Tag Archives: Nuclear Weapon Test

4 November 1962, 06:30 GMT

Dominic Tightrope fireball, 00:00 GMT, 4 November 1962. (Nuclear Weapons Archive)
Dominic Tightrope fireball, 06:30 GMT, 4 November 1962. (Nuclear Weapons Archive)

4 November 1962: A Western Electric M6 Nike Hercules air-defense guided missile was launched from Johnston Island in the North Pacific Ocean. The missile was armed with a W-31 Mod 1 nuclear warhead, and had been modified to include a command arm/fire capability, and an automatic disarm feature. At an altitude of 69,000 feet (21,031 meters), 2 miles (3.2 kilometers) south-southwest of the island, the warhead detonated with an explosive yield of 12 kilotons. This nuclear weapon effects test, Dominic Tightrope, was the final test of the Operation Dominic I test series, and was the last atmospheric nuclear test conducted by the United States.

The Nike Hercules was a long-range, high-altitude surface-to-air guided missile, designed and produced by Western Electric Company and the Douglas Aircraft Company. It was a two-stage missile with a cluster of four Hercules Powder Company M5E1 solid-fuel rocket engines as the boost stage. The second stage was powered by a Thiokol Chemical Corporation M30 solid-fuel rocket engine. The booster stage produced 173,600 pounds of thrust (772.211 kilonewtons)and burned for 3.4 seconds. The second stage engine produced 13,500 pounds of thrust (60.051 kilonewtons) and had a burn time of 29 seconds.

A Nike Hercules air defense missile launch. (U.S. Army)
A Nike Hercules air defense missile launch. (U.S. Army)

The Nike air defense missile system used multiple radars to track incoming target aircraft and the outgoing missile. Computer systems analyzed the data and signals were sent to guide the missile toward the target. This was a complex system and multiple missiles were based together at missile sites around the defended area.

The Nike Hercules was 41 feet (12.497 meters) long, with a maximum diameter of 2 feet, 6.5 inches (0.775 meters). The maximum wing span was 11 feet, 6 inches (3.505 meters). Its weight was 10,710 pounds (4,858 kilograms). The Hercules could reach an altitude of 100,000 feet (30,480 meters) and had a range of 90 miles (145 kilometers). The missile’s maximum speed was Mach 3.65.

The Hercules could be armed with either a M17 high explosive fragmentation warhead or a W-31 nuclear warhead. Although designed to attack jet aircraft, the Nike Hercules also successfully intercepted guided and ballistic missiles, and had a surface-to-surface capability.

The Western Electric SAM-A-25 Nike B was renamed Nike Hercules in 1956 while still in development. It was redesignated Guided Missile, Air Defense M6 in 1958, and MIM-14 in 1963. (“MIM” is Department of Defense terminology for a mobile, ground-launched interceptor missile.) About 25,000 Nike Hercules missiles were built. Initially deployed in 1958, it remained in service with the U.S. Army until 1984.

The W-31 was a boosted fission implosion warhead designed by the Los Alamos Scientific Laboratory. It weighed 900 pounds (408 kilograms) and had a selectable yield of from 2 to 40 kilotons. About 2,550 warheads were produced and remained in service until 1989.

A battery of U.S. Army Nike Hercules SAM-A-25 surface-to-air guided missiles. (U.S. Army)
A battery of U.S. Army Nike Hercules MIM-14 surface-to-air guided missiles. (U.S. Army)

© 2016, Bryan R. Swopes

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30 October 1961

Major Durnovtsev’s Tupolev Tu-95V “Bear A”, carrying the RDS-220 bomb to the target. A Tu-16 “Badger” instrumentation aircraft is just behind, on the bomber’s left quarter.
Tupolev Tu 95 carrying Tsar Bomba
Tupolev Tu-95V carrying the RDS-220 bomb.

30 October 1961: A specially modified Tupolev Tu-95V “Bear A” bomber, under the command of Major Andrei E. Durnovtsev, dropped the RDS-220 thermonuclear bomb from an altitude of 10,500 meters (34,449 feet) over the Mityushikha Bay test range on Novaya Zemlya. The bomb, a three-stage radiation implosion device weighing 27,000 kilograms (59,525 pounds), variously known as “Big Ivan” or “Tsar Bomba,” was retarded by parachute to allow the Bear to escape the blast effects. At 4,000 meters (13,123 feet) above the surface, the bomb detonated.

