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The Tests Code Name: Annie Time and Date: 05:20 March 17, 1953 (local) Location: Area 3, Nevada Test Site (NTS) Height: 300 feet Type: Tower Burst Predicted Yield: 15-20 kilotons Actual Yield: 16 kilotons Two houses and 50 automobiles were exposed to the first shot, Annie, for the Federal Civil Defense Administration. Members of the media were allowed to observe shot Annie, which was designated as an open shot by the AEC. Most of the reports observed the shot from News Nob, some 12 kilometers south of the shot tower. 20 reporters were selected to accompany the troops in trenches 3,200 meters from the blast. 1,700 troops conducted maneuvers around the blast as part of Desert Rock V. Annie was detonated at 5:20 on March 17, 1953 with a yield of 16 kilotons. Annie, officially a weapons development shot, tested an experimental device code named XR3. Additional information to normalize the yield-vs-initiation time curve was sought. The device was a Mk-5 HE assembly using a Type D pit. The total weight of the device was 2,700 lb. Code Name: Nancy Time and Date: 05:10 March 24, 1953 (local) Location: Area 4, Nevada Test Site (NTS) Height: 300 feet Type: Tower Burst Predicted Yield: 35-40 kilotons Actual Yield: 24 kilotons Nancy was a test of the TX-15 "Zombie" thermonuclear weapon design, code named Nevada Zombie. Both the RACER primary and the TX-15 radiation implosion system were tested in the Nevada Zombie device. The device was lighter and smaller then any other thermonuclear weapon being developed at that time. It weighed 11,000 lb., had a diameter of 35.4 inches, and a length of 122 inches. Nancy was fired at 5:10 local time on March 24, 1953 with a yield of 24 kilotons. A sudden wind shift after detonation spread fallout over an area between Desert Rock V troops and their intended objective. The radioactive cloud later approached the troop trenches before moving west and north. The peak intensity measured in the trenches was 0.018 R/h. Of the 2,860 personnel involved in the Nancy shot, 2,350 participated in tactical activities. These involved troop maneuvers, volunteer officer observer program, troop orientation and indoctrination, operational helicopter tests, and damage effects evaluation. Troops were stationed in trenches 3,660 meters from surface zero at shot time. Volunteer officer observers were positioned 2,300 meters south-southwest of ground zero. Code Name: Ruth Time and Date: 05:00 31 March 1953 (local) Location: Area 7, Nevada Test Site (NTS) Height: 300 feet Type: Tower Burst Predicted Yield: 35-40 kilotons Actual Yield: 0.2 kilotons Shot Ruth was the first test of an UCRL (University of California Radiation Laboratory) device. The device was code named Hydride I. It was a fission bomb based on an enriched uranium hydride fuel, similar to the Ray shot 12 days later. The Hydride I was intended to be used as a primary in a compact thermonuclear weapon. The uranium hydride fission device was first conceived during the Manhattan Project, but the idea was not further developed because it was deemed to be unpractical at the time. In theory, a hydride device uses less fissile material to attain a nuclear explosion. However, the device would be very inefficient and only be capable of small yields. Los Alamos scientists remained skeptical of the uranium hydride design. However, Edward Teller, due to his prominent position in the scientific team, was able to push the idea into being developed into an actual device. Shot Ruth was a test of this device, which has a weight of 7400 lb, was 56 inches in diameter and 66 inches long. Ruth was fired at 05:00 on March 31, 1953. The device fizzled, producing a 200 ton yield. The yield was far below the 1.5-3 kiloton predicted yield. The fact that only the top 100 feet of the 300 foot tower was vaporized was a great embarrassment to the URCL team. Much of the shot tower was scattered across the desert floor. Code Name: Dixie Time and Date: 07:30 April 6, 1953 (local) Location: Area 7, Nevada Test Site (NTS) Height: 6022 feet Type: Air Drop Predicted Yield: 8-12 kilotons Actual Yield: 11 kilotons Dixie was the first air drop test of Upshot-Knothole. It was detonated at an altitude of 6022 feet. It missed it’s intended ground zero by 565 feet east and 72 feet north. The bomb, a Mk-5D, was dropped from a B-50 bomber. It weighed 3260 lb and had a diameter of 60 inches and a length of 128 inches. The test experimented with using lithium deuteride as a means of fusion boosting.Radioactive rain would later cover Boston following the Dixie