Operation Upshot Knothole (Encore) Atomic Test

Friday, September 22, 2017

The United States conducted numerous atomic tests in the 1950s in Nevada.  James T. Tracy, Sergeant First Class, U.S. Army, participated in the Atmospheric Nuclear Test Upshot-Knothole (Encore) on May 8, 1953.  This YouTube  video describes the weapon program.  The following is James T. Tracy's personal account of his experience.  It is being submitted to the Wisconsin Veterans Museum Oral History Program.  

Nevada Test Site – 1953

Upshot-Knothole (Encore)

Upshot-Knothole (Encore) was scheduled for May 7, 1953, but due to inclement weather it was postponed until the following day, May 8, 1953.  It was one of eleven atomic detonations in a series that took place at the Nevada Proving Grounds (Camp Desert Rock) in 1953.  The “shot” was of the airburst variety, the bomb being dropped from an aircraft at the tower at ground zero.  18,000 U. S. military personnel took part in these 1953 tests; approximately 1,635 participated at each “shot.”

I was First Sergeant of “D” Company, 701^st Armored Infantry Battalion (AIB), 1^st Armored Division, Fort Hood, Texas and went by troop train from Fort Hood, Texas to Camp Desert Rock, Nevada arriving on or about May 5, 1953.  To get onto the test site the participants all had to have a top security clearance.  Due to my work with the security platoon, 6^th Armored Cavalry Regiment (ACR), Straubing, Germany, I had that security clearance since January of 1949.

On arrival at Camp Desert Rock, we “pitched” our tents on a dry lake bed (Yucca Flats).  We used jackhammers to place the tent spikes in the hardened clay.  We attended classes a couple of days concerning the upcoming detonation scheduled for May 7^th.

The test was cancelled because of inclement weather and on May 8, 1953 at 8:30 a.m. the bomb was dropped from an aircraft at a tower target at ground zero.  We were later told that the Air Force missed the tower by 100 feet from 4 ½ miles in the sky.  We troops were in trenches 4-5 feet deep about six miles from ground zero on our hands and knees and squinting our eyes, as the officer counted down on the loud speaker – 10-9-8-7-6-5, etc.  At the detonation, the ground shook and it seemed like a high-powered search light was placed into our faces.  After a couple of seconds the officer advised us to stand up and look at the beautiful mushroom cloud forming in the sky.  The colors were brilliant – white (ice) forming on top of colors of orange, red, pink, blue, etc. as the desert brush, pebbles, and debris commenced to strike us in the face and front.  The officer on the address system then advised us that we would receive another surprise in about 20 seconds.  The surprise was all of the debris that had struck us in the face was now hitting us in our backs, as the vacuum from the heat was drawing all of the desert debris back to ground zero. 

Shortly thereafter we were ordered to walk across the desert to ground zero to examine the displays at the tower.  Enroute we saw sheep staked about every 500 yards—the first ones with their fur burned; the later ones looked like a cooked roast.  At the time I thought about my veterinarian grandfather and cruelty to animals and the Humane Society and I was really mixed up. 

At the ground zero displays, machine gun barrels were melted and sand bags (burlap) had been burned and were just a pile of sand.  2 ½ ton trucks and jeeps were overturned with all tires and canvas melted and vehicles burned black.  Brick, stone and wooden houses were demolished; mannequins in the homes were charred beyond recognition.  Broom straws were stuck into plastered walls looking like darts in a target!

The troops participating in these exercises wore fatigue uniforms with field jackets and no protective clothing.  The entire scene at ground zero was obliterated chaos.

It was an experience that I will never forget.

James T. Tracy

U.S. Army 

Photos are from the internet, not from James T. Tracy's experience.