Major Durnovtsev's Tupolev Tu-95N Bear A, carrying the RDS-220 bomb to the target. A Tu-16 instrumentation aircraft is just behind, on the bomber's left quarter.
Major Durnovtsev’s Tupolev Tu-95V “Bear A,” carrying the RDS-220 bomb to the target. A Tu-16 instrumentation aircraft is just behind, on the bomber’s left quarter.
The RDS-220 bomb just after drop. The retarding parachute is beginning to deploy.
“Big Ivan” with first stage parachute deployed.

Major Durnovtsev’s Tu-95 was approximately 45 kilometers (28 miles) away at the time of the explosion.

At the same time, a secret United States Air Force JKC-135A instrumentation aircraft, Speed Light Bravo, 55-3127, had flown closer to gather data about the air burst. It was close enough that its special antiradiation paint was scorched. The airplane was later scrapped because of the damage it sustained.

After the data was analyzed by the Foreign Weapons Evaluation Panel (the “Bethe Panel”) the RDS-220 yield was estimated at 57 megatons. This was the largest nuclear weapon detonation in history. It was also the “cleanest,” with 97% of the energy yield produced by fusion. Relative to the size of the explosion, very little fallout was produced.

Tsar Bomba fireball over Novaya Zemlya, 11:32 a.m., 30 October 1961. The fireball has reached a diameter of 5 miles (8 kilometers). Shock waves reflecting off of the ground caused the slight flattening of the bottom of the fireball.

All buildings in the town of Severny, 55 kilometers (34.2 miles) from Ground Zero, were destroyed. Wooden buildings as far as 200 kilometers (124 miles) were destroyed or heavily damaged.

A visible shock wave in the air was seen at a distance of 700 kilometers (435 miles). The shock wave from the explosion traveled around the world three times.

Fully assembled RDS-220 three-stage radiation implosion thermonuclear bomb, with retarding parachute in place, at Arzamas-16 .

The RDS-220 was 8 meters (26.25 feet) long, with a diameter of 2.1 meters (6.89 feet). It weighed 27,000 kilograms (59,525 pounds).

The Tupolev Tu-95 is a long range strategic bomber. It is 151 feet, 6 inches (46.2 meters) long with a wingspan of 164 feet, 5 inches (50.10 meters). The wings are swept at a 35° angle. The bomber is powered by four Kuznetsov NK-12M turboprop engines, producing 14,800 shaft horsepower, each, and turning 8-bladed counter-rotating propellers. It weighs 90,000 kilograms (198,416 pounds) empty, with a maximum takeoff weight of 188,000 kilograms (414,469 pounds). The Bear has a maximum speed of 920 kilometers per hour (572 miles per hour) and an unrefueled range of 15,000 kilometers (9,321 miles). (The Bear A is capable of inflight refueling.) Service ceiling is 13,716 meters (45,000 feet).

A current production Tupolev Tu-95 Bear-H strategic bomber. (U.S. Air Force)
A current production Tupolev Tu-95MS Bear H strategic bomber. (Royal Air Force)

Following the test, Major Durnovtsev was promoted to the rank of Lieutenant Colonel and named Hero of the Soviet Union. He died 24 October 1976.

© 2016, Bryan R. Swopes

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19 July 1957, 14:00:04.6 UTC

Northrop F-89J Scorpion 53-2547 fires a live MB-1 rocket during Operation Plumbbob John, 1400 GMT, 19 July 1957. (U.S. Air Force)

19 July 1957: During 1957, a series of 29 nuclear weapons tests were carried out at the Nevada Test Site, 65 miles (105 kilometers) northwest of Las Vegas under Project Plumbbob. Shot John was the first and only firing of a live nuclear-armed anti aircraft missile.

