons for air defense. Redwing demonstrated the first US airdrop of a deliverable hydrogen bomb - test Cherokee. Because the yields for many tests at Operation Castle in 1954 were dramatically higher than predictions, Redwing was conducted using an "energy budget" - there were limits to the total amount of energy released, and the amount of fission yield was also strictly controlled. Fission, primarily "fast" fission of the natural uranium tamper surrounding the fusion capsule, greatly increases the yield of thermonuclear devices, and contributes the vast majority of the fallout - fusion being a relatively clean reaction.
The detonations in Operation Redwing are listed below:
|Name||Date Time (UT)||Location||Elevation + Height||Delivery||Purpose||Device||Yield||Venting||Notes|
|Lacrosse||May 4, 1956 18:25:29.9||Enewetak, Runit (Yvonne)||2 m (6 ft 7 in) + 5 m (16 ft)||Dry surface||Weapons development||TX-39 primary||40 kt||Mockup of the TX-39. Visible Crater off Runit Island, next to Cactus Dome.|
|Cherokee||May 20, 1956 17:50:38.7||Bikini, Namu (Charlie)||0 + 1,320 m (4,330 ft)||Air drop, free fall||Weapons development||TX-15-X1||3.8 Mt||First air deliverable thermonuke. Navigation error landed weapon 4 miles off aim pt (Namu), negated effects data gathering. An effects test, but also an international political statement about readiness to drop thermonukes.|
|Zuni||May 27, 1956 17:00:56.3||Bikini, Eninmen (Tare)||2 m (6 ft 7 in) + 3 m (9.8 ft)||Dry surface||Weapons development||Mk-41 Bassoon||3.5 Mt||First test of 3 stage device. Clean version using lead tamper, 85% fusion; Tewa is dirty version of same bomb. Design evolved into Mk-41, largest deployed US bomb.|
|Yuma||May 27, 1956 19:56:--||Enewetak, Aomon (Sally)||2 m (6 ft 7 in) + 60 m (200 ft)||Tower||Weapons development||Swift||190 t||Smallest (5 in (130 mm) diameter), lightest (96 lb (44 kg)) air defense warhead to date, a boosted, asymmetrical linear implosion device. Fizzled when boost didn't work.|
|Erie||May 30, 1956 18:15:29.3||Enewetak, Runit (Yvonne)||2 m (6 ft 7 in) + 90 m (300 ft)||Tower||Weapons development||TX-28C primary||14.9 kt||Test of boosted primary for TX-28C (for "clean" version) thermonuke.|
|Seminole||June 6, 1956 00:05:35.0||Enewetak, Bokon (Irene)||2 m (6 ft 7 in) + 2 m (6 ft 7 in)||Dry surface||Weapons development||TX-28 primary||13.7 kt||Exploded in a water tank to simulate pressure dynamics of an underground nuke test. Crater 660x32'.|
|Blackfoot||June 11, 1956 18:00:26.3||Enewetak, Runit (Yvonne)||2 m (6 ft 7 in) + 60 m (200 ft)||Tower||Weapons development||8 kt||Small air defense prototype. A near-minimal diameter spherical implosion system, 11.5" in diameter.|
|Flathead||June 11, 1956 18:00:26.1||Bikini, NE Lagoon||0 + 4.5 m (15 ft)||Barge||Weapons development||TX-28S||365 kt||TX-28S (for "salted") test, intentionally dirty high fallout with 73% fission.|
|Kickapoo||June 13, 1956 23:26:--||Enewetak, Aomon (Sally)||2 m (6 ft 7 in) + 90 m (300 ft)||Tower||Weapons development||Swallow||1.5 kt||Linear implosion, air defense warhead test.|
|Osage||June 16, 1956 01:13:53.1||Enewetak, Runit (Yvonne)||0 + 210 m (690 ft)||Air drop, free fall||Weapons development||XW-25||1.7 kt||Proof test of XW-25.|
|Inca||June 21, 1956 21:26:--||Enewetak, Rujoru (Pearl)||2 m (6 ft 7 in) + 60 m (200 ft)||Tower||Weapons development||XW-45 Swan||15.2 kt||Test of tactical warhead, evolved into XW-45.|
|Dakota||June 25, 1956 18:00:06.2||Bikini, NE Lagoon||0 + 2 m (6 ft 7 in)||Barge||Weapons development||TX-28C||1.1 Mt||Prototype of XW-28C. Became the most versatile, widely-used design in the US, from 1958 to 1990.|
|Mohawk||July 2, 1956 18:06:--||Enewetak, Ebiriru (Ruby)||2 m (6 ft 7 in) + 90 m (300 ft)||Tower||Weapons development||Swan/Flute||360 kt|
|Apache||July 8, 1956 18:00:06.2||Enewetak, Elugelab (Flora)||0 + 2 m (6 ft 7 in)||Barge||Weapons development||XW-27 / Zither||1.9 Mt||Same primary as Lacrosse; Prototype of warhead for Regulus Imissile.|
|Navajo||July 10, 1956 17:00:56.3||Bikini, NE Lagoon||0 + 6 m (20 ft)||Barge||Weapons development||TX-21C||4.5 Mt||95% fusion, cleanest shot ever fired until 1858.|
