Operation Ivy

IVY MIKE BOMB

US Navy operations in the Marshall Islands in late1952 changed history when crew and scientists aboard the USS Estes detonated the first hydrogen bomb. At that time the word thermonuclear became part of our vocabulary.

In mid September news sources reported that the US Air Force came very close accidently detonating a hydrogen bomb over North Carolina almost a decade after the initial tests off Eniwetok Atoll.

News sources reported that on January 24, 1961 an US Air Force B-52 broke up in mid-air over Goldsboro dumping two thermonuclear bombs. The British Guardian said that only a single switch prevented the bomb from detonating after three other safety measures designed to stop unintended detonation failed.  That single switch saved the Eastern seaboard from a nuclear catastrophe. 

USS ESTES

This story hit a personal note. My father, James W. Sparks Sr. was aboard the Navy ship USS Estes AGC-12 when the first hydrogen bomb, “Mike,”  was detonated on Eluglab Island  during  Operation Ivy.

  

Sparks, ME-2, who served in the US Navy, from 1951 through 1954, remembers both Operation Ivy and, the later, Operation Castle bomb tests.   “We were at attention on the deck like rows of corn with our backs towards the explosion when we felt the heat from the blast.  Our ships were about 35 miles from ground zero.  We couldn’t look at the blast, as it would have blinded us,” he said about Ivy.

Sparks added that scientists met with the sailors prior to the test explaining that they didn’t know what the effects blast would be as this was the first time for this type of explosion.  Sparks said that he was on the radiological defense team and used Geiger counters to check for radiation following the tests.

After a tour in warring Korea, the Estes received a refit before heading to the Western Pacific.  Operation Ivy was under the command of Rear Admiral C. W. Wilkins, USN, Commander Task Group 132.2 .   Joining in the maneuver were the Army, Air Force, scientists, journalists and even an actor.

Reed Hadley, of television’s “Racket Squad” narrated a documentary film produced by the US Air Force.  The film, “Operation Ivy,” chronicled events leading to the entry of the US into thermonuclear age in early November 1952 with the detonation of “Mike.” The experimental hydrogen device yielded over 10 megatons of force and vaporized Elugelab Island at Eniwetok Atoll.  All that remained was water and a 164-foot deep crater.

Operation Ivy discharged the two largest bombs up to that time.  Ivy’s testing ushered in the thermonuclear age with the highest pure fission bomb ever exploded.  “Mike” was a 65-ton stationary device not practical for use as weaponry. According to the nuclear weapons archive, “Mike’s” mushroom cloud climbed to 108,000 feet. Thirty minutes after the explosion it stretched 60 miles across with the base joining the stem at 45,000 feet.   The mostly fission powered bomb showered a high level of radiation over the atoll.  A regular fission bomb was used to create the conditions used to initiate “Mike’s” fusion reaction.  Sparks said that they used the atomic bomb to set off the hydrogen one.

Sparks and his fellow sailors aboard the Estes became part of history that day.  The destructive force from the “Mike” bomb was 260 times more powerful than the atomic bomb that flattened Hiroshima in 1945. Sparks said that they later learned that some of the fishermen indigenous to the area suffered from the fallout from the bomb testing in the area.

Operation Ivy’s second thermonuclear bomb was dubbed “King.”  A B-36 bomber dropped the 500- kiloton bomb over Runit Island on November 15, 1952 (GMT).  Unlike “Mike”, “King” was a deliverable bomb that could be used as a cold war weapon.  The resulting cloud reached 74,000 feet with the mushroom base at 40,000 feet.

Following Operation Ivy, the Estes was assigned to resupply government distant early warning radar installations, the “DEW Line” in the far north, under  “Operation Blue Nose.”  At anchor off Point Barrow, Alaska, the ship became entrapped in ice after a wind shift pushed pack ice inshore.  The ship was immobilized for 24 hours before she shook her icy cage.

In early 1954, the USS Estes again headed towards the Marshall Islands for a second series of thermonuclear bomb tests known as “Operation Castle.”  Castle tested a series of high yield devices designed to be delivered as weapons. According to the nuclear weapons archive, the three largest tests ever carried out by the United States were part of Operation Castle. 

An error on one test caused a bomb to be dropped in the wrong target area, according to Sparks.  He remembers that the blast was so strong that it blew out the fire engine room.  Sailors on deck were knocked over unconscious.  Sparks came to watching caps floating down along with hats of the Chiefs.  Calls rang out for the ship to prepare to get underway immediately.  He remembers being on his knees looking towards shock wave flattening out the water.  He said that the bomb was two miles off target.  It was a moment that Sparks thought would be one of his last.

A year later Russia tested its first thermonuclear device and the cold war took a menacing turn. 

It wasn’t the first time the Marshall Islands were used for testing bombs.  Atomic testing transpired in the area during the late 1940s.  Testing continued for another decade leaving some of the islands contaminated with radioactive fallout to this day.

In 1961 a heartbeat moment passed when the final safety switch prevented a thermonuclear device from detonating in North Carolina.  History as we know it might be very different had that switch failed. 

As Imagine and crew prepare for a fifth season on a road not paved, I say a silent prayer of thanksgiving for switches that work.