At 07:00:04.6 a.m., Pacific Daylight Savings Time (14:00 UTC), a U.S. Air Force Northrop F89J Scorpion, serial number 53-2547, flown by Captain Eric W. Hutchison, Pilot, and Captain Alfred C. Barbee, Radar Intercept Officer, launched a Genie MB-1 unguided rocket at an altitude of 18,500 feet (5,640 meters) over NTS Area 10. The rocket accelerated to Mach 3 and traveled 2.6 miles (4,250 meters) in 4.5 seconds when its W-25 warhead was detonated by a signal from a ground station. The resulting explosive yield was 1.7 kilotons.

The fireball of the W-25 warhead, photographed from approximately 5 miles. (U.S. Air Force)
The fireball of the W-25 warhead, photographed from approximately 5 miles. (Photo courtesy of National Nuclear Security Administration/Nevada Field Office)

F-89J 53-2547 was built as an F-89D-60-NO Scorpion, and was one of 350 D-models which were upgraded to the F-89J standard. It was a missile-armed all-weather interceptor with a two man crew assigned to the Air Defense Command.

The Northrop F-89D/F-89J Scorpion was 53 feet, 10 inches long (16.408 meters) with a wingspan of 60 feet, 5 inches (18.415 meters) and overall height of 17 feet, 6 inches (5.334 meters). The F-89D had an empty weight of 25,194 pounds ( kilograms) and maximum takeoff weight of 46,789 pounds ( kilograms).

The Scorpion’s two Allison J35-A-33 engines produced 7,200 pounds of thrust each. The interceptor had a cruise speed of 465 miles per hour (748 kilometers per hour) and a maximum speed of 627 miles per hour (1,009 kilometers per hour) The service ceiling was 49,200 feet (14,996 meters) and maximum range of 1,367 miles (2,200 kilometers).

The F-89J could be armed with two MB-1 Genie rockets, four AIM-4 Falcon guided missiles and 104 2.75-inch FFAR rockets.

F-89s served with the U.S. Air Force and Air National Guard from 1948 until 1969. Today, F-89J 53-2547 is on display at the Montana Air National Guard Base, Great Falls, Montana.

A Douglas MB-1 Genie nuclear-armed air-to-air rocket is loaded aboard the F-89 Scorpion in preparation for Operation Plumbbob John. (U.S. Air Force)
A Douglas MB-1 Genie nuclear-armed air-to-air rocket is loaded aboard the F-89 Scorpion in preparation for Operation Plumbbob John. (U.S. Air Force)

The Douglas Aircraft Company MB-1 Genie was an unguided solid-fuel rocket. Its Thiokol SR49-TC-1 engine produced 36,500 pounds of thrust and gave it a maximum speed of Mach 3.3. Its range was 6 miles (9.6 kilometers). The rocket weighed 822 pounds (373 kilograms) with its W-25 warhead, and was 9 feet, 8 inches (2.95 meters) in length. Detonation was by time delay fuse. Lethal radius of the warhead was estimated to be approximately 1,000 feet (300 meters). In production from 1957 to 1962, 3,150 missiles were produced. The Genie was in service from 1957 to 1988. In 1962, the designation was changed from MB-1 to AIR-2A Genie.

The W-25 was a Los Alamos Scientific Laboratory-designed anti-aircraft warhead. It was an unboosted fission design, using both uranium and plutonium. The warhead weighed approximately 220 pounds (100 kilograms).

Plumbbob John fireball as seen from Indian Springs Air Base, 30 miles away from the detonation. The aircraft in the foreground is a Northrop F-89J Scorpion, sister-ship to the launch aircraft. (U.S. Air Force)

© 2016, Bryan R. Swopes

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9 July 1962, 09:00:09 UTC, T + 13:41

Fireball of Operation Dominc Starfish Prime, 248 miles ( kilometers) above the Pacific Ocean, 9 July 1962.
Fireball of Operation Dominic-Fishbowl Starfish Prime, 248 miles (399.1 kilometers) above the Pacific Ocean, 9 July 1962.

9 July 1962: At 09:00:09 UTC, the United States detonated a thermonuclear warhead over the Pacific Ocean. This was part of the Operation Dominic-Fishbowl test series at Johnston Island, and was designated Starfish Prime.