|Tewa||July 20, 1956 17:00:46.0||Bikini, Yurochi aka Irioj (Dog)||0 + 4.5 m (15 ft)||Barge||Weapons development||Mk-41 ? "Bassoon prime"||5 Mt||87% fission; first US 3 stage device, dirty version of Bassoon tested in Zuni, with tamper change.|
|Huron||July 21, 1956 18:00:16.1||Enewetak, Elugelab (Flora)||0 + 2 m (6 ft 7 in)||Barge||Weapons development||XW-50 ? primary "Egg"||250 kt||2 Stage thermonuke, XW-50 prototype.|
|Wikimedia Commons has media related to Operation Redwing.|
- Chuck Hansen, U. S. Nuclear Weapons: The Secret History (Arlington: AeroFax, 1988)
- United States Nuclear Tests - DOE/NV—209-REV 15
- United States Nuclear Tests at fas.org
- United States Nuclear Tests: July 1945 through September 1992 (Revision 15). Department of Energy, Nevada Operations Office. December 2000. Retrieved 2013-10-26.
- Yang, Xiaoping, Robert North, and Carl Romney (August 2000). CMR Nuclear Explosion Database (Revision 3). SMDC Monitoring Research. Retrieved 2013-10-26.
- Hansen, Chuck (1995). The Swords of Armageddon, Vol. 8. Chukelea Publications (Sunnyvale, CA). ISBN 978-0-9791915-1-0.
- Norris, Robert Standish, and Thomas B. Cochran (1 Feb. 1994). "United States nuclear tests, July 1945 to 31 December 1992". Nuclear Weapons Databook Working Paper. NWD 94-1publisher=Natural Resources Defense Council (Washington, DC). Retrieved 2013-10-26.
- A bomb test may be a salvo test, defined as two or more explosions "where a period of time between successive individual explosions does not exceed 5 seconds and where the burial points of all explosive devices can be connected by segments of straight lines, each of them connecting two burial points and does not exceed 40 kilometers in length". Mikhailov, V. N., Editor in Chief. Catalog of World Wide Nuclear Testing. Begell-Atom, LLC.
- An appended number represents a member of a salvo test. They usually all have the same name, like Tub-A, Tub-B, ..., but early on had separate names, so other members are denoted by "(with xyz)".
- Universal Time at the Pacific Proving Ground is 12 hours before local time; UT dates are one day before local date for UT times before 12:00.
- Rough place name and a Latitude/Longitude reference. Some are extremely accurate; others (like airdrops and space blasts) may be quite inaccurate. '~' indicates a likely pro-forma rough location, shared with other tests in that same area.
- Elevation is the ground level at the point directly below the explosion relative to sea level; height is the additional distance added or subtracted by tower, balloon, shaft, tunnel or other contrivance. For air bursts it is the absolute altitude of the explosion disregarding ground level (though the ground level is given for comparison), and for rockets the ground level is "N/A".
- Atmospheric, airdrop, balloon, gun, cruise missile, rocket, surface, tower, barge and cratering are all disallowed by the Partial Nuclear Test Ban Treaty. Sealed shaft and tunnel are underground, and remained useful under the PTBT.
- Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.
- Designations for test items where known, nicknames for individual bombs in quotes.Names are "Mark #" or "B#" for bombs, "W#" for rocket warheads, "X#" for experimental, plus code names like "Piccolo". "Primary" refers to a test of only the primary (fission) stage of a multi-stage bomb.
- Estimated energy yield in tonnes, kilotonnes, and megatonnes (and yes, they are all metric units).
- Emissions to atmosphere, where known. No entry means unknown, probably none if underground and "all" if not; otherwise notation for whether measured on the site only or off the site, and the maximum amount released, in Curies ("Ci") with metric prefixes.
- The short film Nuclear Test Film - Operation Redwing (1956) is available for free download at the Internet Archive [more]
- The short film Military Effects on Operation REDWING (1956) is available for free download at the Internet Archive [more]
- Summary and review of The Atomic Times