Operation Ivy was the eighth series of American nuclear tests, coming after Tumbler-Snapper and before Upshot–Knothole. The two explosions were staged in late 1952 at Enewetak Atoll in the Pacific Proving Ground in the Marshall Islands.

Background

On January 31, 1950, President Harry S. Truman ordered that the US should continue research into all forms of nuclear weapons, including the development of thermonuclear weapons. The Operation Ivy test series was the first to involve a hydrogen bomb rather than an atomic bomb, and was a key step towards Truman's goal. The bombs were prepared by the US Atomic Energy Commission and Department of Defense aboard naval vessels and were capable of being detonated remotely from the control ship USS Estes.

On August 13, 1952, Operation Texan, a full-scale rehearsal of Operation Ivy, was conducted at Bergstrom AFB, Texas. The rehearsal allowed crews of effects aircraft, drop aircraft, samplers, sampler controllers, and tankers to practice mission and communications procedures.

Tests

Mike

The first Ivy shot, codenamed Mike, was the first successful full-scale test of a multi-megaton thermonuclear weapon ("hydrogen bomb") using the Teller-Ulam design. Unlike later thermonuclear weapons, Mike used deuterium as its fusion fuel, maintained as a liquid by an expensive and cumbersome cryogenic system. The bomb was detonated on November 1, 1952, on Elugelab Island yielding 10.4 megatons, almost 500 times the yield of the bomb dropped on Nagasaki, resulting in the total vaporization of the island. Eight megatons of the yield were from fast fission of the uranium tamper, creating massive amounts of radioactive fallout. The detonation left an underwater crater 6,240 ft (1.9 km) wide and 164 ft (50 m) deep where Elugelab Island had been. Following this successful test, the Mike design was weaponized as the EC-16, but it was quickly abandoned for solid-fueled designs after the success of the Castle Bravo shot two years later.

The outcome of the test was reported to incoming president Eisenhower by Atomic Energy Commission Chairman, Gordon Dean, as follows: “The island of Elugelab is missing!” a captain with the 561st Fighter-Day Squadron, was lost near the end of his mission. After re-emerging from the cloud, both he and his wingman, pilot Captain Bob Hagan, encountered difficulties picking up rendezvous and runway navigational beacons due to "electromagnetic after effects" of the detonation. By the time they were successful in finding the signal, they were dangerously low on fuel, and before reaching the runway on Enewetak, both had depleted their reserves. Hagan made a successful dead-stick landing on the runway, but Robinson was too far out and attempted to ditch. nuclear fission (A-bomb) weapon to date using only nuclear fission (no fusion nor fusion boosting). This test used an unretarded free-fall bomb from a B-36 bomber. The bomber suffered minor heat and blast damage and safely returned to base. This "Super Oralloy Bomb" was intended as a backup to the earlier "Mike" test, if the fusion weapon had failed.

Video

thumb|center|450px|De-classified Operation-Ivy nuclear test AEC information video

Summary

{| class="wikitable sortable"

|+ United States' Ivy series tests and detonations

|-

!style="background:#ffdead;" | Name

!style="background:#efefef;" | Date time (UT)

!style="background:#ffdead;" | Local time zone

!style="background:#efefef;" | Location

!style="background:#ffdead;" | Elevation + height

!style="background:#efefef;" | Delivery,<br />Purpose

!style="background:#efefef;" | Device

!style="background:#ffdead;" | Yield

!style="background:#efefef;" class="unsortable" | Fallout

!style="background:#ffdead;" class="unsortable" | References

!style="background:#efefef;" class="unsortable" | Notes

|-

! Mike

| 19:14:59.4

| style="text-align:center;" | MHT (11&nbsp;hrs)|| Elugelab (Flora), Enewetak Atoll

| +

| dry surface,<br />weapons development

| "Sausage" w/ TX-5 primary

| style="text-align:center;" |

|

|

Despite this, Operation Ivy was not officially acknowledged until April 1, 1954, with the release of a 28-minute film for television which included footage of the explosions. Many Americans expressed moral apprehension towards the creation and testing of the hydrogen bombs using in Operation Ivy. Following the release of the film, President Eisenhower attempted to calm the American public by claiming that the hydrogen bomb was "merely a dramatic symbol" of the nation's fears.

In Sid Meier's Civilization VI and Civilization VII, Operation Ivy is a late game project that the player can construct at one of their cities.

There was an American punk rock band called Operation Ivy, named after the real-life nuclear tests.

References

  • Curtiss Atomic Marines
  • Operation Ivy
  • Analysis of Radiation Exposure for Navy Personnel at Operation Ivy
  • formerly classified
  • formerly unclassified, for civil defense