At 08:46:28 UTC, a Douglas SM-75 Thor intermediate-range ballistic missile (IRBM) was launched from the Thor missile complex on Johnston Island, carrying a W-49 warhead in an AVCO Corporation Mk-2 reentry vehicle. The Mark 4/W-49 reached a peak altitude of 600 miles (965 kilometers) along a ballistic trajectory then began a descent.

Starfish Prime fireball was visible from Honolulu, Oahu. Hawaii.
Starfish Prime fireball was visible from Honolulu, Oahu, Hawaii, 898 miles (1,445.2 kilometers) from Ground Zero.

The W-49 detonated 36 kilometers (22 miles) southwest of Johnston Island at an altitude of 400 kilometers (246 miles) with an explosive yield of 1.45 megatons. The point of detonation deviated from the planned Air Zero by 1,890 feet (576 meters) to the north, 2,190 feet (668 meters) east, and +617 feet (188 meters) in altitude. The fireball was clearly visible in the Hawaiian Islands, more than 800 miles (1,288 kilometers) away.

The electromagnetic pulse (EMP) damaged electrical systems in The Islands, cutting power, damaging equipment and interrupting telephone systems. Brilliant auroras were visible, lasting about 7 minutes. Telstar, an American communications satellite that was placed in Earth orbit the following day, was also damaged by residual radiation from the detonation.

A Douglas SM-75/PGM-17A Thor IRBM. (U.S. Air Force)
A Douglas SM-75 Thor IRBM. (U.S. Air Force)

The Starfish Prime experiment was for the purpose of, “Evaluation of missile kill mechanisms produced by a high altitude nuclear detonation.” The electromagnetic effects on communications were also studied.

The Douglas Aircraft Company SM-75 Thor (redesignated PGM-17A in 1963) was a single-stage nuclear-armed ballistic missile, 65 feet (19.812 meters) long and 8 feet (2.438 meters) in diameter. It weighed 6,890 pounds (3,125.3 kilograms) empty and 110,000 pounds (49,895.2 kilograms) when fueled.

The SM-75 was powered by one Rocketdyne LR79-NA-9 rocket engine which produced 150,000 pounds of thrust. Two Rocketdyne LR101-NA vernier engines of 1,000 pounds thrust, each, provided directional control and thrust adjustments. The Thor was fueled with kerosene and liquid oxygen sufficient for 165 seconds of engine burn time.

The Thor could reach a maximum speed of 11,020 miles per hour (17,735 kilometers per hour) and had a maximum range of 1,500 miles (2,414 kilometers).

The W-49 thermonuclear warhead was designed by the Los Alamos Scientific Laboratory (LASL) and is believed to be a development of the earlier B-28 two-stage radiation-implosion bomb. It incorporated a 10-kiloton W-34 warhead as a gas-boosted fission primary, and had a one-point-safe safety system. The warhead had a diameter of 1 foot, 8 inches (0.508 meters) and length of  4 feet, 6.3 inches (1.379 meters). It weighed 1,665 pounds (755 kilograms).

The flash from the Starfish-Prime detonation, photographed from Maui in the Hawaiian Islands 15 seconds after detonation. (Los Alamos National Laboratory)
The flash from the Starfish-Prime detonation, photographed from Maui in the Hawaiian Islands, 15 seconds after detonation. (Los Alamos National Laboratory)

© 2016, Bryan R. Swopes

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21 May 1956

Major David Crichlow, USAF, Aircraft Commander, Barbara Grace, 21 May 1956. (LIFE photograph via Jet Pilot Overseas)
Major David M. Critchlow, U.S. Air Force, Aircraft Commander, in the cockpit of another aircraft, B-52B-30-BO Stratofortress 53-383. (LIFE Magazine via Jet Pilot Overseas)

21 May 1956: The second test of the OPERATION REDWING series was REDWING CHEROKEE.

A B-52 Stratofortress assigned to the 4925th Test Group (Atomic), Kirtland Air Force Base, Albuquerque, New Mexico, took off from Eniwetok Island (“Fred Island”), the main island of Eniwetok Atoll in the Marshall Islands. The aircraft commander was Major David M. Critchlow, United States Air Force. Other members of the bomber’s crew were Major Charles T. Smith, pilot; Major Dwight E. Durner, bombardier; Major Floyd A. Amundsen, navigator; Lieutenant William R. Payne, timer; Sergeant Richard N. Bingham, radar technician. Colonel Paul R. Wignaff was an official observer.