shot. Code Name: Ray Time and Date: 04:45 April 11, 1953 (local) Location: Area 4, Nevada Test Site (NTS) Height: 100 feet Type: Tower Burst Predicted Yield: 0.5 - 1 kilotons Actual Yield: 0.2 kilotons Ray was the second test of a uranium hydride device, first tested in Ruth. This time deuterium was used, a heavy isotope of hydrogen. The device was called Hydride II and was essentially identical to the Hydride I device. The predicted yield was 0.5-1 kiloton, smaller then the Ruth shot despite the similarity in device design. Ray was fired at 04:35 on April 18, 1953 with a yield of 200 tons. Despite having the same yield as Ruth, which was a fizzle, Ray was not considered a failure because of the lower predicted yield. The shot tower was apparently built to a height of 100 feet instead of 300 feet to ensure it would be fully destroyed. Code Name: Badger Time and Date: 04:35 April 18, 1953 (local) Location: Area 2, Nevada Test Site (NTS) Height: 300 feet Type: Tower Burst Predicted Yield: 35 - 40 kilotons Actual Yield: 23 kilotons Badger was a test of a reduced size cryogenic weapon that descended from the Ivy Mike Sausage device. The device, called Buzzard, was actually a TX-16 thermonuclear weapon design that used a deuterium gas boosted RACER primary. 2,800 DOD personnel participated in five Desert Rock exercise: troop maneuvers, volunteer officer observers, troop orientation and indoctrination, operational helicopter tests, and damage effects evaluation. The largest exercise was a Marine troop maneuver that included a test of the ability of helicopters to transport troops after an atomic attack. Observers were stationed in trenches 3,660 meters southwest of ground zero. Troops began a mock attack on a position 1,830 meters southwest of ground zero after the shockwave had passed. A wind gust blew a portion of the radioactive cloud over several observer trenches, resulting in contamination. Several Marines exceeded the allowable does of 6.0 R/h, some film badges read 7.1 R/h. A full scale thermonuclear version of this device was deployed as an “Emergency Capability” for a short time between late 1953 and early 1954. Due to the success of solid fueled thermonuclear weapons, the full scale version of this device was never tested. The device had a diameter of 56 inches, and weighed 7400 lb. Code Name: Simon Time and Date: 04:30 April 25, 1953 (local) Location: Area 1, Nevada Test Site (NTS) Height: 300 feet Type: Tower Burst Predicted Yield: 35 - 40 kilotons Actual Yield: 43 kilotons Simon was a developmental test of the TX-17/24 thermonuclear weapon design, one of the largest and most powerful nuclear weapons ever built by the United States. The device, code named Simultaneity, had a diameter of 35.4 inches, length of 224 inches and a total weight of 11,000 lb. It used a redesigned RACER primary with 2 kg of enriched uranium; this addition boosted its yield by almost a factor of two. For the first time in nuclear testing history, roadblocks were established outside the test site. The roadblocks were played on U.S. highway 91 between Las Vegas and Alamo, Nevada, and on U.S. Highway 93 between Las Vegas and St. George, Utah. Over 3,000 personnel participated in Desert Rock V exercises. An estimated 550 personnel from all branches of military service participate in observer programs. After an extensive pre-shot orientation, observers were positioned in trenches 3,660 meters south of ground zero. Seven Army officers and one Navy officer occupied trenches 1,830 meters from ground zero for the shot. One officer measured a radiation intensity of 100R/h that dropped to 20-25R/h within one minute. Code Name: Encore Time and Date: 08:30 May 8, 1953 (local) Location: Area 5, Nevada Test Site (NTS) Height: 2423 feet Type: Air Drop Predicted Yield: 30-35 kilotons Actual Yield: 27 kilotons Encore was an extensive weapons effects test as part of the Knothole phase of the operation. It was air dropped and detonated at an altitude of 2423 feet on May 8, 1953. A B-50 bomber out of Kirtland Air Force Base dropped the Mk-6D bomb. 720 Department of Defense personnel took part in weapons effects studies for the Encore shot. The bomb exploded 15 feet west and 937 feet south of the intended ground zero. Troops observed the shot 9,400 meters from ground zero, far enough to rise and look at the explosion before the shockwave arrived. Troops then began a ground assault on positions 5,000 and 1,400 meters south of ground zero. Code Name: Harry Time and Date: 05:05 May 19, 1953 (local) Location: Area 3, Nevada Test Site (NTS) Height: 300 feet Type: Tower Burst