Boeing RB-52B Stratofortress 52-013
Boeing RB-52B-10-BO Stratofortress 52-013, Barbara Grace. (The National Museum of Nuclear Science and History)

The bomber, named Barbara Grace, was a Boeing RB-52B-10-BO Stratofortress, serial number 52-013. In its bomb bay was a TX-15-X1 two-stage radiation implosion thermonuclear bomb, weighing 6,867 pounds (3,114.9 kilograms). The bomb was approximately 136 inches long (3.454 meters), with a diameter of 34.5 inches (0.876 meters). The target was a point on Namu Island, Bikini Atoll, also in the Marshall Islands.

Major Critchlow’s wife was named Barbara, and his mother, Grace. The B-52 was named Barbara Grace in their honor.

This Mark 15 nuclear bomb is similar to the TX-15-X1 used in Redwing Cherokee.
This Mark 15 nuclear bomb is similar to the TX-15-X1 used in REDWING CHEROKEE.

     “CHEROKEE was the first test at Bikini, a test event called for by DOD, and the only shot of the series not expressly for weapons development. The shot was rather a demonstration that the United States could air-deliver multimegaton-yield thermonuclear weapons using B-52 jet bombers. The device, designed and developed by Los Alamos Scientific Laboratory (LASL), was airdropped from a B-52 and exploded at a height of 5,000 feet (1.5 km) above Nam on 21 May 1956. Although a demonstration, the shot provided a large-yield burst well above the surface, and it was therefore of considerable interest for airblast effects experiments. However, the explosion was considerably off target, lessening its value.”

OPERATION REDWING 1956, DNA 6037F, by S. Bruce-Henderson, et al., Defense Nuclear Agency, Chapter 4 at Page 177

Flying at 50,000 feet (15,240 meters), the aircrew misidentified an observation facility on a different island for their targeting beacon. The bomb missed Namu Island by 4 miles (6.4 kilometers), detonating at 4,350 feet (1,325 meters) over the open ocean to the northeast at 0551 hours, local time (1751 GMT). The explosive force of the TX-15 was rated at 3.8 megatons, but because of the error in targeting, most of the test data was lost.

Redwing Cherokee target, Namu Island, Bikini Atoll, May 1956.
Redwing Cherokee target, Namu Island, Bikini Atoll, May 1956.

The REDWING CHEROKEE test was the first time that a thermonuclear weapon had been dropped from an airplane.

Redwing Cherokee fireball (Wikipedia)
Redwing Cherokee fireball, 0551 hours, 21 May 1956. (Wikipedia)

David Madison Critchlow was born at Durkee, Oregon, 17 February 1920, the fourth of six children of J. Ralph Critchlow, a farmer, and Estella Grace Culbertson Critchlow. He enlisted in the U.S. Army Air Corps as a private, 3 December 1942. He was assigned as an aviation cadet, and commissioned a 2nd lieutenant, Army of the United States, 27 June 1944. He was promoted to 1st lieutenant, 18 March 1946. He served in the Air Force during World War II, the Korean War and the Vietnam War.

David Critchlow married Miss Lorraine Calhoun, 9 January 1943. He later married Miss Barbara N. Oder, 9 July 1950. They would have five children.

Major Critchlow, assigned to Detachment 1, 24th Strategic Reconnaissance Squadron, 6th Strategic Wing deployed to Shemya, Alaska, 31 December 1961 with Nancy Rae, a top secret Rivet Ball strategic reconnaissance RC-135S, 59-1491.¹

Colonel Critchlow would later command the 6512 Test Group at Edwards Air Force Base, California, 1 October 1969–29 July 1970. He retired form the U.S. Air Force 1 August 1974.

Colonel David M. Critchlow died 11 December 2002 at the age of 81 years. He is buried at Arlington National Cemetery.

Fifty B-52Bs were built by Boeing at Seattle, Washington. Twenty-seven of these were RB-52B reconnaissance bombers. They were designed to accept a pressurized electronic and photo recon capsule with a two-man crew that completely filled the bomb bay. Without the capsule aboard, they were capable of the same bombing missions as their sister B-52Bs. The change could be made within a few hours.

The B-52B/RB-52B was operated by a six-man flight crew for the bombing mission, and eight for reconnaissance. These were the aircraft commander/pilot, co-pilot, navigator, radar navigator/bombardier, electronic warfare officer and gunner, plus two reconnaissance technicians when required.

The airplane was 156 feet, 6.9 inches (47.724 meters) long with a wingspan of 185 feet, 0 inches (56.388 meters) and overall height of 48 feet, 3.6 inches (14.722 meters). The wings were mounted high on the fuselage (“shoulder-mounted”) to provide clearance for the engines which were suspended on pylons. The wings’ leading edges were swept 35°. The bomber’s empty weight was 164,081 pounds (74,226 kilograms), with a combat weight of 272,000 pounds (123,377 kilograms) and a maximum takeoff weight of 420,000 pounds (190,509 kilograms).

Early production B-52Bs were powered by eight Pratt & Whitney J57-P-1W turbojet engines, while later aircraft were equipped with J57-P-19W and J57-P-29W or WA turbojets. The engines were grouped in two-engine pods on four under-wing pylons. The J57 was a two-spool, axial-flow engine with a 16-stage compressor section (9 low- and 7-high-pressure stages) and a 3-stage turbine section (1 high- and 2 low-pressure stages). These engines were rated at 10,500 pounds of thrust (46.71 kilonewtons), each, or 12,100 pounds (53.82 kilonewtons) with water injection.

The B-52B had a cruise speed of 523 miles per hour (842 kilometers per hour). The maximum speed varied with altitude: 630 miles per hour (1,014 kilometers per hour) at 19,800 feet (6,035 meters), 598 miles per hour (962 kilometers per hour) at 35,000 feet (10,668 meters) and 571 miles per hour (919 kilometers per hour) at 45,750 feet (13,945 meters). The service ceiling at combat weight was 47,300 feet (14,417 meters).

Maximum ferry range was 7,343 miles (11,817 kilometers). With a 10,000 pound (4,536 kilogram) bomb load, the B-52B had a combat radius of 3,590 miles (5,778 kilometers). With inflight refueling, the range was essentially world-wide.

Defensive armament consisted of four Browning Aircraft Machine Guns, Caliber .50, AN-M3, mounted in a tail turret with 600 rounds of ammunition per gun. These guns had a combined rate of fire in excess of 4,000 rounds per minute. 52-013 was one of eighteen RB-52Bs equipped with two M24A1 20 mm autocannon in the tail turret in place of the standard four .50-caliber M3 machine guns.

The B-52B’s maximum bomb load was 43,000 pounds (19,505 kilograms). It could carry a 15-megaton Mark 17 thermonuclear bomb, or two Mark 15s, each with a maximum yield of 3.8 megatons.

Boeing manufactured 744 B-52 Stratofortress bombers, with the final one rolled out at Wichita, Kansas, 22 June 1962. As of 27 September 2016, 77 B-52H bombers remain in service with the United States Air Force.

RB-52B-10-BO 52-013 was delivered directly to Kirtland Air Force Base, 29 April 1955. In addition Operation Redwing, 52-013 also participated in Operation Dominic in 1962, which involved 24 air drops from B-52 bombers. The airplane carried the name Deterrent I painted on its nose, but flew missions with the call sign “Cow Slip Two.”

This individual airplane has dropped more than a dozen live nuclear bombs during weapons testing. Withdrawn from service in 1963, 52-013 was transferred to the National Atomic Museum (now, the National Museum of Nuclear Science & History) at Kirtland in 1971, where it is soon to be restored.

Boeing RB-52B-10-BO Stratofortress 52-013 awaits restoration at the National Museum of Nuclear Science & History. (KAFB Nucleus)
Boeing RB-52B-10-BO Stratofortress 52-013 awaits restoration at the National Museum of Nuclear Science & History. (KAFB Nucleus)

¹ See: “A Tale of Two Airplanes,” by Lieutenant Colonel Kingdon R. Hawes, USAF (Ret) at http://www.rc135.com/0000/INDEX.HTM

© 2017, Bryan R. Swopes

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