Predicted Yield: 37 kilotons Actual Yield: 32 kilotons Harry was a test of the HAMLET device which used a TX-13D heavy weight strategic bomb design. The device weight, without the outer bomb case, was 7,000 lb. It was 56 inches in diameter and 66 inches long, the full weight of the bomb was 8,000 lb. The HAMLET device was the most efficient pure fission design with a yield less than 100 kilotons. The most efficient pure fission design was the King device later tested during Operation Ivy with a yield of 500 kilotons. The device used a new hollow core design, which resulted in a very effective compression of the fissile core. The device was designed by Los Alamos scientist Ted Taylor. Harry was fired at 05:05 on May 19, 1953. 1000 troops observed the shot. The fireball lasted for an unusually long time, 17 seconds. The test became infamous because it resulted in the greatest exposure of down-winders to radioactive fallout of any continental United States test. The radioactive cloud, which rose to an altitude of 38,000 feet, passed directly over St. George, Utah, 100 miles to the east. St. George had a population of 5,000 at the time. Up until 1958, it is estimated that a cumulative total of 85,000 person-roentgens of external gamma ray exposure occurred since the beginning of testing in the continental United States. Of this, Harry contributed 30,000 by itself. In the following summer, the Hollywood film The Conqueror, starring John Wayne, was shot in a canyon near St. George. Legend has it that John Wayne developed cancer, and later died, due to this test. 91 members of the 220 member cast developed cancer. For these reasons, the test came to be known as “Dirty Harry”. Code Name: Grable Time and Date: 08:30 May 25, 1953 (local) Location: Area 5, Nevada Test Site (NTS) Height: 524 feet Type: Air Burst Predicted Yield: 14 kilotons Actual Yield: 15 kilotons Grable was a unique test in nuclear history. It was the first and only test of a nuclear device shot out of an artillery cannon. The artillery piece, nick-named ‘Atomic Annie’, was a 280mm that weighed 88 tons. Two of these cannons traveled to the Nevada Test Site. The two cannons were shipped by rail from Fort Sill, Oklahoma, to Las Vegas, Nevada, along with a 28 man artillery crew. From Las Vegas, the cannons traveled by road to the test site. Because of the immense weight of the cannons, they could only be moved on paved road or specially prepared surfaces. The two cannons were placed side by side just east of Mercury Highway, seven miles south of Frenchman Flat. Both of these cannons conducted practice shots for a month with high explosives shells in preparation for the live nuclear shot. The gun had a muzzle velocity of 2060 ft/sec and a range of up to 20 miles. The device that was to be fired during the Grable shot was a Mk-9 artillery shell. The Mk-9 was a gun-type nuclear device that used oralloy as the fissile material. The 280mm shell itself was 54.4 inches long weighed 803 lb. This was also the first test of a gun-type device and the second detonation of one (the other being the Hiroshima Little Boy bomb). The live nuclear shell was fired on May 25, 1953 and detonated at 8:30 local time. It was set to explode 524 feet above Frenchman Flat. The shell traveled 11,000 yards and detonated 86 feet west, 137 feet south, and 24 feet above the intended burst point. Grable, like Encore, was primarily a weapons effects test as part of the Knothole phase. It caused an unanticipated amount of damage to the test structures surrounding the blast, taking the weapons effects personnel by surprise. Code Name: Climax Time and Date: 04:15 June 4, 1953 (local) Location: Area 7, Nevada Test Site (NTS) Height: 1334 feet Type: Air Drop Predicted Yield: 50-70 kilotons Actual Yield: 61 kilotons Climax was a proof test of the high yield and light weight fission bomb Mk-7 bomb. It was dropped from a B-36 bomber and detonated at an altitude of 1334 feet. It exploded 172 feet west and 232 feet north of the intended ground zero. The bomb was 30.5 inches wide and 183 inches long, and weighed 1840 lb. It was small enough to be carried by high speed fighter-bombers. The Mk-7 was the lightest and most compact implosion bomb yet designed. It used a composite COBRA core in a Type D pit, which was later used as a primary in several high yield thermonuclear devices in the Castle test series. The yield of the shot, 61 kilotons, was the largest continental United States test up until that time. It was later surpassed by the Hood shot during Operation Plumbbob.

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